Risks Associated with Application of Municipal Biosolids to Agricultural Lands in a

Canadian Context

Literature Review

Jorge E. LoyoPDF, Department of Chemistry and Biology

CWN WebinarNovember 12, 2015

Authors

Risks Associated with Application of Municipal Biosolids to Agricultural Lands in a Canadian ContextP.I./Co-P.I.:

Dr. Lynda McCarthy, Ryerson UniversityDr. Jorge Loyo, Ryerson University

Contributors:Melanie Raby, Ryerson UniversityMichael Payne, Black Lake EnvironmentalDr. Ann Huber, Soil Resources GroupJohn Lavery, Sylvis EnvironmentalKasia Caputa, Sylvis EnvironmentalLaura Taylor, Ryerson UniversityAlicia Falls, Ryerson University

Review available at: http://www.cwn-rce.ca/assets/resources/pdf/McCarthy-Risks-Biosolids-2015.pdf

Background

2012 CWN Call for ProposalsEssential outcome … improved support for decision makers and practitioners involved in the management of municipal biosolids with respect to disposal through application to agricultural lands …

A detailed report which evaluates and interprets leading research and integrates it with best current knowledge and practice and identifies and evaluates relevant risks associated with, and that impact the practicability of, the application of municipal biosolids on agricultural lands over the range of conditions and practices in place in Canada.

Key elements … for a national consultation workshop … to elevate the discussion on practice and policy options, risks, and opportunities for the application of municipal biosolids on agricultural lands in Canada.

Project focus: ESOCs and pathogens

Background

Risk = Hazard x Exposure

Project focus: ESOCs and pathogens

Source: plasticisers.org

Background

Risk = Hazard x Exposure

Project focus: ESOCs and pathogens

Exposure – Concentration in biosolids (surrogate)

Hazard – Intrinsic properties of compound (pathogen)

= Risk

This presentation

1. Exposure – What we know about:

•  Effects of sludge treatment (biosolids production)

•  Fate in soil after land application

•  Uptake by plants and bioaccumulation

•  Impact studies

2. Hazards:

•  To public health

•  To the environment

3. Risk assessment

4. Public perception

5. Validation workshop and National Biosolids Agenda

Definitions

Biosolids: Product of municipal sludge treatmentPathogens: Organisms capable of causing disease (esp. to

humans)ESOCs: Emerging substances of concern

•  Different terms:

-  Emerging pollutants

-  TOrCs, micropollutants

-  PPCPs, PiE

•  Environmental presence (trace amounts)

•  Not regulated

•  Potential toxic effects

Source: 3Dchem

Source: Wikipedia

ESOCsTable 3.3. Summary of the chemicals present in biosolids and considered for the different studies discussed in this chapter.

a Values correspond to average concentrations in biosolids (mg/kg dry weight). b These compounds were not included in the risk assessment due to lack of data. c For the full list of individual compounds see Higgins et al. (2010).

Exposure

Wastewater Wastewater Treatment Effluent

Sludge

Sludge Treatment

Biosolids Land

Application

Landfilling

Incineration WtE

Transport

Transformation E X P O S U R E

Effects of sludge treatment on ESOCs

•  Few ESOCs studied – from consistently removed to recalcitrant, interconversion (NPEs)

•  Anaerobic digestion – most studied treatment

•  Effects of operating parameters (T, SRT) – not clear

•  Mass balances in WWTPs – net mass reduction (generally)

•  Estrogenicity – Aerobic digestion more effective than anaerobic (composting and pelletization reduce, anaerobic digestion and lime addition increase)

•  Overall WWTP – estrogenicity reduction

Effects of sludge treatment on pathogens

•  Most studies on fecal indicators and Salmonella

•  Anaerobic digestion – most studied treatment

•  Operating parameters – T improves inactivation

•  Treatment reduces total organisms (some viruses and prions resistant)

•  Anaerobic digestion resistant organisms (Clostridium, Cryptosporidium, Giardia) more sensitive to aerobic wastewater treatment in liquid phase

•  Reactivation and regrowth of bacteria peaks and decreases to original levels or lower

ESOCs fate after biosolids land application

•  Site-specific phenomenon, driven by:

-  compound and soil physicochemical properties

-  environmental variables (T, moisture)

