13008 Federal Register I Vol. 58, No. 44 / Tuesday, March 9, 1993 I Rules and Regulations

SUPPLEMENTARY INFORMATION:

List of Subjects in 32 CFR Part 988

Weather modification.Authority: 10 U.S.C. 8013.

PART 988--REMOVED]

Accordingly, 32 CFR,..hapter VII, isamended by removing part 988.Patsy J. Conner,Air Force Federal Register Liaison Officer.[FR Doec. 93-5293 Filed 3-8--93; 8:45 amlBILJNG CODE 3910-01-M

ENVIRONMENTAL PROTECTION

AGENCY

40 CFR Part 50

[AD-FDL-4601--6

National Ambient Air QualityStandards for Ozone-Final Decision

AGENCY: U.S. Environmental ProtectionAgency (EPA).ACTION: Final decision.

SUMMARY: In accordance with sections108 and 109 of the Clean Air Act (Ad),the EPA announced on August 10, 1992its proposed decision under section109(d)(1) that revisions of the nationalambient air quality standards (NAAQS)for ozone (03) are not appropriate at thistime. The level of the existing primaryand secondary standards for 03 is 0.12parts per million (ppm). The standardsare attained when the expected numberof days per calendar year withmaximum hourly averageconcentrations above 0.12 ppm is equalto or less than 1, as determined by theInterpretation of the National AmbientAir Quality Standards for Ozone(appendix H). In the same notice, theEPA a!so announced its plans, in viewof the large number of recent scientificpapers and ongoing research on the

ealth and welfare effects of 03, toproceed as rapidly as possible with thenext review of the air quality criteriaand standards for 03.

This document announces the EPA'sfinal decision under section 109(d)(1)that revisions of the primary andsecondary standards are not appropriateat this time. Since publication of theAugust 10 1992 notice, the EPA hasinitiated action to update the air qualitycriteria upon which this decision isbased so that the recent information onhealth and welfare effects of 0. can beconsidered as rapidly as possible in thenext criteria and standards review.EFFECTIVE DATE: This action is effectiveApril 8. 1993.

ADDRESSES: A docket containinginformation relating to the EPA's reviewof the 03 primary and secondarystandards (Docket No. A-92-17) isavailable for public inspection in theCentral Docket Section of the U.S.Environmental Protection Agency,South Conference Center, room 4, 401 MStreet SW., Washington, DC. The docketmay be inspected between 8 a.m. and 3p.m. on weekdays, and a reasonable feemay be charged for-copying. Theinformation in the docket constitutesthe complete basis for the decisionannounced in this notice. For theavailability of related information, seeSUPPLEMENTARY INFORMATION.FOR FURTHER INFORMATION CONTACT: Mr.John H. Haines, Air QualityManagement Division (MD-12), U.S.Environmental Protection Agency,Research Triangle Park, NC, 27711,telephone (919) 541-5533.

SUPPLEMENTARY INFORMATION:

Availability of Related InformationCertain documents are available from:

U.S. Department of Commerce, NationalTechnical Information Service, 5285Port Royal Road, Springfield, Virginia22161. Available documents include:the revised criteria document, AirQuality Criteria for Ozone and OtherPhotochemical Oxidants (five volumes,EPA-600/8-84-O20aF-eF, August 1986;NTIS # PB-87142949, $168.00 papercopy), and the 1989 staff paper, Reviewof the National Ambient Air QualityStandards for Ozone: Assessment ofScientific and Technical Information-OAQPS Staff Paper (EPA-450/2-92-001, June 1989; NTIS # PB-92-190446,$43.00 paper copy and $i7.00microfiche). (Add $3.00 handling chargeper order.) The criteria documentsupplement, Summary of Selected NewInformation on Effects of Ozone andOther Photochemical Oxidants (EPA-600/8-88-105F) is available at no costfrom the Center for EnvironmentalResearch Information (CERI), telephone(513) 56.9-7562. A limited number ofcopies of other documents generated inconnection with this standard reviewcan be obtained from: U.S.Environmental Protection AgencyLibrary (MD-35), Research TrianglePark, NC, 27711, telephone (919) 541-2777. These and other relateddocuments are also available in the EPAdocket identified above.

The contents of this notice are listedin the following outline:1. Background

A. Legislative Requirements Affecting ThisRule

I. Primary and Secondary Standards2. Related Control Requirements

B. Existing Standards for OzoneC. Review of Air Quality Criteria and

Standards for Ozone and OtherPhotochemical Oxidants; Developmentof the Staff Paper

D. Decision DocketE. Litigation

H. Summary of the 1992 Proposed DecisionA. The Primary StandardB. The Secondary Standard

II. Summary of Public Comments on theProposed Decision

IV. Rationale for Final DecisionA. The Primary StandardB. The Secondary StandardC. Final Decision

V. Regulatory ImpactsA. Regulatory Impact AnalysisB. Impact on'Small Entities

Vi. Other ReviewsReferencesAppendix IAppendix II

I. Background

A. Legislative Requirements AffectingThis Rule

1. Primary and Secondary Standards

Two sections of the Act govern theestablishment and revision of NAAQS.Section 108 (42 U.S.C. 7408) directs theAdministrator to identify pollutantswhich "may reasonably be anticipatedto endanger public health and welfare"and to issue air quality criteria for them.These air quality criteria are toaccurately reflect the latest scientificknowledge useful in indicating the kindand extent of all identifiable effects onpublic health or welfare which may beexpected from the presence of apollutant in the ambient air.

Section 109 (42 U.S.C. 7409) directsthe Administrator to propose andpromulgate "primary" and "secondary"NAAQS for pollutants identified undersection 108. Section 109(b)(1) defines aprimary standard as one "the attainmentand maintenance of which, in thejudgment of the Administrator, based onthe criteria and allowing an adequatemargin of safety, is requisite to protectthe public health." A secondarystandard, as defined in section109(b)(2), must "specify a level of airquality the attainment and maintenanceof which, in the judgment of theAdministrator, based on the criteria, isrequisite to protect the public welfarefrom any known or anticipated adverseeffects associated with the presence ofthe pollutant in the ambient air."Welfare effects as defined in section302(h) (42 U.S.C. 7602(h)) include, butare not limited to, "effects on soils,water, crops, vegetation, manmadematerials, animals, wildlife, weather,visibility and climate, damage to anddeterioration of property, and hazards iutransportation, as well as effects on

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economic values and on personalcomfort and well-being."

The U.S. Court of Appeals for theDistrict of Columbia Circuit has heldthat the requirement for an adequatemargin of safety for primary standardswas intended to address uncertaintiesassociated with inconclusive scientificand technical information available atthe time of standard setting. It was alsointended to provide a reasonable degreeof protection against hazards thatresearch has not yet identified. [LeadIndustries Association v. EPA, 647 F.2d1130, 1154 (DC Cir. 1980), cert. denied,101 S.Ct. 621 (1980); AmericanPetroleum Institute v. Costle, 665 F.2d1176, 1177 (DC Cir. 1981), cert. denied,102 S.Ct. 1737 (1982)]. Both kinds ofuncertainties are components of the riskassociated with pollution at levelsbelow those at which human healtheffects can be said to occur withreasonable scientific certainty. Thus, byselecting primary standards that providean adequate margin of safety, theAdministrator is seeking not only toprevent pollution levels that have beendemonstrated to be harmful but also toprevent lower pollutant levels that shefinds may pose an unacceptable risk ofharm, even if the risk is not preciselyidentified as to nature or degree.

In selecting a margin of safety, theEPA considers such factors as the natureand severity of the health effectsinvolved, the size of the sensitivepopulation(s) at risk, and the kind anddegree of the uncertainties that must beaddressed, Given that the "margin ofsafety" requirement by definition onlycomes into play where no conclusiveshowing of adverse effects exists, suchfactors, which involve unknown or onlypartially quantified risks, have theirinherent limits as guides to action. Theselection of any particular approach toproviding an adequate margin of safetyis a policy choice left specifically to theAdministrator's judgment. LeadIndustries Association v. EPA, supra,647 F.2d at 1161-62.

Section 109(d)(1) of the Act requiresthat not later than December 31, 1980.and at 5-year intervals thereafter, theAdministrator shall complete athorough review of the criteriapublished under section 108 and thenational ambient air quality standardsand shall make such revisions in suchcriteria and standards as may beappropriate. Section 109(d)(2) (A) and.(B) require that a scientific reviewcommittee be appointed and providethat the committee "shall complete areview of the criteria and the nationalprimary and secondary ambient airquality standards and shall recommendlo the Administrator any revisions of

existing criteria and standards as may beappropriate."

The process by which the EPA hasreviewed the existing air quality criteriaand standards for 03 under section109(d) is described in a later section ofthis notice.

2. Related Control RequirementsStates are primarily responsible for

ensuring attainment and maintenance ofambient air quality standards once theEPA has established them. Under title Iof the Act (42 U.S.C. 7410), States areto submit, for EPA approval, Stateimplementation plans (SIP's) thatprovide for the attainment andmaintenance of such standards throughcontrol programs directed to sources ofthe pollutants involved. The States, inconjunction with the EPA, alsoadminister the prevention of significantdeterioration program (42 U.S.C. 7470-7479) and the visibility protectionprogram (42 U.S.C. 7491-749-2) for theseand other air pollutants. In addition,Federal programs provide fornationwide reductions in emissions ofair pollutants through the Federal motorvehicle control program under title II ofthe Act (42 U.S.C. 7521-7574), whichinvolves controls for automobile, truck,bus, motorcycle, and aircraft emissions;the new source performance standardsunder section 111 (42 U.S.C. 7411); andthe national emission standards forhazardous air pollutants under section112 (42 U.S.C. 7412).

