Occupational exposure of farm workers to pesticides: biochemical parameters and evaluation of genotoxicity

Evaluation of genotoxic effects in workers and residents of rural areas exposed to pesticides in Brazil

Brazil is one of the world's largest consumers of pesticides. This intense use impacts the environment and exposes a wide range of individuals to pesticides, including rural workers who are occupationally exposed and rural residents who are environmentally exposed. We aimed to evaluate the effects of occupational exposure to pesticides on the health of rural workers and rural residents. We conducted an epidemiological study with 104 farmers and 23 rural residents of Casimiro de Abreu (Rio de Janeiro, Brazil). A comparison group (urban residents) comprised 103 residents of the urban area of the same city. We determined the activity of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) using a modified version of Ellman's method to evaluate exposure. In addition, we performed genotoxic and mutagenic analyses with the comet assay and the cytokinesis-block micronucleus (CBMN) assay. There was a reduction in cholinesterase activity, mainly BChE, in rural workers and rural residents compared with urban residents (p = 0.002). There was an increase in genotoxic effects in rural workers compared with urban residents (comet assay, p < 0.001; CBMN assay, p < 0.001). In addition, there was a greater chance of genotoxic changes in rural workers exposed to pesticides based on the comet assay (odds ratio [OR] 7.6, 95 % confidence interval [CI] 6.6-15.9) and the CBMN assay (OR 22.7, 95 % CI 10.3-49.9). We found that individuals occupationally exposed to pesticides are more likely to have genotoxic effects. These findings are useful for the development of programs to monitor populations exposed to genotoxic substances and allow the development of strategies for the prevention, control, and surveillance of effects that result from occupational and environmental exposures to pesticides.

The Comet Assay as a Tool in Human Biomonitoring Studies of Environmental and Occupational Exposure to Chemicals-A Systematic Scoping Review

Biomonitoring of human populations exposed to chemical substances that can act as potential mutagens or carcinogens, may enable the detection of damage and early disease prevention. In recent years, the comet assay has become an important tool for assessing DNA damage, both in environmental and occupational exposure contexts. To evidence the role of the comet assay in human biomonitoring, we have analysed original research studies of environmental or occupational exposure that used the comet assay in their assessments, following the PRISMA-ScR method (preferred reporting items for systematic reviews and meta-analyses extension for scoping reviews). Groups of chemicals were designated according to a broad classification, and the results obtained from over 300 original studies (n = 123 on air pollutants, n = 14 on anaesthetics, n = 18 on antineoplastic drugs, n = 57 on heavy metals, n = 59 on pesticides, and n = 49 on solvents) showed overall higher values of DNA strand breaks in the exposed subjects in comparison with the unexposed. In summary, our systematic scoping review strengthens the relevance of the use of the comet assay in assessing DNA damage in human biomonitoring studies.

Effect of arsenic and copper in kidney of mice: Crosstalk between Nrf2/ Keap1 pathway in apoptosis and pyroptosis

Arsenic (As) and copper (Cu) are two common contaminants in the environment. When organisms are exposed to As or/ and Cu in large quantities or for sustained periods, oxidative stress is induced, adversely affecting kidney function. However, the molecular mechanisms involved in As or/ and Cu-induced nephrotoxicity remain elusive. In this experiment, wild-type C57BL/6 and Nrf2-knockout mice (n = 24 each) were exposed to arsenic trioxide and copper chloride alone or in combination. Our research findings indicate that exposure to As or/ and Cu can activate the Nrf2 antioxidant pathway by upregulating the levels of Nrf2, HO-1, CAT, and downregulating the level of Keap1, thereby reducing As or/ and Cu-induced oxidative stress. Meanwhile, exposure induced kidney cell pyroptosis and apoptosis by promoting the expression of NLRP3 inflammasomes and Caspase-3, which peaked in mice co-treated with As and Cu. Subsequently, we investigated its role in As or/ and Cu-induced kidney injury by knocking out Nrf2. Our results show that after knocking out Nrf2, the expression of antioxidant factors CAT and HO-1 significantly decreased. Based on the low antioxidant capacity after Nrf2 knockout, the levels of NLRP3 inflammasome, GSDMD, and Caspase1 were significantly upregulated after exposure to As and Cu, indicating more severe cellular pyroptosis. In addition, the level of Caspase3-mediated apoptosis was also more severe. Taken together, there is crosstalk between Nrf2-mediated antioxidant capacity and apoptosis/ pyroptosis induced by exposure to As or/ and Cu. Depletion of Nrf2 alters its antioxidant capacity, ultimately leading to more severe apoptosis, pyroptosis, and nephrotoxicity.

Lipid peroxidation and changes in major antioxidant markers in copper quinolate fungicide-exposed rats

The present study investigated the toxic effects of sub-chronic exposure to copper quinolate (CuQ) fungicide on liver and kidney function. Twenty-four adult male Wistar rats were equally divided into a control group, and three treated groups received, respectively, by oral gavage, three increasing doses of CuQ: 47; 67.1; and 94 mg/kg b.w corresponding, respectively, LD50/100, LD50/70, and LD50/50 daily for 8 weeks. CuQ resulted in a significant increase in the serum enzymatic activity of aspartate aminotransferase (AST), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), and the serum levels of urea, creatinine, uric acid, and malondialdehyde, along with a marked decrease in alanine aminotransferase (ALT) activity, and the contents of total protein and albumin compared to those of the control group. Furthermore, glutathione content and the enzymatic activity of superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), and glutathione peroxidase (GPx) decreased significantly in a dose-dependent manner with respect to CuQ. The adverse effects of CuO were supported by the histopathological evaluations of liver and kidney tissues. Conclusively, sub-chronic CuQ exposure was shown to induce kidney and liver oxidative damage and dysfunction.

