Weed Killers By The Glass
September 1, 1995

Weed Killers By The Glass: Danville, Illinois

Citizen Monitoring Results

Danville drinking water is contaminated with cancer causing weed killers at levels that frequently exceed federal standards. Tests of city tap water found up to seven pesticides or metabolites in a single sample. The most common pesticide contaminant was atrazine, which was found in every tap water sample tested between May 15 and July 1, 1995. Cyanazine was found in 94 percent of these same samples. During this test period approximately 250 infants in Danville consumed infant formula reconstituted with water contaminated with up to seven toxic weed killers. (Note 1: Ershow, Abby G., and Cantor, Kenneth P. 1989. Total Water and Tapwater Intake in the United States: Population-Based Estimates of Quantities and Sources. Life Sciences Research Office; Federation of American Societies for Experimental Biology. Bethesda, MD)

Most of these weed killers are used in corn production. Since 1985, taxpayers have subsidized Illinois corn growers at a rate of $607 million per year, for a ten year total of $6.07 billion. Farmers in turn pay nothing to clean up the water. The pesticide industry claims that farmers' weed control cost would double if these polluting herbicides were banned. Assuming the industry claim is true, the added costs to farmers would amount to just 11 percent of the value of the subsidy taxpayers pay to these corn farmers each year.



Causes mammary gland cancer in female rats in repeated studies.(Note 2: Copley, Marion. 1989. Follow-up to the Third Peer Review of Atrazine. EPA. Washington, D.C.; International Agency for Research on Cancer. 1991. World Health Organization. IARC Monographs on the Evolution of Cancer Risk to Humans. Vol. 53.) Classified by the EPA as a possible human carcinogen. Federal health standard in drinking water -- 3 parts per billion (ppb), European Drinking Water Standard -- 0.1 ppb.


  • Found in 100 percent of 16 tap water samples
  • 88 percent of samples were above the federal health standard
  • Highest level found -- 18 ppb, six times the federal health standard.
  • Average concentration -- 8.71 ppb, nearly three times the federal health standard.



Causes mammary gland cancer in rats and birth defects in rats and rabbits in repeated studies. Causes genetic mutations. According to the EPA this makes cyanazine a potent carcinogen.(Note 3: Dykstra, William. 1991. Peer Review of Cyanazine (Bladex). EPA. Washington, D.C.) Classified by the EPA as a possible human carcinogen, required birth defects warning on the product label. Federal health guideline in drinking water -- 1 ppb. European Drinking Water Standard -- 0.1 ppb.


  • Found in 94 percent of samples
  • 94 percent of samples were above the federal health advisory.
  • Highest level found -- 34.00 ppb, thirty-four times the federal health advisory.
  • Average concentration -- 10.71 ppb, more than ten times the federal health advisory.


Tests for Multiple Weed Killers


  • Seven pesticides or metabolites -- atrazine, cyanazine, simazine, metolachlor, desisopropylatrazine, desethylatrazine, alachlor, and acetochlor -- were found in a single sample of Danville tap water collected on June 1, 1995.
  • These seven pesticides or metabolites include one pesticide classified by the EPA as a probable human carcinogen, four classified as possible human carcinogens, one pesticide that causes birth defects in animal studies, and three pesticides that disrupt the normal functioning of the hormone system.
  • Federal drinking water standards do not account for this simultaneous exposure to multiple pesticides (or other contaminants) in drinking water, and allow cancer risks from these weed killers up to 29 times higher than the federal government allows from the same chemicals in food.


    Use of 6 Major Herbicides on Illinois Corn Reached 32.4 Million Pounds in 1994, up by 6 Million Pounds Since 1990


    Herbicide Acres Treated, 1994 Use, 1994 (lbs.)
    Acetochlor 580,000 973,000
    Alachlor 1,972,000 5,041,000
    Atrazine 9,628,000 11,345,000
    Cyanazine 2,668,000 6,933,000
    Metolachlor 3,712,000 7,713,000
    Simazine 348,000 415,000

    (Note 4: USDA 1995. Agricultural Chemical Usage: 1994 Field Crops Summary.)