Emerging Contaminant Threats and the Great Lakes


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Chemical contaminants form a vast chemical soup in the Great Lakes, and from available data, we know exposure may be cause for concern. This workshop will discuss the threat of “emerging contaminants” in the Lakes, as well as give an overview of research, policy implications and recommendations for moving forward.

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  • Coprostanol: cholesterol metabolite and biomarker of fecal contamination Cholesterol: N-N-diethyltoluamide: DEET Caffeine: natural pesticide; nonselective adenosine receptor antag & phoshpodiesterase inhibitor Tri(2-chloroethyl) phosphate: flame retardant Triclosan: antibacterial & antifungal agent in soap, toothpaste, mouthwash, etc. 4-Nonylphenol: degradation product from detergents 4-Nonylphenol monoethoxylate: degradation product from detergents Ethanol 2-butoxy-phosphate: pesticide 4-Octylphenol monoethoxylate: probably from detergent Bisphenol A – used to make plastics (polycarbonates); estrogenic Cotinine – nicotine metabolite; activates nicotine receptors 4-Nonylphenol diethoxylate – degradation product from detergents 5-methyl-1H-benzotriazole: Fluoranthene: polycyclic aromatic hydrocarbon (PAH); combustion; carcinogen 1,7-Dimethylxanthine: caffeine metabolite; Pyrene: Polycyclic aromatic hydrocarbon (PAH); combustion Trimethoprim: antibiotic; dihydrofolate reductase inhibitor; urinary tract infections 1,4-Dichlorobenzene: used in moth balls & urinal cakes (replaces naphthalene) Diazinon: organophosphate insecticide; inhibits acetylcholinesterase 4-Methyl phenol: cresols; used to dissolve other chemicals, make insecticides Acetominophen: Tylenol Tetrachloroethylene: dry cleaning fluid; group 2A carcinogen 4-Octylphenol diethoxylate: detergent product Erythromycin: antibiotic Estriol: produced during pregnancy by placenta; bioidentical hormone therapy NO longer used in U.S. as of 2008 Linocmycin: antibiotic Sulfamethoxazole: antibiotic (sulfonamide) Phthalic anhydride: plasticizer for plastics; probably endocrine disruptor Carbaryl: carbamate insecticide; acetylcholinesterase inhibitor; third most used insecticide in U.S. – agriculture, gardens, forestry, etc.; probable carcinogen
  • DEET’s likely Target = - Anopheles gambiae Odorant binding protein 1 (AgamOBP1))
  • PAHs include very toxic substances and are suspected endocrine disruptors
  • Emerging Contaminant Threats and the Great Lakes

    1. 2. U ERG Mission <ul><li>The U rban W atershed E nvironmental R esearch G roup undertakes scholarly activities, community and K-12 outreach, and collaborative initiatives related to the Lake Huron to Lake Erie waterway and associated watersheds. These activities are intended to benefit human health and the watershed ecosystems, as well as inform scientists, public policy, those who reside in the region, and others interested in access to clean and affordable water. </li></ul>http://uwerg.cs.wayne.edu/
    2. 3. Huron – Erie Connecting Channel and the ‘St Clair Watershed’ Ron Beck, USGS Land Processes Data Center, Satellite System
    3. 4. Emerging contaminants <ul><li>Definition </li></ul><ul><ul><li>USGS: “chemical and microbial constituents that have not historically been considered as contaminants” http://toxics.usgs.gov/regional/emc/ </li></ul></ul><ul><li>Many contaminants not removed by water treatment processes </li></ul><ul><li>(e.g., PPCPs) </li></ul><ul><li>Sources: </li></ul><ul><ul><li>Waste water discharge </li></ul></ul><ul><ul><li>Surface runoff: urban and agricultural </li></ul></ul><ul><ul><li>Industrial </li></ul></ul><ul><ul><li>Ground water (e.g., landfills) </li></ul></ul>