Investigating the relationship between non-occupational pesticide exposure and metabolomic biomarkers

The relationship between pesticide exposures and metabolomics biomarkers is not well understood. We examined the changes in the serum metabolome (early biomarkers) and the metabolic pathways associated with various pesticide exposure scenarios (OPE: overall exposure, PEM: exposure in months, PEY: exposure in years, and PEU: reported specific pesticides use) using data from the Northern Finland Birth Cohort 1966 31-year cross-sectional examination. We utilized questionnaire data on pesticide exposures and serum samples for nuclear magnetic resonance (NMR)-based metabolomics analyses. For exposures and metabolites associations, participants size varied between 2,361 and 5,035. To investigate associations between metabolomics biomarkers and exposure to pesticide scenarios compared to those who reported no exposures multivariable regression analyses stratified by sex and adjustment with covariates (season of pesticide use, socioeconomic position (SEP), alcohol consumption, BMI, and latitude of residence) were performed. Multiple testing by Benjamini-Hochberg false discovery rate (FDR) correction applied. Pesticide exposures differed by sex, season of pesticide use, alcohol, SEP, latitude of residence. Our results showed that all pesticide exposure scenarios were negatively associated with decreased HDL concentrations across all lipoprotein subclasses in women. OPE, PEY, and PEU were associated with decreased branched-chain amino acid concentrations in men and decreased albumin concentrations in women. OPE, PEY and PEU were also associated with changes in glycolysis metabolites and ketone bodies in both sexes. Specific pesticides exposure was negatively associated with sphingolipids and inflammatory biomarkers in men. In women, OPE, PEM, and PEU were associated with decreased apolipoprotein A1 and increased apolipoprotein B/apolipoprotein A1 ratio. Our findings suggest that identification of early biomarkers of disease risk related to pesticide exposures can inform strategies to reduce exposure and investigate causal pathways. Women may be more susceptible to non-occupational pesticide exposures when compared to men, and future sex-specific studies are warranted.

Copper in grape and wine industry: Source, presence, impacts on production and human health, and removal methods

Heavy metals are of particular concern in grape and wine processing, especially copper. The sources of copper are diverse, including vineyard soil, copper-containing pesticides on the fruit surface, copper wine-making equipment, and exogenous addition in winemaking. Copper has potential risks to human nerves, metabolism, and others. It can inhibit yeast growth, delay fermentation, and also mediate oxidation reactions, which has a huge impact on the nutritional quality and sensory quality of fresh wine and aged wine. It is therefore crucial to detect, quantify, and remove copper from grapes and wine. However, the copper situations in the wine industries of various countries are complicated and diverse, and the existing forms of copper are quite different, which makes the research challenging. This review summarizes and analyzes the existence and influence of copper in the wine industry by analyzing the sources of, the current situation regarding, and the detection and removal methods for copper in wine. With the study, a better understanding of copper's impact on wine production will be gained, facilitating further control of copper in wine and helping the wine industry grow.

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.

Is micronucleus assay in oral exfoliated cells a useful biomarker for biomonitoring populations exposed to pesticides? A systematic review with meta-analysis

The systematic review (SR) with meta-analysis aimed to infer if micronucleus assay using oral mucosal cells a useful biomarker for biomonitoring populations continuously exposed to pesticides (EP). The SR has been made in accordance with the PRISMA-P guidelines. The PICOS strategy has focused to answer the following question: "Does exposure to pesticides cause genetic damage in oral cells?" The literature search was made in the following scientific databases: Web of Science, PubMed/Medline, and Scopus. The approach was defined as follows: standardized mean difference (SMD) and 95% confidence intervals (CI). The quality assessment of manuscripts was obtained by the EPHPP (Effective Public Health Practice Project). The GRADE tool was chosen for assessing the quality of evidence. A total of 108 articles were selected in this setting. After screening abstracts and titles, 23 manuscripts were evaluated for eligibility. After reviewing the studies, two were considered weak and 22 were classified as moderate or strong. The meta-analysis data pointed out statistically significant differences in volunteers exposed to EP (SMD = 1.23, 95% CI, 0.69 to 1.77, p < 0.001), with a Tau2 = 1.44; Chi2 = 566.38, and p < 0.001, so that the selected manuscripts were considered heterogeneous and the I2 of 97% indicated high heterogeneity. Taken together, this review was able to validate the micronucleus assay in oral exfoliated cells as a useful biomarker in individuals continuously exposed to EP because the studies categorized as moderate and strong have demonstrated positive response related to mutagenesis.

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.

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.

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

We carried out a meta-analytical review of possible DNA damage resulting from occupational exposure to pesticides in farmers in the scientific literature. After the search, screening, and eligibility criteria steps, we included 42 studies to analyze random effect calculation. DNA damage in farmers occupationally exposed to pesticides represents an effect of SMD 4.63 [CI 95% 3.94-5.32; p <0.001]. We observed a high heterogeneity rate between the studies and an asymmetry of the bias analysis results. We performed a meta-regression on the parameters. The Olive Tail Moment (OTM) was the most effective comet assay parameter in the evaluated studies. The Damage Index (DI) was more conservative and highlighted the variability between studies caused by distinct methodologies that showed more significant effects and greater deviations. An analysis of confounding factors demonstrated a slight DNA damage in smokers who were occupationally exposed to pesticides compared to nonsmokers, indicating genotoxicity but smaller than the pesticide effect. The present study shows the greater risk that occupationally exposed rural workers have of developing related diseases due to pesticides' genotoxic effect.

Os agrotóxicos no contexto da Saúde Única

RESUMO A industrialização da agricultura e da pecuária, além de gerar um ambiente propício à disseminação de agentes infecciosos, é responsável pelo uso generalizado de diversas substâncias tóxicas que afetam a saúde humana, animal e ambiental. O objetivo deste estudo foi promover a reflexão sobre o uso de agrotóxicos e medicamentos veterinários como elementos de debate na construção da Saúde Única. Para isso, foi realizada uma revisão exploratória literária de artigos, livros e documentos oficiais disponíveis em plataformas de banco de dados. A discussão inclui as problemáticas do uso de substâncias tóxicas em plantas e animais. Aborda, também, como os resíduos oriundos de sua utilização impactam a qualidade de alimentos, ar, solo, água com consequências à saúde humana. Embora essa discussão seja escassa na temática de Saúde Única, é fundamental que, além da participação da sociedade civil organizada, gestores públicos assegurem, por meio de políticas públicas, maior segurança e controle na utilização de substâncias tóxicas na agricultura e na pecuária.

Non-occupational exposure to pesticides and health markers in general population in Northern Finland: Differences between sexes

BACKGROUND

Occupational exposure to pesticides has been reported among general population worldwide. However, little is known about the associations between non-occupational exposure to pesticides, and biological markers of health and their response by sex.

OBJECTIVES

We aimed to assess the associations between non-occupational overall pesticide exposure, length of exposure and specific pesticides reported with 35 biological markers of health representing cardiometabolic, haematological, lung function, sex hormones, liver and kidney function profiles, and vitamin D in Finnish cohort.

METHODS

31-year cross-sectional examination of the Northern Finland Birth Cohort 1966 provided blood samples for biomarker measurements in 1997-1998. Number of subjects varied between 2361 and 5037 for given exposures and certain outcome associations. Multivariable regression analyses were performed to examine associations between overall pesticide exposure (OPE), length of pesticide exposure in months (PEM), in years (PEY), and specific pesticides use (PEU) or not with cardiometabolic [SBP, DBP, TC, LDL, HDL, triglycerides, fasting glucose, insulin, HOMA-IR, HOMA-B, HOMA-S, hs-CRP], hematological [WBC, RBC, Hb, HCT, MCV, MCH, MCHC, platelets], lung function (FVC, FEV1), sex hormones [luteinizing hormone (LH), testosterone (TT), sex-hormone binding globulin (SHBG)], liver and kidney function profiles [total protein, albumin, globulin, ALP, ALT, GGT, urea, creatinine], and vitamin D adjusting for sex, BMI, socioeconomic position (SEP) and season of pesticide use.