B. Existing Standards for OzoneThe principal focus of this standard

review is on the health and welfareeffects of 03. Ozone produced in theambient air is commonly referred to astropospheric 03. It is chemicallyidentical to stratospheric 03, which isconcentrated miles above the earth'ssurface and provides a protective shieldfrom excess ultraviolet radiation. Incontrast, tropospheric 03 producesharmful effects due to its oxidativeproperties and its proximity to humans,plants, and materials. Ozone is notemitted directly from mobile orstationary sources but, like otherphotochemical oxidants, commonlyexists in the ambient air as an

* atmospheric transformation product.Ozone formation is the result ofchemical reactions of volatile organiccompounds (VOC's), nitrogen oxides(NO.), and oxygen (02) in the presenceof sunlight and generally at elevatedtemperatures.

Ozone is a highly reactive gas whichat sufficient concentrations can producea wide variety of harmful effects. Atelevated concentrations, 03 canadversely affect human health,

vegetation, materials, economic values,and personal comfort and well-being.Hourly average ambient 03 levels rangefrom 0.03 ppm in the most remote ruralareas to 0.30 ppm and higher in themost pollutedurban areas. A detaileddiscussion of formation, concentrations,and effects of 03 can be found in the1986 Air Quality Criteria Document(U.S. EPA, 1986), the Criteria DocumentSupplement (U.S. EPA, 1992), and theStaff Paper (U.S. EPA, 1989).

On April 30, 1971, the EPApromulgated primary and secondaryNAAQS for photochemical oxidantsunder section 109 of the Act (36 FR8186). These were set at an hourlyaverage of 0.08 ppm total photochemicaloxidants not to be exceeded more than1 hour per year. On April 20, 1977, theEPA announced (42 FR 20493) the firstreview and updating of the 1970 AirQuality Criteria Document forPhotochemical Oxidants in accordancewith section 109(d)(1) of the Act. Inpreparing the Air Quality CriteriaDocument, the EPA provided a numberof opportunities for external review andcomment. The EPA made two drafts ofthe document available for publiccomment, and these drafts were peerreviewed by the Subcommittee onScientific Criteria for PhotochemicalOxidants of the EPA Science AdvisoryBoard. The EPA published the finalrevised Air Quality Criteria for Ozoneand Other Photochemical Oxidants onJune 22, 1978.

Based on the 1978 revised Air QualityCriteria Document (U.S. EPA, 1978) andtaking into account the advice andrecommendations of the Subcommittee,on June 22, 1978, the EPA proposed (43FR 16962) revisions to the then-currentprimary and secondary NAAQS forphotochemical oxidants. The proposedchanges included raising the primarystandard to 0.10 ppm, retaining the 0.08ppm secondary standard, changing thechemical designation of the standardsfrom photochemical oxidants to 03, andchanging to standards with a statisticalform (i.e., expected exceedances) ratherthan a deterministic form (i.e., not to beexceeded more than x number of timesper year).

After taking into account publiccomments, the EPA announced its finaldecision on the proposed revisions tothe 1971 standards (44 FR 8202,February 8, 1979). The final rulemakingrevised the level of the primary standardfrom 0.08 ppm to 0.12 ppm, set thesecondary standard identical to theprimary standard, changed the chemicaldesignation of the standards fromphotochemical oxidants to 03, andrevised the definition of the point atwhich the standard is attained to when

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the expected number of days percalendar year with maximum hourlyaverage concentrations above 0.12 ppmis equal to or less than one asdetermined by appendix H.

C. Review of Air Quality Criteria andStandards for Ozone and OtherPhotochemical Oxidants; Developmentof the Staff Paper

On March 17, 1982 (47 FR 11561), theEPA announced that it was undertakingplans to revise the existing 1978 AirQuality Criteria Document for Ozoneand Other Photochemical Oxidants andon August 22, 1983, announced (48 FR38009) that review of primary andsecondary standards for 03 had beeninitiated. A detailed summary of thereview and revision process waspresented in the August 10, 1992proposal notice (57 FR 35542).

The EPA subsequently provided anumber of opportunities for publicreview and comment, including makingavailable two drafts of the revisedcriteria document (49 FR 29845; 51 FR11339), prepared by the EPA'sEnvironmental Criteria and AssessmentOffice (ECAO), and holding two publicmeetings of the Clean Air ScientificAdvisory Committee (CASAC) (March4-6, 1985 and April 21-22, 1986). TheEPA placed transcripts of the CASACmeetings in the docket (ECAO-C 1-1) for the 1986 Air Quality CriteriaDocument. The EPA considered thenumerous and often extensivecomments received from the public andthe CASAC members in preparing thefinal document. On October 22, 1986,the CASAC sent the Administrator a"closure letter," outlining key issuesand recommendations and indicatingthat it was satisfied with the final draftof the 1986 Air Quality CriteriaDocument. Following closure, a numberof scientific articles were published oraccepted for publication and appearedto be of sufficient importanceconcerning potential health and welfareeffects of 03 to warrant preparation of asupplement to the criteria document. Inearly 1988, the ECAO began preparationof the Supplement and made draftcopies available to the CASAC and thepublic in November 1988.

After the CASAC meeting on March4-6, 1985, the EPA's Office of AirQuality Planning and Standards(OAQPS) began work on the first draftof the Staff Paper (Review of theNational Ambient Air Quality Standardsfor Ozone:

Assessment of Scientific andTechnical Information-OAQPS StaffPaper). The CASAC reviewed first andsecond drafts of the Staff Paper at publicmeetings of the CASAC held on April

21-22, 1986 and December 14-15, 1987,and transcripts of these meetings havebeen placed in the docket. Numerouswritten and oral comments werereceived on the drafts from the CASAC,representatives of organizations,individual scientists, and otherinterested members of the public. TheCASAC concluded that sufficient newinformation existed to recommendincorporation of relevant newinformation into a third draft of the StaffPaper. In early 1988, the EPA beganworking on a third draft of the StaffPaper and made available copies to theCASAC and the public in November1988.

The CASAC held a public meeting onDecember 14-15, 1988 to review thedraft Supplement and draft Staff Paper.Major issues included: The definition ofadverse health effects of 03, thesignificance of health studies suggestingthat exercising individuals exposed for6 to 8 hours to 03 levels at or below 0.12ppm may experience inflammation andtransient decreases in pulmonaryfunction, the possibility that chronicirreversible effects may result from long-term exposures to elevated levels of 03,and the importance of analyses whichindicate agricultural crop damage maybe better defined by a cumulativeseasonal average than by a 1-hour peaklevel of 03. In its "closure letter" of May1, 1989, (reprinted as appendix I of thisnotice) the CASAC indicated that thedraft Supplement and draft Staff Paper"provide an adequate scientific basis forthe EPA to retain or revise primary andsecondary standards for ozone"(CASAC, 1989).

D. Decision Docket

On March 17, 1992, the EPA createda docket (Docket No. A-92-17) for thisdecision. The docket incorporated thestandard review docket (Docket No.OAQPS A-83-04), created in 1983, andthe separate docket established forcriteria.document revision (Docket No.ECAO-CD-81-1), created in 1981.

E. Litigation

On October 22, 1991, the AmericanLung Association and other plaintiffsfiled suit under section 304 of the Actto compel the EPA to complete itsreview of the criteria and standards forO under section 109(d)(1) of the Act[American Lung Association v. Reilly,No. 91-CV-4114 (JRB) (E.D.N.Y.)]. TheU.S. District Court for the EasternDistrict of New York subsequentlyissued an order requiring the EPA tosign a Federal Register noticeannouncing its proposed decision onwhether to revise the standards for 03by August 1, 1992 and to sign a Federal

Register notice announcing its finaldecision by March 1, 1993.

H. Summary of the 1992 ProposedDecision

On August 10, 1992 (57 FR 35542).the EPA published its proposeddecision under section 109(d)(1) thatrevisions to existing 1-hour primary andsecondary standards are not appropriateat this time. (Consistent with the orderin the American Lung Association case,the Administrator signed the proposeddecision on August 1, 1992.) The noticeexplained in some detail (see 57 FR35546) that the proposed decisionwould complete the EPA's review ofinformation on health and welfareeffects of 03 assembled over a 7-yearperiod and contained in the 1986 AirQuality Criteria Document and itsSupplement. The review included anevaluation of key studies publishedthrough early 1989, the 1989 Staff Paperassessment of the most relevantinformation in these documents, and theadvice and recommendations of theCASAC as presented both in thediscussion of these documents at publicmeetings and in the CASAC's 1986 and1989 "closure letters."

Under section 109(b) of the Act,primary and secondary NAAQS are tobe based on the air quality criteriaissued under section 108. Additionally,under section 109(d), the EPA mustperiodically conduct a "thoroughreview" of the criteria taking intoaccount the advice andrecommendations of the CASAC as thebasis for periodic decisions on whetherrevisions of NAAQS are appropriate.When Congress enacted the latterrequirement in 1977, it was well awarethat implementation of the NAAQS canhave profound economic and social, aswell as environmental, consequences.Understandably, it required that theEPA's periodic decisions on whether torevise the NAAQS be based on scientificstudies that had been rigorouslyassessed and incorporated into airquality criteria and whose implicationsfor public health and welfare had beencarefully considered by both the EPAand the CASAC. In view of this, theAugust 10, 1992 notice made clear thatthe Administrator did not take intoaccount recent studies on the health andwelfare effects of 03 because thesestudies had not been assessed in the1986 Air Quality Criteria Document norits Supplement, nor had they undergonethe rigorous review process (includingCASAC review) required to incorporatethem into a new criteria document.

