'Emerging’ Organic Contaminants and their Contaminants 2010_FWR CIWEM.pdf · Toxicity,...
Transcript of 'Emerging’ Organic Contaminants and their Contaminants 2010_FWR CIWEM.pdf · Toxicity,...
'Emerging’ Organic Contaminants and their
Potential Significance for the Agricultural
Recycling of Biosolids
Stephen Smith & Bradley ClarkeDepartment of Civil and Environmental Engineering
What’s the problem?
Over 50 million unique chemicals in CAS (Chemical Abstracts Service) database 143,000 registered in industrial use in EuropeAll potential biosolids contaminants that derive from industrial, urban and domestic sourcesEnvironmental and health concerns:Toxicity, mutagenicity, carcinogenicity,
endocrine disruption, developmental toxins, ecotoxicity, antibiotic resistance
Strategic Reviews of OCs in Sludge
• Smith 1994 FWR Report• Smith 1996 Agricultural Recycling of Sewage Sludge and
the Environment. CAB INTERNATIONAL• Smith 2000 Progress in Environmental Science 2• ICON 2001 Pollutants in Waste Water and Sewage
Sludge, Final Report to European Commission• Schowanek et al 2004 Reg Tox Pharm 40• Smith and Black 2006 Sources and Impacts of Past,
Current and Future Contamination of Soil - Organic Contaminants, Final Report to DEFRA
• Schowanek et al 2007 Reg Tox Pharm 49• Jensen et al 2007 Chemosphere 69• Smith 2009 Philosophical Transactions of the Royal
Society A 367, 3871-3872.
Behaviour in Soil-Water-Plant System
•Toxic compounds present in trace amounts•Three categories of behaviour:
• Rapid volatilisation• Rapid biodegradation and no persistence• Strong adsorption of persistent compounds
•Sludge Soil Plant Human (USEPA Pathway 1)
• No bioconcentration in crops detected (<0.01) • Negligible uptake = minimal human exposure
0
500
1000
1500
2000
2500
3000
1966 1976 1986 1996 2006
Co
nce
ntr
atio
ns
ng
g-1lip
id
DDT PCBs
BDEs PFOS
Trends in Environmental Exposure?
Norén et al. (2000) Chemosphere 40, 1111-1123 Karrman et al. (2007) Environ. Health Persp. 115, 226-230
Human Milk Concentrations
Hites (2004) Environ. Sci. Technol. 38, 945-956She et al. (2007) Chemosphere 67, S307-S317
Sensationalised badly designed biosolids research
promotes negative public perception
Sensationalised badly designed biosolids research
promotes negative public perception
Understanding the Risks
ContaminantPathwayReceptorEcological
1. Soil microbes2. Soil organisms3. Higher trophic animal4. Define receptors
Human1. Direct Exposure2. Plant uptake3. Animal uptake4. Water contamination
Biosolids amended soil
Food Chain Human Exposure
Key Questions
•Are there organic pollutants that may impact on the safe land application of biosolids?
•What are the likely candidates?
•How much research has been conducted internationally?
•What are the key research priorities to ensure the long-term sustainable management of biosolids?