    4. 6. 30 Most frequently detected organic wastewater contaminants out of 95 measured: Coprostanol Cholesterol N-N-diethyltoluamide Caffeine Tri(2-chloroethyl) phosphate Triclosan 4-Nonylphenol 4-Nonylphenol monoethoxylate Ethanol 2-butoxy-phosphate 4-Octylphenol monoethoxylate Bisphenol A Cotinine 4-Nonylphenol diethoxylate 5-methyl-1H-benzotriazole Fluoranthene 1,7-Dimethylxanthine Pyrene Trimethoprim 1,4-Dichlorobenzene Diazinon 4-Methyl phenol Acetominophen Tetrachloroethylene 4-Octylphenol diethoxylate Erythromycin Estriol Lincomycin Sulfamethoxazole Phthalic anhydride Carbaryl from Kolpin et al. 2002
    5. 7. Detection frequency of organic wastewater contaminants ranked from higher to lower (~ 88% to 21% of samples) [# of compounds in category] <ul><li>Steroids [4] </li></ul><ul><li>Nonprescription drugs [5] </li></ul><ul><li>Insect repellent [1] </li></ul><ul><li>Detergent metabolites [5] </li></ul><ul><li>Disinfectants [3] </li></ul><ul><li>Plasticizers [7] </li></ul><ul><li>Fire retardants [2] </li></ul><ul><li>Antibiotics [22] </li></ul><ul><li>Insecticides [7] </li></ul><ul><li>Polycyclic Aromatic Hydrocarbons (PAH) [6] </li></ul><ul><li>Reproductive hormones [11] </li></ul><ul><li>Other prescription drugs [14] </li></ul><ul><li>Antioxidants [5] </li></ul><ul><li>Fragrances [2] </li></ul><ul><li>Solvent [1] </li></ul>from Kolpin et al. 2002
    6. 8. from Kolpin et al. 2002 Complex mixtures in streams
    7. 9. Pharmaceuticals ( for treatment, prevention, or diagnosis of disease ) <ul><li>Nature of the chemical involved </li></ul><ul><ul><li>parent molecule: chemically synthesized or derived from nature </li></ul></ul><ul><ul><li>metabolite (metabolism by organism changes chemical structure) </li></ul></ul><ul><ul><li>transformation product (chemical change after excretion) </li></ul></ul><ul><ul><li>chemical complexes (in environment) </li></ul></ul><ul><ul><li>parent molecule or prodrug </li></ul></ul><ul><ul><li>specific biological target(s) by design </li></ul></ul><ul><li>Mechanism or mode of action (MOA) </li></ul><ul><ul><li>mechanism most often associated with drug receptor </li></ul></ul><ul><ul><li>often > 1 MOA for given drug </li></ul></ul><ul><ul><li>MOA observed depends on concentration </li></ul></ul><ul><ul><li>selectivity decreases with increasing concentration </li></ul></ul>
    8. 10. A Biological Target: Cell Receptors Modified from: Cell-Cell Interactions Category: Basic Biology • Science Education Posted on: November 23, 2006, by Coturnix http://scienceblogs.com/clock/2006/11/cellcell_interactions.php
    9. 11. Non-therapeutic chemical agents with specific and intended biological targets (not exhaustive list) <ul><li>Antibiotics used in agriculture (e.g., CAFOs) </li></ul><ul><li>Chemical Pesticides (e.g., organochlorides, organophosphates, carbamates, trazines, glyphosate, etc.) </li></ul><ul><ul><li>Insecticides </li></ul></ul><ul><ul><li>Herbicides </li></ul></ul><ul><ul><li>Fungicides </li></ul></ul><ul><ul><li>Rodenticides </li></ul></ul><ul><ul><li>Other </li></ul></ul><ul><li>Insect repellants (e.g., DEET) </li></ul>
    10. 12. Non-therapeutic chemicals with unexpected molecular targets: Endocrine disruptors (not exhaustive list) <ul><li>Polychlorinated biphenyls (PCBs) – industrial lubricants and coolants </li></ul><ul><li>Polybrominated biphenyl ethers (PBDEs) – flame retardants used in plastics </li></ul><ul><li>Phthalates – plasticizer (e.g., softens plastic) </li></ul><ul><li>Bisphenol A (BPA) – used to make plastics, particularly polycarbonate </li></ul><ul><li>Nonylphenols – degradation product of detergents </li></ul><ul><li>Polycyclic aromatic hydrocarbons (PAHs) – incomplete combustion products </li></ul><ul><li>Perfluorooctanoic acid (PFOA) – surfactant, emulsifier, other uses </li></ul><ul><li>DDT – pesticide that interferes with reproductive development </li></ul>
    11. 13. Chemicals with potential for synergistic or additive environmental effects: Conceptual example Industry and Agriculture Pharmaceuticals and Personal Care Products (PPCPs) Action : Endocrine Disruption, Antimicrobial, etc.