Because of the scientific and technicalcomplexity of such assessments, theEPA estimated that 2 to 3 years would

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be necessary to rigorously assess theover 1,000 new studies and incorporatekey information into a revised criteriadocument, to evaluate the significanceof the key information for decision-making purposes, to develop staffrecommendations for the Administrator,and to provide appropriateopportunities for the CASAC review andpublic comment. Given the importanceof these new studies and concern aboutthe health and welfare effects of 03, theAugust 10, 1992 notice also outlined theEPA's plans to proceed as rapidly aspossible with the next review of thecriteria and standards for 03.A. The Primary Standard

In reaching his August 10, 1992proposed decision that revisions of theexisting 03 primary standard were notappropriate, the Administratorconsidered the health effectsinformation assessed in the 1986 AirQuality Criteria Document, theSupplement that updated thatinformation, the 1989 Staff Paper, andthe advice and recommendations of theCASAC in its 1989 "closure letter."Based on his review of this information,the Administrator concurred with thestaff and the CASAC conclusions thatthe preliminary information on effectsof prolonged exposures to 03 was notsufficient to support the establishmentof a new 6- to 8-hour standard to protectagainst prolonged exposures, or aseasonal or other long-term standard toprotect against chronic effects. Inreaching this proposed determination,the EPA recognized that a number ofnew studies, particularly on 6- to 8-hourexposures to 03, had been published inthe scientific literature since early 1989.Mindful of this, as well as research inprogress on the chronic effects of 03. theEPA made clear in the proposal that itintended to proceed with the nextperiodic review of the air quality criteriaas rapidly as possible. The notice addedthat when this new information hadbeen incorporated into the air qualitycriteria, a more informed decision couldbe made as to whether adding a new 6-to 8-hour standard and/or a seasonal orother long-term standard would beappropriate.

The EPA also carefully considered thehealth effects information on 1- to 3-hour exposures to 03 contained in theair quality criteria. Based on theseassessments and taking into account theadvice and recommendations of theCASAC in Its 1989 "closure letter," theAdministrator in August 1992 reachedthe proposed determination thatrevisions of the existing 1-hour primarystandard were not appropriate toprovide increased protection against 1-

to 3-hour exposures to 03. The standardlevel is below the levels wherecontrolled human 1- to 3-hour exposurestudies found substantial changes inpulmonary function and symptoms. Inreaching this conclusion, theAdministrator was mindful that themean group response observed in thecontrolled human studies up to 0.15ppm 03 would at most be characterizedas mild, and that most of the responderswithin this population of normalhealthy individuals reportedlyexperienced only mild to moderateresponses under very heavy exercise(U.S. EPA, 1989, pp. VII-53 to VII-56),Although there was a difference ofopinion among the EPA's scientificadvisors as to the significance ofdecrements in lung function in therange of 10 to 20 percent whenaccompanied by symptoms (CASAC,1989), it was the Administrator'sjudgment that the lesser effectsassociated with exposure to 03 in therange of 0.12 ppm to 0.15 ppm observedin the controlled human studies did notconstitute adverse effects for purposesof section 109 of the Act.

The EPA also considered othersensitive population groups whoseresponse to 03 had not been fullycharacterized. Although someepidemiology studies considered in the1986 Air Quality Criteria Document andits Supplement suggested that exposureto 03 at ambient concentrations mayresult in the aggravation of asthma andpreexisting respiratory disease, theAdministrator concurred with the staff'sview that the direct use of these studieswas limited by uncertainties aboutindividual exposure levels and the roleof other pollutants. In addition,although individuals with preexistinglung disease are not more responsive to03 than healthy persons in controlledhuman exposure studies, the same smallchange in pulmonary function may havemore impact on people whose lungfunction is already compromised. Whilicertain others (field/epidemiologyptudies) suggested that these sensitivegroups may be at somewhat greater riskat levels of 0.12 ppm 03 and higher,compared to normal healthy individualsin controlled human exposure studies,the Administrator concluded thesestudies did not provide a sufficient basisfor lowering the existing standard. TheAdministrator also considered andconcurred with the staffrecommendations that 03 should remainas the surrogate for controlling ambientconcentrations of photochemicaloxidants and that the existing form ofthe standard should not be revised.

B. The Secondary StandardIn reaching the proposed decision that

revision of the existing 1-hour 03secondary NAAQS was not appropriate,the EPA carefully considered thewelfare effects information assessed inthe 1986 Air Quality Criteria Documentand its Supplement, the 1989 StaffPaper assessment, and the advice andrecommendations of the CASAC in its1989 "closure letter." A principalreason for the proposed decision wasthe Administrator's judgment that therewas insufficient information in the airquality criteria to specify a new form,averaging period, and level of asecondary standard that would be moreprotective of forest tree species as wellas agricultural crops. The notice addedthat when information had becomeavailable from research currently underway on key aspects of 03 exposuredynamics that are important forassessing the effects of 03 on forest treespecies and had been incorporated intothe air quality criteria during the nextreview, a more informed judgmentcould be made as to whether revision ofthe secondary standard is appropriate.

The EPA also carefully considered theavailable information on the effects of03 on agricultural crops alone. Althoughthe National Crop Loss AssessmentNetwork (NCLAN) studies haveprovided extensive data on the effects of03 on crops, the appropriateness of theseasonal mean exposure indicator usedin these studies had been subject tomuch criticism during the developmentof revised air quality criteria. Because ofthis and other shortcomings of thisexposure index that are discussed morefully in the August 10. 1992 proposalnotice, the EPA concluded that the useof the 7-hour seasonal mean derivedfrom NCLAN data for standard-settingpurposes would be inappropriate. TheCASAC also recognized this andrecommended that retrospectiveanalyses be undertaken in order toidentify a more appropriate exposureindex that would offer protection fromboth repeated 03 peaks of concern andlong-term 03 exposures. While theseanalyses had identified severalindicators that showed promise, theAdministrator concurred with the staff'sview that it would be premature to basea change in the form and averaging timeof the secondary standard on thepreliminary results presented in theSupplement to the 1986 Air QualityCriteria Document and the Staff Paper.

The Administrator also consideredtightening the current secondarystandard as an interim measure. Henoted that, throughout the review of theair quality criteria and staff assessment,

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no consensus had been reached on anappropriate range of alternative 1-hourstandards. The staff had great difficultythroughout the review in develoingand justifying alternative levels lowthat of the current standard due to thelack of data (U.S. EPA, 1980, p. XI-13).In the end, while the staff relied on thepreliminary results of the Lee et al.(1988) study to conclude that the upper-end of the proposed range (0.12 ppm)offered little protection for vegetation(U.S. EPA, 1989, pp. X--16 to XI-18),the staff also determined that the studywas too preliminary to serve as a basisfor recommending changes In the formand averaging time of the standard.Even if the results of the Lee et al.(1988) study provided a sufficient basisfor revising the standard downwardfrom 0.12 ppm to 0.10ppm, as somehad suggested, it was theAdministrator's Judgment that such achange would provide only marginalimprovement because a 1-houraveraging period was not the mostappropriate exposure indicator for thefull range of exposures, as discussed inthe August 10, 1992 proposal, andwould be seriously reconsidered duringthe next standard review. In the interim,it would have imposed adisproportionate and largelymeaningless burden on States to reviewand make appropriate revisions inapplicable SIP's.

Given the above information, it wasthe Administrator's udgment that themost prudent course of action was toretain the current secondary standarduntil a more informed decision could bemade during the next standard review.

II Summary of Public Comments onthe Proposed Decision

A limited number of comments werereceived on the August 10, 1992proposed decision. Of 27 writtensubmissions, 10 were provided byindividual industrial companies orindustry associations, eight by Federaland State government agencies andother entities, seven by environmentaland public interest groups, one by theCASAC Chairman, and one by aninterested Individual. In addition, threepersons presented testimony at theSeptember 1,1992 publL nearing. Ofthe three presentations, one individualwas highly critical of the EPA'sproposed decision and presentedbasically the same arguments as thosemade in the written commentssubmitted by his organization; thesecond maintained that newlypublished studies supported the needfor a revised standard; and the thirdindividual supported the proposeddecision and his testimony closely

paralleled his organization's writtencomments. The public hearingtranscript and a more detailed summaryof the comments received and the EPA'sresponses have been placed in DocketNo. A-92-17.

Of the 27 comments received, 11concurred in general with theAdministrator's proposed decision thatrevision of the primary and secondarystandards is inappropriate at this time.Some of these commenters alsomaintained that any new studiespublished after closure on the airquality criteria should undergo rigorousevaluation, be reviewed by the CASACand the public, and be incorporated intoa revised criteria document before beingconsidered for standard setting.

In contrast, 14 comments disagreedwith the proposed decision that revisionof the primary and secondary standardsis inappropriate at this time. Withrespect to the primary standard, most ofthese commenters maintained that anew 6- to 8-hour standard should beestablished to protect against healtheffects associated with mutkihour orprolonged exposures to 03. In support oftheir position, these oommenters, for themost part, relied on recent studies thathave not undergone the rigorous reviewin a criteria document, including theCASAC and public review, necessarybefore incorporation into the air qualitycriteria. Apparently In recognition ofthis, these commenters typically werecritical of the EPA for not updating thecriteria document before announcing itsproposed decision, and some alsomaintained that the Act does notpreclude the EPA and the CASAC fromconsidering information not in thecriteria document in setting standards.Several of these commenters alsoexpressed the view that CASAC reviewwas not required before such studiescould be used. Many of the samecommenters maintained that the recentstudies should, at a minimum, beconsidered in determining whether theexisting 1-hour standard provides an

.adequate margin of safety.Another commenter in this group

argued that the preliminary studies onprolonged exposures that wereconsidered by the EPA strongly suggestand, In the judgment of the commenter,provide a sufficient basis for a new 6-to -hour standard. This commenterrecognized, however, that newer studies(published after early 1989) that supportthese preliminary findings are not partof the air quality criteria that serve asthe basis for the proposed decision. Inview of this, the commenter urged theEPA not to wait the 2 to 3 years neededto fully evaluate these new studies,update the criteria document and staff

paper and submit them to the CASACand public review, but instead todevelop an alternative primary standardmore expeditiously.

