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Enst 403/Envr 403:Spring 2009

Tues, Thurs room 11AM-12:15AM

Location: Dey Hall room 201

Call number 36019, Section 001               

http://www.unc.edu/courses/2009fall/enst/403/001/

Richard Kamens; 966 5452 kamens@unc.edu

http://airsite.unc.edu/~kamens/

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Textbook "Environmental Chemistry by

Colin Beard and Michael Cann, ISBN 0-7167-4877-0, publishers W.H. Freeman and Company, New York, 652 pages, 2005

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Who is Richard Kamens Professor of Atmospheric chemistry

and teach graduate classes in Environmental chemistry

Direct a smog chamber research gorup Focus on aerosol formation in the

atmosphere Direct a student exchange program

between UNC and Thai Universities

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Killer Particles

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On smoggy days in LA, Atlanta, Beijing and other major cities ~50 - 80% of FINE particle organic carbon comes from atmospheric reactions.

Atmospherically aged aerosols appear to be more toxic than freshly emitted particles.

A strong need for predictive aerosol models that can simulate complex atmospheric processing?

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Development of chemical mechanisms from organics that produce particles:

CH3Aromatics

Terpenes

OH

+ O2

OH

H

OOH

OH

OO

CH2

OOHO

CH2

HOOO

O

NO

NO2

O

OH

O

H H

O

CH3O

O

HNO

NO2

+ O2

+

+

d-limonene

+

keto-limonene

++

limononaldehyde

+

0.65

0.35

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Link the phases that toxics exist in

particleand particleChemical nature of gasTemperature

Humidity

Trace toxic gas

Thermodynamic Equilibrium

TSPC

CK

gas

partp

Cgas +surf Cpart

KR T

p M wpLo

7 5 0 1

1 0 9

. fom

8

9

Predict organic particle formation in the presence of complex urban atmospheres

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20

25

8:00 10:24 12:48 15:12 17:36

g/m

3

0.0

0.15

0.3

0.45

7 10 13 16

Time (EDT)

pp

m

O3

NOy

NONO2

10

0

10

20

30

40

8 11 14 17

LDT

g

/m3

``

Aerosol Model and data from particles generated from aromatics and O3 and NOx in sunlight

1ppmC o-xylene

1ppmC toluene

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Field site director for a UNC-Thai exchange

Since 2001, UNC undergraduates (CEP) participated in a 6+ month experience in Thailand that begins at the end of May and finishes in late December.

Small groups of UNC students come together with Thai students to study and work on a research project at Thai universities.

Thai students come back with UNC students for a semester at UNC.

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Impact of Bio-fuels Use on Photochemical Smog

The widespread use of gasohol and bio-diesel in Bangkok will most likely lead to an increase in ground level ozone.

Bio-fuel use will benefit the Thai economy.

Bio-fuels can supply at most 10% of the Thai petroleum needs.

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Introduction to Environmental Chemistry

Environmental chemistry may be defined as "the study of sources, reactions, transport, effects, and fates of chemical species in water, soil, and air environments, and the effects of technology thereon.” Manahan, 1994

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Class objectives:

Highlight some important areas in environmental chemistry

present some of the common techniques that environmental chemists use to quantify process that occur in the environment

It is assumed that everyone has courses in calculus and general chemistry.

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Class objectives:

We will cover general topics: Global warming, Strat. O3, aerosols, photochemical smog, acid rain, etc.

Develop relationships will be used to help quantify equilibrium and kinetic processes

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Thermodynamics

ui = uo1 +RT ln pi/p*

iL

fi = i Xipi*pure liquid

RT ln fi hx /fio

pure liq = RT lnfi H2O /fi

opure liq

fi hx = fi H2O

ln Kp = a 1/T+b

20amb

ambmfusiL T

TT

R

Spp is

)()(lnln **

Vapor pressure

)]()( ln.*lnT

T

T

Tp bbiL 58119

How to calculate boiling points

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Vapor pressure and Henry’s law

KPC

P Viawi

iwiw

satsat

satsat

iL*

iw

Solubility and activity coefficients

Octanol-water partitioning coefficients

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Additional Principles

Organic Acid-bases and LFERs

diffusion

chemical spills and mass transfer

Organic reactions in the environment

Solid- liquid interactions

photochemistry

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Homework, quizzes, exams To insure that most of us stay

reasonably current with the lectures and readings, an option is to have 8-10 unannounced quizzes throughout the semester.

They will take ~10 minutes. Quizzes will count 10% of your grade.

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Another option is a set of short questions to be answered and handed in before most lectures (20% of your grade)—your choice!

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There will be a homework problem set associated with each lecture. These are due one week after the completion of the chapter or lecture series.

These problem sets should take between 1 and 3 hrs.