RESULTS

This cohort study on up to 5037 adults with non-occupational OPE, PEM, PEY and PEU differed by sex and SEP. In regression analyses, all the exposures were positively associated with total cholesterol and low-density lipoprotein cholesterol, and PEU was negatively associated with high-density lipoprotein cholesterol in females. OPE and PEM were positively associated with haematocrit in females and PEU with platelets in males. PEU was negatively associated with mean corpuscular haemoglobin. OPE and PEM were positively associated with LH in males. OPE was negatively associated with total protein and albumin in males.

DISCUSSION

In Finnish young adults, non-occupational overall pesticide exposure, length of exposure and specific pesticides were associated with multiple biological markers of health. The biological markers seem to be indicative of adverse effects of pesticides and warrant for further studies to replicate the findings and determine the underlying mechanisms.

21-Day dermal exposure to aircraft engine oils: effects on esterase activities in brain and liver tissues, blood, plasma, and clinical chemistry parameters for Sprague Dawley rats

This dermal study tested the potential toxicity of grade 3 (G3) and 4 (G4) organophosphate-containing aircraft engine oils in both new (G3-N, G4-N) and used states (G3-U, G4-U) to alter esterase activities in blood, brain and liver tissues, clinical chemistry parameters, and electrophysiology of hippocampal neurons. A 300 µl volume of undiluted oil was applied in Hill Top Chamber Systems®, then attached to fur-free test sites on backs of male and female Sprague Dawley rats for 6 hr/day, 5 days/week for 21 days. Recovery rats received similar treatments and kept for 14 days post-exposure to screen for reversibility, persistence, or delayed occurrence of toxicity. In brain, both versions of G3 and G4 significantly decreased (32-41%) female acetylcholinesterase (AChE) activity while in males only G3-N and G4-N reduced (33%) AChE activity. Oils did not markedly affect AChE in liver, regardless of gender. In whole blood, G3-U decreased female AChE (29%) which persisted during recovery (32%). G4-N significantly lowered (29%) butyrylcholinesterase (BChE) in male plasma, but this effect was resolved during recovery. For clinical chemistry indices, only globulin levels in female plasma significantly increased following G3-N or G4-N exposure. Preliminary electrophysiology data suggested that effects of both versions of G3 and G4 on hippocampal function may be gender dependent. Aircraft maintenance workers may be at risk if precautions are not taken to minimize long-term aircraft oil exposure.

Toxicokinetic analysis of commonly used pesticides using data on acute poisoning cases from Hyderabad, South India

Organophosphorus pesticides (OPs) interfere with the activity of acetylcholinesterase (AChE), a vital enzyme that regulates the functioning of the nervous system, resulting in acetylcholine (Ach) accumulation at the synapses and myoneural junctions. It remains unknown whether the commonly used OPs in South India also interfere with the AChE activity and their toxicokinetics in humans remains poorly understood. We collected peripheral blood samples from OP-associated suicide cases (hospitalised) and analysed the pesticide concentration and AChE activity, and the toxicokinetics of six commonly used pesticides. LC-MS/MS was used for the estimation of pesticide concentration. Based on a comparison of six pesticide kinetic profiles and toxicokinetic parameters, we concluded that chlorpyrifos ingestion resulted in the highest concentration of chlopyrifos among the identified pesticides, followed by acephate, triazophos, propanil, while dimethoate exhibited the lowest concentration. Based on a time-course analysis, we observed a faster elimination phase for monocrotophos and dimethoate. We observed that there was a significant decrease in the mean concentration of monocrotophos (64 ng/mL) (P = 0.015), while the mean value of AChE (1.08 unit/mL) increased over time. While monocrotophos and dimethoate elimination phases were remarkable in human subjects, the other pesticides did notdemonstrate similar elimination phases owing to their low rate of metabolism and high stability.

Encapsulation of Synthesized Plant Growth Regulator Based on Copper(II) Complex in Chitosan/Alginate Microcapsules

A new copper complex, trans-diaqua-trans-bis [1-hydroxy-1,2-di (methoxycarbonyl) ethenato] copper (abbreviation Cu(II) complex), was synthesized and its plant growth regulation properties were investigated. The results show a sharp dependence of growth regulation activity of the Cu(II) complex on the type of culture and its concentration. New plant growth regulator accelerated the development of the corn root system (the increase in both length and weight) but showed a smaller effect on the development of the wheat and barley root systems. Stimulation of corn growth decreased with increasing Cu(II) complex concentration from 0.0001% to 0.01% (inhibition at high concentrations-0.01%). The development of corn stems was also accelerated but to a lesser extent. Chitosan-coated calcium alginate microcapsules suitable for delivery of Cu(II) complex to plants were prepared and characterized. Analysis of the FTIR spectrum showed that complex molecular interactions between functional groups of microcapsule constituents include mainly electrostatic interactions and hydrogen bonds. Microcapsules surface exhibits a soft granular surface structure with substructures consisting of abundant smaller particles with reduced surface roughness. Release profile analysis showed Fickian diffusion is the rate-controlling mechanism of Cu(II) complex releasing. The obtained results give new insights into the complexity of the interaction between the Cu(II) complex and microcapsule formulation constituents, which can be of great help in accelerating product development for the application in agriculture.

Assessment of anilofos-induced mutagenicity in bone marrow and germ cells of Swiss albino mice

Anilofos is an organophosphate compound and is used extensively as a preemergence and early postemergence herbicide for the management of sedges, annual grasses, and some broad-leaved weeds in rice fields. The present study was aimed to assess the mutagenic potential of anilofos after sub-chronic exposure in Swiss albino mice. For this, a combined approach employing micronucleus (MN), chromosomal aberration (CA) studies and sperm-head abnormalities (SHAs) was used. Three dose levels of 1%, 2%, and 4% of maximum tolerated dose (MTD) (235 mg/kg b.wt.), that is, 2.35, 4.7 and 9.4 mg/kg b.wt., respectively, were administered orally daily for 90 days. A higher incidence of micronucleated erythrocytes (polychromatic erythrocytes + normochromatic erythrocytes), significant increase in CA frequency, and significant decrease in the ratio of polychromatic/normochromatic erythrocytes (P/N) ratio were observed at the 4.7 and 9.4 mg/kg b.wt. dose levels. A significant increase in SHA was observed in all treatment groups (2.35, 4.7, and 9.4 mg/kg b.wt.) from the control group. In conclusion, anilofos exposure of 2% and 4% of MTD caused a higher rate of micronucleated erythrocytes, increased frequency of CA, increase in SHA, and lower P/N ratio, and pesticide exposure of 1% of MTD only resulted in higher SHAs. Thus, anilofos was found to have mutagenic potential in mice when administered daily orally at dose rate of 4.7 and 9.4 mg/kg b.wt. for 90 days.