Several commenters questioned theadequacy of the existing 1-hour primarystandard, particularly with respect toprotection it affords the elderly andchildren, and recommended that thestandard be revised downward. Onecommenter noted that his State'sadvisory committee, withresponsibilities similar to those of theCASAC, had recommended a morestringent 1-hour standard based onmany of the same studies, including thepreliminary studies on prolongedexposure, considered in this review.Of the 14 comments that did not

support the proposed decision, onlyfour provided specific comments on thesecondary standard. Of these fourcomments, two were highly critical ofthe EPA for not considering recently.published information in reaching theproposed decision. As in the case of theprimary standard, these counmeutersmaintained that the EPA was notprecluded from considering newlypublished peer-reviewed studies whenreaching a decision on whetherrevisions to the secondary standard areappropriate. One of these commenlerscited a number of newly publishedstudies, as well as some in press, tosupport the position that the existing i-hour secondary standard should berevised downward to a maximum of0.10 ppm orbe augmented by a newexposure index expressed as acumulative seasonal standard of 14.2ppm-hours. The same commenter wasalso critical of the EPA for not acceptingstaff and CASAC recommendations forrevising the existing 1-hour standard.

A third commenter also urged theEPA to consider lowering the existing I-hour secondary standard as an interimmeasure until such time as a new andmore appropriate expoeure index couldbe developed that would be protectiveof crops and forest tree species, andultimately forest ecosystems. In supportof this position, the commenter cited aseries of newly published studies andsome that are still in press or

* manuscript form on effects of O% onforest tree species. The fourth commenton the secondary standard expressed theview that a lower 1-hour primarystandard would also substantiallyreduce the impact of 03 on agriculturalcrops.

The final two comments on theAugust 10, 1992 proposal did not takean explicit position on the merits of theproposed decision. in the first of these,the commenter, a past Chairman of theCASAC, submitted a manuscript that

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critically reviewed health effectsinformation on 03, with particularemphasis on studies published after theCASAC completed its review of the airquality criteria that served as the basisfor the August 10, 1992 proposal, aswell as other 03 health effectsinformation that is just emerging. Basedon this review, the author concludedthat the CASAC, after having theopportunity to review this newinformation, would be unlikely to reachthe same conclusions as it did in 1989.

The second of these comments is anAugust 31, 1992 letter from the then-Chairman of the CASAC to theAdministrator. In his letter (reprinted asappendix II of this notice) the Chairmannoted with interest the EPA's plans notto revise the 03 standards and to initiatea new assessment of the health andenvironmental effects of 03. He addedthat the purpose of his letter was toexpress the Committee's willingness toassist the EPA in carrying out this newassessment in an expeditious manner.The Chairman also noted that acarefully planned strategy forpreparation of the criteria document andstaff paper would be essential in viewof the magnitude and complexity of thetask, particularly with respect to thereview, integration, and interpretationof old and new scientific information.

IV. Rationale for Final Decision

A. The Primary StandardThe August 10, 1992 proposal

discussed in some detail the underlyinghealth effects information and therationale for the EPA's proposeddetermination under section 109(d)(1)that revisions to the existing primarystandard were not appropriate. Aftertaking into account the publiccomments and for the reasons discussedbelow, the EPA again concludes, basedon the rationale presented in the August10, 1992 proposal notice, that revisionsto the existing primary standard are notappropriate at this time.

For the most part, the commentersthat objected to the proposed decisionon the primary standard did not disputethe EPA's assessment of the healtheffects information that served as thebasis for the proposed decision, nor didthey maintain that the EPA erred inconcluding that this information did notprovide a sufficient basis forestablishing a new 6- to 8-hour primarystandard. Instead, they argued that theEPA improperly excluded fromconsideration studies that werepublished in the peer-reviewedliterature after early 1989 and that as aresult the proposed decision was basedon "stale" data. In their view, the EPA

should have updated the criteriadocument prior to reaching theproposed decision. Absent that, somemaintained that the Act does notpreclude the use of peer-reviewedstudies in standard setting even thoughthey have not been incorporated into theair quality criteria.

As discussed more fully in theproposal notice (57 FR 35546, 35554),the EPA was fully aware of the newstudies on the health effects of 03 andacknowledged that they had not beentaken into account. Based on applicablestatutory requirements and the volumeof material requiring careful evaluation,the EPA estimated that it would take 2to 3 years to incorporate these newhealth studies, as well as new studies onwelfare effects, into a revised criteriadocument; to evaluate the significanceof key information for decision-makingpurposes; to develop staffrecommendations for the Administrator;and to provide for CASAC review andpublic comment. Given various legalconstraints and the fact that the EPAhad already missed both the 1985 and1990 deadlines for completion of reviewcycles under section 109(d), theAdministrator concluded that the bestcourse of action was to complete thecurrent review based on the existing airquality criteria and at the same time toproceed as rapidly as possible with thenext review of the criteria and standardsfor 03.

Having considered the comments onthis issue, the EPA adheres to thatconclusion. A number of commentersnoted the complexity of the issues thatthe EPA would have to address whenupdating the air quality criteriadocument and staff paper, including thelarge volume of new material that wouldhave to be evaluated, incorporated intothe revised documents, and submittedfor CASAC review and public comment(e.g., Docket No. IV-D-20). The CASACalso recognized that the preparation ofa revised criteria document and staffpaper would not be an easyundertaking. In his August 31, 1992letter to the Administrator, theChairman of the CASAC noted that "acarefully planned strategy forpreparation of the criteria document andstaff position is essential in view of themagnitude and complexity of the task."He added that "the review, integrationand interpretation of the old and newinformation will be a substantialundertaking. In addition, it will beimperative that the next staff positionpaper carefully consider alternativeorms of the ozone standard, both in

terms of averaging times, such as daily(6-24 hour), as well as frequency ofoccurrence, and seasonal standards, in

addition to the traditional one-hourstandard. This too, will requiresubstantial preparation effort and. Isuspect, ample time for debate"(McClellan, 1992).

The EPA has considered the viewurged by some commenters that healthand welfare effects studies published inthe peer-reviewed literature after early1989 should be considered even thoughnot incorporated into the air qualitycriteria. The language of section109(b)(1) and 109(b)(2) makes clear thatprimary and secondary standards are tobe based on scientific informationassessed in air quality criteria issuedunder section 108 of the Act.Furthermore, under section 109(d),which was added to section 109 in1977, the EPA must periodicallyconduct "a thorough review" of the airquality criteria taking into account theadvice and recommendations of thescientific review committee known asthe CASAC. Taking these provisionstogether, it is clear that the Actcontemplates that the EPA base itsNAAQS decisions on scientific studiesthat have been reviewed by the CASACand incorporated into air qualitycriteria.1

The EPA's interpretation not only isthe most straightforward reading of thestatutory scheme, but it makes goodsense in the context of this decision. Asdiscussed in the August 10, 1992proposal notice (57 FR 35546),implementation of the NAAQS can haveprofound economic and social as well asenvironmental consequences, and it isunderstandable that Congress wouldrequire them to be based on scientificstudies that had been rigorouslyassessed not only by the EPA but alsoby an independent advisory committee(i.e., CASAC). Under the statute, theprocess for performing this assessmentis preparation or revision of a criteriadocument [see Lead IndustriesAssociation v. EPA, 647 F.2d 1130,1136-37 (DC Cir. 1980), cert. denied,101 S. Ct. 621 (1980)]. During thatprocess, a large number of studies,though published in peer-reviewedjournals, are typically judged unsuitablefor use in standard setting. In other

I Since the 1970 amendments, the EPA has takenthe view that NAAQS decisions are to be based onscientific studies that have been assessed in airquality criteria [see. e.g. 36 FR 8186 (April 30, 1971)(the EPA based promulgation of original NAAQS forsix pollutants on scientific studies discussed in theair quality criteria and limited consideration ofcomments to those concerning validity of scientificbasis); 38 FR 25678, 25679-80 (September 14,1973)(the EPA revised'air quality criteria for sulfuroxides to provide basis for reevaluation ofsecondary NAAQS)I. This longstandinginterpretation has been strengthened by theaddition of the 1977 amendment that provides forCASAC review of air quality criteria.

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words, publication in a pee-reviewedjournal does not in itself establish thevalidity or usefulness of a given study.As'Administrator Reilly noted, "itwould be premature to drawconclusions on either the scientificmerit or the ultimate implications ofparticular studies prior to a rigorous andcomprehensive assessment' * * by theEPA and CASAC" (57 FR 35546).

For these reasons, the EPA concludesthat it may not consider studies notincorporated into air quality criteria andreviewed by the CASAC when setting orrevising NAAQS. 2 Given theextraordinary importance of the NAAQSfor 03, the EPA further concludes thatconsideration of such studies in thisinstance would be inappropriate even ifpermitted under section 109.

At times, the EPA has found itappropriate to supplement a criteriadocument before completing its reviewof the corresponding NAAQS. Forexample, the EPA in 1986 preparedaddenda to the criteria document forparticulate matter and sulfur oxides sothat newly published studies could beincorporated and, thus, serve as part ofthe basis for determining whetherrevisions to the air quality standardswere appropriate. Similarly, the EPAprepared the0O Supplemgnt that ispartof the basis for today's decision so thatnewly published studies could beproperly considered. The EPA'sdiscretion to delay completion of Itsperiodic reviews under section 109(d)or such purposes is not unlimited,

however, and at some point the processof incorporating new studies must endso that decisions can be made. TheChairman of the CASAC emphasizedthis in his August 31, 1992 lotter whenhe noted -it is crucial that at aparticular point in time, that isunderstood by all parties, theknowledge base on ozone besummarized and used for relatorypurposes" (McClellan, 1992).

