RWU NE-4153, USDA Forest Service, Northeastern Research Station, Delaware, Ohio, USA
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Last updated: January 23, 2002	Contact: Anantha Prasad

Environmental Contaminants: (Click image to enlarge)
trends74.JPG 31.17 KB		A brief assessment on the trends in contaminants.
trends75.JPG 74.51 KB		The pH of rainfall shows a marked increasing trend from the central US eastward. The acid rain has been shown to cause detrimental effects in some lakes. Low pH problems are also evident as acid mine drainage, with over 12,000 km of streams with this type of problem. Schmitt CJ. 1998. Environmental Contaminants. Pages 131-165 in Mac MJ, Opler PA, Puckett Haecker CE, Doran PD. Status and trends of the nation's biological resources. U.S. Department of the Interior, U.S. Geological Survey, Reston, Va.
trends76.JPG 65.56 KB		Overall, however, most basins (over 60% of them in the northeast) suffer more from excessive nutrients and suspended solids. McCorkle, C.O.Jr. and J.E. Halver, co-chairs. 1982. Impacts of emerging agricultural trends on fish and wildlife habitat. National Research Council. National Academy Press. Washington, D.C. 303 pp.
trends77.JPG 94.34 KB		This map shows the distribution of threatened or impaired waters, according to EPA. Percentages of impaired land (polluted by sediments, nutrients, pathogens, pesticides, or heavy metals) by hydrologic unit code (large basin) is presented. http://www.epa.gov/owow/tmdl/atlas/ US EPA. 2000. Total maximum daily load (TDML) program. EPA-840-B-00-002 . US EPA. Washington, D.C.
trends78.JPG 105.96 KB		Thelarge hypoxic zone in the Gulf of Mexico is indicative of excessive nutrients moving down the Mississippi River. The graph shows that the trend in nitrate flux has been generally up since 1960. McIsaac et al.'s model showed that a 12% reduction in agricultural fertilization would reduce nitrates in the Gulf by 33%. This 12% cutback should be reasonable since farmers generally are adding >30% more N than necessary. McIsaac GF, David MB, Gertner GZ, Goolsby DA. 2001. Nitrate flux in the Mississippi River. Nature 414:166-167.
trends79.JPG 55.00 KB		Overall pesticide use was up dramatically from 1960-1980, then has leveled off. Schmitt CJ. 1998. Environmental Contaminants. Pages 131-165 in Mac MJ, Opler PA, Puckett Haecker CE, Doran PD. Status and trends of the nation's biological resources. U.S. Department of the Interior, U.S. Geological Survey, Reston, Va.
trends80.JPG 121.07 KB		The Cornbelt and CA are some of largest users of agricultural chemicals. Over 60% of chemicals are used on corn or soybeans. Schmitt CJ. 1998. Environmental Contaminants. Pages 131-165 in Mac MJ, Opler PA, Puckett Haecker CE, Doran PD. Status and trends of the nation's biological resources. U.S. Department of the Interior, U.S. Geological Survey, Reston, Va.