A Systematic Review of Studies on Genotoxicity and Related Biomarkers in Populations Exposed to Pesticides in Mexico

Abstract

In agricultural activities, pest control is essential, and the most effective method is the use of chemical agents that also represent an important source of exposure to potentially toxic compounds. Pesticides constitute a heterogeneous group of compounds designed specifically to control different pests. Besides measuring their levels or that of their metabolites in air, plasma, serum, blood, urine, etc., some studies reported increased DNA damage levels after occupational or environmental pesticides exposure, evidenced by several cytogenetic biomarkers such as chromosomal aberrations (CA), sister chromatid exchanges (SCE), micronuclei frequency (MN) together with other nuclear abnormalities (NA), alkaline comet assay, but also changes in oxidative stress parameters and miRNA levels. Single or combined, these techniques have also been used in genotoxic biomonitoring studies of workers occupationally exposed to pesticides in Mexico. Despite being a country with great agricultural activity and reported excessive pesticide use, genotoxic studies have been relatively few and, in some cases, contradictory. A review was made of the studies available (published until the end of 2020 on PubMed, Web of Science, Redalyc and Scielo, both in English and Spanish) in the scientific literature that evaluated occupational exposure of human samples to pesticides assessed with DNA damage and related biomarkers in Mexico.

Effect of Pesticide Exposure over DNA Damage in Farmers from Los Reyes, Michoacan in Mexico

“…Many health problems have been correlated to pesticide contact [ 18 ] and DNA damage. In some countries, like Mexico, there is a lack of information on actual human exposure to different pesticides [ 19 ] and effects at the genetic level in populations occupationally exposed to these compounds [ 8 ].…”

“…They can affect the functioning of various organs and/or systems (nervous, endocrine, reproductive and immune, among others) [ 6 ]. The use of pesticides has also been associated with genetic damage [ 2 , 7 , 8 , 9 ]. Though most biomonitoring and genotoxicity research have been done in advanced nations, they are most relevant to emerging nations.…”

“…In Mexico, around 7 million people work in agriculture and it is estimated that 25.4% of its population may be directly exposed to pesticides. Despite this, few studies have been developed in Mexico and in some cases their results have been contradictory [ 8 ]. Thus, the purpose of the present study is to estimate the possible effects caused by exposure to complex mixtures of pesticides in agricultural workers despite strict standards of protection and hygiene in the handling of pesticides in the Municipality of Los Reyes, State of Michoacán, in Mexico, through the analysis of genetic damage using the comet assay or single-cell alkaline electrophoresis assay in whole blood.…”

Síntomas y signos por exposición directa e indirecta a plaguicidas en habitantes de Bailadores, Municipio Rivas Dávila, Estado Mérida, 2018

“…La exposición ocupacional o directa ocurre en todas las etapas del desarrollo, formulación, fabricación y uso de plaguicidas (Sánchez-Alarcón et al, 2021); no obstante, son los trabajadores agrícolas quienes poseen el mayor riesgo debido a sus prácticas de aplicación y cosecha (Honles et al, 2022). Adicionalmente, la población general que habita en zonas cercanas a las áreas donde se aplican los plaguicidas tambien está expuesta en forma indirecta o pasiva, debido a que estos productos o sus residuos pueden estar presentes en los alimentos y en el agua de consumo (OMS, 2018).…”

The effect of low doses of chlorpyrifos on blood and bone marrow cells in Wistar rats

“…Their harmful effects are mostly mediated by reactive oxygen species (ROS), oxidative tissue damage, or their covalent bonds with cellular macromolecules ( 3 , 4 ). Although the number of studies focused on biological effects of currently used pesticides has increased in the last two decades ( 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 ), the issue of pesticide genotoxicity remains controversial.…”