Farmers exposed to pesticides have almost five times more DNA damage: a meta-analysis study

Agricultural exposures and DNA damage in PBMC of female farmers measured using the alkaline comet assay

OBJECTIVE

Several studies investigated the link between agricultural occupational exposures and DNA damage, in an attempt to bring elements of biological plausibility to the increased cancer risk associated with them. However, only a few of these studies focused on females.

METHODS

The comet assay was performed on PBMC (Peripheral Blood Mononuclear Cells) samples from 245 females working in open field farming and cattle raising, located in the Normandy area of France. Individual questionnaires on tasks performed were administered at the time of sampling to directly assess exposures. Environmental exposures were issued from a questionnaire assessing the farm productions. Linear regression analyses were done using the DNA damage scores.

RESULTS

Regarding direct exposures, several tasks associated with exposure to potentially harmful chemicals were not associated with DNA damage, but a longer duration of use of herbicide on meadows (p = 0.05) or of cleaning and upkeep of agricultural equipment (p = 0.06) revealed higher DNA damage levels, although the number of exposed women was low. Several indirect and/or environmental exposures were associated with DNA damage in multivariate analyses: a larger surface of meadows (p = 0.006) or the presence of poultry (p = 0.03) was associated with less DNA damage, while the presence of swine (p = 0.01) was associated with higher DNA damage. Smokers and former smokers had less DNA damage than non-smokers (p = 0.0008 and p = 0.03).

CONCLUSIONS

We report modified levels of DNA damage for those environmentally exposed to meadows, poultry and pig farming, underlining the need for a better knowledge of the potential health risks experienced by females in this setting.

Current status of pesticide effects on environment, human health and it's eco-friendly management as bioremediation: A comprehensive review

Pesticides are either natural or chemically synthesized compounds that are used to control a variety of pests. These chemical compounds are used in a variety of sectors like food, forestry, agriculture and aquaculture. Pesticides shows their toxicity into the living systems. The World Health Organization (WHO) categorizes them based on their detrimental effects, emphasizing the relevance of public health. The usage can be minimized to a least level by using them sparingly with a complete grasp of their categorization, which is beneficial to both human health and the environment. In this review, we have discussed pesticides with respect to their global scenarios, such as worldwide distribution and environmental impacts. Major literature focused on potential uses of pesticides, classification according to their properties and toxicity and their adverse effect on natural system (soil and aquatic), water, plants (growth, metabolism, genotypic and phenotypic changes and impact on plants defense system), human health (genetic alteration, cancer, allergies, and asthma), and preserve food products. We have also described eco-friendly management strategies for pesticides as a green solution, including bacterial degradation, myco-remediation, phytoremediation, and microalgae-based bioremediation. The microbes, using catabolic enzymes for degradation of pesticides and clean-up from the environment. This review shows the importance of finding potent microbes, novel genes, and biotechnological applications for pesticide waste management to create a sustainable environment.

Somatic DNA Damage Response and Homologous Repair Gene Alterations and Its Association With Tumor Variant Burden in Breast Cancer Patients With Occupational Exposure to Pesticides

Homologous recombination is a crucial pathway that is specialized in repairing double-strand breaks; thus, alterations in genes of this pathway may lead to loss of genomic stability and cell growth suppression. Pesticide exposure potentially increases cancer risk through several mechanisms, such as the genotoxicity caused by chronic exposure, leading to gene alteration. To analyze this hypothesis, we investigated if breast cancer patients exposed to pesticides present a different mutational pattern in genes related to homologous recombination (BRCA1, BRCA2, PALB2, and RAD51D) and damage-response (TP53) concerning unexposed patients. We performed multiplex PCR-based assays and next-generation sequencing (NGS) of all coding regions and flanking splicing sites of BRCA1, BRCA2, PALB2, TP53, and RAD51D in 158 unpaired tumor samples from breast cancer patients on MiSeq (Illumina) platform. We found that exposed patients had tumors with more pathogenic and likely pathogenic variants than unexposed patients (p = 0.017). In general, tumors that harbored a pathogenic or likely pathogenic variant had a higher mutational burden (p < 0.001). We also observed that breast cancer patients exposed to pesticides had a higher mutational burden when diagnosed before 50 years old (p = 0.00978) and/or when carrying BRCA1 (p = 0.0138), BRCA2 (p = 0.0366), and/or PALB2 (p = 0.00058) variants, a result not found in the unexposed group. Our results show that pesticide exposure impacts the tumor mutational landscape and could be associated with the carcinogenesis process, therapy response, and disease progression. Further studies should increase the observation period in exposed patients to better evaluate the impact of these findings.

DNA damage in a Chilean population exposed to pesticides and its association with PON1 (Q192R and L55M) susceptibility biomarker

The active ingredients in pesticides are known to be genotoxic that can cause mutations, chromosomal aberrations, or other types of DNA damage. Early detection of genotoxicity reduces the risk of developing diseases such as cancer or suffering from reproductive disorders. In turn, the genotoxic risk depends on the intrinsic capability of the individual to metabolize and eliminate the xenobiotic from the organism. This study aimed to determine if two polymorphisms of paraoxonase-1 (PON1), which is involved in the metabolism of several organophosphate (OP) pesticides, are predictors of susceptibility to DNA damage in agricultural workers and inhabitants of rural areas chronically exposed to pesticides. A cross-sectional study was made considering three groups: agricultural workers (occupational exposure, OE, n = 85), rural inhabitants (environmental exposure, EE, n = 60), and an unexposed group conformed by people living far from agricultural areas (U, n = 33). The level of individual DNA damage was measured using the comet assay, and genotyping was done to determine the PON1 Q192R and L55M polymorphisms. Acetylcholinesterase and butyrilcholinesterase activities were also measured to determine exposure to OP. Individuals belonging to EE and OE groups displayed higher levels of DNA damage compared with U group (p < .001). OP exposure was the main predictor of genotoxicity (β = 16.19; 95% CI: 1.85, 30.52), instead of PON1 polymorphisms (β = -12.20; 95% CI: -27.87, 3.48). These results confirm the genotoxic effects of pesticide exposure and suggest that the catalytic efficiency of PON1 to metabolize OP pesticides becomes negligible in individuals with a history of long-term environmental or occupational exposure to these substances.