Modulation of DNA damage by XPF, XPG and ERCC1 gene polymorphisms in pesticide-exposed agricultural workers of Punjab, North-West India

Inter-individual variations in DNA repair capacity (DRC) for repairing pesticide-induced DNA oxidation damage may influence adverse health outcomes. We aimed to evaluate whether polymorphisms in genes involved in nucleotide excision repair (NER) pathway could modulate DNA damage in pesticide-exposed agricultural workers. Xeroderma pigmentosum group F (XPF) (Arg415Gln, G1244A, rs1800067), xeroderma pigmentosum group G (XPG) (Asp1104His, G3507C, rs17655), excision repair cross complementation group 1 (ERCC1) (3'UTR, C8092A, rs3212986) and ERCC1 (Asn118Asn, C19007T, rs11615) polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique in 225 pesticide-exposed agricultural workers and 225 controls from Punjab, North-West India. The assessment of DNA damage was carried out by alkaline comet assay. Kruskal-Wallis test was used to evaluate the association of gene polymorphisms in NER pathway with DNA damage. Pesticide-exposed agricultural workers carrying variant XPF Gln/Gln (AA) genotype showed higher comet tail length (p < 0.01) than wild type Arg/Arg (GG) genotype. The comet tail length (p < 0.01) was found to be significantly increased in exposed agricultural workers carrying XPG His/His (CC) genotype than wild-type Asp/Asp (GG) genotype. In relation to the individuals carrying wild type ERCC1 3'UTR CC genotype, exposed individuals with variant ERCC1 3'UTR CA genotype showed elevation in the comet tail length (p = 0.029). However, we found no association of ERCC1 Asn118Asn (C19007T) genotype with DNA damage. These results indicate that XPF, XPG and ERCC1 genes of NER pathway may modulate the efficacy of the DNA repair system against pesticide exposure in our population.

Assessment of chromosomal aberrations among agricultural workers exposed to pesticides in Punjab, India

Chromosomal aberrations (CAs) are an important tool for assessment of exposure to pesticides. Genotoxic potential of pesticides is a principal risk factor for long-term health effects. The present study was aimed toward the assessment of CAs among agricultural workers exposed to pesticides and comparison with nonagricultural workers not exposed to pesticides. A total of 296 subjects were enrolled in the study: exposed (n = 148) and nonexposed subjects (n = 148) from Punjab. A significantly high frequency of aberrations was seen in peripheral blood lymphocytes of exposed subjects as compared with nonexposed ones. Most CAs were present as loss (aneuploidy) and were observed significantly in subjects having a history of alcohol consumption. It can be, thus, concluded that agricultural workers exposed to a mixture of pesticides, in addition to being alcoholic, are at a greater risk of genotoxic damage. It is highly recommended that the agricultural workers are educated regarding the potential hazards of occupational exposure to pesticides.

Impact of single nucleotide polymorphisms in the OGG1 and XRCC1 genes on modulation of DNA damage in pesticide-exposed agricultural workers in Punjab, North-West India

Pesticide-induced DNA damage is primarily repaired by base excision repair (BER) pathway. However, polymorphism in DNA repair genes may modulate individual's DNA repair capacity (DRC) leading to increased genotoxicity and adverse health effects. Our first study in North-West Indian population aimed to evaluate the impact of OGG1 rs1052133 (Ser326Cys; C1245G), XRCC1 rs1799782 (Arg194Trp; C26304T) and XRCC1 rs25487 (Arg399Gln; G28152A) polymorphisms on the modulation of pesticide-induced DNA damage in a total of 450 subjects (225 pesticide-exposed agricultural workers and 225 age- and sex-matched controls). DNA damage was estimated by alkaline comet assay using silver-staining method. Genotyping was carried out by PCR-RFLP using site-specific restriction enzymes. Mann-Whitney U-test revealed elevation in DNA damage parameters (p < 0.01) in pesticide-exposed agricultural workers than controls. Chi-square test showed significant (p < 0.05) differences in the XRCC1 Arg194Trp (C26304T) and Arg399Gln (G28152A) genotypes among two groups. Multivariate logistic-regression analysis revealed that heterozygous genotypes of OGG1 rs1052133 (326Ser/Cys; 1245CA), XRCC1 rs1799782 (194Arg/Trp; 26304CT) and XRCC1 rs25487 (399Arg/Gln; 2815GA) were positively associated (p < 0.05) with elevated DNA damage parameters in pesticide-exposed agricultural workers. Our results strongly indicate significant positive association of variant OGG1 and XRCC1 genotypes with reduced DRC and higher pesticide-induced DNA damage in North-West Indian agricultural workers.

Heavy Metal-Induced Cerebral Small Vessel Disease: Insights into Molecular Mechanisms and Possible Reversal Strategies

Heavy metals are considered a continuous threat to humanity, as they cannot be eradicated. Prolonged exposure to heavy metals/metalloids in humans has been associated with several health risks, including neurodegeneration, vascular dysfunction, metabolic disorders, cancer, etc. Small blood vessels are highly vulnerable to heavy metals as they are directly exposed to the blood circulatory system, which has comparatively higher concentration of heavy metals than other organs. Cerebral small vessel disease (CSVD) is an umbrella term used to describe various pathological processes that affect the cerebral small blood vessels and is accepted as a primary contributor in associated disorders, such as dementia, cognitive disabilities, mood disorder, and ischemic, as well as a hemorrhagic stroke. In this review, we discuss the possible implication of heavy metals/metalloid exposure in CSVD and its associated disorders based on in-vitro, preclinical, and clinical evidences. We briefly discuss the CSVD, prevalence, epidemiology, and risk factors for development such as genetic, traditional, and environmental factors. Toxic effects of specific heavy metal/metalloid intoxication (As, Cd, Pb, Hg, and Cu) in the small vessel associated endothelium and vascular dysfunction too have been reviewed. An attempt has been made to highlight the possible molecular mechanism involved in the pathophysiology, such as oxidative stress, inflammatory pathway, matrix metalloproteinases (MMPs) expression, and amyloid angiopathy in the CSVD and related disorders. Finally, we discussed the role of cellular antioxidant defense enzymes to neutralize the toxic effect, and also highlighted the potential reversal strategies to combat heavy metal-induced vascular changes. In conclusion, heavy metals in small vessels are strongly associated with the development as well as the progression of CSVD. Chelation therapy may be an effective strategy to reduce the toxic metal load and the associated complications.