The EPA also considered thecomments that specifically address the

This conchusion does not vitit the role ofpublic cemment In the tandard-setting process, asSeveral commenters have summed. Broadlyspeaking. the EPA believes c=m intended theAdministrator to consider comments that addresssuch tssues u the scientific merit, the implications,and the proper use of studies discussed i& criteriadocoments. Jost as the Administator mightsonsider staff opinions or recommendations onsuch materse in s staff paper or other analyticaldomment. By contrast, the EPA does not believeCongres intended to allow hnersted parties to addnew studies to the basis for decision, circumventingte wou satdy they would otherwisemdapo by thesimple expedient of attaching then.to pub commnmts. Of course. if mew studiles thatappear to be important ws brought to the EPA'sattention in public comments or otherwise, i maybe appropriate to supplements a cisw documentas discussed below.

rotection afforded by the edsting 1-our standard against 1- to 3-hour

exposures to 03. Several commentersmaintained that the EPA erred inreaching its proposed decision becausepotentially sensitive population groupssuch as children, the elderly, andwomen had not been properlyconsidered. While age has been

-suggested as a factor which couldmodify responsiveness to 03 exposure,controlled-exposure studies conductedon human subjects do not showchildren or the elderly to have greaterchanges in lung function than othersubjects. In one studyby McDonnell atal. (1985), changes In lun spirometry inchildren were similar fotho found inadults exposed under similarconditions, except that no significantincreases in symptoms were found inchildren (U.s EPA, 198, p. 12-35).With regard to the elderly, subjects 50years of age or olderwere found by Bediat al (1988) and Bedi and Horvath(1987) to have smaller changes in lungfunction than youger subjects whenexposed to simaiWr03 levelst usleading to the suggestion that a possibledrop-off in responsiveness to Or-induced pulmonary function changesoccurs sometime In middle age (U.S.EPA, 1902, p. -1). As for genderdifferences, ther were no significantdifferences in pulmonary function[forced expiratory volume (FEV) andforced vital capacity (FVC)] betweenmen and women exposed to 03(Drechaler-Parks at al., 1987; Relsenaueret al., 1988), although the data suggestwomen may be somewitat moreresponsive to 03 than men becausewomen had slightly lower mean*exet ise rates during the studies (U.S.EPA, 1992, p. 3-61). For these reasons,the EPA concludes that thecharacterization of the sensitivepopulations most affected by short-termexposure to 03 presented in the August

.10, 1992 proposal notice (57 FR 35549)is in accordance with the air qualitycriteria.

Several commenters questioned theadequacy of the margin of safetyprovided by the existing 1-hourstandard. In general, these commentersargued that the standard should betightened to provide increasedprotection against effects of prolonged(6- to 8-hour) exposures. Onecommenter also referred to short-termexposures; he noted that his State'sadvisory committee, withresponsibilities simila tothose of theCASAC, had identified a lowestobserved effects level of 0.12 ppm forexposures of I to 2 hours based on Its -

assessment of McDonnell et &1. (1983)

and Gong et al., (19W8). This commenteradded that after considering anadditional study indicating thatmultihour exposures at 0.12 ppm andbelow produced decrements in lungfunction (IWoy at l., 1985), as well asmounting evidence of cumulative effectsfrom chronic exposure to 03, his Stateagency had adopted a 1-hour 0%standard of 0.09 ppm in 1987, citing theneed to provide an adequate margin ofsafety to "prevent substantial risk ofharm to human health as a result ofshort-term exposures and to provideprotection against probable effects oflong-term exposures." This commenteradded that evidence for a moreprotective margin of safety is morecompelling now because of multihourstudies (Spektor et al.. 1988ab) andcontrolled human exposure studies(Folinsbee at al., 1989; Horstman t al.,1989) reporting decrements inpulmonary function at 0.12 ppm andwer as well as multihour studies

reporting-biochemical indicators ofinflammation (Koren et al., 1988ab).This commenter concluded by notingthat adoption of a 1-hour standard morestringent than the current one wouldprovide a greater degree of protectionagainst multihour exposures.

With respect to short-term exposures,the EPA also considered McDonnell ela). 11983) and Gong -t a]. (1986).inconjunction with other studiesdiscussed in the air quality criteria andreached a quite different conclusion asto the significance of effects reported- at0.12 ppm 03. As discussed in theproposal notice (57 FR 35547,35548),controlled-exposure studies of humansubjects (McDonnell t al. 1983; Gong atal. 1986) reported small but statisticallysignificant, transient declines Inulmonary function (e.g., reductions in

lung volume and air flow), which Insome cases were accompanied bysymptoms [e.g., cough, chest pain,throat irritation, shortness of breath)during exposure to O in the range of0.12 to 0.15 ppm. These effects,however, were reported only whensubjects were engaged In very heavyexercise (V.=68-89 liters per minute).Without heavy exercise, even the mostsensitive subjects did not experiencestatistically-significant decrements inlung function (FEV,.o) at low-level 03exposures (around 0.12 ppm after I to3 hours). As discussed in the staff paper,the magnitude of effects which can bemeasured at these exposure levels, evenwith heavy exercise, is not generallyconsidered to be adverse to health (U.S.EPA, 1989, pp. V11-53 to VU-56).

As discussed In the proposal notice,another key point that emerged duringthe-review of these and other studies

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was the high degree of variability inresponsiveness between individualsexposed to similar 03 levels. This wasevident from the number of studies(Gibbons and Adams, 1984; Linn et aL,1986; Avol et al., 1984; Schelegie andAdams, 196) that found nostatittically-significant response atexposures (0.12 to 0.15 ppm 03) andexercise levels (V, = 55 to 86 liters perminute) similar to those in McDonnellet al. (1983) and Gong eta]. (1986). Intwo of these studies (Avol et al., 1984;Linn et al.. 1986), statistically-significant changes in FEV, began toappear at 0.16 ppm 03.

Recognizing that between 5 and 20percent of otherwise healthy individualsmay be more responsive to 03 duringexercise and, therefore, might be athigher risk, the EPA also examined theintersubject variability reported byMcDonnell et al. (1983) and Kulle eta].(1985). For these studies, the effectsexperienced by even the most sensitiveindividuals exposed to 0.12-0.15 ppm03 for 1 to 3 hours ranged from -9 to-16 percent decline in FEV.o with few,if any, symptoms. These effects havebeen characterized as only mild tomoderate (U.S. EPA, 1989, pp. VII-53 toV1l-56).

The EPA's assessment of these andother controlled-exposure studies ofhuman subjects led Administrator Reillyto conclude, taking into account thedifferences of opinion among CASACmembers on this point that the lessereffects associated with 1- to 3-hourexposures to 03 in the range of 0.12 to0.15 ppm did not constitute adverseeffects for purposes of section 109 of theAct. The EPA adheres to that judgment.

With respect to prolonged exposures,the EPA also evaluated Lioy et a]. (1985)as part of its assessment of the emergingresearch in this area. Lioy et a). (1985)conducted a summer camp field studyof children engaged in outdoor activitiesfor periods of several days to weeks,during which they were exposed toambient 03 for several hours per day.This study reported that statistically-significant, short-term pulmonaryfunction decrements, compared toinitial baseline values, could bemeasured even when the 03 NAAQSwere not exceeded. The effectsincreased with exposure to increasinglevels of 03. The pulmonary functiondecrements reported, however, could beattributed in part to factors such as otherpollutants or heat. Moreover, the healthsignificance of pulmonary functiondecrements of the duration andmagnitude reported in this study isunclear (U.S. EPA, 1989, pp. VI-53 toVU-56).

Based on the its assessment ofMcDonnell et al. (1983), Gong et a].(1986). and Uoy et a]. (1985). the EPAdoes not agree that these three studieswarrant revision of the 1-hour 0%NAAQS, either to provide greaterIrotection against short-term (1- to 3-

our) effects or to provide a margin ofsafety against the effects of multihourexposures. As noted above, the EPAadheres to Administrator Reilly'sjudgment that effects associated with 1-to 3-hour exposures in the range of 0.12ppm to 0.15 ppm do not constituteadverse effects. The EPA also believesthat tightening the 1-hour standard toprovide "surrogate" protection againstmultihour exposures would beinappropriate for reasons discussedbelow. Under section 116 of the Act, ofcourse, the States are free to establishambient air quality standards that aremore stringent than the NAAQS.Because decisions on such questions aswhether detectable responses to airpollution are significant enough to beregarded as adverse health effects,whether a given margin of safety isadequate, or whether it is appropriate touse a short-term standard to providesurrogate protection against the effectsof multihour exposures are inescapablyjudgmental (see, e.g., Lead IndustriesAssociation v. EPA, supra, 647 F.2d at1144, 1160, 1161-62), differentdecision-makers may well come todifferent conclusions.

The preliminary information onmultihour exposures cited by thiscommenter and others was consideredby the CASAC in its assessment of theadequacy of the existing 1-hourstandard (CASAC Transcript. 1988). TheCASAC was divided on whether itwould be appropriate to set a lower 1-

* hour standard as a surrogate to protectagainst multihour exposures. In anyevent, the CASAC could not reach aconsensus on an appropriate range forsuch a standard. The CASAC noted inits "closure letter" that "this lack ofconsensus is reflective of majordeficiencies in our knowledge baseregarding health and welfare effects oflong-term exposure (beyond a fewhours) to ozone. The data base is verylarge and adequate for knowledgeableindividuals to reach agreement on theeffects of acute exposure to ozone in therange appropriate for setting a 1-hourstandard. However. there is not anadequate data base on the effects ofmultiple hour or seasonal exposures toozone* * *." (CASAC, 1989).

Administrator Reilly was very awareof the views of the CASAC on thesepoints. Taking those views into account.he determined that the appropriatenessof revising the existing 1-hour primary

standard should be judged in terms ofthe large body of information on acute(1- to 3-hour) exposures to 03, and thatthe preliminary information onmultihour or prolonged exposuresshould be evaluated in terms of whetherit provided a sufficient basis for settinga new multihour standard. This was theapproach adopted In the proposalnotice, and the EPA continues to believeit is the proper one. Tightening the 1-hour standard to a degree appropriatefor surrogate protection againstprolonged or multihour exposureswould require many if not all of thesame determinations that would beneeded to establish a multihourstandard. At a minimum, only after anappropriate multihour averaging periodand concentration level of concern hadbeen established, would it be possible tocompute, based on 03 air qualityrelationships, a 1-hour value that wouldgenerally (but not always) provide thesame approximate level of protection.Given the preliminary nature of theinformation available, making suchdeterminations now would bepremature. As discussed above, theCASAC in essence undertook such anassessment in its deliberations andcould not roach a consensus due to thelack of an adequate data base.