-  application methods

•  From persistent in soil (TCS, PBDEs) to very mobile (iopromide)

•  Lab studies and models tend to overestimate sorption and biodegradation

•  Migration through soils/groundwater (e.g., sorption to colloidal matter) not well understood

•  PPCPs – most do not reach groundwater; concentrations lower in tile drainage and surface runoff vs WWTP effluents

Pathogen fate after biosolids land application

•  Site-specific phenomenon; most relevant processes:

-  aerosolization

-  survival/inactivation

-  transport in the soil

•  Aerosolization – short distance exposure (occupational risk)

•  Pathogen survival – organism and environment dependant (bacteria lowest survival rates)

•  Pathogen transport – hydrology and soil dependant

ESOCs uptake by plants and bioaccumulation

•  ESOCs uptake by plants

-  demonstrated

-  environmentally-relevant conditions

-  human health risk considered minimal

•  Bioaccumulation by earthworms

-  demonstrated

-  soil, biosolids aging

-  artificial solids, spiking

-  effects?

Impact studies

•  Plants

-  positive impact (growth, biomass, yield), nutrients and soil structure

•  Invertebrates (earthworms, springtails, and nematodes)

-  mixed results; causality

-  springtails more sensitive indicator of toxicity than earthworms; reproduction a more sensitive endpoint than lethality

•  Microbial communities:

-  biomass, respiration rate, and enzymatic activity increase (except with high concentrations of heavy metals)

-  community structure changes; impact unknown

In short(er)

What do we know? What do we not know?

•  Treatment and fate – highly variable, compound-/organism-, process-, environment-dependant à surrogates

•  Plant uptake and earthworm bioaccumulation – demonstrated, environmental relevance

•  Impact – causality

What are the risks?

Hazards

Risk = Hazard x ExposureExposure – Concentration in biosolids (surrogate)

Hazard – Intrinsic properties of compound (pathogen)

= Risk

RQ =PECsoil

PNECsoil

HazardsRisks Associated with Municipal Biosolids Application to Agricultural Lands in Canada – Literature Review

141

Table 10.2. Example of risk quotient calculations for selected ESOCs.

Chemical Conc. biosolids, μg/kg 1

PEC soil, μg/kg Kd Endpoint, μg/L Factor PNEC soil,

μg/kg RQ Endpoint AHTN 4,015 63 481 3 33 100 160 0.4 NOEC, D. rerio 4 AHTN 4,015 63 481 3 105 mg/kg (soil) 100 1,050 0.06 LOEC (soil), F. candida 5 ATN 90 2 1.4 15 6 1,800 100 272 0.005 NOEC, D. magna 7 ATN 90 2 1.4 15 6 78 10 120 0.01 PNEC, green algae 8 AZM 205 3.2 316 9 5.2 1,000 1.6 2 NOEC, P. subcapitata 10 AZM 205 3.2 316 9 0.15 1,000 0.047 67 PNEC, bacteria 11 CBZ 67 1 25 12 25 100 6.3 0.2 NOEC, C. dubia 13 CIP 3,610 56 20,000 6 5 1,000 100 0.6 EC50, M. aeruginosa 14 EE2 25 2 0.4 56 12 0.00031 10 0.0017 220 NOEC, D. rerio 15 FRS 543 8.5 40 9 10 1,000 0.4 21 LOEC, riverine biofilm 16 GFB 56 0.88 1.3 12 1.5 100 0.0019 450 LOEC, C. auratus 17 HHCB 8,975 140 618 3 140 100 865 0.2 LOEC, P. promelas 18 HHCB 8,975 140 618 3 105 mg/kg (soil) 100 1,050 0.1 LOEC (soil), E. fetida 18 IBP 522 8.1 28 12 1 10 2.8 3 LOEC, O. latipes 19 MCZ 441 6.9 957 3 27 1,000 26 0.3 IC50, aromatase (in vitro) 20 NOR 558 8.7 3,200 9 38 1,000 120 0.07 EC50, M. wesenbergii 21 OFX 276 4.3 300 6 21 1,000 6.3 0.7 EC50, M. aeruginosa 22 PRP 30 0.47 2 58 12 9 100 5.2 0.09 NOEC, C. dubia 23 SMZ 5.2 0.08 7.9 12 81 1,000 0.64 0.1 EC50, L. minor 24 1: Median value in WEAO (2010); 2: High end of range in CCME (2010); 3: Langdon et al. (2010); 4: Carlsson and Norrgren (2004); 5: Balk and Ford (1999); 6: Martín et al. (2015); 7: Küster et al. (2010); 8: Jones et al. (2002); 9: Narumiya et al. (2013); 10: Harada et al. (2008); 11: Kümmerer and Henninger (2003); 12: Martín et al. (2012); 13: Ferrari et al. (2003); 14: Halling-Sørensen et al. (2000); 15: Schäfers et al. (2007); 16: Lawrence et al. (2005); 17: Mimeault et al. (2005); 18: EC (2008); 19: Flippin et al. (2007); 20: Trösken et al. (2004); 21: Ando et al. (2007); 22: Robinson et al. (2005); 23: Ferrari et al. (2004); 24: Brain et al. (2004).