Exposure to multiclass pesticides among female adult population in two Chinese cities revealed by hair analysis

The high use of pesticides worldwide and the constant exposure of humans to these toxic-by-design chemicals have drawn the attention on the possible consequences on human health. However, information on the exposure of the general population to pesticides remain very limited in most countries, especially in urban areas. In the present work, hair analysis was conducted to investigate the exposure of 204 urban women living in two Chinese cities (Baoding and Dalian) to 110 pesticides and 30 metabolites of the following families: organochlorines, organophosphates, carbamates, pyrethroids, neonicotinoids, phenylpyrazoles, acid herbicides, urea herbicides and azoles. Results showed that 71 pesticides and 23 metabolites were found in the hair samples, with concentrations ranging up to 1070 pg/mg in hair. In each hair sample, the number of detected chemicals ranged from 25 to 50, demonstrating the cumulative exposure to pesticides among Chinese women in the studied regions. The concentrations of 38 chemicals (e.g., p-nitrophenol, diethyldithiophosphate, λ-cyhalothrin, permethrin, carbendazim and tebuconazole) were significantly different between women in Baoding and Dalian, indicating the regional differences in exposure to pesticide. Using a multiple regression analysis, we found that concentrations of a few dominant pesticides were associated with age, body mass index (BMI), cooking frequency and regions. These results can provide baseline information on exposure of female adult Chinese population to multiple pesticides and support future studies focused on the health effects associated with pesticide exposure.

Chromosomal Instability in Farmers Exposed to Pesticides: High Prevalence of Clonal and Non-Clonal Chromosomal Alterations

Introduction

An important economic activity in Colombia is agricultural production and farmers are frequently exposed to pesticides. Occupational exposure to pesticides is associated with an increased incidence of various diseases, including cancer, Parkinson’s disease, Alzheimer’s disease, reproductive disorders, and birth defects. However, although high genotoxicity is associated with these chemicals, information about the type and frequency of specific chromosomal alterations (CAs) and the level of chromosomal instability (CIN) induced by exposure to pesticides is scarce or absent.

Methods

In this study, CAs and CIN were assessed in peripheral blood lymphocytes (PBLs) from five farmers occupationally exposed to pesticides and from five unexposed individuals using GTG-banding and molecular cytogenetic analysis.

Results

A significant increase in clonal and non-clonal chromosomal alterations was observed in pesticide-exposed individuals compared with unexposed individuals (510±12,2 vs 73±5,7, respectively; p<0.008). Among all CAs, monosomies and deletions were more frequently observed in the exposed group. Also, a high frequency of fragilities was observed in the exposed group.

Conclusion

Together, these findings suggest that exposure to pesticides could be associated with CIN in PBLs and indicate the need for the establishment of educational programs on safety precautions when handling pesticides, such as wearing gloves, masks and boots, changing clothes and maintaining proper hygiene, among others. Further evaluation in other similar studies that include a greater number of individuals exposed to pesticides is necessary.

Assessment of DNA damage and cholinesterase activity in soybean farmers in southern Brazil: High versus low pesticide exposure

The aim of this study was to evaluate the DNA damage in soybean growers during two agricultural periods of a crop season (high and low exposure) and a control group, as well as butyrylcholinesterase (BChE) activity during these exposure periods in order to estimate the degree of BChE inhibition for the exposed group. DNA damage in peripheral whole blood was evaluated by the comet assay and plasma BChE activity was accessed as a measure of exposure to cholinesterase inhibitors. None of the soybean growers reported using full Personal Protective Equipment (PPE). BChE was lower in high exposure period than in low exposure period and DNA damage index was significantly increased in the high exposure period than in the low exposure period. In addition, DNA damage in both exposure periods was higher than control group. No correlation was found between exposure time and DNA damage and BChE activity. However, negative correlation was observed between DNA damage in high and low exposure periods. The results indicate that soybean growers are exposed to cholinesterase inhibitors and to pesticides mixtures with genotoxic potential.

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.

Genotoxic action of Luna Experience-SC 400 fungicide on rat bone marrow

Background: Fungicides describe all chemicals used to control fungi that infect plants. Luna Experience SC-400 is a new line of fungicide that consist of Fluopyram and Tebuconazole. Objective: In this study, We investigated the genotoxicty and cytotoxicty of Luna Experience-SC 400 using comet assay, micronucleus test and polychromatic erythrocytes number in rat bone marrow. The present study is the first report indicating the effects of genotoxic and cytotoxic of Luna experience SC-400 on rat bone marrow cells. Material and Methods: We used three different doses (5mg/kg, 10mg/kg, 20mg/kg) of Luna Experience SC 400 at 48 h intervals during 30 days by gavage in rats.Genotoxicity was evaluated using comet assay and micronucleus test and cytotoxicity was measured the PCE/NCE rate in rat bone marrow. Results: Based on these experimental results, we report that Luna Experience-SC 400 fungicide presents genotoxic and cytotoxic potential on rat bone marrow. There is a significant difference between negative control group and all the doses of Luna Experience-SC 400 (p < 0.05) for comet assay and micronucleus. Even moderate and high doses of fungicides seem to have reached the values of almost positive control group for Genetic Damage Index (GDI) and Damaged Cell Percentage (DCP). In this study, we also investigated the PCE/NCE rate. Fungicide caused a decrease in the level of significant in the PCE/NCE ratio (p < 0.05). Conclusion: Our in vivo study suggests that the gavage exposure to Luna experience SC 400 used in the present investigation may be genotoxic and cytotoxic in rat bone marrow in view of these findings. Because this findings is first report represented in the pesticide biology, it is important to carry out more investigations using various cytogenetic tests under different experimental conditions to definitively resolve the the possible genotoxic and cytotoxic risk associated with new generation pesticides-fungicides.

Health care and exposure to pesticides in periurban horticulture: the case of the Green Belt of the City of Cordoba, Argentina

This article aims to analyze health care and exposure to pesticides within the context of productive and reproductive practices or the everyday life of horticulturists in the Green Belt of the City of Cordoba (GBCC), Argentina, from the individual, particular and general domains as the comprehensive framework of health determining processes. An explanatory analytical study was implemented which included the use of mixed methodologies between 2013 and 2017. A triangulation analysis was carried out of the results of the quantitative and qualitative aspects. It was observed that the dominant agricultural productive model has determined the deterioration of the productive conditions and exposure to pesticides of the horticultural population of the GBCC. Deficient systems for regulating land use, weak legislation and control from the State in accordance with the context impact on everyday life and block the horticulturists' individual health protection practices.