Based on its review of the record, theEPA concludes that there is insufficientinformation on prolonged or multihourexposures to provide a reasoned basisfor lowering the existing 1-hour primarystandard to serve as a surrogate for alonger-term standard. Even if there weresufficient information available, theadoption of a tighter 1-hour standard asa surrogate for a longer-term standardwould be a poor policy choice. Whenestablishing a new or revised standard,the averaging time selected shouldmatch to the extent practicable theexposure period associated with thehealth effects of concern. While 1-hourpeak 03 levels correlate well withlonger-term 03 levels in many areas ofthe country, the variability of air qualityrelationships means that the adoption ofa 1-hour standard as a surrogate wouldnot assure uniform protection for theentire country. As a result, some areaswould have to over-control to meet thelower 1-hour value while others, eventhough they attained the lower 1-hourstandard, would not necessarily receivethe desired level of protection againstprolonged or multihour exposures. Forthese reasons, the EPA concludes thatthe'more reasoned approach is toproceed as rapidly as possible with thenext review of the air quality criteria sothat recently published studies can beappropriately considered. Being aware

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of many of these new studies, the EPAbelieves they will provide importantnew information so that a moreinformed decision can be made withrespect to the need for and specification-of a new standard to address the publichealth concerns associated withprolonged or multihour exposures to 03.

In the proposal notice, the Agencyestimated that it would take 2 to 3 yearsto update the air quality criteria forozone and develop staffrecommendations for the Administrator,following the relatively complex processoutlined in Section III of the notice. Aspreviously noted, a number ofcommenters, including the immediatepast Chairman of the CASAC, havestressed the magnitude and complexityof the task. Others have argued that thenewer studies raise serious concernsabout the adequacy of the existingstandards. The Agency continues tobelieve that a rigorous assessment of thenew studies is necessary to assure asound decision. Because of theextraordinary importance of this publichealth issue, however, theAdministrator intends to move theprocess ahead as quickly as possibleand, if appropriate, to propose revisionsof the standards at the earliest possibledate. To that end, the Administrator hasdirected the Agency staff to examine allpossible ways of accelerating theprocess consistent with assuring asound decision.

B. The Secondary StandardThe rationale for the proposed

determination under section 109(d)(1)that revisions to the existing secondarystandard are not appropriate at this timewas presented in some detail in theAugust 10, 1992 proposal (57 FR 35550).Based on this information,Administrator Reilly concluded that themost prudent course of action was toretain the current standard until a moreinformed decision could be madeduring the next standard review. Aftertaking into account the publiccomments on the secondary standardand for the reasons discussed below, theEPA again concludes; based on therationale presented in the August 10,1992 proposal notice, that revisions tothe existing secondary standard are notappropriate at this time. As discussed inthe summary of public comments above,only four commenters opposed theproposed decision on the secondarystandard. Several of these commentersargued that the EPA should haveconsidered studies published in thepeer-reviewed literature aftercompletion of the air quality criteria andstaff paper that served as the basis forthe proposed decision. As in the case of

the primary standard, and for the samereasons, the EPA concludes thatsecondary'NAAQS must and should bebased on information contained In theair quality criteria. Again, the EPAbelieves the proper course of action isto proceed as rapidly as possible withthe next review of the air quality criteriaso that the more recent studies can befully evaluated. In this regard, the EPAnotes the number of new studies, someof which are still in press, cited by oneof the commenters (see Docket NumberIV-D-27) on the effects of 03 on forests.As discussedin the August 10, 1992proposal, this is precisely the type ofinformation that, once it has beenincorporated into the air quality criteria,will assist the EPA in reaching a moreinformed decision on a new form,averaging period, and level of asecondary standard that would be moreprotective of forest tree species andagricultural crops. As in the case of theprimary standard, once the reviewprocess is completed, the EPA willreach a determination as to whetherrevisions are appropriate and announceits proposed decision as quickly aspossible thereafter.

Two commenters also argued that theEPA should give further considerationto the staff's and the CASAC'srecommendations on tightening theexisting 1-hour secondary standard. Asdiscussed in the August 10, 1992proposal, Administrator Reilly was'aware that both the staff and the CASAChad great difficulty throughout theirreview of the air quality criteria andstandards for 03 in determining anappropriate range for a 1-hoursecondary standard (U.S. EPA, 1989, p.XI-15). In the end, the staff had to relyon the preliminary results of the Lee eta]. (1988) study to develop and specifya range of alternative levels below thatof the current standard. Even afterconsidering the staff's new assessmentbased on the Lee study, the CASACcould not reach a consensus (CASAC,1989). As noted in the proposal notice,the staff found this study toopreliminary to serve as the basis forrecommending changes in the form andaveraging time of the standard. Giventhe preliminary status of data thatprovided the basis for staffrecommendations and the CASAC'sclearly expressed view that a 1-houraveraging period was not the mostappropriate exposure indicator,Administrator Reilly was initiallyInclined not to consider any revisionsbecause of the absence of sufficientinformation to specify a new form,averaging time, and level for thesecondary standard.

Being mindful of.the opinionexpressed by the CASAC in its "closureletter" Administrator Reilly did,however, consider lowering the 1-hourstandard as an interim measure. Asdiscussed in the August 10, 1992proposal, even if the results of the Leeet al. (1988). study provided a sufficientbasis for revising the standarddownward from 0.12 to 0.10 ppm, as aninterim measure, it was AdministratorReilly's judgment that such a changewould provide only marginalimprovement because a 1-houraveraging period is not the mostappropriate exposure indicator for thefull range of exposures that affect crops'and forest tree species and will have tobe reconsidered during the next review.Administrator Reilly also concludedthat, in the Interim, such a changewould have imposed a disproportionateand largely meaningless burden onStates to review and make appropriaterevisions in applicable SIP's. Havingconsidered the public comments on theIssue, the EPA adheres to thesejudgments.

C. Fiial Decision

For the reasons discussed above andin the August 10, 1992 proposal notice(57 FR 35542), it is the Administrator'sjudgment under section 109(d)(1) thatrevisions to the existing primary andsecondary NAAQS are not appropriateat this time. Because a large body of newinformation on the health and welfareeffects of 03 has been published in thescientific literature since completion ofthe air quality criteria upon which thisdecision is based, the EPA has alreadyinitiated action to update the air qualitycriteria (57 FR 38832, August 27, 1992).As discussed above, the EPA willproceed with the next review of thecriteria and standards for 03 andannounce its proposed decision onrevisions of the standards as rapidly aspossible.

V. Regulatory Impacts

A. Regulatory Impact Analysis

Under Executive Order 12291, theEPA must judge whether an action is a"major" regulation for which aRegulatory Impact Analysis (RIA) isrequired. For reasons set forth in theproposal notice, the EPA has judged thattoday's decision on the primary andsecondary NAAQS is not a major action.The EPA, therefore, has deemedunnecessary the preparation of either afinal RIA or a final EnvironmentalImpact Statement.

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B. Impact on Small Entities

Under the Regulatory Flexibility Act(RFA), 5 U.S.C. 601 et seq., the EPAmust prepare initial and final regulatoryflexibility analyses assessing the impactof certain rules on small entities. Forreasons set forth in the proposal notice,the EPA has determined that the impactassessment requirements of the RFA areinapplicable to this final decision.

VL Other Reviews

This decision was submitted to theOffice of Management and Budget(OMB) for review. Written commentsfrom the OMB and the EPA writtenresponses to these comments areavailable for public inspection at theEPA's Central Docket Section (DocketNo. A--92-17), South Conference Center,room 4, Waterside Mall, 401 M StreetSW., Washington, DC.

Dated: March 1, 1993.Carol M. Browner,Administrator.

REFERENCESAvol, E.L.; Llnn, W.S.; Venet, T.G.; Shamoo,

D.A.; and J.D. Hackney (1984),Comparative respiratory effects of ozoneand ambient oxidant pollution exposureduring heavy exercise, J. Air Pollut.Control Assoc. 34: 804-809.

Bedi, J.F. and S.M. Horvath (1987),Longitudinal case study of pulmonaryfunction response to ozone, Am. J. Med.82: 860-861.

Bedi, J.F.; Horvath, & M.; and D.M.Drechsler-Parks (1988), Reproducibilityof the pulmonary function response ofolder men and women to a 2-hour ozoneexposure, JAPCA 38: 1016-1019.

Clean Air Scientific Advisory Committee(1986), Closure Letter to Lee Thomas,October 22, 1986.

Clean Air Scientific Advisory Committee(1988), Transcript of meeting held inWashington, D.C. on December 14-15,1988.

Clean Air Scientific Advisory Committee(1989), Closure Letter to William K.Reilly, May 1, 1989.

Drechsler-Parks, D.M.; Bedi, J.F.; and S.M.Horvath (1987). Pulmonary functionresponses of older men and women toozone exposure, Exp. Gerontol. 22: 91-101.

Folinshee, L.I., and M.J. Hazucha (1989).Persistence of ozone-induced changes inlung function and airwayresponsiveness. In: Schneider, T.; Lee,S.D.; Wolters, G.J.R.; Grant, L.D., ads.,Atmospheric ozone research and itspolicy implications: proceedings of the3rd US-Dutch international symposium;May 1988; Nijmegen. The Netherlands,Amsterdam, The Netherlands, ElsevierScience Publishers; pp. 483-492 (Studiesin Environmental Science 35).

Gibbons, S.L and W.C. Adams (1984).Combined effects of ozone exposure andambient heat on exercising females, J.Appl. Physiol. 57: 450-456.

