Assessment of exposure to pesticides in rural workers in southern of Minas Gerais, Brazil

Glyphosate contamination of drinking water and the occurrence of oxidative stress: Exposure assessment to rural Brazilian populations

Studies reported that continuous application of glyphosate can cause disturbance in aquatic/terrestrial environments. As such, the objective of this study is to discuss the risk of exposure to the herbicide in drinking water and to assess the oxidative stress in the consumers rural populations of Casimiro de Abreu/ RJ and Paraguaçu/ MG, Brazil. For this, water samples (n=69) were analysed from the home of volunteers, by FMOC derivatizing- LC-FLD method. The oxidative stress was analysed determining lipid peroxidation (MAD) and defense enzymes (SOD and CAT) in serum samples from rural population (n=42) compared to urban residents (n= 42). Results of the analysis from drinking water, despite the low and moderate risk, by the hazard quotient (HQ), revealed that the population is environmentally exposed to the glyphosate. The relevant findings showed that is important to implement monitoring/ biomonitoring programs to prevent pollution and toxic effects in the rural populations.

Biomonitoring and risk assessment of human exposure to triazole fungicides

Risk assessment and biomarkers were evaluated in volunteers exposed to triazole fungicides in southern Minas Gerais, Brazil. Volunteers were divided into two groups: occupationally and environmentally exposed to pesticides (n = 140) and those unexposed (n = 50) from urban areas. Urine samples were analyzed by GC-MS for triazoles, and samples from men and women in the exposed group were quantified. Groups were further stratified by sex to evaluate the biomarkers results. Oxidative stress was indicated by biomarker analysis for occupationally exposed men with elevated malondialdehyde levels and reduced superoxide dismutase and catalase activity (p < 0.0001). Bile acid levels were also elevated in the exposed group (p < 0.0001). Biomarkers in this study suggest recent, reversible changes due to pesticide exposure. Liver enzyme levels showed no significant differences. The highest Estimated Daily Intake for epoxiconazole ranged from 0.534 to 6.31 μg/kg-bw/day for men and 0.657-8.77 μg/kg-bw/day for women in the exposed group. Considering the highest detected urinary triazole value, the calculated Hazard Quotient for epoxiconazole was 0.789 for men and 1.1 for women. Results indicate a health risk associated with environmental triazole exposure, highlighting the importance of biomonitoring in risk assessment to prevent intoxication and assist in mitigating adverse health effects from chronic pesticide exposure.

Urinary dialkylphosphate metabolites in the assessment of exposure to organophosphate pesticides: from 2000 to 2022

The general population and workers are exposed to organophosphate insecticides, one of the leading chemical classes of pesticides used in rural and urban areas, in the control of arboviruses and agriculture. These pesticides cause environmental/occupational exposure and associated risks to human and environmental health. The objective of this study was to carry out an integrative review of epidemiological studies that identified and quantified dialkylphosphate metabolites in the urine of exposed populations, focusing on the vector control workers, discussing the application and the results found. Searches utilized the Pubmed, Scielo, and the Brazilian Digital Library of Theses and Dissertations (BDTD) databases between 2000 and 2021. From the 194 selected studies, 75 (39%) were with children/adolescents, 48 (24%) with rural workers, 36 (19%) with the general population, 27 (14%) with pregnant women, and 9 (4%) with vector control workers. The total dialkylphosphate concentrations found in the occupationally exposed population were higher than in the general population. Studies demonstrate that dialkylphosphates are sensitive and representative exposure biomarkers for environmental and occupational organophosphate exposure. The work revealed a lack of studies with vector control workers and a lack of studies in developing countries.

Assessment of cellular damage with cytome assay among environmental/occupational triazole

The use of triazole fungicides is common in Minas Gerais, Brazil. However, the risk arising from excessive and often unprotected exposure can be harmful to farmers. Therefore, we evaluated volunteers, exposed to triazole fungicides for cellular damage caused by this pesticide. In the buccal micronucleus cytome assay (BMCyt), cells were analyzed. Urinary triazoles were analyzed by the Liquid-Liquid Extraction coupled with Gas-chromatography/mass-spectrometry (LLE-GC/MS). Statistical differences were found for all cell types evaluated in residents of rural areas (n = 145). Analysis of variance showed statistical difference in kariolytic and pyknotic cells, between the groups of men and women living in rural areas, with higher incidence in the male group. Likewise, higher concentrations triazoles in urine samples in the male group were observed. Greater cellular damage suggests increases in DNA damage, chromossomal instability and cell deaths. The results showed the urgency of the public management with the implementation of measures to minimize the pesticides exposure.

Genetic instability in farmers using pesticides: A study in Brazil with analysis combining alkaline comet and micronucleus assays

The use of pesticides to prevent and control pests also increases food production. Pesticides are widely used by contemporary farmers, especially in Brazil, where the economy is based on agriculture. The objective of this study was to evaluate the genotoxic potential of pesticide use in rural workers in Maringá, Paraná, Brazil. DNA damage in whole blood cells was measured by the comet assay, while the frequency of cell types, abnormalities, and nuclear damage was estimated using the buccal micronucleus cytome assay. Samples of buccal mucosa were collected from 50 male volunteers (27 not exposed to pesticides and 23 occupationally exposed to pesticides). Among them, 44 volunteered for blood sampling (24 unexposed and 20 exposed). In the comet assay, the exposed farmers had a higher damage index than non-exposed ones. There were also statistically significant differences between the groups in the buccal micronucleus cytome assay. Farmers exhibited an increase in basal cell numbers, and cytogenetic alterations, represented by condensed chromatin and karyolitic cells. Comparisons between cell morphologies and epidemiological factors indicated an increased number of condensed chromatin and karyolitic cells in individuals who were responsible for preparation and transportation of pesticides to agricultural machines. Thus, the participants in this study who were exposed to pesticides were more sensitive to genetic damage, and thereby, more susceptible to diseases resulting from such damage. These results demonstrated that health policies should be developed for pesticide-exposed farmers to better mitigate risks and damage to their health.

