Pesticides are widely used toxic contaminants that are common in drinking water supplies across the US. Exposure to pesticides in drinking water can cause severe health effects, including Parkinson's disease and cancer.

Recently hazardous drinking water contaminants such as arsenic, lead and PFAS have come under the spotlight. While these toxins certainly deserve our attention, there is another group of toxic contaminants that are not getting the attention they deserve. Pesticides are widely used in the agricultural industry to protect crops from weeds, insects, mollusks, rodents, and birds, for example, in order to maximize crop yields. These toxic substances are liberally applied to soils, plants and even animals to control pests. The US, which uses 407,779 tons of pesticides annually, is the second largest user of pesticides after China. In the US, pesticides are widely used both in agriculture (on 900,000 farms) and by private households (an estimated 70 million households have at least one pesticide in the home, many have as many as five).

Pesticides by their very nature are designed to be poisonous in order to control the pest species they target. Consequently, they can cause debilitating health impacts when we are exposed to them either directly or indirectly.

Indirect exposure to pesticides occurs when we drink or cook with water that contains pesticides. Glyphosate, for example, is a extremely harmful herbicide that is widely used across the US to control weeds on farms, gardens and recreational facilities. It can leach through soils and get into groundwater, or get carried into surface water systems used as a source of drinking water with rainwater runoff. As glyphosate is soluble in water, boiling water will not remove it.

According to Water Online, pesticides have been detected in 41% of wells that supply households with drinking water, including private wells that are not regulated by the Safe Drinking Water Act.

Health Impacts Associated with Pesticide Exposure

The health impacts of pesticide exposure vary according to the substance you have been exposed to. Atrazine and simazine are the two most common pesticides found in drinking water. Both these pesticides are regulated by the EPA, with atrazine having a maximum allowable limit of 3 parts per billion (ppb) and simazine 2 ppb. However, many other toxic pesticides occur in drinking water, yet they are unregulated and therefore not monitored, which is reason for concern.

It typically takes several years of exposure to pesticides before health effects start showing up. Ultimately, the health risk depends on how toxic the pesticide is, the level of contamination in drinking water, and the frequency and levels exposed to daily when drinking contaminated water.

Exposure to pesticides in drinking water has been linked with health conditions such as cancer and neurological conditions. Paraquat — a highly prevalent pesticide used to control pests on crops such as almonds, citrus, corn, garlic, grapes, peanuts, pears, soy and wheat — is a water soluble pesticide that has been shown to cause severe health conditions, including Parkinson's disease. Paraquat damages the region of the brain that controls the release of dopamine - a neurotransmitter that sends messages to the part of the brain that controls body movement and coordination. Loss of control of movement and coordination are key symptoms in people suffering from Parkinson's disease, which is irreversible, typically gets worse as time goes by, and sadly has no known cure.

How Can We Minimize Exposure to Pesticides in Drinking Water?

The EPA monitors and regulates a long list of contaminants commonly found in drinking water, including some pesticides, but many remain unmonitored and unregulated. Municipal drinking water systems typically chlorinate water to kill pathogenic microbes, but this process only removes around 60% of the pesticides found in water. If you are concerned about pesticides in the water you use for drinking or cooking, you can invest in a good quality home water filter fitted activated carbon filter cartridges. The Berkey wataer filter is fitted with Black Berkey activated carbon purification elements and can remove common pesticides such as glyphosate and atrazine.