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Some of these could appear on exams

There will be two exams

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Important Environmental Issues

Global warming and stratospheric ozone depletion

Concentration of environmental pollutants at the poles; pesticides in foods, etc.

Buildup of environmental chemicals in the oceans; contamination of soil and ground water

Particle exposure, photochemical oxidant exposure, acid deposition

Energy shortages

There are more than 70,000 100, 000 synthetic chemicals that are in daily use:– solvents– components of detergents– dyes and varnishes– additives in plastics and textiles– chemicals used for construction– antifouling agents– herbicides, insecticides,fungicides– pharmaceuticals

Why the interest?

Polynuclear Aromatic HC (PAHs) Dioxins PCBs CFCs DDT O3, NO2, aerosols, SO2

Some examples of environmental chemicals

Formed from small ethylene radicals “building blocks” produced when carbon based fuels are burned

Sources are all types of burning

in ChiangMai, Thailand: a) 2-stroke motorcycle

engines b) cars- light diesels c) open burning d) barbecued meat??

PAHs

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Combustion Formation of PAH

Badger and Spotswood 1960

(I) (II) (III) (IV)

C

C

C

C

C

C

CC

CC

CC

(VII) (VI) (V)

Benzo a Pyrene

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Some PAH structures

anthracene

phenanthrene

fluoranthenenaphthalene

benz(a)anthracene

benzo(a)pyrene [BaP]

Naphthalene, phenanthrene and anthracene are found in the gas phase

pyrene and fluoranthene are in both the gas and particle phase

BaA and BaP are mostly on the particles, Why???

PAHs

Metabolized to epoxides which are carcinogenic; O PAH

are indirect acting mutagens in bacterial mutagenicity tests (Ames-TA98+s9)

methyl PAHs are often more biologically active than PAHs

PAHs

Professor Gernot Grimmer extracted different types of smoke particles

He then took the extract and applied it to mouse skin

and implanted it into rat lungs

How did he obtain extracts? How did he fractionate his extracts??

Carcinogenic tests with PAHs

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Extraction by soxhlet extraction starts with solvent (MeCl2) in a flask

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Hot solvent fills this chamber and bathes the filter

Heat

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The solvent in the filter chamber then drains back into the heated flask withchemicalsfrom the particleson the filter

Heat

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The organic liquid in the soxhlet flask can be concentrated by evaporation by a dry nitrogen stream or rotary evaporation

the extract can then be fractionated into different polarity compound groups

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Professor Grimmer fractionated the exhaust extracts

HPLC

PAH 2&3 rings

Total

PAHs>3 rings

Total

Total-PAHs

uv orfluorescencedetector

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skin painted mice implanted rat lungs

What did Grimmer see when exposed rats and mice to the different fractions?

0

10

20

30

40 %

can

cers

TotalTotal-PAHs

PAHs 2&3 ringsPAHs > 3 rings

rat lungs Mouse-skin

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Analysis of reaction products

soxhlet extraction for 3 hours– blow up with dry gentle flow of nitrogen to

about 0.5 to 1 ml evaporation to about 0.5 to 1 ml 1 to 2 ul injected directly to GC-MS (EI and CI) The remainder solution: derivatization

These are some of the most toxic organics in the environment - LD50

Created by burning organics which have chlorine; incineration is a big source of atmospheric dioxins and furans

bleaching in making paper is another source

Chlorinated dibenzo dioxins and Furans

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Combustion Formation of Dioxins from Polychlorinated phenol

O H

PolychlorinatedPhenol

Flame

OH .

.OO H

C ly

+

O

O H

+ OH

Chlorinated dibenzo dioxin

ClxO

O

Shaub & Tsang, ES&T 1983.

Cly

Clx

ClxCly

Clx

They have the following general structures

O

O Clx

Cly chlorinated dioxin

They have the following general structures

O

O Clx

Cly chlorinated dioxin

O Clx

Cly chlorinated furan

The most toxic is either the 2,3,7,8 tetrachlorodibeno dioxin or furan

More than 200 different structures are possible

O

O

Cl

Cl

Cl

Cl

These types of compounds produce toxic enzymes: arylhydrocarbon hydroxylase and 7-ethoxyresorufin deethylase

At low concentrations they may behave as environmental estrogens

Environmentally, they are unreactive and can be transported long distances

They did not start to show up in the environment until the 1920s when there was a big increase in the production of chloro-organics (Professor Ron Hites, and students)

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Environmental Fate of Chlorinated Dioxins and Furans

(Czuczwa and Hites, 1984)

Collected core sediment samples from southern Lake Huron in the USA

Based on sedimentation rates they established age vs. concentration profiles for chlorinated dioxins and furans

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US coal consumption vs chlorinated aromatic production

0

100

200

300

400

500

600

700 U

S c

oal

in 1

0^6

shor

t-to

ns

0

200

400

600

800

10^6

lbs

Cl-a

rom

atic

s

1860 1880 1900 1920 1940 1960 1980

Year

Coal

chloro-aromatics

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Chlorinated aromatic production vs dioxinand furan conc. in lake core samples

0

200

400

600

800

1000

1200 To

tal d

ioxi

ns a

nd fu

rans

in p

pt

0

200

400

600

800

10^6

lbs

Cl-a

rom

atic

s

1900 1920 1940 1960 1980

Year

chlorinateddioxins andfurans

chloro-aromatics

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PCBs in the U.S. Great Lakes

PCBs were banned in the early 1970s

In 1980 Eisenreich and co-workers estimated that still 85% of the PCBs in the US great lakes came from atmospheric sources.