Disturbance of cellular calcium homeostasis plays a pivotal role in glyphosate-based herbicide-induced oxidative stress

Glyphosate-based herbicides (GBHs) are the most worldwide used pesticides. The wide application of GBHs contaminates the soil and, consequently, water and food resources reaching human consumption. GBHs induce oxidative stress in non-target organisms, leading to a pro-inflammatory and pro-apoptotic cellular status, promoting tissue dysfunction and, thus, metabolic and neurobehavioral changes. This review presents evidence of oxidative damage induced by GBHs and the mechanism of cell damage and health consequences. To summarize, exposure to GBHs may induce disorders in calcium homeostasis related to the activation of ion channels. Also, alterations in pathways related to redox state regulation must have a primordial role in oxidative stress caused by GBHs.

Degradation of Praguicide Disulfoton Using Nanocompost and Evaluation of Toxicological Effects

Organophosphates (OPPs) are an important element of modern agriculture; however, because they are being used excessively, their residues are leaching and accumulating in the soil and groundwater, contaminating aquatic and terrestrial food chains. An important OPP called disulfoton is frequently used to eradicate pests from a wide range of crops, including Brazil's coffee crops. Additionally, it does not easily degrade in the environment, and as such, this compound can slowly build up in living organisms such as humans. Moreover, this compound has been classified as "extremely hazardous" by the World Health Organization. This study evaluated the degradation efficiency of disulfoton using a Fenton-like reaction catalyzed by magnetite nanoparticles and determined the toxicity of the by-products of the degradation process using the bioindicator Allium cepa. Further, the removal efficiency of disulfoton was determined to be 94% under optimal conditions. On the other hand, the Allium cepa bioassay showed different toxic, cytotoxic, genotoxic, and mutagenic outcomes even after the remediation process. In conclusion, the Fenton process catalyzed by magnetite nanoparticles presents great efficiency for the oxidation of disulfoton. However, it is important to highlight that the high degradation efficiency of the Fenton-based process was not sufficient to achieve detoxification of the samples.

Occupational exposure to pesticides and its association with telomere length - A systematic review and meta-analysis

BACKGROUND

Telomere length is a common biomarker for the cumulative effect of environmental factors on aging-related diseases, therefore an association has been hypothesized between occupational exposure to pesticides and shorter telomere length.

OBJECTIVE

This study is a systematic review and meta-analysis aiming to examine the association between telomere length and occupational exposure to pesticides.

METHODS

We systematically searched in SciELO, PubMed, Scopus, Embase, Cochrane, Lilacs, Science Direct, and Web of Science databases for all observational studies containing measurements of telomere length on groups occupationally exposed to pesticides. Data were synthesized through qualitative synthesis and meta-analysis. We estimated the associations between exposed and non-exposed groups by using the natural log of the response ratio (lnRR). Heterogeneity was quantified using the Cochran Q test and I² statistics.

RESULTS

Six studies were included in the qualitative synthesis and meta-analysis, with a total of 480 participants exposed to pesticides. The time of exposure evaluated 391 participants that had a range of 5 to >30 years of occupational exposure. Most studies presented shorter telomere length in the occupationally exposed group. From the six studies included in the meta-analysis, three presented telomere length measurement as a single copy gene (T/S), and three presented telomere length measurement as base pairs (bp). The statistical analysis pooled estimates (log ratio of means) of the telomere length in both measurements (T/S and bp) showed a shortening of telomere length in the exposed group when compared with the non-exposed (control) group. Two of six studies reported longer telomere length in the group exposed to pesticides.

DISCUSSION

Our findings suggest an association between occupational exposure to pesticides and shorter telomere length. However, we found a small number of studies to include in our meta-analysis, being required more high-quality studies to strengthen our findings and conclusions.

Health Effects of Pesticide Exposure in Latin American and the Caribbean Populations: A Scoping Review

BACKGROUND

Multiple epidemiological studies have shown that exposure to pesticides is associated with adverse health outcomes. However, the literature on pesticide-related health effects in the Latin American and the Caribbean (LAC) region, an area of intensive agricultural and residential pesticide use, is sparse. We conducted a scoping review to describe the current state of research on the health effects of pesticide exposure in LAC populations with the goal of identifying knowledge gaps and research capacity building needs.

METHODS

We searched PubMed and SciELO for epidemiological studies on pesticide exposure and human health in LAC populations published between January 2007 and December 2021. We identified 233 publications from 16 countries that met our inclusion criteria and grouped them by health outcome (genotoxicity, neurobehavioral outcomes, placental outcomes and teratogenicity, cancer, thyroid function, reproductive outcomes, birth outcomes and child growth, and others).

