U ERG MissionU ERG Mission

The UUrban WWatershed EEnvironmental RResearch GGroup 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.

http://uwerg.cs.wayne.edu/

Huron – Erie Connecting ChannelHuron – Erie Connecting Channeland the and the ‘‘St Clair WatershedSt Clair Watershed’’

Ron Beck, USGS Land Processes Data Center, Satellite System

Emerging contaminantsEmerging contaminants• Definition

USGS: “chemical and microbial constituents that have not historically been considered as contaminants” http://toxics.usgs.gov/regional/emc/

• Many contaminants not removed by water treatment processes(e.g., PPCPs)

• Sources:

–Waste water discharge

–Surface runoff: urban and agricultural

–Industrial

–Ground water (e.g., landfills)

30 Most frequently detected organic 30 Most frequently detected organic wastewater contaminants out of 95 measured:wastewater contaminants out of 95 measured:

CoprostanolCholesterolN-N-diethyltoluamideCaffeineTri(2-chloroethyl) phosphateTriclosan4-Nonylphenol4-Nonylphenol monoethoxylateEthanol 2-butoxy-phosphate4-Octylphenol monoethoxylateBisphenol ACotinine4-Nonylphenol diethoxylate5-methyl-1H-benzotriazoleFluoranthene

1,7-DimethylxanthinePyreneTrimethoprim1,4-DichlorobenzeneDiazinon4-Methyl phenolAcetominophenTetrachloroethylene4-Octylphenol diethoxylateErythromycinEstriolLincomycinSulfamethoxazolePhthalic anhydrideCarbaryl

from Kolpin et al. 2002

Detection frequency of Detection frequency of organic wastewater organic wastewater

contaminantscontaminants

ranked from higher to lower (~ 88% to 21% of samples)

[# of compounds in category]

Steroids [4]Nonprescription drugs [5]Insect repellent [1]Detergent metabolites [5]Disinfectants [3]Plasticizers [7]Fire retardants [2]Antibiotics [22]Insecticides [7]Polycyclic Aromatic Hydrocarbons (PAH) [6]Reproductive hormones [11]Other prescription drugs [14]Antioxidants [5]Fragrances [2]Solvent [1]

from Kolpin et al. 2002

from Kolpin et al. 2002

Complex mixtures in streams

PharmaceuticalsPharmaceuticals(for treatment, prevention, or diagnosis of disease)

Nature of the chemical involved – parent molecule: chemically synthesized or derived from nature– metabolite (metabolism by organism changes chemical structure)– transformation product (chemical change after excretion)– chemical complexes (in environment)– parent molecule or prodrug – specific biological target(s) by design

Mechanism or mode of action (MOA)– mechanism most often associated with drug receptor– often > 1 MOA for given drug– MOA observed depends on concentration– selectivity decreases with increasing concentration

A Biological Target: Cell ReceptorsA Biological Target: Cell Receptors

Modified from:Cell-Cell Interactions

Category: Basic Biology • Science EducationPosted on: November 23, 2006, by Coturnix

http://scienceblogs.com/clock/2006/11/cellcell_interactions.php

Non-therapeutic chemical agents with Non-therapeutic chemical agents with specific and intended biological targetsspecific and intended biological targets

(not exhaustive list)

• Antibiotics used in agriculture (e.g., CAFOs)• Chemical Pesticides (e.g., organochlorides, organophosphates,

carbamates, trazines, glyphosate, etc.)– Insecticides– Herbicides– Fungicides– Rodenticides– Other

• Insect repellants (e.g., DEET)

Non-therapeutic chemicals with unexpected Non-therapeutic chemicals with unexpected molecular targets: Endocrine disruptors molecular targets: Endocrine disruptors

(not exhaustive list)

• Polychlorinated biphenyls (PCBs) – industrial lubricants and coolants

• Polybrominated biphenyl ethers (PBDEs) – flame retardants used in plastics

• Phthalates – plasticizer (e.g., softens plastic)

• Bisphenol A (BPA) – used to make plastics, particularly polycarbonate

• Nonylphenols – degradation product of detergents

• Polycyclic aromatic hydrocarbons (PAHs) – incomplete combustion products

• Perfluorooctanoic acid (PFOA) – surfactant, emulsifier, other uses

• DDT – pesticide that interferes with reproductive development

Chemicals with potential for synergistic or additive Chemicals with potential for synergistic or additive environmental effects: Conceptual exampleenvironmental effects: Conceptual example

Industry and Agriculture

Pharmaceuticals andPersonal Care Products

(PPCPs)

Action:EndocrineDisruption,

Antimicrobial,etc.

Exposure to emerging contaminantsExposure to emerging contaminants

• How are organisms affected? – route of entry– sub-lethal versus lethal– acute versus chronic exposure– biological mechanism

• What are the relative vulnerabilities of individual species?

• What are the ecosystem level effects?

Environmental Sciences:Contaminant Transport and Distribution

Biological Sciences:Ecotoxicology

Biomedical Sciences:Human Toxicology

Evaluating impact of contaminants Evaluating impact of contaminants on the environment and human healthon the environment and human health

Effects on Aquatic LifeEffects on Aquatic Life• Levels below threshold for biological effect?

• Endocrine disruption at low exposure levels (e.g., ng/L)

• Pseudo-persistence and bioaccumulation

• Little known about: – metabolism of chemicals by aquatic life

– biological impact from individuals to ecosystem

• Phylogenetic conservation of biological molecules

• Similarity of targets similarity in response

• Key issue: Exposure often involves complex chemical mixtures

• Key issue: Changing environment – unknown effects on chemical soup(Human population growth, Increasing industrialization, Climate change)

Possible evidence of endocrine Possible evidence of endocrine disruption in Saint Clair watersheddisruption in Saint Clair watershed

• Gonadal intersex in Lake St Clair Male White Perch probably caused by exposure to estrogenic substancesKavanagh et al. (2004) Environmental Health Perspectives 112: 898-902

• Fewer males in Aamjiwnaang First Nation community (near Sarnia)Mackenzie et al. (2005) Environmental Health Perspectives 113: 1295-1298

• Decrease in males of Aamjiwnaang First Nation community blamed on petrochemical plants, but causal relationship remains elusive Webster (2006) Lancet 9509: 462-463

SummarySummary

• Many compounds introduced into the aquatic environment

• Very similar molecular targets can be found in‘lower’organisms

• Individual chemical concentrations mostly very low (e.g., < 1 g/L)

• Endocrine disruption reported at very low concentrations

• Complex mixtures increase the likelihood of adverse biological effects (e.g., additive effects, synergistic effects, etc.)

• 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.

A complex relationship A complex relationship with the natural world !with the natural world !

Environmental Life-Cycle of Pharmaceuticals by CG Daughton, US EPA, 2006Environmental Life-Cycle of Pharmaceuticals by CG Daughton, US EPA, 2006

ReferencesChristen, 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.

Colborn, T and Thayer, K (2000) Aquatic ecosystems: Harbingers of endocrine disruption. Ecological Applications 10: 949-957.

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.

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

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.

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.

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.