Results of buccal micronucleus cytome assay in pesticide-exposed and non-exposed group

Since many different pesticides have been used occupationally, there have been inconsistent results regarding DNA damages among greenhouse workers. Thus, the aim of the study is to evaluate DNA damages, cell death, and chromosomal instability by using the buccal micronucleus cytome (BMcyt) assay in greenhouse workers and to compare those with a non-exposed group. The BMcyt assay was applied to the exfoliated buccal cell samples collected from 66 pesticide-exposed and 50 non-exposed individuals. We evaluated the frequency of micronucleus (MN), nuclear bud (NBUD), binucleated (BN) cells, and karyolitic (KL), pyknotic (PY), and karyorrhectic (KH) cells. The results showed that the MN, BN, PY, and KH frequencies of the pesticide-exposed group were significantly higher than those of the controls (P ˂ 0.05, P ˂ 0.05, P ˂ 0.01, and P ˂ 0.05, respectively). We observed that the MN, BN, PY, and KH frequencies in the autumn were statistically different compared with those in the control group (P = 0.037 for MN, P = 0.001 for BN, P = 0.016 for PY, and P = 0.033 for KH). The same comparison was done in the spring for the control, and there was a statistically significant difference for MN (P = 0.046) and PY (P = 0.014). We can conclude that pesticide exposure in greenhouse workers was one of the factors that altered DNA damages, cell death, and chromosomal instability in oral mucosa cells.

Occupational exposure to pesticides and thyroid function in Brazilian soybean farmers

INTRODUCTION

Agriculture production has been supported especially by the use of pesticides for crop protection and pest control. Although the agricultural production has been increased by pesticides use, these substances also reach non-target organisms and may become a risk to the health of farmers. Several epidemiological studies in human have investigated the association between exposure to pesticides and altered serum levels of thyroid hormones, reporting both positive and negative results. Overall, the impact of pesticides on human thyroid function is still limited.

OBJECTIVE

The aim of this study was to access serum levels of free thyroxin (FT4), total triiodothyronine (TT3), thyroid-stimulating hormone (TSH), and butyrylcholinesterase (BChE) in soybean farmers in southern Brazil.

METHODS

The exposed group was composed by 46 rural workers and 27 subjects not exposed to pesticides composed the control group. All subjects had blood samples collected by venipuncture in order to analyze the serum levels of FT4, TT3, TSH and BChE.

RESULTS

The results showed a significant decreasing in TSH and increasing in TT3 and FT4 in rural workers, compared to control group. BChE levels were lower in exposed group than in control group. The results suggest that farmers are exposed to mixtures of pesticides with endocrine disruptor properties.

Effect of pesticide exposure on the cholinesterase activity of the occupationally exposed tea garden workers of northern part of West Bengal, India

Context: Pesticide poisoning and related deaths are a global concern, but there is little information about its effect on the occupationally exposed tea garden workers of North Bengal. Objective: This study investigates the level of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) in the blood of the tea garden workers at risk of exposure to a mixture of pesticides. Materials and methods: The study sample consisted of pesticide exposed workers, non-exposed (control), smokers and alcoholics. AChE and BuChE activity was measured and tested for significance. Results: Results showed that AChE activity was half in the pesticide exposed individuals than controls (p≤ 0.001). BuChE activity was also significantly decreased in the pesticide exposed individuals than controls (p≤ 0.001), while AChE and BuChE activity in smokers and alcoholics were not different from that of controls. However, significantly decreased AChE and BuChE activities were recorded in pesticide exposed workers compared to smokers and alcoholics. Conclusions: The results indicated that the decrease in enzyme activities in tea garden workers was due to mixed pesticides (containing organophosphates) exposure. Age was not found to influence the enzyme activities. However, the gender had little effect on the enzyme activities but the effect was not so prominent.

Early prediction of liver carcinogenicity due to occupational exposure to pesticides

Several studies linked between pesticides exposure and development of liver cancer, through several mechanisms inform of genotoxicity, cytotoxicity, tumor promotion, immunotoxicity and hormonal actions. This study aimed to estimate novel biomarkers for early prediction of liver malignancy due to occupational exposure to pesticides in two groups of workers with different socioeconomic standard (highly educated urban researchers and low educated rural pesticides sprayers). This study included 50 urban researchers and 50 rural pesticides sprayers occupationally exposed to pesticides. They were compared with 50 non-exposed urban researchers and 50 non-exposed rural subjects. Several tumor biomarkers were estimated; P53 protein, Alfa fetoprotein (AFP), and Alpha-L-fucosidase (AFU). Additionally, telomerase enzyme activity, Relative telomere length (RTL), and DNA damage using comet assay were measured. Furthermore, the glutathione-S-Transferase (GST) gene polymorphisms were identified for both exposed groups. Statistical analysis revealed elevated level of tumor biomarkers among exposed subjects relative to control groups in spite of being within the normal range. Increase in the DNA damage was detected, with shortening of telomere length and decrease in telomerase enzyme activity in pesticides-exposed subjects compared to their controls. Most of these changes were related to the levels of butyrylcholinesterase. Subjects with GSTT1 genotype were suggested to be more susceptible to hepatic carcinogenicity. Telomere relative length and comets assay together with GST genes polymorphisms could be used as early predictors for liver cancer susceptibility among pesticides exposed workers.

A Framework for Automatic Recognition of Cell Damage on Microscopic Images using Artificial Neural Networks

Despite several technological advances in the past years, the vast majority of microscopy examinations continue to be performed in a very laborious, time-consuming manner, requiring highly experienced personnel to spend several hours to visually examine each microscope slide. Due to recent improvements in modern Digital Image Processing, professionals that work on microscopic exams could benefit from new tools that can apply image processing possibilities to their specific field. We propose a framework consisting of an image segmentation stage, feature extraction, and then a Shallow Neural Network related to human perception. The framework is used to classify among 5 types of animal cell damage analyzed in a case study. The case study used applies the Single Cell Gel Electrophoresis assay (SCGE, also known as comet assay) to the cells of land mollusk Helix aspersa in order to measure the DNA damage caused by mutagenic agents. To train and analyze the performance of our approach, we used a dataset manually segmented by a biologist and comprised of 130 slide samples with labeled cells. Our framework proved to be robust, achieving an average accuracy of 88.3%.