RESULTS

Most published studies were conducted in Brazil (37%, n = 88 ) and Mexico (20%, n = 46 ), were cross-sectional in design (72%, n = 167 ), and focused on farmworkers (45%, n = 105 ) or children (21%, n = 48 ). The most frequently studied health effects included genotoxicity (24%, n = 62 ) and neurobehavioral outcomes (21%, n = 54 ), and organophosphate (OP) pesticides were the most frequently examined (26%, n = 81 ). Forty-seven percent (n = 112 ) of the studies relied only on indirect pesticide exposure assessment methods. Exposure to OP pesticides, carbamates, or to multiple pesticide classes was consistently associated with markers of genotoxicity and adverse neurobehavioral outcomes, particularly among children and farmworkers.

DISCUSSION

Our scoping review provides some evidence that exposure to pesticides may adversely impact the health of LAC populations, but methodological limitations and inconsistencies undermine the strength of the conclusions. It is critical to increase capacity building, integrate research initiatives, and conduct more rigorous epidemiological studies in the region to address these limitations, better inform public health surveillance systems, and maximize the impact of research on public policies. https://doi.org/10.1289/EHP9934.

Children Environmentally Exposed to Agrochemicals in Rural Areas Present Changes in Oxidative Status and DNA Damage

Rural children are exposed to several chemicals. This study evaluated the environmental co-exposure of rural children to cholinesterase inhibitor insecticides and metals/metalloids, and the resulting oxidative stress and DNA damage. Seventy-two children (5 to 16 years old) were studied at two different moments: period 1, when agrochemicals were less used, and period 2, when agrochemicals were extensively used in agriculture. Biomonitoring was performed by evaluating butyrylcholinesterase (BuChE) activity in serum; arsenic (As), chromium (Cr), lead (Pb), and nickel (Ni) levels in blood; malondialdehyde (MDA) in plasma; glutathione peroxidase (GSH-Px) and glutathione S-transferase (GST) activities in whole blood; non-protein thiol levels in erythrocytes; and micronuclei (MN) assay in exfoliated buccal cells. Cr and As levels were higher than the reference values in both periods, and Ni levels were higher than the reference values in period 2 alone. BuChE activity was inhibited in period 2 compared with period 1. In period 2, there was an increase in endogenous antioxidants and a decrease in MDA, probably demonstrating a compensatory mechanism as a response to increasing xenobiotics. Also in period 2, the MN frequency increased and BuChE and As were positively associated, suggesting co-exposure. On the other hand, in period 1, it was observed that Cr, Ni, and Pb blood levels were negatively associated with GSH-Px and GST, while MDA was positively associated with As levels. Our findings demonstrated an imbalance in endogenous antioxidants, contributing to genotoxicity and lipoperoxidation, probably in response to exposure to xenobiotics, especially carcinogenic elements (Cr, As, and Ni).

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.

Brazilian workers occupationally exposed to different toxic agents: A systematic review on DNA damage

The evaluation of genotoxicity in workers exposed to different toxic agents is very important, especially considering the association between these exposures in a chronic context and DNA damage. Assessing biomarkers of exposure and, when possible, early biomarkers of effect, contributes to elucidating the potential toxic mechanisms involved in genotoxicity and its contribution to chronic non-communicable diseases. In Brazil, the biggest country in South America, workers are exposed to hazardous physical and chemical agents. Considering that these exposures occur, in most cases, throughout the worker's whole life, this is an important public health concern in Brazil. Therefore, this systematic review aims to analyze occupational exposure to chemical and physical agents and the association with DNA damage in studies carried out in Brazil from 1980 to 2021. A systematic and comprehensive literature search was performed in different databases based on occupational exposure to chemical and physical agents and DNA damage. Only full articles on studies that investigated experimental evidence on occupational exposure in Brazil and assessed DNA damage were included, amounting to 89 articles. Five main occupational exposure groups were identified: pesticides (36%), organic solvents (20%), dust and particles (16%), metals (11%), and ionizing radiation (6%). Another group called "others" included studies (11%) that did not fall into these main groups. It was found that comet assay and micronucleus tests are the most adopted methods to detect DNA damage. Occupational exposures were most associated with DNA damage. However, further improvements in study design would be needed to better characterize the association between biomonitoring and DNA damage, particularly to account for confounding factors.

Respiratory, hepatic, renal, and hematological disorders among adolescent females environmentally exposed to pesticides, Menoufia governorate, Egypt

