Clinical, cytogenetic and toxicological studies in rural workers exposed to pesticides in Botucatu, São Paulo, Brazil

Chromosomal Damage, Chromosome Instability, and Polymorphisms in GSTP1 and XRCC1 as Biomarkers of Effect and Susceptibility in Farmers Exposed to Pesticides

In the department of Boyacá, Colombia, agriculture stands as one of the primary economic activities. However, the escalating utilization of pesticides within this sector has sparked concern regarding its potential correlation with elevated risks of genotoxicity, chromosomal alterations, and carcinogenesis. Furthermore, pesticides have been associated with a broad spectrum of genetic polymorphisms that impact pivotal genes involved in pesticide metabolism and DNA repair, among other processes. Nonetheless, our understanding of the genotoxic effects of pesticides on the chromosomes (as biomarkers of effect) in exposed farmers and the impact of genetic polymorphisms (as susceptibility biomarkers) on the increased risk of chromosomal damage is still limited. The aim of our study was to evaluate chromosomal alterations, chromosomal instability, and clonal heterogeneity, as well as the presence of polymorphic variants in the GSTP1 and XRCC1 genes, in peripheral blood samples of farmers occupationally exposed to pesticides in Aquitania, Colombia, and in an unexposed control group. Our results showed statistically significant differences in the frequency of numerical chromosomal alterations, chromosomal instability, and clonal heterogeneity levels between the exposed and unexposed groups. In addition, we also found a higher frequency of chromosomal instability and clonal heterogeneity in exposed individuals carrying the heterozygous GSTP1 AG and XRCC1 (exon 10) GA genotypes. The evaluation of chromosomal alterations and chromosomal instability resulting from pesticide exposure, combined with the identification of polymorphic variants in the GSTP1 and XRCC1 genes, and further research involving a larger group of individuals exposed to pesticides could enable the identification of effect and susceptibility biomarkers. Such markers could prove valuable for monitoring individuals occupationally exposed to pesticides.

Profile of Chromosomal Alterations, Chromosomal Instability and Clonal Heterogeneity in Colombian Farmers Exposed to Pesticides

Pesticides are a group of environmental pollutants widely used in agriculture to protect crops, and their indiscriminate use has led to a growing public awareness about the health hazards associated with exposure to these substances. In fact, exposure to pesticides has been associated with an increased risk of developing diseases, including cancer. In a study previously published by us, we observed the induction of specific chromosomal alterations and, in general, the deleterious effect of pesticides on the chromosomes of five individuals exposed to pesticides. Considering the importance of our previous findings and their implications in the identification of cytogenetic biomarkers for the monitoring of exposed populations, we decided to conduct a new study with a greater number of individuals exposed to pesticides. Considering the above, the aim of this study was to evaluate the type and frequency of chromosomal alterations, chromosomal variants, the level of chromosomal instability and the clonal heterogeneity in a group of thirty-four farmers occupationally exposed to pesticides in the town of Simijacá, Colombia, and in a control group of thirty-four unexposed individuals, by using Banding Cytogenetics and Molecular Cytogenetics (Fluorescence in situ hybridization). Our results showed that farmers exposed to pesticides had significantly increased frequencies of chromosomal alterations, chromosomal variants, chromosomal instability and clonal heterogeneity when compared with controls. Our results confirm the results previously reported by us, and indicate that occupational exposure to pesticides induces not only chromosomal instability but also clonal heterogeneity in the somatic cells of people exposed to pesticides. This study constitutes, to our knowledge, the first study that reports clonal heterogeneity associated with occupational exposure to pesticides. Chromosomal instability and clonal heterogeneity, in addition to reflecting the instability of the system, could predispose cells to acquire additional instability and, therefore, to an increased risk of developing diseases.

Does farming have an effect on health status? A comparison study in west Greece

Investigating the health status of agricultural workers is a challenging goal. Contradictory outcomes concerning farmers' health are reported in the literature. In this cross-sectional study, certain clinical and neurobehavioral health outcomes were compared between farmers and non-farmers living in the same rural area. Farmers (328) and non-farmers (347), matched per age and sex, were selected randomly in an agricultural area in West Greece. Both groups underwent haematological and biochemical examinations and were administered two neurobehavioral tests, namely the Mini-Mental State Examination (MMSE) and the Montgomery-Åsberg Depression Rating Scale (MADRS). Sociodemographic, personal medical, nutritional and lifestyle data were recorded. According to personal statements, farmers suffered from hypertension, cardiovascular, orthopaedic and ENT problems in higher frequency. Haematocrit, haemoglobin and serum cholinesterase's activity were found to be lower among farmers. Lower prevalence of hypertension and better performances on MMSE and MADRS tests were recorded in young farmers in relation to young non-farmers, while these findings were reversed in older ages. Odds Ratios were calculated through multivariate logistic regression models. Factors affecting these impairments remain to be clarified.