Nonoccupational Exposure of Agricultural Area Residents to Pesticides: Pesticide Accumulation and Evaluation of Genotoxicity

Although many studies related the toxic effects of pesticides on agricultural workers, little research has been done about agricultural area residents. The purpose of this work was to monitor the presence of pesticides, as well as their genotoxic and cytotoxic potential, in humans with blood samples collected from control and intensive agricultural areas in the Thrace region. Pesticide accumulations were determined by LC-MS/MS. Cytotoxicity and genotoxicity were analyzed by comet assay, and the effect of pesticide accumulation on oxidative stress, DNA repair, and molecular chaperone response were analyzed by qRT-PCR assays in the human blood samples. The agricultural area residents had a significantly higher concentration of pesticides than those in the control area at all three sampling times, and the total pesticide amounts were 4.3 and 10 times significantly higher in blood sampled in the pesticide use period (August 2015 and 2016, respectively) than in the nonuse period (November 2015). The results showed that the pesticide level in blood during the use period led to oxidative stress, DNA damage (mean comet length and % tail DNA), and unfolded/misfolded protein response. Particularly, in pesticide use season, difference between these parameters was found statistically significant with comparison to control. Our results indicate that individuals residing around a monoculture rice farming area comprise an at-risk group as a result of increased genotoxicity evidenced in human blood. We suggest that biological monitoring efforts should be used to control nonoccupational exposures to pesticides and thus safeguard the health of agricultural area residents.

Subjective Symptoms of Male Workers Linked to Occupational Pesticide Exposure on Coffee Plantations in the Jarabacoa Region, Dominican Republic

Acute and sub-acute effects of pesticide use in coffee farmers have rarely been investigated. In the present field study, self-reported health symptoms from 38 male pesticide users were compared to those of 33 organic farmers. Results of cytological findings have been reported in an accompanying paper in this issue. The present second part of the study comprises a questionnaire based survey for various, potentially pesticide related symptoms among the coffee farmers. Symptom rates were generally higher in exposed workers, reaching significance in nine out of 19 assessed symptoms. Significantly increased symptom frequencies were related to neurotoxicity, parasympathic effects and acetylcholine esterase inhibition, with the highest differences found for excessive salivation, dizziness and stomach ache. We revealed a lack of precautionary measures in the majority of farmers. Better education, regulations, and safety equipment are urgently needed.

Evaluation of DNA damage in traffic police wardens of Pakistan due to cadmium and zinc

Air quality in urban areas is generally poor especially at traffic intersections and roadsides due to continuous vehicular emissions comprising poly aromatic hydrocarbons, heavy metals, benzene, diesel soot etc. The objective of this study was to compare the primary DNA damage in traffic police wardens occupationally exposed to airborne Cd and Zn (exposed group) and educational institution with negligible exposure to airborne Cd and Zn (control group). Blood levels of Cd and Zn in traffic police wardens and control group were determined by Flame Atomic Absorption Spectroscopy (FAAS) and DNA damage was assessed by using Comet assay. The results of this study showed significantly higher amount of Cd (0.18±0.06mgL^-1) and Zn (4.87±1.34mgL^-1) in the blood of traffic police wardens as compared to control group and according to World Health Organization, these values are 18 and 3 times more to the permissible limit of Cd and Zn respectively in human blood. In addition, significantly higher numbers of DNA damaged cells (28±13%) were observed in traffic police wardens as compared to control group (3.6±2%). Comet tail length was found to be doubled (4.7±1.7μm) in traffic police wardens as compared to the control group (2±1.2μm). These results could be linked to the concentrations of Cd and Zn in blood of traffic police wardens. In conclusion, our results showed that accumulation of Cd and Zn was higher in traffic police wardens due to air pollution (Zn and Cd) and has more damaged DNA of traffic police wardens in Pakistan.

Evaluation of hematological and biochemical parameters of pesticide retailers following occupational exposure to a mixture of pesticides

AIMS

This study was undertaken to ascertain whether light occupational exposure to pesticides by retailers might be associated with any liver, kidney, nervous system dysfunction or hematological abnormalities.

MAIN METHODS

In this cross-sectional study, 70 male pesticide retailers (cases) and 64 male subjects, randomly selected from the constructions workers of city council contractors, as the referent group, were investigated. Urine and blood samples were taken from all subjects for urine analysis, hematological and biochemical parameters. Data analysis was conducted through SPSS v.19 using t-test and chi-square test.

KEY FINDINGS

The results of urine analysis showed that the frequency of abnormal urine tests was significantly higher in cases than in referent individuals. Similarly, the results of CBC showed that the mean values of monocyte, hemoglobin, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin and platelet distribution width were significantly lower, and mean corpuscular hemoglobin concentration and red blood cell distribution width were significantly higher in retailers. No significant differences were found for other parameters.

SIGNIFICANCE

These findings indicate that an association exists between exposure to pesticides by retailers and early subtle and sub-clinical changes in the urine tests and hematological parameters. Engineering measures are recommended to eliminate exposure to pesticides and to prevent its associated outcomes.

DNA damage and epigenetic alteration in soybean farmers exposed to complex mixture of pesticides

Exposure to pesticides can trigger genotoxic and mutagenic processes through different pathways. However, epidemiological studies are scarce, and further work is needed to find biomarkers sensitive to the health of exposed populations. Considering that there are few evaluations of soybean farmers, the aim of this study was to assess the effects of human exposure to complex mixtures of pesticides. The alkaline comet assay modified with restriction enzyme (hOGG1: human 8-oxoguanine DNA glycosylase) was used to detect oxidised guanine, and compared with the buccal micronucleus cytome assay, global methylation, haematological parameters, biochemical analyses (serum glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase, gamma-glutamyl-transferase and butyrylcholinesterase), and particle-induced X-ray emission (PIXE) for the analysis of inorganic elements. Farm workers (n = 137) exposed to different types of pesticides were compared with a non-exposed reference group (control; n = 83). Results of the enzyme-modified comet assay suggest oxidation of guanine in DNA generated by pesticides exposure. It was observed that DNA damage (comet assay and micronucleus test) was significantly increased in exposed individuals compared to the unexposed group. The micronucleus test demonstrated elimination of nuclear material by budding, defective cytokinesis and dead cells. Occupationally exposed individuals also showed genomic hypermethylation of DNA, which correlated with micronucleus frequency. No differences were detected regarding the haematological and biochemical parameters. Finally, significantly higher concentrations of Al and P were observed in the urine of the soybean farmers. DNA damage could be a consequence of the ability of the complex mixture, including Al and P, to cause oxidative damage. These data indicate that persistent genetic instability associated with hypermethylation of DNA in soybean workers after long-term exposure to a low-level to pesticides mixtures may be critical for the development of adverse health effects such as cancer.