Adolescent females are often environmentally exposed to pesticides by living near agricultural fields, by using pesticides at home, or by having contact with contaminated clothes and pesticide application work tools. This study assessed respiratory, hepatic, renal, and hematological health disorders that might arise due to environmental exposure to pesticides among adolescent females. A cross-sectional study was conducted with 100 adolescent females environmentally exposed to pesticides that had one or more of their family members working as seasonal pesticide applicators and 50 nonexposed (control) adolescent females from Menoufia governorate, Egypt. The studied period of pesticide application season of the cotton crop was from May 1 to September 1, 2017. Participants completed a self-administered questionnaire about pesticide exposure and respiratory, hepatic, renal, and hematological disorders. In addition, serum acetylcholinesterase (AChE), spirometry, complete blood count, and liver and kidney function tests were measured pre and post-pesticide application season. The control adolescent females had a higher AChE activity, a lower prevalence of respiratory symptoms, and higher means of spirometric measurements than the exposed group. During the pre- and postseason, the exposed group presented a prevalence of (6%, 24%) for cough, (4%, 11%) for rhinitis, and (6%, 26%) for dyspnea during the pre and postseason, respectively. In addition, there was a decrease in means of spirometric measurements (FEV₁%, FEV₁/FVC%, FEF _25-75%, and PEF%) in the postseason compared to preseason among the exposed group. Also, there were significant associations between (AChE) activity and both the prevalence of respiratory manifestations and spirometric measurements among the exposed females. On the other hand, there was a statistically significant increase in red blood corpuscle (RBC) and lymphocyte counts, and a statistically significantly lower mean hemoglobin level among the exposed group (postseason) than each of their pre-season values and the control group (P < 0.05). AChE level, total protein, albumin, and albumin/globulin (A/G) ratio levels were statistically significantly lower, while SGPT, SGOT and globulin, blood urea, and serum creatinine mean levels were statistically significantly higher among the exposed group (postseason) than either of their preseason or the control group (P < 0.05). There was a positive correlation between the AChE level and all studied CBC parameters for the exposed group reaching a statistically significant level with basophils (P < 0.05). Also, there was a negative correlation between the AChE level and each of SGPT, SGOT, ALP, globulin, blood urea, and serum creatinine for the exposed group reaching a statistically significant level with each of SGPT and SGOT (P < 0.05). At the same time, a nonsignificant positive correlation was found between AChE level and each of total protein, albumin, and A/G ratio (P > 0.05). So, environmental exposure to organophosphorus pesticides has a detrimental impact on respiratory, hepatic, renal, and hematological systems of adolescent females living in rural districts at the Menoufia governorate. Educational and training intervention programs on pesticide handling and safety precautions are recommended for protecting both pesticide workers and their family members who might be exposed.

Degradation of toxic agrochemicals and pharmaceutical pollutants: Effective and alternative approaches toward photocatalysis

Emerging concern regarding the remediation of environmental pollution has expanded tremendously in recent years. Pharmaceutical industries and agricultural sectors release an enormous amount of residues containing toxic pollutants at trace levels which poses a serious impact on the environment and human health. To cope with the effect of hazardous and toxic contaminants, numerous methodologies have been developed for the treatment of effluents released from the agrochemical and pharmaceutical industries. Amongst them, photocatalysis has gained much more attention for the degradation of pollutants due to its low cost, higher capability, green and eco-friendly approaches. Photocatalysts are the substrate that plays a key role in pollutant removal through photocatalysis by accelerating the necessary chemical reactions using a light source. In this review, the recent progress on photocatalysis and its fundamental mechanism in agrochemicals and pharmaceutical pollutant degradation was summarized. This review concisely discusses the incorporation of various metal oxides and nanomaterials into semiconductors for the effective degradation of contaminants. The current status and future research on different sectors and the difficulties in the photocatalytic removal of agrochemical and pharmaceutical pollutants are also reviewed in detail.

Methylation patterns of the CDKN2B and CDKN2A genes in an indigenous population exposed to pesticides

The INK4 -ARF locus includes the CDKN2B and CDKN2A genes and is functionally relevant in the regulation of both cell proliferation and senescence. Studies have reported modifications of DNA methylation in this locus by exposure to environmental contaminants including pesticides; however, until now, specific methylation profiles have not been reported in genetically conserved populations exposed to occupational pesticides. The aim of this study was to determine the methylation profiles of the CDKN2B and CDKN2A genes in a genetically conserved population exposed to pesticides. A cross-sectional and analytical study was carried out in 190 Huichol indigenous persons. Information related to pesticide exposure, diet and other variables were obtained through the use of a structured questionnaire. Blood and urine samples were collected for methylation test and dialkylphosphates (DAP) determination, respectively. DNA methylation was measured by the pyrosequencing of bisulfite-treated DNA and DAP concentrations by gas chromatography-tandem mass spectrometry (GC/MS). The most frequent metabolite in the population was dimethylthiophosphate. The farmer group presented a higher methylation percentage of CDKN2B than the non-farmer group, but no differences in CDKN2A were observed between groups. A positive correlation between methylation of CpG site 3 of CDKN2B and time working in the field was observed in the farmer group. An association between methylation percentage of CDKN2B and age was also observed in the non-farmer group. These results suggest that pesticide exposure and exposure time in Huichol indigenous individuals could modify the methylation pattern of the CDKN2B gene.

Pesticide exposure and genotoxic effects as measured by DNA damage and human monitoring biomarkers

Occupational pesticides exposure rises health concern due to genotoxicity and accumulation of pesticides in human biological matrices. Continuous and sublethal exposure to pesticides had been associated with oxidative stress, mutagenic and cell death. Exposure to pesticides exhibits increased level of DNA damage even if no detectable amounts of pesticides are seen in biological matrices by binding specific areas in the DNA. This interferes normal body systems and mutation in gene encoding specific activities which may lead to a wide range of cancer. Presence of pesticides compounds in human biological matrices had been evident from various studies. However, detection methods are complex and inconsistent, making it difficult to compare and generalize findings. This article provides insight into genotoxic effects, presence of pesticides and their metabolites in human biological matrices and the resultant health effects as measured by DNA damage, acetylcholinesterase (AChE) activity inhibition and other biomarkers of pesticides exposure.