Total Flux = Jair + Jrain + Jparticles

Jair = vw ( Cw-P/KH)

if resistance to mass transfer is in the water phase

Jair = va (Cw KH - P)/RTif resistance is in the gas phase

Polychlorinated biphenyls (PCBs)

RT ln fair /fio

pure liquid = RT lnf H2O /fi

opure liquid

fair = f H2O

In the late 1980s a fugacity model was used to represent the distribution of PCBs in different environmental compartments

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In 1990 Eisenreich and co-workers reported that ambient measurements over the great lakes were generally constant for the past 10 years.

For the past 15 years sources to the lakes had declined because of the PCB ban.

Based on mass transfer calculations it was proposed that during the summer months the lakes were actually a source of atmospheric PCBs.

used as coolants - insulation fluids in transformers, capacitors , plastercisers, additives to epoxy paints

are thermally stable and biologically stable

can exist in the gas and particle phases

Polychlorinated biphenyls (PCBs)

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Cl y

Cl x

PCB structures

Environmentally, they used to be considered unreactive, but there is evidence for some bio-degradation; they can be transported long distances

Up until the 1970s there was a lot of dumping of industrial wastes in the USA

In one example, from 1950 to 1975 there were two capacitor manufacturing plants on the Hudson river in New York State, which discharged into the river.

Levels in the river sediments downstream from the plants exhibited concentrations of 10 ppm which was a factor of two higher than commonly found.

Dredging was considered financially impossible

it was also believed that is very difficult to bio-degrade PCBs with multiple chlorine atoms

Investigations in the 1980s revealed that PCBs in sediments were being slowly converted to the mono and dichloro forms via very slow anaerobic processes.

{CH2O} + H2O + 2Cl-PCB---> CO2 +2H++ 2Cl-- +2H-PCB

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What do we do now, when new compounds are introduced into the environment...??

toxicity?? low concentration health effects? damage to the ecosystem ? where will it show up in the

environment? how is it transported in the

environment and what is its life-time?

In 1976 there was a significant industrial explosion in the town of Seveso, Italy that spewed out chlorinated dioxins.

735 people were evacuated from the immediate vicinity.

Now excess cancers are showing up.

Some examples of environmental exposures

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Seveso, Italy Dioxin release

Over the past eight years the birth ratio has changed from 106 males: 100 females to 26:48

observed increases in cancers

decline in number of males born

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A similar observation has been made in the bird population

In the Great Lake region of the USA during the 1980’s, hatchlings of crested cormorants with a crossed bill deformity were almost always female

Male birds did not show the deformity

Scientist speculate that the chemicals causing the deformity were killing the males before they hatched.

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1. There is a general concern that if we observe abnormalities in wildlife, similar kinds of mechanisms may exist in humans.

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Mercury poisoning off the coast of Minamata, Japan is an example

Fishermen in the 1950s noticed sea birds were dying and feral cats that scavenged fish from the docks were “stiff legged”

Cerebral palsy and mental retardation started showing up in children.

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2. Toxic loads

Scientists have hypothesized that the fetus is sharing the mother’s toxic load, and may actually provide some protection to the mother by reducing her internal exposure.

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2. Toxic loads

Children get 12% of their lifetime exposure to dioxins during the 1st year.

Their exposure is 50 times greater than an adult during a very critical developmental period.

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2. Toxic loads

Firstborns from dolphins off the coast of Florida usually die before they separate from their mothers

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2. Toxic loads It is speculated that mother dolphins

unload 80% of their accumulated pollutants into their calves, probably during nursing.

The greatest exposures occurs with the 1st born

Does this have any implications for humans?

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3. Pesticide exposures

Children of farm families in the western Minnesota area of the US have significantly higher rates of birth defects than the general population.

The highest rates are among children conceived in the spring when spraying of pesticides is most intense; male babies had far more birth defects than females

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4. The end points may not only be cancer, but compromised immune systems and generally poorer health.

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4. Immune systems & Mother’s milk

In the Netherlands researchers have found that children with higher levels of dioxins and PCBs in their bodies have more health problems (immune system and hormonal changes) than children with lower levels.

