Photo Protection of Pesticides by UV Absorbers- A Useful Strategy for Reducing Loss: A Review

Pesticide residues are often exposed to sunlight before they diffuse into plants. Many pesticides undergo photodegradation and break down into various photoproducts that may pose risks to living organisms if accidentally ingested. One promising strategy to mitigate pesticide photodegradation is the incorporation of UV light absorbers into their formulations. Significant advancements have been made in protecting both bio-based and synthetic pesticides from ultraviolet (UV) radiation. One of the major limitations in the application of pesticides is their susceptibility to photodegradation, which leads to a significant reduction in their efficacy. The incorporation of UV absorbers into pesticide formulations offers a promising strategy to enhance both their stability and effectiveness. The use of UV absorbers can substantially prolong the environmental persistence and performance of pesticides. As part of this review, we present herein case studies on three representative insecticides, namely Azadirachtin, Chlorpyrifos and Disulfoton. The case studies revealed that UV absorbers play a crucial role in minimizing the photodegradation of pesticides. Specifically, water-soluble quaternary ammonium UV absorbers (QAUVAs) led to a 22-26% increase in the recovery of the insecticide disulfoton compared to samples without UV protection. Similarly, the use of suitable UV absorbers enhanced the post-exposure recovery of azadirachtin and chlorpyrifos by 24% and 30%, respectively. This method not only reduces the need for frequent pesticide applications, thereby lowering associated costs, but also supports environmental sustainability and boosts agricultural efficiency. This review highlights our contributions to advancing pesticide photostabilization through the use of UV Absorbers.