Identification of pesticides in water samples by solid-phase extraction and liquid chromatography-electrospray ionization mass spectrometry

The Contaminants of Emerging Concern (CECs), including pesticides, have been a trending topic and Brazil is the country with the highest usage of pesticides worldwide. This study aimed to measure the presence of pesticide residues in the water from different sources in the city of Porto Alegre. We analyzed 55 samples from drinking water treatment plants, public water sites, and sewage treatment plants from winter 2018 to summer 2020 by solid-phase extraction and high-performance liquid chromatography-electrospray ionization mass spectrometry. Among 184 pesticides evaluated, 107 matched validation criteria (linearity, trueness, accuracy, repeatability, reproducibility) and 15 of them were detected in different water samples, including seven insecticides, five antifungals, and three herbicides, with a wide range of toxicity levels and noticeable seasonal differences. For the worst-case scenario evaluation, 20 out of 22 (90.9%) samples exceeded the Risk Quotient of 1. The sum of pesticide concentrations exceeded 100 ng L^-1 in 66.7% of samples in February 19 and in 75% of samples in February 20 and the total pesticide concentration has reached the worrisome mark of 1615 and 954.96 ng L^-1 respectively. Therefore, our results make evident the need to promote public policies to achieve better water quality monitoring. PRACTITIONER POINTS: Among 184 pesticides evaluated, 107 matched validation criteria (linearity, trueness, accuracy, repeatability, reproducibility). A total of 55 different water samples were analyzed, and 15 pesticides were detected and five quantified. For the worst-case scenario evaluation, 20 out of 21 samples exceeded the Risk Quotient of 1 on Feb/20. The pesticide concentrations sum exceeded 100 ng L^-1 in 66.7% of samples on February 19 and in 75% of samples on February 20. It is mandatory to improve water monitoring to guide the development of public policies concerning its quality.

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

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.

Endpoints as human biomarkers in exposure assessment of triazoles fungicides

Potential endpoint biomarkers were evaluated in the assessment of exposure to triazoles, in the southern region of Minas Gerais, Brazil. Volunteers were divided into three groups: occupationally exposed and rural residents (n = 21), non-occupationally exposed and rural residents (n = 35) and non-occupationally exposed and urban residents (n = 30). Of all endpoints evaluated, plasma concentration of androstenedione (p < 0.001) and glycine-conjugated bile acids presented statistical differences in the three studied groups (p < 0.05). However, our findings concerning oxidative stress and testosterone levels, plus that related to unconjugated and taurine conjugated bile acids, suggested that more studies are necessary to evaluate their potential as biomarkers for triazole exposure, as statistical significance was not attained between the groups. Our human population data contributes to the development of triazole exposure risk assessment with respect to these potential effect biomarkers, in potentially vulnerable groups and individuals.

Assessment of Cytogenetic Damage and Cholinesterases' Activity in Workers Occupationally Exposed to Pesticides in Zamora-Jacona, Michoacan, Mexico

Pesticides have been considered as potential chemical mutagens; however, little is known about toxic and genotoxic effects during pesticide application in Zamora-Jacona, Michoacan State in Mexico. This study sought to determine DNA damage and cholinesterase activities inhibitions in 54 agricultural workers exposed to complex mixtures of pesticides vs. control group (26 individuals) using Comet assay in peripheral whole blood, micronucleus (MN) test in oral mucosa cells, Cytokinesis-blocked MN assay in lymphocytes (L-CBMNcyt) and measuring AChE and BChE activities in whole blood and plasma samples, respectively. Exposed subjects demonstrated significantly elevated levels of primary (Comet assay: tail intensity, tail length, tail moment, Olive tail moment) and permanent DNA damage (MN assay: in blood/buccal cells; frequencies of nuclear buds, binucleated cells, cells with condensed chromatin, karyorrhexis, pyknosis, and karyolysis). However, inhibition of cholinesterase activities (AChE and BChE) was not observed in the workers. Confounding factors including sex, age, BMI, working exposure period, protection level, smoking habit (cigarettes per day units), alcohol consumption (weekly), medication, were considered in the analysis. These combined techniques demonstrated usefulness in the health hazards risks pesticide exposure assessment and suggested the need for periodic monitoring together with the education and the training of occupational workers for the safe application of potentially harmful pesticides.

Occupational use of agrochemicals results in inhibited cholinesterase activity and altered reproductive hormone levels in male farmers from Buea, Cameroon

The efficiency of agro pesticides and fertilizers in eliminating pests and scaling up crop yield has motivated farmers to increase their use. Unfortunately, health hazards caused on farmers by these agrochemicals are of growing concern, though not well elucidated. In order to evaluate the effects of occupational exposure to agrochemicals on some key parameters of male farmers' health in Buea Subdivision, Cameroon, a total of 101 men, including 62 farmers using the agrochemicals and a reference population of 39 men not involved in occupational utilization of the agrochemicals, were interviewed on use of protective equipment, exposure symptoms and reproductive health status. Thereafter, serum cholinesterase [acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE)] activities, total antioxidant capacity and reproductive hormones [follicle-stimulating hormone (FSH), luteinizing hormone and testosterone] were assessed. Results revealed that farmers mainly used insecticides followed by fungicides, herbicides and fertilizers, but with inadequate protective measures. The use of agrochemicals resulted in several exposure symptoms including weakness, itches, burning sensation, headache, sneezing, coughing and vomiting, as well as decrease in serum AChE activity when compared to the reference population. The agrochemicals impacted negatively on the farmers' reproductive health as evidenced by increased FSH levels. Taken altogether, these results suggested that exposure to agrochemicals adversely affects farmers' health. Therefore, there is a need to further sensitize the farmers on the use of protective equipment to mitigate the exposure and resulting health hazards.