List of Contaminants Reviewed
IncludedAntibiotics and pharmaceuticalsBenzothiazolesBisphenol AOrganotins (OTs)Polybrominated diphenyl ethers (PBDEs)Polychlorinated alkanes (PCAs)Polychlorinated naphthalenes (PCNs)Polydimethylsiloxanes (PDMS)Perfluorochemicals (PFCs)Phthalate acid esters (PAEs)Quaternary ammonium compounds (QACs)SteroidsSynthetics musksTriclosan (TCS) & triclocarban (TCC)
ExcludedChlorinated dioxins/furans (PCDD/Fs)Polyaromatic hydrocarbons (PAHs)Polychlorinated biphenyls (PCBs)Nonylphenol (NP)Linear alkyl benzene sulphonate (LAS)
Assessment Criteria
Soil persistencePotential risks to human food chainEcological bioaccumulationSoil ecotoxicityExtent and quality of the research
Biosolids Conc. Mean (Range) mg kg-1 DS
WWTP % Removal
Soil Persistence Half Life
Food Chain Possible, Uncertain or No
Bioaccumulation Yes, No or Likely
Ecotoxicity Yes, No or Uncertain
Research Numerous, Some or Few
Antibiotics & Pharmaceuticals
Development of antibiotic resistance (human health) Ecological consequences
Short residence time in aquatic environment
Longer persistence in soil (i.e., carbamazapine 21 months, plant uptake)
Many contain non-polar core and polar functional groupNorwegian Risk Assessment
Identified 14 of 1400 for further research
Sig. below PNEC US EPA Biosolids Survey
72 pharmaceuticals
Biosolids Conc. Low mg/kg
WWTP Unchanged/Unknown
Soil Persistence Unknown; generally reported in days
Food Chain Possible
Bioaccumulation No
Ecotoxicity Uncertain
Research More required
Drug (mg kg-1 dry soil)
Agricultural soil PEC Park areas PEC PNEC
Mesalazin 0.98 6.70 12
Ranitidin 0.04 0.30 5277
Sotalol 0.02 0.15 4095
Metoprolol 0.02 0.13 589
Atorvastatin 0.05 0.34 11
Tetracycline 0.01 0.08 8.8
Ciprofloxacin 0.04 0.29 26
Carisoprodol 0.10 0.68 24368
Gabapentin 0.06 0.39 20460
Benzothiazoles
2-Mercaptobenzothiazole MBT
2-Hydroxybenzothiazole OBT
Rubber vulcanizing agents Polymerisation of sulphur with rubber
Proposed German limit
MBT+OBT: 0.6 mg kg-1 DS
Lack of empirical data
No specific reason why it was chosen?
Aquatic toxicity
Studies indicate that these compounds are biodegradable
Biosolids Conc. Unknown
WWTP Unknown
Soil Persistence Unknown
Food Chain Uncertain
Bioaccumulation No
Ecotoxicity Uncertain
Research Small
Bisphenol A
Used in coatings of cans, plastics, dental fillings etc.Endocrine disruptor 1×10-6 less than 17β-estrodiol
Human exposure occurs in domestic environmentSig. reductions in WWTPRapidly dissipated in soilUnlikely to pose issue for biosolids reuse
Biosolids Conc. 0.28 (0.01 - ~ 325)
WWTP Up to 99%, biodegradation
Soil Persistence 3 days
Foodchain No
Bioaccumulation No
Ecotoxicity No
Research Small
Bisphenol A
Organotins
•Used since 1960s for industrial and agricultural purposes
• PVC stabliser• Fungicides• Insecticides• Wood preservative
•High toxicity observed in aquatic environment•Restricted use of TBT•More research required
Biosolids Conc. 0.86 (0.02 – 6)
WWTP >80% sedimentation
Soil Persistence < 2 months
Human Health Uncertain
Bioaccumulation Possible
Ecotoxicity Yes
Research Small
Tributyltin TBT
Phthalates acid esters
Biosolids Conc. 58 (0.26 – 3514)
WWTP Biodegradation (23 – 60%)
Soil Persistence <100 days
Foodchain No
Bioaccumulation No
Ecotoxicity No
Research Large
DEHP
•Used since 1950s as a plasticizer•Concern as EDC•Degrades during WWTP•Degrades in soil•Unlikely to enter food chain
020406080
100120140160180
Con
cent
ratio
n m
g kg
-1dw
Polybrominated diphenyl ethers (PBDEs)