    12. 14. Exposure to emerging contaminants <ul><li>How are organisms affected? </li></ul><ul><ul><li>route of entry </li></ul></ul><ul><ul><li>sub-lethal versus lethal </li></ul></ul><ul><ul><li>acute versus chronic exposure </li></ul></ul><ul><ul><li>biological mechanism </li></ul></ul><ul><li>What are the relative vulnerabilities of individual species? </li></ul><ul><li>What are the ecosystem level effects? </li></ul>
    13. 15. Evaluating impact of contaminants on the environment and human health Environmental Sciences: Contaminant Transport and Distribution Biological Sciences: Ecotoxicology Biomedical Sciences: Human Toxicology
    14. 16. Effects on Aquatic Life <ul><li>Levels below threshold for biological effect? </li></ul><ul><li>Endocrine disruption at low exposure levels (e.g., ng/L) </li></ul><ul><li>Pseudo-persistence and bioaccumulation </li></ul><ul><li>Little known about: </li></ul><ul><ul><li>metabolism of chemicals by aquatic life </li></ul></ul><ul><ul><li>biological impact from individuals to ecosystem </li></ul></ul><ul><li>Phylogenetic conservation of biological molecules </li></ul><ul><li>Similarity of targets similarity in response </li></ul><ul><li>Key issue : Exposure often involves complex chemical mixtures </li></ul><ul><li>Key issue : Changing environment – unknown effects on chemical soup </li></ul><ul><ul><li>(Human population growth, Increasing industrialization, Climate change) </li></ul></ul>
    15. 17. Possible evidence of endocrine disruption in Saint Clair watershed <ul><li>Gonadal intersex in Lake St Clair Male White Perch probably caused by exposure to estrogenic substances </li></ul><ul><li>Kavanagh et al. (2004) Environmental Health Perspectives 112: 898-902 </li></ul><ul><li>Fewer males in Aamjiwnaang First Nation community (near Sarnia) </li></ul><ul><li>Mackenzie et al. (2005) Environmental Health Perspectives 113: 1295-1298 </li></ul><ul><li>Decrease in males of Aamjiwnaang First Nation community blamed on petrochemical plants, but causal relationship remains elusive Webster (2006) Lancet 9509: 462-463 </li></ul>
    16. 18. Summary <ul><li>Many compounds introduced into the aquatic environment </li></ul><ul><li>Very similar molecular targets can be found in ‘lower’organisms </li></ul><ul><li>Individual chemical concentrations mostly very low (e.g., < 1  g/L) </li></ul><ul><li>Endocrine disruption reported at very low concentrations </li></ul><ul><li>Complex mixtures increase the likelihood of adverse biological effects </li></ul><ul><li>(e.g., additive effects, synergistic effects, etc.) </li></ul><ul><li>Ignorance about the biology of ‘lower’organisms and the transport and distribution of contaminants magnifies the problem when considering the complexity of population and ecosystem dynamics in a changing world. </li></ul>
    17. 19. A complex relationship with the natural world ! Environmental Life-Cycle of Pharmaceuticals by CG Daughton, US EPA, 2006
    18. 20. References <ul><li>Christen, V, Hickmann, S, Rechenberg, B, Fent, K (2010) Highly active human pharmaceuticals in aquatic systems: A concept for their identification based on their mode of action. Aquatic Toxicology 96: 167-181. </li></ul><ul><li>Colborn, T and Thayer, K (2000) Aquatic ecosystems: Harbingers of endocrine disruption. Ecological Applications 10: 949-957. </li></ul><ul><li>Daughton, CG and Ternes, TA (1999) Pharmaceuticals and Personal Care Products in the Environment: Agents of Subtle Change? Environmental Health Perspectives 107(6): 907-938. </li></ul><ul><li>Daughton, CG (2010) “Drugs and the Environment: Stewardship & Sustainability,” National Exposure Research Laboratory, Environmental Sciences Division, US EPA, Las Vegas, Nevada, report NERL-LV-ESD 10/081, EPA/600/R-10/106. www.epa.gov/nerlesd1/bios/daughton/APM200-2010.pdf </li></ul><ul><li>Kolpin DW, Furlong ET, Meyer MT, Thurman, EM, Zaugg, SD, Barber, LB, Buxton, HT (2002) Pharmaceuticals, hormones, and other organic wastewater contaminants in US streams, 1999-2000: A national reconnaissance. Environmental Science & Technology (36) 6: 1202-1211. </li></ul><ul><li>Kummerer, K. (2009) The presence of pharmaceuticals in the environment due to human use - present knowledge and future challenges. Journal of Environmental Management 90: 2354-2366. </li></ul><ul><li>Morley, NJ (2009) Environmental risk and toxicology of human and veterinary waste pharmaceutical exposure to wild aquatic host-parasite relationships. Environmental Toxicology and Pharmacology 27: 161-175. </li></ul>