Gong, H., Jr.; Bradley, P.W.; Simmons, M.S.;and D.P. Tashkin (1986), Impairedexercise performance and pulmonaryfunction in elite cyclists during low-levelozone exposure in a hot environment.Am. Rev. Respir. Dis. 134: 726-733.

Horstman, D.; McDonnell, W.; Folinsbee, L.;Abdul-Salaam, S.; and P. ives (1989),Changes In pulmonary function andairway reactivity due to prolongedexposure to typical ambient ozone (03)levels, In: Schneider, T.; Lee, S.D.;Wolters, G.J.R.; Grant, L.D., eds.Atmospheric ozone research and itspolicy implications: proceedings of the3rd US-Dutch international symposium;May 1988; Nijmegen, The Netherlands.Amsterdam, The Netherlands: ElsevierScience Publishers; pp. 755-762 (Studiesin Environmental Science 35).

Koran, H.S.; Devlin, R.B.; Graham, D.E.;Mann. R.; and D.H. Horstman (1988a),Cellular and biochemical changes in thelower airways of subjects exposed toozone, Research Triangle Park. NC U.S.Environmental Protection Agency,Health Effects Research Laboratory;report no. EPA/600/D-88/031, Availablefrom: NTIS; Springfield. VA; PB88-170048.

Koren, H.S.; Devlin, R.B.; Graham, D.E.;Mann, R.; Horstman, D.H.; Kozumbo,W.J.; Becker, S.; and W.F. McDonnell(1988b), Cellular and biochemicalchanges in the lower airways of subjectsexposed to ozone, In: Sorg, C., ed. Thealveolar macrophage , Local Immunity 4:36-49.

Kulle, T.J.; Sauder. LR.; Hebel, J.R.; and C.D.Chatham, M.D. (1985), Ozone responserelationships in healthy nonsmokers,Am. Rev. Respir. 0is. 132: 36-41.

Lee, E.H.; Tingey, D.T.; and W.E. Hogsett(1988), Interrelationship of ExperimentalExposure and Ambient Air Quality Datafor Comparison of Ozone ExposureIndices and Estimating AgriculturalLosses. U.S. Environmental ProtectionAgency, Office of Air Quality Planningand Standards, Research Triangle Park.N.C.

Linn, W.S.; Avol, E.L; Shamoo, D.A.; Spier,C.E1; Valencia, LM.; Venet, T.G.; Fischer,D.A.; and J.D. Hackney (1986), A dose-response study of healthy heavilyexercising men exposed to ozone atconcentrations near the ambient airquality standard, Toxicol. Ind. Health 2:99-112.

LIoy, P.J.; Vollmuth, T.A.; and M. Lippmann(1985), Persistence of peak flowdecrement in children following ozoneexposures exceeding the NationalAmbient Air Quality Standard, J. AirPollut. Control Assoc. 35: 1068-1071.

McClellan, 11O. (1992), Letter from Chairmanof Clean Air Scientific AdvisoryCommittee to the EPA Administrator,dated August 31, 1992.

McDonnell, W.F.; Horstman, D.H.; Hazucha,M.J.; Seal. E.. Jr.; Haak, ED.; Salaam, S.;and D.E. House (1983). Pulmonaryeffects of ozone exposure duringexercise: dose-response characteristics, J.Appl. Physiol: Respir. Environ. ExercisePhysioL 54: 1345-1352.

McDonnell, W.F., III; Chapman, R.S.; Leigh,M.W.; Strope, G.L; and A.M. Collier(1985), Respiratory responses ofvigorously exercising children to 0.12ppm ozone exposure, Am. Rev. Respir.Dis. 132: 875-879.

Reisenauer, C.S.; Koenig, J.Q.; McManus,MIS.; Smith, M.S.; Kusic, G.; and W.E.Pierson (1988). Pulmonary responses toozone exposures in healthy Individualsaged 55 years or greater, J. Air Pollut.Control Assoc. 38: 51-55.

Schelegle, KS. and W.C. Adams (1986),Reduced exercise time in competitivesimulations consequent to low levelozone exposure. Med. ScL Sports Exerc.18: 408-414.

Spektor, D.M.; Llppmann, M.; Lloy. P.J.;Thurston, G.D.; Citak, K.; James, D.J.;Bock, N.; Spelzer, F.E.; and C. Hayes(1988a). Effects of ambient ozone onrespiratory function in active normalchildren, Am. Rev. Respir. Dis. 137: 313-320.

Spektor, S.M.; Llppmann, M.; Thurston, G.D.;Lioy, P.J.; Stecko, J.; O'Connor, G.;Garshick. K; Speizer, F.E.; and C. Hayes(1988b), Effects of ambient ozone onrespiratory function in healthy adultsexorcising outdoors, Am. Rev. Respir.Dis. 138: 821-828.

U.S. Environmental Protection Agency(1978), Air Quality Criteria for Ozoieand Other Photochemical Oxidantr.Office of Research and Development.Washington, D.C., EPA Report No. EPAZ-600/8-78-004.

U.S. Environmental Protection Agency(1986), Air Quality Criteria for Ozoneand Other Photochemical Oxidants. DraftFinal, Environmental Criteria andAssessment Office, EPA Report No.EPA-600/8-84/020a to 020e, Availablefrom: NTIS, Springfield, VA; PB 87-142949.

U.S. Environmental Protection Agency(1989), Review of the National AmbientAir Quality Standards for OzoneAssessment of Scientific and TechnicalInformation: OAQPS Staff Paper,.Research Triangle Park, NC: Office of AirQuality Planning and Standards, EPAReport No. 450/2-92-001.

U.S. Environmental Protection Agency(1992), Summary of Selected NewInformation on Effects of Ozone onHealth and Vegetation: Supplement toAir Quality Criteria for Ozone and OtherPhotochemical Oxidants, ResearchTriangle Park. NC: Office of Health andEnvironmental Assessment.Environmental Criteria and AssessmentOffice;, EPA/600/-48/105A, Availablefrom NTIS, Springfield, VA.

Appendix I

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13018 Federal Reg ster I Vol. 58, No. 44 / Tuesday, March 9, 1993 / Rules and Regulations

May 1, 1989*The Honorable William K. Reilly,Administrator, U.S. Environmental

Protection Agency,401 M Street SW.,Washington, DC 20460

Dear Mr. Reilly: I am pleased to transmitvia this letter the advice of the Clean AirScientific Advisory Committee (CASAC)concerning the National Ambient Air QualityStandards for Ozone. CASAC has reviewedand offered comments directly to EPA staffon the EPA criteria document "Air QualityCriteria for Ozone and Other PhotochemicalOxidants (1986)," the draft "CriteriaDocument Supplement (1988)," and theOffice of Air Quality Planning and Standardsstaff position paper "Review of the NationalAmbient Air Quality Standards for OzoneAssessment of Scientific and TechnicalInformation (1988)" and related supportdocuments.

CASAC previously reached closure on the1986 Criteria Document. At a meeting heldon December 14-15,1988, CASAC came toclosure on the "Criteria DocumentSupplement (1988)" and the 1988 StaffPosition Paper and concluded that theyprovide an adequate scientific basis for EPAto retain or revise primary and secondarystandards for ozone. While reaching closureat this time, the Committee did note anemerging data base on the acute health effectsresulting from 6-plus hours of ozoneexposure, providing evidence 6f the possibleneed for a standard with a 6-8 houraveraging time. However, it was theCommittee's view that it would be some timebefore enough of this developing informationwould be published in scientific journals toreceive full peer review and, thus, be suitablefor inclusion in a criteria document. CASACconcluded such information can better beconsidered in the next review of the ozonestandards.

CASAC did not reach a consensus opinionon endorsement of the staff position paperrecommendation that "the range of 1-houraverage ozone levels of concern for standardsetting purposes is 0.08-0.12 ppm for aprimary standard." The opinion of theCASAC Ozone Review Committee wasdivided with regard to the upper range of thestandard with eight individuals favoring arange with an upper value of 0.12 ppm, threeindividuals favored an upper bound in therange of 0.10-0.12 ppm, four individualsfavored an upper bound value no higher than0.10 ppm, and one individual abstained fromoffering an opinion. Several individuals whosupported an upper value of 0.12 ppm aswell as all of the other individuals whofavored a lower value fur the upper end ofthe range expressed the view that at 0.12ppm there was little or no margin of safety.As you are aware, the margin of safety isintended to provide protection againstadverse effects which have not yet beenuncovered by research and effects whosemedical significance is a matter ofdisagreement. Finally, several members ofthe subcommittee favored development of astandard with a more statistically robustupper bound on 'the annual distribution ofozone concentrations rather than reliance onthe current expected exceedance form of thestandard. While the Committee offers no

further advice on what form the Agencyshould consider, we would caution youagainst any form which alters the degree ofhealth protection afforded by the currentstandard.

CASAC had substantial discussion of theissue of what are or are not adverse healtheffects. This discussion was aided by thepresentation of this issue in the staff positionpaper. Within CASAC there was diversity ofopinion; some members felt that healthyindividuals experience adverse effects whenozone exposure induced any of the responsescategorized as moderate (i.e., >10%decrement in FEV, or mild to moderaterespiratory symptoms) in the staff positionpaper, while a few members believed thatadverse effects would not be experienceduntil ozone induced more severe effects (i.e.,>20% decrement in FEV, and moderate tosevere respiratory symptoms). The view ofsome individuals on this matter was-influenced by recognition that resolution ofthe adverse health effect issue represents ablending of scientific and policy judgmentsand, thus, we feel It appropriate to informyou of the range of our views on this matter.