This was linked to levels of PCBs in Mother’s milk.

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4. Mother’s milk

Overall, however, it was concluded that nursing was still of greater benefit than bottle feeding babies, but that even mild exposures may weaken immunity

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4. Mother’s milk

Mother’s milk from Inuit Indians in the Canadian Arctic has 7 times the PCBs as mother’s milk from women in the urban industrialized areas of southern Quebec.

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4. Mother’s milk

During the first year, Inuit babies suffer through 20 times more colds than babies in southern Quebec.

Acute ear infections are rampant.

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4. Mother’s milk

Babies nursed by mothers with the highest contamination levels in their milk are afflicted with more acute ear infections than bottle fed Inuit babies.

Many of these children don’t seem to produce enough antibodies for childhood vaccinations to take.

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5. PCBs and lower intelligence

There is evidence of lower intelligence in babies exposed to PCBs.

In adults, a blood-brain barrier insulates the brain from many potentially harmful chemicals circulating through the body

In a human child this barrier is not fully developed until 6 months after birth.

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5. PCBs and lower intelligence

In 1979 in Taiwan, more than 2000 people were exposed to PCB-contaminated cooking oil.

In the 1st 3 months many babies died outright. As the surviving children grew up, many were slower intellectually than other kids their age, were hyperactive and had behavioral problems.

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5. PCBs and lower intelligence

Similar observations were made in "high-PCB kids" in the Lake Michigan area.

This was associated with mothers eating salmon and trout from the Lake during the years before their children were born.

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5. PCBs and lower intelligence

At age 4 the high exposure group had poor short term memories. At age 11 the 30 most highly exposed kids had average IQ scores that were 6 points lower than the lowest-exposed group.

biomarker-metabolites???

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7. Sexual impairment

There is evidence for sexual impairment in both animals and humans from high PCB exposures and other environmental chemicals.

Male beluga whales in the very polluted St. Lawrence River have exhibited female organs.

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7. Sexual impairment

Highly exposed humans, alligators and panthers exhibit smaller male sex organs and low sperm counts.

Testicular cancers have nearly doubled among older teenagers in the US between 1973 and 1992.

In previous lectures I have said these have been linked to toxic exposures....long way from finding proof.

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7a. Sexual impairment

In a newer study (Hardwell et al, Environ Presp, 2003) looked at woman who’ve had substantial exposure to certain environmental pollutants are more likely to have sons who develop testicular cancers (men ~ 30 years of age)

From 1973-1999 testicular cancers up 67%

Men with test-cancers had high cis nona chloridane, not PCBs, etc

Mothers, however, had high PCBs, HCB (hexa-chlorobenzenes) and cis nona chloridane

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7b. Sexual impairment

These same mothers probably had high exposures when environmental contaminants peaked in Scandinavia in the 1970s

Richard Sharpe of Edinburogh and Niels Skakkebek (Denmark) propose that exposure to endocrine disruptors before birth can alter testicular-cell development and some of these cells may be cancerous after puberty.

This may also may explain rising rates of male infertility, and other sexual deformities

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8. Endocrine disrupters

These studies have led to the notion of environmental "endocrine disrupters".

In the lock and key relationship between hormone and receptor molecules, these "hormone impostors" can:

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8. Endocrine disrupters

bind with receptors and trigger biological processes

or bind with receptors and tie up an active hormone site

Some of these have been called environmental estrogens

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9. Other chemicals

From a historical perspective, everyone is now carrying at last 250 measurable chemicals that were not part of human chemistry before the 1920s (Peter Myers, 1996)

The most basic toxicity testing results cannot be found in the public record for nearly 75% of the top volume chemicals in commercial use in the USA

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9. Other chemicals

In other words, the public cannot tell whether a large majority of the highest-use chemicals in the United States pose health hazards or not (Amicus Journal, p23, Spring 1998).

An example are phthalates that go into many types of plastics which have been shown to reduce the sperm counts in mice.

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9. Other chemicals

Bisphenol-A (BPA) is an additive in polycarbonate plastics used in food liners, dental sealants, and dental fillings.

BPA causes increased prostate size in mice exposed to tiny doses while in the womb. These doses were 25,000 times smaller than the EPA threshold.

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9. Phthalates

Exposure of female rates to 200 to 1000 mg/kg body weight results in much lower testosterone in male offspring( L. Earl Gray. Jr. EPA, RTP, J. Tox and Ind. Health, Mar, 1999).

Exposures to the herbicide linuron made the epididymis (sperm-storing organ in rats) much smaller in male rats.

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epididymus

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Recommendations During the insecticide spraying season,

farmers should not try to have children. Limit exposures to pesticides around the home. When possible, buy foods that were grown

without pesticides. Governments must try to limit PCB introduction

into the environment. If incineration is used, chlorinated plastics

should be removed, along with modern technology.