Recently included as UN POPEnvironmental contaminant
Biosolids Conc. 1.36 (0.01 – 4.69)
WWTP Sedimentation
Soil Persistence 20 years
Food chain Yes
Bioaccumulation Yes
Ecotoxicity Uncertain
Research Large
PBDEs0
200
400
600
800
1000
1200
1400
1600
1800
1981 1986 1991 1996 2001
Con
cent
ratio
n ng
g-1
lipid
Lake Ontario Lake Michigan Lake Huron
Used as fire retardantElectronics
Norstrom et al. (2002) Env. Sci. Techol. 36, 4783-4789 North American Great Lakes ecosystem in 2000 was determined by analysis of herring gull eggs analysing archived samples between 1981 and 2000
Polybrominated diphenyl ethers (PBDEs)
Recently included as UN POPEnvironmental contaminant
Biosolids Conc. 1.36 (0.01 – 4.69)
WWTP Sedimentation
Soil Persistence 20 years
Food chain Yes
Bioaccumulation Yes
Ecotoxicity Uncertain
Research Large
PBDEs
Used as fire retardantElectronics
0
0.5
1
1.5
2
2.5
3
3.5
4
Con
cent
ratio
n m
g kg
-1dw
Polychlorinated alkanes
Produced since 1930sClass of industrial chemicals comprising chlorinated straight-chain hydrocarbonsApplications include:
Extreme pressure lubricant additives Plasticizers Flame-retardants Paint additives
Analytical challenge 10,000+ isomersExtremely high concentrations reportedDetected in humans Similarity to United Nations POPs
Biosolids Conc. 910 (1.8 – 9700)
WWTP Unknown
Soil Persistence Unknown
Food chain Yes
Bioaccumulation Yes
Ecotoxicity Uncertain
Research Small
Short chain PCAs – C10-13
Medium chain PCAs – C14-17
Long chain PCAs – C18-30
Concentrations 1000 times higher
than PCBs
Polychlorinated naphthalenes
Used since early 1900sPrecedes/parallels PCBsApplications include
Dielectric fluids Engine oil additives Electroplating Wood preservatives Lubricant Dye production
Voluntary phased out in USA in 1970s1990s production ~ 150000 tonnesUnited Nations POPs candidateDioxin-like toxicity
Biosolids Conc. 0.044 (0.001 – 0.19)
WWTP Unknown; sedimentation
Soil Persistence Unknown
Food chain Yes
Bioaccumulation Yes
Ecotoxicity Uncertain
Research Small
Polydimethylsiloxanes – PDMS
Man-made organosilicone polymerWidely used in industrial applications and consumers products including:
Textiles treatment Household Personal care products Antifoam for food processing &
WWTPLow toxicityRapid abiotic degradationLargely removed through WWTP
94% unchanged
Biosolids Conc. 632 (122 – 5155)
WWTP Sedimentation (94%)
Soil Persistence 28 days
Food chain No
Bioaccumulation No
Ecotoxicity No
Research Good understanding
n ranges between 100 and >10000
Perfluorochemicals (PFOS & PFOA)
Accumulating in humansWidely detected in environmentUsed to make products resistant to heat, oil, stains, grease and waterCommon applications include:
Non-stick cookware Breathable membranes Stain-resistant carpets & fabrics Fire fighting foams Surfactants
Increases during WWTP Found in sediment and effluent
Recently included as UN POPRestrictions introduced (PFOS - Directive 2006/122/EC and under review as WFD PHS)
Biosolids Conc. 0.20 (0.01 – 3.12)
WWTP Increasing; in effluent & sludge
Soil Persistence Unknown
Food chain Yes
Bioaccumulation Yes
Ecotoxicity Uncertain
Research More required
Perfluorooctanoic acid PFOA
Perfluorooctane sulphonatePFOS
Quaternary Ammonium Compounds
Cationic surfactants (many)Commonly applications:
Fabric softeners, hair conditioners, disinfectants, biocides, emulsifiers, wetting agents
Source control of DTDMAC as aquatic toxinRelaced by DEEDMAC as more biodegradableLink to antibiotic resistance?