Of particular concern to CASAC is thepotential for effects arising from exposures toozone with daily peak concentrations at ornear 0.12 ppm for periods of 6-8 hours andwith co-exposure to other pollutants. Thisconcern is due to air quality analyses whichhave shown that even in areas which do notrepeatedly exceed the ozone standard, ozoneconcentrations can remain close to 0.12 ppmfor several hours per day for extendedperiods of time in summer. There wasconcern based on recent controlled humanexposure, epidemiology and toxicologystudies, that such prolonged exposures couldresult in increased respiratory impairment.Further, for people exposed to these ozoneconcentrations over a lifetime, the possibilitythat chronic irreversible effects may result isof concern, although such changes have notbeen demonstrated.

The Committee noted that the CriteriaDocument Supplement failed to cite anddiscuss a group of "ecological"epidemiological studies of the effects ofozone on various measures of human healthsuch as hospitalizations for respiratoryillnesses or exacerbation of chronicrespiratory problems. Although these studieshave obvious limitations in establishingcause and effect relationships, they havecertain strengths which can aid in regulatorydecision-making. Studies of this type shouldbe discussed and evaluated in future criteriadocuments as a complementary source ofinformation.

While reaching closure on the staffposition paper recommending a 1-hourstandard, CASAC urged that the Agencyprovide increased support for research thatwill prove an improved scientific basis forevaluating the need for standards with multi-hour or seasonal averaging times. Clearly, theobvious, research on this criticalenvironmental health issue must besupported now in order for results to beavailable for consideration in the next 5-yearreview cycle. CASAC has enumerated theseresearch needs in some detail in a September1987 submission to the Agency. The

Committee feels these researchrecommendations are still valid and shouldbe incorporated as expeditiously as possibleinto the Agency research program.

CASAC did not reach a consensus opinionon endorsement of the staff position paperrecommendation of "a 1-hour averaging timestandard in the range of 0.06-0.12 ppm" fora secondary standard. The CASAC OzoneWelfare Effects Subcommittee thatconsidered this matter reached a dividedopinion; two favored a range with an uppervalue of 0.12 ppm, three favored an uppervalue of less than 0.12 ppm, and five favoredan upper value of 0.10 ppm. The Committeenoted that the form of the standard was ofcritical importance in protecting againstozone effects on vegetation. The Committeewas of the opinion that a cumulative seasonalstandard would be more appropriate than a1-hour standard and felt that such a standardcould be developed. CASAC favored issuanceof a cumulative seasonal standard formassuming its development would not furtherdelay the standard setting process. If thisform of standard cannot be developed in timefor the current review, the Committee is ofthe opinion that you should give seriousconsideration to setting a 1-hour secondarystandard with a maximum of 0.10 ppm. TheCommittee took note of the lack ofinformation on the effects of ozone on forestecosystems and urged support for research toremedy this deficiency.

In closing, I would like to briefly commenton CASAC's failure to reach a consensus asto the appropriate range for setting the ozonestandards. This lack of consensus is reflectiveof major deficiencies in our knowledgeregarding health and welfare effects of long-term exposure (beyond a few hours) to ozone.The data base is very large and adequate forknowledgeable individuals to reachagreement on the effects of acute exposure toozone in the range appropriate for setting a1-hour standard. However, there is not anadequate data base on the effects of multiplehour or seasonal exposures to ozone,especially as regards whether such exposuresmay produce chronic health effects. This isespecially troubling since such long-termexposures to ozone occur in many parts ofthe United States and involve many millionsof people and thousands of acres of crop andforest lands. As a result, there continues tobe concern for the public health and welfarethreat which may be posed by chronicexposure to ozone. It is critical that the database on health and welfare effects related tomultiple hour, seasonal and lifetimeexposures of ozone be increased through anaccelerated and expanded research effort.This must be done so that futureconsiderations of ozone standards will derivefrom a stronger scientific base.

CASAC recognizes that your statutoryresponsibility to set standards requires publichealth policy judgments in addition todeterminations of a strictly scientific nature.While the Committee ii willing to furtheradvise you on the ozone standards, we see noneed, in view of the already extensivecomments provided, to review the proposedozone standards prior to their publication inthe Federal Re'ter. In this instance, thepublic comment period will provide

Federal Register / Vol. 58, No. 44 / Tuesday, March 9, 1993 / Rules and Reglations

sufficient opportunity for the Committee toprovide any additional comments or reviewthat may be necessary.

CASAC would appreciate being keptinformed of progress on establishing revisedor new ozone standards and plans forresearch on ozone effects. Please do nothesitate to contact me if CASAC can be offurther assistance on this matter.

Sincerely,Roger 0. McClellan, D.V.M.Chairman, Clean Air Scientific AdvisoryCommittee.

Appendix HAugust 31, 1992Hon. William K. Reilly,Administrator, U.S. Environmental

Protection Agency, 401 M Street SW.,Washington, DC 20460

Dear Mr. Reilly: The members of the CleanAir Scientific Advisory Committee (CASAC)have noted with interest the announcementthat the Agency is not revising the nationalair quality standard for ground-level ozone atthis time and is initiating a new assessmentof the health and environmental effects ofozone. The purpose of this letter is toindicate the willingness of the CASAC toassist the Agency in carrying out a review ofthe new assessment in an expeditiousmanner. To facilitate CASAC involvement, itwould be useful for the Committee to bebriefed at an early date on the Agency's plansfor development of the new criteriadocument on the health and environmentaleffects of ozone and the subsequentdevelopment of a staff position paper on theozone standard(s).

A briefing for CASAC would provide theopportunity for both CASAC and otherinterested persons to comment on theAgency's plan for carrying out the importanttask of preparing new documents. With thisas background, CASAC can plan itsassociated review of the criteria documentand staff position paper in a timely manner.The briefing would also provide anopportunity for the Agency and otherscientists to describe the state of researchnow in progress on ozone that willpotentially be completed and subjected topeer-review in time for its inclusion in a newassessment. This Is especially Importantsince research on ozone is, and should be,ongoing because of the importance of ozoneas a pollutant. Nonetheless, it is crucial thatat a particular point In time, that isunderstood by all parties, the knowledge baseon ozone be summarized and used forregulatory purposes. A side benefit of thesummarization process is that It can alsoserve to identify information needs which inturn provides input for establishing theresearch agenda for the future.

The CASAC members are of the opinionthat a carefully planned strategy forpreparation of the criteria document and staffposition paper is essential in view of themagnitude and complexity of the task. Asyou and your staff are aware, substantial newinformation has been published since the lastcriteria document and supplement and staffposition paper were prepared. Other studieswhich may yield significant new informationinclude the National Toxicology Program

chronic bioassay with rodents exposed toozone and new human exposure assessmentmodels are nearing completion. The review,integration and interpretation of the old andnew information will be a substantialundertaking. In addition, it will beimperative that the next staff position papercarefully consider alternative forms of theozone standard, both in terms of averagingtime, such as daily (6-24 hour), as well asfrequency of occurrence, and seasonalstandards, in addition to the traditional onehour standard. This, too, will requiresubstantial preparation effort and, I suspect,ample time for debate.

The CASAC is anxious to assist in theseimportant activities and looks forward tohearing from you as to when the Agency willbe ready to brief CASAC on the proposedplans for preparation and review of the ozonecriteria document and staff paper.

Sincerely,Roger 0. McClellan, D.V.M.,Chairman, Clean Air Scientific AdvisoryCommittee.[FR Doc. 93-5266 Filed 3-8-93; 8:45 am)BILUNO CODES6OG-

DEPARTMENT OF HEALTH ANDHUMAN SERVICES

Administration for Children andFamilies

45 CFR Part 1303

RIN: 0970-ABO0

Head Start Program; TechnicalCorrection

AGENCY: Administration on Children,Youth and Families (ACYF),Administration for Children andFamilies (ACF).ACTION: Technical correction to finalrule.

SUMMARY: This document contains atechnical correction that adds the Officeof Management and Budget approvalnumber for information collectionrequirements in the Head Start final ruleon appeals, published December 14,1992 (57 FR 59260).DATES: This correction is effectiveMarch 9, 1993.FOR FURTHER INFORMATION CONTACT:Joseph A. Mottolo, ActingCommissioner, Administration onChildren, Youth and Families, P.O. Box1182, Washington, DC 20013, (202) 205-8347.

SUPPLEMENTARY INFORMATION:

Background

The Administration on Children,Youth and Families published a finalrule on December 14, 1992 (57 FR59260) which revises and clarifies for

Head Start grantees and delegateagencies the requirements concerningappeals by grantees from terminationand denial of refunding actions. Thefinal rule also includes provisions onappeals by current or prospectivedelegate agencies of grantee's rejectionsof, or failures to act on, applications, orgrantee's terminations of grants orcontracts.

Need for CorrectionAs published, §§ 1303.10 through

1303.23 contained informationcollection requirements for which anOMB approval number was required.OMB approved and assigned a numberto those sections on January 22, 1993,which this correction will show in asection added at the end of the rule,specifically for the OMB number.

Correction of PublicationAccordingly, the publication of the

Head Start Program final rule on appeals(57 FR 59260) is corrected as follows:On page 59271, at the end of § 1303.23,add:

§ 1303.24 OMB control number.The collection of information

requirements in sections 1303.10through 1303.23 of this part wereapproved on January 22, 1993, by theOffice of Management and Budget andassigned OMB control number 0980-0242.Neil J. Stillman,Deputy Assistant SecretaryforInformationResources Management.[FR Doc. 93-5301 Filed 3-8-93; 8:45 am]BILUNG CODE 4130-Cl-M

FEDERAL COMMUNICATIONS

COMMISSION

47 CFR Parts 0 and 1[DA 92-1115]

Reorganization of the Field Operationsand Private Radio BureausAGENCY: Federal CommunicationsCommission.ACTION: Final rule.

SUMMARY: This amendment changes theCommission's Rules To incorporate thereorganization between the PrivateRadio Bureau and the Field OperationsBureau. The reorganization wasnecessary in order to promote a moreefficient and effective organizationalstructure.EFFECTIVE DATE: October 1, 1992.FOR FURTHER INFORMATION CONTACT:Tom Sullivan, Office of ManagingDirector, (202) 632-0923.

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