Atrazine is a type of herbicide that is used to selectively control dicot or broadleaf weeds such as velvetleaf, pigweed, and cocklebur in corn and sorghum fields. Selective control allows target weeds to be managed with little or no damage to the crop. It has been found that atrazine can be well tolerated by crops of actively growing sorghum and corn, as they absorb and metabolize it, detoxifying it. In certain areas of the country, up to 90% of corn crops have been treated with atrazine. So, how does this extensive use affect our water supplies?
Why is Atrazine Effective?
Atrazine is considered to be an economical and effective method of reducing crop losses. It is widely used as it can eliminate or significantly reduce the need for inter row cultivation. Atrazine is commonly used in soybean, corn, sugar cane, pine tree, sorghum and pineapple crops. It is also used as a non specific industrial site herbicide.
Atrazine is effective as a weed control measure, but is also relatively nontoxic to animals. The reason for this is that it inhibits the process of photosynthesis in the susceptible plants. This process only occurs in green leaves and plant stems where light is converted into chemical energy. This process does not occur in animals.
Since atrazine is so widely used, it is a concern for water supplies. It also has a relatively long half life of up to 100 days and is not strongly absorbed by the soil.
Acute oral toxicity for atrazine, as per laboratory testing is 5100 mg per kilogram. This would mean that if a 150 pound person ingested 0.75 pounds of atrazine, they would have a 50 percent probability of having a fatal reaction. As a comparison, 2.5 ounces of aspirin or a half pound of table salt offers the same probability of being poisoned.
Chronic toxicity levels are harder to quantify. Since the measurement of chronic effects on lab animals are not feasible, it is difficult to extrapolate the levels of exposure for humans. The EPA has set the Maximum Contaminant Level for atrazine at 3 parts per billion, due to the results of a two generation rat study reporting a mammary tumor. For this reason, the EPA created a 5000 fold safety factor.
Atrazine in Water Supplies:
Atrazine can be detected in groundwater and in most cases this is due to leaching, cleanup activities, atrazine loading or spray loading back siphoning accidents. It is not usually recommended to use atrazine in an area where the mixing of groundwater and surface water could lead to contamination of shallow aquifers. Unfortunately, the EPA database for Pesticides in Groundwater has indicated a number of atrazine detections at concentrations exceeding the MCL in several states including Nebraska.
Although the use of atrazine is common practice, if you are concerned about the impact on your water quality, you should speak to a fully certified WQA water treatment professional. Your professional will be able to discuss the residential water technology options to solve any potential issues.
About The Author, Terry Reeh, EcoWater Systems of Nebraska:
With more than 25 years experience in the residential and commercial water treatment space, Terry is a WQA (Water Quality Association) certified water specialist, LEVEL 3, as well as a WQA certified sales representative. Terry currently sits on EcoWater Systems (a Berkshire Hathaway Company) national Peers committee, as a water treatment expert advising other water professionals with less experience on best trade and technology practices. EcoWater Systems of Nebraska is one of the biggest water treatment and water delivery businesses in the state.