First, a portion of the Environmental Protection Act of 1990 (the California statewide initiative proposed for the November ballot) calls for phasing out the use of pesticides that cause cancer and birth defects by 1996. Present EPA standards are for testing, approving and using pesticides so that, by 1996, a pesticide which has not passed all the required tests and met the required health studies will no longer be registered or used.
There are three main classes of herbicides (Miller, Living in the Environment, p. 520) : Contact herbicides, systemic herbicides, and soil sterilants. Princep, Karmex, and Roundup are the main herbicides: and these are often combined with each other, with other herbicides, and with mixing agents.
Triazines such as atrazine or simazine (Pricep), are broadleaf and grassy weed killers which interfere with photosynthesis. They are often combined with pentachlorophenols (PCP's) and/or other chlorophenols. Much controversy exists over their effects in the environment. They cause eye irritation and are harmful if ingested, inhaled or absorbed through the skin. They are toxic to fish. The label on Princep explicitly warns the applicator to keep the product out of any body of water and not to contaminate water sources for irrigation or drinking. Thus, the effects of Princep in the environment are toxic.
It is obvious that the use of herbicides threatens groundwater supplies of residents in the county. The chemicals or their contaminants and/or residues may dissolve in rainwater runoff, leach through to the water table, mix with the groundwater, and contaminate the supply. Most contamination is discovered only after drinking water has been affected. Sometimes it is never discovered, making documentation of its effects on residents extremely difficult. "Clearly the most effective solution to groundwater contamination is prevention" (Lutgans/Tarbuck, 1989, Essentials of Geology, p. 156).
These are phenoxy compounds such as 2,4-d, 2,4,5-T and Silvex, or substituted ureas such as diuron (Karmex), norea and fenuron. These herbicides work as pre-emergent killers and also by creating so much growth that plants die from lack of nutrients to support such excessive growth. Volumes of field studies on these herbicides link them with cancer and birth defects in humans. The Ames test (using Salmonella bacteria) has shown that approximately 90% of organic chemical carcinogens also act as mutagensÑ"supporting the hypothesis that carcinogens act by mutation of DNA" (Grenn, Forest, Herbicides and People, 1982, p. 170).
Glyphosate (Roundup), Treflan, Dymid, Dowpon, Sutan, etc., are systemic, nonselective agents which kill soil microorganisms essential for plant growth. They are hazardous to humans and domestic animals, may cause eye irritation, are harmful if swallowed, and should not be allowed to contaminate "swamps, bogs, marshes or potholes" (label on Roundup Can). The EPA considers glyphosphate a possible human carcinogen. Also, N-nitroso-glyphosate (NNG) may be a trace contaminant in glyphosate or when glyphosate combines with nitrites in the soil: most N-nitroso compounds are carcinogenic.
I would like to address the issue of safety in the use of pesticides, because the most hazardous industry in the United States is agriculture. Injuries and deaths from accidents account for many of the casualties, but poisonings, skin diseases and respiratory conditions from exposure to toxic agents also debilitate and kill thousands of farmworkers every year.
Most people, even those who mix and apply the pesticides, do not take these chemicals seriously enough. Some labels carry strict precautionary warnings for usÑfor instance, to wear protective clothing, to use a respirator, not to spray on a windy day, not to allow certain chemicals to get near a water source, etc.
If a farmworker has not been properly instructed, trained or outfitted when given the job of applying a dangerous pesticide, he may absorb some of the chemicals through the skin, inhale the spray or gases, or even ingest some from contamination of the hands. Perhaps a member of his family could be exposed from contact with his clothing at home. Later he or a child in his family could become ill but not realize the cause. He may experience nausea and begin to vomit, develop itchiness or a rash, or have muscle twitches or spasms.
According to the California environmental laws, employers are required to train their workers in safe handling of pesticides and to provide them with medical supervision if they handle pesticides extensively, to maintain and inspect safety equipment, to protect workers who may enter fields where they may be exposed to pesticides or their residues, and warn workers not to enter treated fields during the safety interval. Employers also must maintain records of their pesticide applications by filing use reports with the Department of Food and Agriculture.
If a patient is suffering from pesticide poisoning or from pesticide exposure, he should see a physician. The physician is required by law to report pesticide-related illnesses to the county health officer.
Hopefully, we will be able to stop the use of the toxic pesticides and yet still maintain use of effective low-toxicity pesticides in order to keep agricultural production high.
Copyright Mendocino Environmental Center 2004
Permission granted to excerpt or use this article if source is cited