Multi-biomarker responses to pesticides in an agricultural population from Central Brazil

We evaluated farmworkers exposed to pesticides and individuals with no history of occupational exposure to pesticides. It was performed the comet assay to evaluate DNA damage. The immunophenotyping of TCD4⁺ lymphocyte subpopulations in peripheral blood was performed by flow cytometry. The single nucleotide polymorphisms (SNPs) in PON1, XRCC1, IL6, IL6R, TNF-α, and MIR137 genes were evaluated by real-time PCR. The exposed group was composed mostly by males (69.44%), with direct exposure to pesticides (56%) and with an average age range of 46 ± 13.89 years, being that 58.3% of farmworkers directly exposed to pesticides and reported the full use of personal protective equipment (PPE). DNA damage was greater in the exposed group (p < 0.05), reinforced by the use of PPE to denote a lower degree of DNA damage (p = 0.002). In this context, in the exposed group, we demonstrated that the use of PPE, age, gender and intoxication events were the variables that most contributed to increase DNA damage (p < 0.0001). Besides, the exposed group showed a significant increase in the subpopulations of T lymphocytes CD3⁺CD4⁺ (p < 0.05) and CD3⁺CD4⁺CD25⁺ (p < 0.0001) and a significant decrease in CD3⁺CD4⁺CD25^-FOXP3⁺ (p < 0.05). SNPs in the TNF-α (rs361525) gene presented a difference in the genotype distribution between the groups (p = 0.002). The genotype distribution of TNF-α (rs361525) was also positively correlated with the DNA damage of the exposed group (r = 0.19; p = 0.01), demonstrating a higher risk of DNA damage in the farmworkers presenting the A mutated allele. Our findings demonstrate that pesticides can exert various deleterious effects on human health by damaging the DNA as well as by influencing the immune system in the case of both direct or indirect exposure and these issues are associated to age, gender, intoxication and the nonuse of PPE.

Occurrence of pesticides in waters from the largest sugar cane plantation region in the world

In this study, a multi-residue method was used to analyze 13 pesticides and 1 degradation product in surface and groundwater in the region with the largest sugar cane production in the world. The potential effects of individual pesticides and their mixtures, for aquatic life and human consumption, were evaluated. For the surface water, 2-hydroxy atrazine, diuron, carbendazim, tebuthiuron, and hexazinone were the most frequently detected (100, 94, 93, 92, and 91%, respectively). Imidacloprid (2579 ng L^-1), carbendazim (1114 ng L^-1), ametryn (1101 ng L^-1), and tebuthiuron (1080 ng L^-1) were found at the highest concentrations. For groundwater, tebuthiuron was the only quantified pesticide (107 ng L^-1). Ametryn, atrazine, diuron, hexazinone, carbofuran, imidacloprid, malathion, carbendazim, and their mixtures presented risk for the aquatic life. No risk was observed for the pesticides analyzed in this work, alone or in their mixtures for human consumption.

Biochemical, hematological and immunological parameters and relationship with occupational exposure to pesticides and metals

This study aimed to evaluate biomarkers of exposure to cholinesterase inhibitors insecticides (AChE and BuChE activities) and metals (As, Cd, Cr, Mn, Ni, and Pb blood levels) and their associations with biochemical, hematological, and immunological parameters in farmers from Southern Brazil. One hundred and sixteen individuals were divided into two groups: 62 farmers (exposed group) and 54 subjects non-occupationally exposed (NOE) to agrochemicals. Erythrocyte (AChE) and serum (BuChE) cholinesterases activities were significantly reduced as well as blood Cd and Pb levels were increased in farmers when compared to NOE group (p < 0.05). Farmers presented increased glucose and urea levels compared to NOE group, which were inversely associated with AChE and positively correlated with Cd (p < 0.05), respectively. In addition, Cd was inversely associated with the hematological cells counts, which were significantly reduced in farmers (p < 0.05). C3 complement was higher in farmers and was positively associated with blood Pb (p < 0.05). Surface protein expression analysis revealed a downregulation of LFA-1 and ICAM-1 in farmers. Inverse associations were found between LFA-1 and blood As, Cr, and Ni levels (p < 0.05). Taken together, our results pointed to a relationship between agrochemicals and metals exposure and biochemical, hematological, and immunological disorders that can lead to several chronic conditions.

Considerations for cholinesterase biomonitoring in flower and ornamental plant greenhouse workers

Flower cultivation in greenhouses enhances productivity and ensures high-quality product supply throughout the year. However, under such protected environments, climate conditions are designed to favor flower growth and can intensify occupational exposure to pesticides. In this study, flower greenhouse workers were tested for cholinesterase inhibition, a valuable indicator of occupational exposure to organophosphate and carbamate pesticides. The quantified inhibition was also associated with working practices using these outcomes to explore ways in which provisions of regulatory Occupational Health Control Programs can be met considering the peculiarities of this working environment. Despite their preliminary nature, and considering that workers had not been previously tested, the obtained results suggested that the designed pre- and post-screening process, enabled biomonitoring of the exposed population. The pre-exposure sample was collected after 11 days from pesticide spraying and the post-exposure sample was collected no later than 10 days after pesticide spraying. AChE activity was significantly depressed in flower greenhouse workers, comparing pre- and post-exposure intervals. Nursery workers, often overlooked, presented greater inhibition of AChE activity. Such finding is consistent with effects believed to be associated with the described job and the way activities are conducted, once nursery workers are regularly exposed to low levels of pesticides owing to their continuous contact with sprayed crops. As predicted by Occupational Safety and Health Standards, establishing biomonitoring programs is achievable, despite the intensive use of pesticides. Quantification is important to target the exposed population but is not sufficient to assure good working conditions and avoid exposure. Administrative and working practices, such as job misclassification, non-compliance with national regulations for occupational health control, pesticide handling, lack of REI protocols, and unsuitable delivery of PPE, must be addressed. Anything less will contribute to worsening an already bleak picture in terms of occupational safety and health in flower and ornamental plant greenhouses.

