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IowaCity

Weed Killers By The Glass: IowaCity

September 1, 1995

Weed Killers by the Glass

Iowa City, Iowa

 

Citizen Monitoring Results

Iowa City drinking water is contaminated with cancer causing weed killers at levels that frequently exceed federal standards for at least one herbicide. Tests of city tap water found five different pesticides or metabolites in a single sample. The most common pesticide contaminant is atrazine, which was found in every tap water sample tested between May 15 and July 1, 1995. Cyanazine was also found in every sample. During this test period approximately 325 infants in Iowa City consumed infant formula reconstituted with water contaminated with five 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 Iowa corn growers at a rate of $809 million per year, for a ten year total of $8.09 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.

 

Atrazine

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
  • Highest level found -- 2.80 ppb
  • Average concentration -- 1.66 ppb.

 

Cyanazine

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 100 percent of tap water samples
  • Forty-four percent of samples exceeded the federal health advisory.
  • Highest level found -- 1.50 ppb, above the federal health advisory.
  • Average concentration --0.89 ppb.

 

Tests for Multiple Weed Killers

 

  • Five pesticides or metabolites -- atrazine, cyanazine, metolachlor, alachlor, and desethylatrazine -- were found in a single sample of Iowa City tap water collected on June 2, 1995.
  • These five pesticides or metabolites include one pesticide classified by EPA as a probable human carcinogen, three pesticides classified as possible human carcinogens, one pesticide that causes birth defects in animal studies, and two 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 Iowa Corn Reached 32.1 Million Pounds in 1994, up 4.85 Million Pounds Since 1990

 

Herbicide Acres Treated, 1994 Use, 1994 (lbs.)
Acetochlor 1,170,000 2,164,000
Alachlor 1,690,000 4,115,000
Atrazine 8,580,000 7,471,000
Cyanazine 3,380,000 7,768,000
Metolachlor 4,940,000 10,664,000
Simazine 0 0

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

 

 

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