Pesticides have greater impacts on animals, plants, and microorganisms than previously thought

With growing food demand and pest resistance to pesticides, better risk assessment is necessary, say the study’s authors. Pesticides are found in nearly all ecosystems in various mixtures and concentrations, but their effects on non-target organisms remain unclear.  The study was led by Chinese scientists from Shanghai Key Laboratory of Chemical Biology, School of Pharmacy, East China University of Science and Technology, Shanghai, China.

Researchers spent over a decade compiling 1,705 scientific papers for a meta-analysis, offering a comprehensive view on the topic. The authors stress that insights from this quantitative synthesis are crucial for developing a critical framework for pesticide use at national and international levels.

The authors of the study present a synthesis of the effects of 471 different pesticide active ingredients on 830 species of non-target organisms (plants, animals and microorganisms) at different levels in the food chain. According to the study, all organisms, including pollinators, fish and amphibians, show negative responses in their growth, reproduction, behaviour and survival.

Analyses from lab and field experiments show that new EU-approved pesticides have similar effects to older ones. The authors found little evidence that new active ingredients reduce risks.

“The pesticide authorisation process is complex and lengthy. Surprisingly, our study reveals that pesticides have far-reaching non-target impacts,” says Christoph Scherber, deputy director of the LIB and head of the Centre for Biodiversity Monitoring and Conservation Science. “Herbicides, meant to control plants, harm insects, while insecticides in turn may negatively affect plant growth.”

Scherber suggests that the use of pesticides should be re-evaluated due to their numerous side effects. Studies indicate that agricultural biodiversity can reduce pest infestation without these negative impacts. Practices such as co-cultivation of crops and domestic animals, and diversification of agricultural systems, such as intercropping, enhance biodiversity. Additionally, flower strips, fallow land, and hedgerows provide habitats for natural predators and can mitigate wind and water erosion. Scherber: ‘In this way, a diverse agricultural landscape can lead to a more efficient control of herbivorous pest populations and contribute to yield stability.’