Determination of AChE levels and genotoxic effects in farmers occupationally exposed to pesticides

Pesticides can cause cytogenetic effects and lower the acetyl cholinesterase (AChE) levels in farmers exposed to pesticides. In this study, 210 farmers exposed to pesticides and 160 non-exposed individuals were enrolled for determining the genotoxicity and AChE levels. The AChE levels were determined in plasma and RBC lysate from blood samples collected from farmers and control subjects. AChE (true and pseudo) estimation done by the colorimetric method revealed that there was a progressive fall in both the RBC and plasma AChE levels in exposed individuals compared to unexposed individuals, which correlated with the severity of exposure (253.5 versus 311.1 and 142.3 versus 152.1; P < 0.001). Cytogenetic studies showed an increase in DNA damage and higher chromosomal aberrations (CAs) in exposed farmers compared to the control subjects (26.13 versus 07.61 and 21.37 versus 1.52; P < 0.001). When comparing the AChE levels with DNA damage and structural CA frequencies, there was a negative linear correlation. Therefore based on these findings, it is concluded that genotoxic biomarkers like CA frequencies, DNA damage data along with AChE levels are important parameters for determining farmer's health who are exposed to pesticides in any situation.

Headache caused by handling the pesticide Antracol Combi WP 76: a case report

We report on headache caused by the pesticide Antracol Combi WP 76. A headache caused by handling of pesticides should be distinguishable from migraine and headaches from other causes. This 29-year-old woman, who handled pesticides, presented with very strong headache with nausea and vomiting. Poisoning by this pesticide cannot be proven toxicologically, and there is no antidote. Following isolation from the pesticide and abundant hydration, the pain gradually decreased. History, clinical signs and neuroradiological examinations excluded other possible causes of the headache. In treatment of patients in rural areas, attention should also be paid to the pesticide Antracol Combi WP 76 as a possible cause of headaches.

Uso de agrotóxicos no Município de Cachoeiras de Macacu (RJ)

O artigo apresenta um levantamento efetuado no ano de 1997 em 40 propriedades rurais de Cachoeiras de Macacu (RJ) acerca da percepção de risco e das práticas de uso dos agrotóxicos. A pesquisa de campo foi feita com agricultores (40 questionários) e com autoridades (entrevistas abertas). A análise dos resultados demonstrou que 22,5% dos agricultores reportaram já terem sido intoxicados por agrotóxico, sendo o inseticida Decis 25 CE e o herbicida Gramoxone (ambos extremamente tóxicos) os mais utilizados na região. Verificou-se que 85% dos agricultores não utilizavam Equipamentos de Proteção Individual (EPI), que 27,5% jogavam embalagens de agrotóxicos no rio ou no mato, que 60% de entrevistados nunca foram treinados para manusear agrotóxicos e que 85% disseram não precisar de receituário agronômico para comprá-los. Quanto à percepção do risco do uso de agrotóxicos, foram identificadas três categorias: 70% percebem, mas continuam usando; 27% não percebem o risco; 3% percebem e não utilizam mais. Discutem-se as razões para estas práticas de risco, comparando-se com achados de outros autores.

[Chromosome instability induced by agrochemicals among farm workers in Passo Fundo, Rio Grande do Sul, Brazil]

A major share of the grain farming (wheat and soybeans) in the State of Rio Grande do Sul is in the Passo Fundo area. For crop pest control, large amounts of agrochemicals (fungicides, insecticides, and herbicides) are used. To evaluate the genotoxicity of these products, the micronucleus test was performed in farm workers directly exposed to these chemicals. Heparinized blood samples were drawn by venipuncture from 30 exposed workers and 30 non-exposed controls. Micronuclei frequency was evaluated by counting 1,000 binucleated cells per individual in both groups. Smoking habits, age, and duration of exposure showed no effect on the frequency of micronuclei in both groups. However, statistical analysis showed significantly higher mean numbers of binucleated cells with micronuclei in exposed individuals (14.3/1,000 cells) as compared to controls (7.1/1,000 cells), allowing the authors to conclude that the micronucleus test is an efficient biological assay for monitoring population exposure to mixtures of agrochemicals.

Influence of paraquat, glyphosate, and cadmium on the activity of some serum enzymes and protein electrophoretic behavior (in vitro)

In vitro study for the determination of the toxicity of some pesticides (glyphospate and paraquat) and cadmium chloride (CdCl2) on the activities of serum acetylcholinesterase (AChE), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (AlP), and acid phosphatase (AcP) is described. Changes in electrophoretic patterns of serum proteins were also tested. Results revealed that glyphosate was effective on all enzymes except AcP. Its IC50 values (the concentration of compound that inhibits 50% of the enzyme activity in 1 h at 37 degrees C) were 714.3, 750, 54.2, 270.8, and 71.4 mM for AChE, LDH, AST, ALT, and AlP, respectively. The inhibitory effect of paraquat varied markedly among all enzymes. The IC50 values of paraquat were 321.4 and 750 mM for AST and ALT, respectively. It had mild effect on AChE and LDH; and no effect on the activities of AlP and AcP. The effect of CdCl2 was pronounced with AChE, ALT, AlP, and AcP, and no effect on LDH and AST was found. The corresponding IC50 values were 77.7, 22.2, 33.3, and 83.3 mM for AChE, ALT, AlP, and AcP, respectively. Polyacrylamide gel electrophoretic patterns of serum proteins showed marked differences with glyphosate and CdCl2 but not with paraquat. The results suggest that the in vitro enzyme-activity test seems to have a potential for the assessment of pesticide and heavy metal toxicity.