Biosolids Conc. Mean (Range)
WWTP Sedimentation &biodegradation
Soil Persistence 17 - 40 days
Food chain No
Bioaccumulation No
Ecotoxicity No
Research Few
R1-4 represent alkyl or aryl substituent’s
0
1000
2000
3000
4000
1991 1992 1993 1994
DTD
MAC
Con
cent
ratio
n m
g kg
-1dw
DTDMAC: ditallow dimethylammonium chlorideDEEDMAC: diethyl ester dimethylammonium chloride
Steroids
Humans primary source to WWTP Natural and synthetic Released as inactive polar conjugates
Female hormones degrade rapidlyHormone precursors regularly detected US EPA survey e.g. cholesterolUnlikely to be problematic for biosolids land applicationAnalytical problems
17 α-ethinyloestradiol
Biosolids Conc. Varied
WWTP High biodegradation
Soil Persistence Days
Human Health No
Bioaccumulation No
Ecotoxicity No
Research Small
17α-oestradiol oestrioloestrone
Synthetic Musks
Inexpensive substitutes for natural musks used since 1930sOriginal nitromusks toxic (15%)Replaced with polycyclic musks (85%)PECs < PNECsProposed German limits in sludge
Biosolids Conc. 14 (1.9 – 81)
WWTP Sedimentation & biodegradation
Soil Persistence Unknown
Food chain No
Bioaccumulation No
Ecotoxicity No
Research More required
AHTN
HHCB
0102030405060708090
100
Con
cent
ratio
n m
g kg
-1dw
Triclosan and Triclocarban
Widely used antimicrobials in personal care products, including:
Shampoos Soaps Cosmetics Skin-care lotions Creams Mouth rinses Toothpaste
Typical concentration 0.1 to 0.3% (w/w)
Triclosan
Triclocarban
Biosolids Conc. 24 (0.19 – 441)
WWTP Sedimentation & biodegradation
Soil Persistence <1 year
Food chain No
Bioaccumulation Yes
Ecotoxicity Yes
Research Small
0102030405060
mg
kg-1
dw
Triclosan Triclocarban
Typical Concentrations
0.01
0.1
1
10
100
1000
10000
Con
cent
ratio
n m
g kg
-1dw
•Higher than bulk chemicals •3 magnitudes higher than PCBs
Relatively high concentrations compared to other POPs
Very low concentrations
POPsBulk ChemicalPersonal Care
Persistence Food chain Ecological Soil Ecotoxicity Research Score2 – Yes
1 - Uncertain0 – No
2 – Possible1 - Uncertain
0 - No
2 - Yes1 - Possible
0 - No
2 - Yes1 - Uncertain
0 - No
3 - Lack of data2 - Few studies 1 - Consistent
0 - Many & similar
( /11)
Antibiotics 0 2 0 1 2 5
Benzothiazoles 1 1 0 1 3 6Bisphenol A 0 0 0 0 2 2Organotins 1 1 2 1 2 7Phthalates 0 0 0 0 1 1PBDEs 2 2 2 1 0 7PCAs 2 2 1 1 3 9PCNs 2 2 1 1 3 9Siloxanes 0 0 0 0 1 1PFCs 2 2 2 1 3 10QACs 0 0 0 0 2 2Steroids 0 0 0 0 2 2Synthetic Musks 1 0 1 0 1 3Triclosan 1 0 2 2 2 7Triclocarban 1 0 2 2 2 7
Assessment Matrix (somewhat subjective)
Assessment Scores
Score Contaminant
10 Perfluorochemicals (PFOS, PFOA)
9 PCAs; PCNs7 Organotins; PBDEs; Triclosan; Triclocarban6 Benzothiazoles5 Antibiotics and pharmaceuticals3 Synthetic musks2 Bisphenol A; QACs; Steroids1 Phthalates; Siloxanes
Key Recommendations
1.Long-term vigilance• Assessment, monitoring and research
2.Empirical measurements• Concentrations, fate and impacts
3.High concentration of PCAs• Risk to health due to POP characteristics?
4.PFCs have a unique chemistry for a UN POP • Potential environmental mobility?