ESOCs risk assessment

Metals/Organic compounds: USEPA’s CFR 40 Part 503 rule

ESOCs: No regulations•  Academic reviews & prioritization (Imperial College)•  Professional organizations (WEAO, WERF)•  Government assessments (Norway and Denmark)

ESOCs risk assessmentTable 3.3. Summary of the chemicals present in biosolids and considered for the different studies discussed in this chapter.

a Values correspond to average concentrations in biosolids (mg/kg dry weight). b These compounds were not included in the risk assessment due to lack of data. c For the full list of individual compounds see Higgins et al. (2010).

ESOCs risk assessment

What do we know? What do we not know?

•  Risk assessment for few ESOCs – human risk considered low

•  Lack of (eco)toxicity and fate data•  ESOCs chosen from existing information (reactive

approach)•  Chemical-by-chemical approach (excludes mixtures,

transformation products)•  Need for different strategy

Microbial risk assessment

Risk dependent on organism, route of exposure, biosolids treatment, land application practices, time

High risk variation: very low (vegetable consumption) to relatively high (occupational exposure)

Overall public health risk low—very low for crop ingestion

Current indicator organisms might underestimate risks

Limited epidemiology work

How to assess risk?

RQs – chemical-by-chemical

Infection incidence

Not answering the question, use a different approach!

Ecosystem assessment

Overall ESOCs strategy

What is the risk evaluating strategy?

How much risk are we willing to tolerate?

Source: Health Canada

Public perception of biosolids

Tends to be negative:

•  Lack of awareness

•  Presence of pathogens and industrial sewage

•  Odour emissions

•  Reports of health effects associated with biosolids land application

•  Bad management practices

•  Lack of information and community involvement

•  Limited epidemiology work

•  Public vs. expert understanding of risk

Risk communication processes

Emerging organic pollutants

Improved analytical capacity = detection of chemicals in lower concentrations

Source: Wikipedia

Source: Wikipedia

Source: cuomoz.com

ESOCs in the news

Source: Nate Beeler

Body burden

Many chemicals found in our

bodies

Body burden

Source: ES&T

And now?

So, we have all this information, what now?

Validation workshop

Biosolids Risk in Context, January 22, 2015 in Ottawa, ON

Over 20 experts from academia, government, and industry

Overall research needs:

•  Additional evidence-based information needed for RA

•  Approach biosolids issues as an ongoing process

•  Long-term field studies

•  Connect biosolids projects à overall picture of sustainability

•  Investigate ESOCs removal in wastewater treatment as a whole

Public acceptance

Communication improvement

Validation workshop

Main characteristics of a good biosolids program:

•  Sustainable (socially, economically, and environmentally)

•  Climate-friendly

•  Beneficial use of the biosolids

•  Publicly supported

Canadian National Biosolids Research Agenda

Topics:

•  ESOCs and pathogens risk assessment process

•  Phosphorus availability, removal, and release

•  National communication strategy

•  Odour and other nuisances

•  Long-term impact studies

•  Promotion of beneficial uses of biosolids

•  Climate change mitigation

Refine agenda with other biosolids-related organizations and residuals managers

National Biosolids Consortium?

Contact information

Dr. Lynda McCarthy Professor Ryerson University l3mccart@ryerson.ca

Thank you The literature review can be downloaded from: http://www.cwn-rce.ca/assets/resources/pdf/McCarthy-Risks-Biosolids-2015.pdf