Pesticides and Health

Pesticides are chemical poisons, designed to kill plants and animals such as insects (insecticides), weeds (herbicides), rodents (rodenticides), and mold or fungus (fungicides). They include active ingredients (those intended to kill the target) and inert ingredients, which are often not "inert" at all.

Pesticides can be absorbed through the skin, swallowed or inhaled. Pesticides often stray from their point of application to settle on neighbors' properties, clothes lines, pools, toys and furniture. Children and pets often track pesticide residues into the house. Studies show that only 5% of pesticides reach target weeds. The rest runs off into water or dissipates in the air. Drift from landscaping can range from 12 feet to 14.5 miles. More serious effects appear to be produced by direct inhalation of pesticide sprays than by absorption or ingestion of toxins. Wisconsin studies have found pesticides in several underground aquifers, leading to drinking water contamination (see links below).

Many people are falsely reassured by government "registrations" of pesticides. However, many of the safety tests used to test these products are inadequate. They test for short-term effects of chemicals on healthy (not sick, elderly, or immuno-suppressed, etc.) adult (not young) animals (not humans). They test one chemical at a time, even though we are exposed to many chemicals at once as part of our modern chemical lifestyles. Some of the companies testing pesticides have been charged and convicted of falsifying residue and environmental studies that were used to support pesticide registration in the U.S. and Canada. Research shows, that several pesticides become even more toxic as they break down. Because safety testing has not been adequate, current pesticide applications are essentially a giant experiment using the general public. We're guinea pigs for the chemical industry.

In the U.S. it is a violation of federal law to state that the use of pesticides is safe, because pesticides are toxic by definition.

Pesticide Health Effects


The World Health Organization estimates that there are three million cases of pesticide poisoning each year and up to 220,000 deaths, primarily in developing countries. Pesticide exposure can cause a range of neurological health effects such as memory loss, loss of coordination, reduced speed of response to stimuli, reduced visual ability, altered or uncontrollable mood, general behavior changes, and reduced motor skills. These symptoms are often very subtle and may not be recognized by the medical community as a clinical effect. Other possible health effects include asthma, allergies, and hypersensitivity, and pesticide exposure is also linked with cancer, hormone disruption, and problems with reproduction and fetal development. Children seem to be greatly susceptible to the toxic effects of pesticides. The Natural Resource Defense Council has collected data which recorded higher incidence of childhood leukemia, brain cancer and birth defects. These results correlated with early exposure to pesticides. At lower doses, birds and other wildlife may develop many of the same conditions listed for humans.

Example: The pesticide 2, 4-D is the most common herbicide used by lawn companies and is found in stores under names that sound safe like "Weed 'n Feed." But this pesticide was a component of the infamous Agent Orange defoliant used during the Vietnam War and it frequently is contaminated with traces of dioxin. Dioxin is one of the most toxic manmade substances known, with effects very similar to PCBs. 2, 4-D is under special review by the U.S. Environmental Protection Agency because of concerns about chronic health and environmental effects, but it is still being used in the meantime.

Inert Ingredients

A little-known secret of the chemical industry is that the "inert" ingredients, which are the carriers or bulking agents for pesticides, are often as toxic, or more toxic, than the "active" ingredients, yet this information is not required on the labels. The public purchaser and even professional applicators usually have no idea as to these chemical contaminants. According to a 2000 report produced by the New York State Attorney General, “The Secret Ingredients in Pesticides: Reducing the Risk,” 72 percent of pesticide products available to consumers contain more than 95 percent inert ingredients; fewer than 10 percent of pesticide products list any inert ingredients on their labels; more than 200 chemicals used as inert ingredients are hazardous pollutants in federal environmental statutes governing air and water quality; and, of a 1995 list of inert ingredients, 394 chemicals were listed as active ingredients in other pesticide products.

A Green Bay example of this problem is Kadant Grantek Inc., at the corner of Liberty and Ashland on the city's west side. This company takes contaminated sludges from Georgia-Pacific Corporation's nearby paper mill. They dry the sludge, pelletize it, and send the pellets to a chemical company in Illinois, where it is used as the carrier "inert ingredient" for mosquito insecticides. Ironically, the original sludge was created as part of a water pollution control process, to prevent waste chemicals from entering an aquatic environment (the Fox River) - but the Kadant Grantek pellets are being spread back into wetlands and other aquatic environments in an effort to kill mosquitos. It's a complete circle. The paper company sludge is contaminated with PCBs, dioxins, toxic metals, and a host of other toxic substances, but people who buy and use the mosquito insecticide will never know this. (Kadant Grantek pellets are also used for kitty litter and as a carrier for livestock pharmaceuticals. Those customers are also uninformed.)

The Pesticide Myth

For 50 years, the public and farmers have been told that chemical pesticides are essential for modern farming and to feed the world's population, when this isn't true. Pesticides weaken the ecosystem which had sustained human agriculture for thousands of years, damaging soil microbes and eliminating beneficial insects and predators. In addition, pests continually mutate to become pesticide resistant. Despite a 10-fold increase in insecticide use in recent years, studies have shown a proliferation in types of pests from fewer than 10 to more than 300. Of the 25 most serious insect pests in California in 1970, 24 were secondary pests (produced because of insecticides) and 73% are resistant to one or more insecticides.

Gardeners, farmers, and foresters need to return to tried and true pest control methods such as crop rotation, companion planting, and biological controls. Integrated Pest Management (IPM), which uses less toxic chemicals, and only infrequently, is the true pest control of the future. Ecological methods of pest control must replace the over-dependence on chemicals that now threatens us all. Numerous studies show that IPM can save significant amounts of money for farmers, at the same time they're protecting their health and environment.

Pesticide Profits

Unfortunately, the chemical corporations have powerful incentives for promoting pesticides despite the harm they create. The pesticide markets are extremely profitable. As of 2013, seven corporations controlled 71% of the global seed market; there used to be hundreds. Many of the top seven seed corporations also dominate the pesticide market, creating a chokehold on the agricultural input sector such that non-genetically engineered seeds become hard to find and they can raise prices at will. In the U.S., these powerful industries also enjoy unprecedented influence over the regulatory system tasked with protecting public health and the environment from the dangers of their products. The world's six largest agrochemical manufacturers had over 75% of global sales in 2013, down from 10 companies in the late 1980s. With the recent merger of Dow AgroScience and DuPont in 2016 and other possible mergers occurring in the future, this percentage is expected to rise. As of August 2016, five agrochemical companies ruled the market. These include: Syngenta, Bayer, Dow and DuPont, BASF, and Monsanto

National Efforts to Reduce Pesticides

Pesticides & Profit -

What’s in a Pesticide? -

Effects of Pesticides -

What is a Pesticide? -

Agrochemical Company Shares and Mergers -

© Clean Water Action Council

P.O. Box 9144

Green Bay, WI 54308

(920) 421-8885

Office location:
A307 MAC Hall, UW-Green Bay
2420 Nicolet Drive
Green Bay, WI 54311