Pesticide Use and Serum Acetylcholinesterase Levels among Flower Farm Workers in Ethiopia-A Cross-Sectional Study

The flower industry in East Africa has grown in recent years, especially in the production and export of roses. The aim of this study was to assess pesticide use on selected flower farms in Ethiopia. Serum cholinesterase levels in workers were used as a marker of pesticide exposure. This study was a cross-sectional study involving 588 workers from 15 different flower farms. It had a response rate of 95.5%. The participants included 277 males (mean age 26 years; 148 pesticide sprayers and 129 non-sprayers) and 311 females (mean age 25 years; 156 working in greenhouses and 155 working outside the greenhouses). The researchers undertook structured interviews, blood sampling, and walkthrough surveys. Descriptive statistics and Poisson regression were used in the statistical analyses. A total of 154 different trade names of pesticides were found. Of them, 31 (27%) were classified as moderately hazardous by the WHO, and 9% were organophosphates. Serum levels of cholinesterase deviating from 50-140 Michel units were considered abnormal. Abnormal serum cholinesterase levels (above 140 Michel units) were found in 97 participants (16.5%, 95% confidence interval 13.7-19.7%). There were no differences between the four job groups regarding cholinesterase levels. The high prevalence of abnormal serum cholinesterase levels might indicate the presence of pesticide intoxication. Thus, there is a need for routine monitoring of all workers exposed to pesticides, not only sprayers.

Assessment of Primary Health Care for rural workers exposed to pesticides

OBJECTIVE

To evaluate the attributes of Primary Health Care (PHC) for rural workers; to analyze sociodemographic conditions, history of poisoning and hospitalizations for pesticides and use of personal protective equipment; and to verify exposure to pesticides by determining bioindicators.

METHODS

Cross-sectional, descriptive-analytical study with a sample of 1,027 rural workers living in municipalities belonging to a regional health department in Southern Minas Gerais, whose PHC is governed by the Family Health Strategy model. We used the adult version of the Primary Care Assessment Tool (PCATool Brazil) and a structured questionnaire to collect socioeconomic data, history of poisoning and hospitalization for pesticides and use of personal protective equipment. Blood samples were collected to measure biomarkers of pesticide exposure and signs of renal and hepatic sequelae.

RESULTS

Low education was prevalent, as well as the intense contact of workers with pesticides. Frequent use of personal protective equipment was higher among men, as was the history of poisoning and hospitalizations for pesticides. Rates of 20% poisoning, 15% liver disease and 2% nephropathy were detected. Signs of hepatotoxicity were more frequent in men. Gender differences were all statistically significant. Regarding PHC, only the attribute "degree of affiliation" had a high score. None of the poisoning cases detected in the study were previously diagnosed.

CONCLUSIONS

Despite the high coverage of the Family Health Strategy, occupational risk and its consequences have not been detected by health services, which do not seem oriented to primary care, even lacking their essential attributes. There is a need for immediate and effective adaptation of public policies regarding the health of rural workers, with adequate training of teams and review of the portfolio of PHC services offered.

Biomonitoring of Acetylcholinesterase (AChE) Activity among Smallholder Horticultural Farmers Occupationally Exposed to Mixtures of Pesticides in Tanzania

Biomonitoring of pesticides exposure has currently become a matter of great public concern due to the potential health effects of pesticides. This study assessed levels of acetylcholinesterase (AChE) inhibition and associated health effects in uncontrolled smallholder farming systems in rural Tanzania. A cross-sectional study was conducted of 90 exposed farmers and 61 nonexposed controls from horticultural zones. A structured questionnaire was administered, and a capillary blood sample of 10 μl was used to measure AChE activity using an Erythrocyte Acetylcholinesterase Test Mate Photometric Analyzer kit (Model 400). A multiple logistic regression model was used to investigate determinants of pesticide exposure. The study revealed that smallholder farmers are occupationally exposed to pesticides. Exposed farmers had significantly lower AChE levels. The use of personal protective equipment (PPE) did not significantly reduce the likelihood of AChE inhibition. Women, younger and older farmers, and underweight, overweight, and obese farmers were at increased risk of AChE inhibition. Increase in age (10 years) increased likelihood of AChE inhibition by 6.7%, while decrease in BMI increased likelihood of AChE inhibition by 86.7% while increased pesticides contact hours increased risk of having lower AChE at about 3 times. The number of exposure symptoms (14.10 ± 7.70) was higher in exposed farmers than unexposed. Self-reported symptoms are confirmed to correlate to lower AChE. Prevalence of tiredness (71.6% against 15.5%), fatigue (64.8% against 27.6%), soreness in joints (59.1% against 20.7%), thirst (52.3% against 12.1%), skin irritation (52.1% against 17.2%), salivation and abdominal pain (50% against 8.6% and 31.0%, respectively), muscle weakness (47.7% against 24.1%), and memory loss (47.7% against and 29.3%) differed significantly between exposed and control. This study provides useful information regarding the level of occupational and environmental exposure to pesticides in smallholder horticultural production systems. Pesticides use needs to be controlled at farm level by developing pesticides monitoring and surveillance systems.