Hematological Abnormality, Oxidative Stress, and Genotoxicity Induction in the Greenhouse Pesticide Sprayers; Investigating the Role of NQO1 Gene Polymorphism

The widespread use of pesticides in agriculture represents a threat to the human populations exposed to them. In this cross-sectional study, the hematological and biochemical parameters, plasma cholinesterase (PChE) activity, oxidative stress, genotoxicity, and NAD(P)H: quinone oxidoreductase 1 (NQO1) C609T polymorphism were measured in 100 greenhouse workers occupationally exposed to pesticide mixture and 104 normal healthy controls. There was a decrease in erythrocytes (5.45%, p = 0.026) and hemoglobin (3.26%, p = 0.025), and an increase in mean corpuscular hemoglobin (3.54%, p = 0.013) in the exposed workers. Sprayers showed a reduction in PChE (23%) and GSH (50%) levels, and an increase in lipid peroxidation (LPO) (55%), protein carbonyl (145%), Superoxide dismutase activity (61%), and total antioxidant capacity (35%) (p < 0.001 for all parameters but LPO: p = 0.009). Genotoxicity parameters were significantly high in the exposed cases (for all parameters: p < 0.001 but tail length: p = 0.002). There was a significant correlation between oxidative stress and genotoxicity parameters, and also between these biomarkers and PChE activity. The NQO1 C609T polymorphism was not significantly associated with studied biomarkers. The findings indicate that occupational exposure to a mixture of pesticides can induce hematotoxicity, oxidative stress, and genotoxicity in greenhouse workers.

Markers of genotoxicity and oxidative stress in farmers exposed to pesticides

The effects of chronic exposure to pesticides can lead to the development of several diseases, including different types of cancer, since the genotoxic and mutagenic capacity of these substances can be observed. The objective of this study is to investigate the relation between the occupational exposure to various pesticides and the presence of DNA damage and oxidative stress. Blood samples from 50 rural workers (41 men and 9 women) exposed to pesticides, 46 controls (20 men and 26 women) from the same city (Antônio Carlos, Santa Catarina state, Brazil) and 29 controls (15 men and 14 women) from another city (Florianópolis, Santa Catarina state, Brazil), were evaluated using the comet assay and the cytokinesis-block micronucleus (CBMN) technique for genetic damage, and the test of thiobarbituric acid reactive substances (TBARS) and catalase (CAT) activity for the oxidative stress. Cholinesterase activities were also determined, but there was no statistical difference among exposed workers and controls. Significant differences were found in DNA damage among groups. The comet assay performed on peripheral blood lymphocytes of these individuals had a significantly higher DNA damage index in the exposed group comparing to controls (p < 0.0001). MNi (p < 0.001), NBUDs (p < 0.005) and NPBs (p < 0.0001) were also found to be significantly higher in the exposed group. The TBARS values were significantly higher comparing to the Florianopolis control group (p < 0.0001). Even though CAT values were higher than controls, there was no statistical difference. Thus, it is concluded that the exposed individuals, participants of this study, are more subject to suffer genetic damage and, consequently, more susceptible to diseases resulting from such damages.

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

The aim of the study was to assess of occupational exposure to pesticides in rural workers using genotoxicity test, bioindicators and clinical evaluation. Blood, urine and buccal samples from persons, rural workers exposed to a complex mixture of pesticides with organophosphates (n=94) and without organophosphates (n=94) were collected to compare the activities of cholinesterases, the levels of urinary dialkyl phosphates, genotoxicity data, from a cytome assay. Biomarkers were analysed by traditional/published methods Control group consisted of 50 other persons, non- occupationally exposed to pesticides from the city of Alfenas, Minas Gerais, Brazil. All subjects underwent a clinical evaluation. In the group exposed to organophosphates, the activity of acetylcholinesterase, butyrylcholinesterase and total cholinesterase was lower by 63.8%, 12.8%, and 14.8%, respectively, and 92.6% of the group had dialkyl phosphates present in their urine. The cytome assay was used to measure biomarkers of DNA damage (micronuclei and/or elimination of nuclear material by budding), cytokinetic defects (binucleated cells), and proliferative potential (basal cell) and/or cell death (condensed chromatin, karyorrhectic, pyknotic, and karyolytic cells). The group exposed to organophosphates showed significant changes in all these parameters compared to the control group and showed significant changes in budding, condensed chromatin and karyolytic cells compared with the group non-exposed to organophosphates. Data from the clinical evaluation showed significant changes in the central nervous, respiratory and auditory systems. The studied biomarkers are able to distinguish occupational and environmental exposure to pesticides and the data showed hazardous exposure to organophosphates and afforded valuable data to estimate the risk to cancer development.

Molecular detection of M. tuberculosis and M. bovis and hematological and biochemical analyses in agricultural sprayers exposed to pesticides: A cross-sectional study in Punjab, Pakistan during 2014-2016

We determined the correlation between a pesticide exposure, physical health and susceptibility toward tuberculosis along with hematological indices and liver enzymes' alterations in sprayers exposed to pesticides. Molecular detection of Mycobacterium tuberculosis and Mycobacterium bovis was detected by targeting histone-like protein (hupB) gene. The WBC (white blood cells) and RBC (red blood cells) levels of male sprayers and non-sprayers were significantly different (P<0.05). In female spray workers, the WBC and neutrophils levels were significantly different as compared with non-sprayers. Overall, in both male and female pesticide-exposed sprayers, mean values of alanine amino transferase and aspartate amino transferase were higher as compared with unexposed workers. M. Tuberculosis were detected in 15% male sprayers and 36% female sprayers while, M. bovis was detected in 5% male sprayers and 10% female sprayers. A χ²-test indicated that there existed a significant different (P<0.05) between positive and negative M. tuberculosis and M. bovis in both male/female spray workers out of total. The susceptibility of pesticide-exposed sprayers to tuberculosis and alterations in hematology and liver enzymes is crucial for health. Toxic effects of pesticides may lead to a weak immune system and increased tuberculosis susceptibility.

Organochlorine pesticides, their toxic effects on living organisms and their fate in the environment

Organochlorine (OC) pesticides are synthetic pesticides widely used all over the world. They belong to the group of chlorinated hydrocarbon derivatives, which have vast application in the chemical industry and in agriculture. These compounds are known for their high toxicity, slow degradation and bioaccumulation. Even though many of the compounds which belong to OC were banned in developed countries, the use of these agents has been rising. This concerns particularly abuse of these chemicals which is in practice across the continents. Though pesticides have been developed with the concept of target organism toxicity, often non-target species are affected badly by their application. The purpose of this review is to list the major classes of pesticides, to understand organochlorine pesticides based on their activity and persistence, and also to understand their biochemical toxicity.