Persistent and Emerging Contaminants: The Problem
Organic Contaminants
Persistent organic pollutants (POPs), like chlorinated solvents and polychlorinated biphenyls (PCBs), or persistent pesticides, have been known for many years to enter our waterways by industrial and agricultural pathways.1 In comparison to what we know about the structure and chemistry of the POPs themselves, little is known about their specific sources, the pathways and rates of their degradation, and the fate of their more polar degradation intermediates and products (e.g., hydroxylated polycyclic aromatic hydrocarbons and haloacetic acids) particularly in complex environmental systems.2 These compounds may exhibit fate, modes of toxicity and dose-response effects that differ from the parent compound.
Emerging contaminants including pharmaceuticals & personal care products (PPCPs), endocrine disrupting compounds (EDCs), and disinfection byproducts (DBPs) have recently been measured in water sources throughout the US.4 The presence of PPCPs and EDCs in streams has been attributed to widespread domestic use of these compounds, followed by wastewater treatment that is only partially effective in their removal, prior to discharge into receiving waters. Thousands of different pharmaceutical substances are used including painkillers, antibiotics, contraceptives, antidepressants, and impotence drugs. In Arizona effluent discharge constitutes a significant fraction of surface water flux5 and the reclamation of wastewater for beneficial use is critical to sustained regional growth.
Inorganic Contaminants
Inorganic contaminants (e.g., metals, metalloids, and radionuclides) enter the hydrologic cycle as a result of mining, groundwater pumping, nuclear weapons production, and industrial activities, all of which have been prevalent in the Southwestern US. In particular, historical precious metal mining is a major source of environmental pollution in the Southwest, where both waterborne and airborne forms of particulate metals are dispersed into terrestrial and aquatic ecosystems and biota. In Arizona alone, there are more than 60,000 abandoned and/or inactive mines and an estimated 320 km of mine-contaminated surface water.7 Since many of the contaminant metals of concern (e.g., Hg, As, Pb, Cu, Cd, Zn) are sparingly soluble in water, their presence in the aqueous phase is often the result of their complexation with dissolved organic matter or colloids.
The Arizona Laboratory for Emerging Contaminants is working to detect, characterize, and quantify the full range of contaminants and associated dissolved and nano-particulate species impacting natural and engineered waters in the Southwestern US.
References
- Reid, B. J., Jones, K. C., Semple, K. T., 2000. Bioavailability of persistent organic pollutants in soils and sediments - a perspective on mechanisms, consequences and assessment. Environmental Pollution 108, 103-112.; Galiulin, R. V., Bashkin, V. N., Galiulina, R. A., 2002. Review: Behavior of persistent organic pollutants in the air-plant-soil system. Water Air and Soil Pollution 137, 179-191.
- Parikh, S. J., Chorover, J., Burgos, W. D., 2004. Interaction of phenanthrene and its primary metabolite (1-hydroxy-2-naphthoic acid) with estuarine sediments and humic fractions. Journal of Contaminant Hydrology 72, 1-22.
- Johnson, P. D., Dawson, B. V., Goldberg, S. J., 1998. A review: Trichloroethylene metabolites: Potential cardiac teratogens. Environmental Health Perspectives 106, 995-999; Lewis, T. E., Wolfinger, T. F., Barta, M. L., 2004. The ecological effects of trichloroacetic acid in the environment. Environment International 30, 1119-1150; Selmin, O., Thorne, P. A., Caldwell, P. T., Johnson, P. D., Runyan, R. B., 2005. Effects of trichloroethylene and its metabolite trichloroacetic acid on the expression of vimentin in the rat H9c2 cell line. Cell Biology and Toxicology 21, 83-95; Van de Wiele, T., Vanhaecke, L., Boeckaert, C., Peru, K., Headley, J., Verstraete, W., Siciliano, S., 2005. Human colon microbiota transform polycyclic aromatic hydrocarbons to estrogenic metabolites. Environmental Health Perspectives 113, 6-10.
- Kolpin, D. W., Furlong, E. T., Meyer, M. T., Thurman, E. M., Zaugg, S. D., Barber, L. B., Buxton, H. T., 2002. Pharmaceuticals, hormones, and other organic wastewater contaminants in U.S. streams, 1999-2000: A national reconnaissance. Environ. Sci. Technol. 36, 1202-1211.; Wallace, B., Purcell, M., Furlong, J., 2002. Total organic carbon analysis as a precursor to disinfection byproducts in potable water: Oxidation technique considerations. Journal of Environmental Monitoring 4, 35-42.; Zwiener, C., Richardson, S. D., 2005. Analysis of disinfection by-products in drinking water by LC-MS and related MS techniques. Trends Anal. Chem. 24, 613-621.; Field, J. A., Johnson, C. A., Rose, J. B., 2006. Special issue on emerging contaminants. Environmental Science & Technology 40, 7106-7106.
- Quanrud, D. M., Quast, K., Conroy, O., Karpiscak, M. M., Gerba, C. P., Lansey, K. E., Ela, W. P., Arnold, R. G., 2004. Estrogenic activity and volume fraction of waste water origin in monitoring wells along the Santa Cruz River, Arizona. Ground Water Monitoring and Remediation 24, 86-93.
- del Pino, M. P., Durham, B., 1999. Wastewater reuse through dual-membrane processes: opportunities for sustainable water resources. Desalination 124, 271-277.
- Frisch-Gleason, R., 1995. Controlling and Remediating Surface and Groundwater Pollution from Inactive and Abandoned Mines: A Survey of Management Practices, Arizona Geological Survey. Arizona Geological Survey, T., AZ, Open-File Report. 95-13.
- Weng, L. P., Temminghoff, E. J. M., Lofts, S., Tipping, E., Van Riemsdijk, W. H., 2002. Complexation with dissolved organic matter and solubility control of heavy metals in a sandy soil. Environmental Science & Technology 36, 4804-4810; Honeyman, B. D., 1999. Geochemistry - Colloidal culprits in contamination. Nature 397, 23-24.
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