Neurobehavioral and Menstrual Disorders among Adolescent Females Environmentally Exposed to Pesticides, Menoufia Governorate, Egypt

Background

Adolescent females living in agricultural areas where crops are routinely sprayed by pesticides are expected to be environmentally exposed to pesticides' health hazards partially as those occupationally exposed.

Objective

to assess menstrual and neurobehavioral disorders among adolescent females environmentally exposed to pesticides.

Methods

This was a cross-sectional study conducted on 100 pesticide exposed adolescent females who had one or more of family members are pesticides' seasonal applicators and 50 non- exposed adolescent females matched for age and education, served as controls at Menoufia governorate, Egypt during the period of pesticide application season of cotton crop from the first days of May to the end of September 2017. A self-administered and a series of neurobehavioral tests were administered and serum Acetylcholinesterase (AChE) activity was assessed.

Results

A significant lower AChE activity levels were found in the exposed group than controls (Mean±SD=238.49± 23.83 vs 303.35±78.54 IU/L; respectively). There were significant higher mean scores of trail making test (parts 1 and 2) and significant lower mean scores of (similarities test, Benton visual retention test, block design test, Santa Ana dexterity test (dominant and non-dominant hands) and Beery visuo-motor imitation test in the exposed group than the controls (P<0.05). Also, the exposed group reported more prevalent irregular menstrual cycle (26.8%) and intermenstrual bleeding (28.2%) compared to the control participants (8.1% and 8.1%; respectively).

Conclusion

Adolescent females living in agricultural areas and from families whose one or more members are pesticides' applicators have significantly lower neurobehavioral performance, report more prevalent menstrual irregularities and have lower levels of serum AChE compared to a control group. The neurobehavioral deficits demonstrated a dose-response relationship AChE levels in the exposed participants. This necessitates the need for implementation of health education programs to prevent or reduce health effects associated with pesticide exposure to adolescent females.

Multiresidue analysis and evaluation of the matrix effect on 20 pesticides in Brazilian maize (Zea mays L.) flour

Maize consists of a cereal widely used in the preparation of different food products. Brazil is one of the world's largest maize producers. Several types of pesticides have been applied in maize crop, which can lead to the contamination of the derived products. The present work aims at the validation of multiresidue method to analyze the matrix effect and level of pesticides in maize flour. Twenty residues were investigated in samples commercialized in the state of Ceará, Brazil. The method was satisfactorily validated, according to parameters recommended by European Union. About 55% of the pesticides had an intense negative matrix effect. Multiresidue analyzes showed the presence of traces of fenitrotion in 20% of maize flour samples. Detected levels were below maximum residue limits recommended for maize. The results indicate that maize products need continuous monitoring to ensure food security.

Performance of machine-learning algorithms to pattern recognition and classification of hearing impairment in Brazilian farmers exposed to pesticide and/or cigarette smoke

The use of pesticides has been increasing in agriculture, leading to a public health problem. The aim of this study was to evaluate ototoxic effects in farmers who were exposed to cigarette smoke and/or pesticides and to identify possible classification patterns in the exposure groups. The sample included 127 participants of both sexes aged between 18 and 39, who were divided into the following four groups: control group (CG), smoking group (SG), pesticide group (PG), and smoking + pesticide group (SPG). Meatoscopy, pure tone audiometry, logoaudiometry, high-frequency thresholds, and immittance testing were performed. Data were evaluated by artificial neural network (ANN), K-nearest neighbors (K-NN), and support vector machine (SVM). There was symmetry between the right and left ears, an increase in the incidence of hearing loss at high frequency and of downward sloping audiometric curve configuration, and alteration of stapedial reflex in the three exposed groups. The machine-learning classifiers achieved good classification performance (control and exposed). The best classification results occur in high type (I and II) datasets (about 90% accuracy) in k-NN test. It is concluded that both xenobiotic substances have ototoxic potential; however, their combined use does not present additive or potentiating effects recognizable by the algorithms.

Genotoxicological analyses of insectivorous bats (Mammalia: Chiroptera) in central Brazil: The oral epithelium as an indicator of environmental quality

The micronucleus (MN) test of the human buccal mucosa was developed more than 30 years ago, although this technique has only recently been applied to wild mammals. This paper presents a pioneering study in the genotoxicological evaluation of the exfoliated cells of the buccal mucosa of bats. The assay was applied to two insectivorous bat species (Noctilio albiventris and Pteronotus parnellii) sampled in riparian corridors located in the city of Palmas (capital of the Brazilian state of Tocantins), with the results being compared with those obtained for a third insectivorous species (Nyctinomops laticaudatus), which has established a colony under a road bridge in the same region. This colony represents one of the largest molossidae populations ever recorded in Brazil. A significantly higher frequency of micronuclei was recorded in this colony, as well as a number of other nuclear abnormalities, including binucleated cells, cells with condensed chromatin and karyolysis, in comparison with the bats from the riparian corridors, indicating that the bats from the bridge colony are more susceptible to genotoxic damage. Thus, it is demonstrated the importance of the biomarker (MN) for use in wild animals and allows to conclude that colony bats are more susceptible to genotoxic damages.