In the last decades, the use of pesticides has grown worldwide. However, there is great worry about the impact of pesticides on human health, due to their wide distribution and possible long-term effects. Complex mixtures with different formulations are often used, including a variety of genotoxic compounds. Thus, genotoxicity tests form an important part of cancer research and risk assessment of potential carcinogens. This study aimed to conduct a meta-analytical review of possible genetic damage resulting from occupational exposure in farmworkers and workers employed in pesticide production, both ever in comparison to non-exposed people, using comet assay (CA), micronucleus test (MN) and telomere length (TL) data available in the scientific literature. A total of 145 datasets were evaluated. The results showed that the occupationally exposed workers had more DNA damage in CA and MN than non-exposed workers. The TL result did not show difference between groups. When the data were categorized by gender (male, female or both), crop (general, tobacco, fruits, soybeans, cotton) and occupation (manufacturing or farmworkers), the study found that the exposed group always presented higher damage than the non-exposed individuals, in CA and MN. More studies with TL are needed to obtain a more precise response, and to segregate the effect of tobacco farming from pesticide exposure. When TL was segregated by gender, women and men presented difference between exposed and non-exposed groups. In general, the publication bias impact was modest. If all relevant studies were included, the key finding (i.e. the effect of pesticide exposure increases the genotoxicity and mutation rate) would probably remain unchanged. Lastly, it is important to highlight the importance of the use of personal protective equipment (PPE), and offer safer options to farmworkers (e.g. organic farming or less toxic alternatives).
Occupational exposure to pesticides: Genetic danger to farmworkers and manufacturing workers - A meta-analytical review