New-generation pesticides are often developed to replace earlier, more toxic chemicals in effort to clean up the environmental and human health impacts of these older agricultural pesticides. However, it is important to continually monitor impacts of all pesticides and indeed, a recent study published in Science of the Total Environment found that new-generation pesticides are the most prevalent chemicals detected in streams in an intensive agriculture region of California. These chemicals were designed to replace harmful organophosphate pesticides linked to many environmental and human health issues. Using an older, common method as well as a newly developed method aimed at detecting new pesticide formulas, researchers screened samples from 85 streams for 223 different pesticide compounds. 83 streams (98%) tested positive for at least one pesticide, and 81% of the samples tested positive for two or more pesticides. One third of the samples detected 10+ pesticides. Nearly half of the 253 pesticides were detected at least once, indicating that a wide variety of chemicals continues to be used and contaminate nearby waterways.

The most commonly detected pesticide was a new-generation diamide insecticide, and the top six most commonly detected chemicals were new-generation pesticides. When the potential toxicity of the detected pesticides was assesses, the researchers found more potential toxicity to invertebrates than fish or plants, largely because the majority of pesticides detected were insecticides. Because of the common occurrence and potential toxicity of these new-generation pesticides the researchers recommend that monitoring methods be continuously updated and efforts remain vigilant to comprehensively assess pesticide occurrence and impacts on non-crop habitats.

For more details see recent blog post by inside climate news on this topic.

Banner Photo Credit:  Yulian Alexeyev; unsplash.com