Cholinesterase inhibition and its association with hematological, biochemical and oxidative stress markers in chronic pesticide exposed agriculture workers

Chronic exposures to cholinesterase-inhibiting pesticides adversely affects the health of agricultural workers in India

Biomonitoring of pesticide exposure has become a public concern because of its potential health effects. The present study investigated the acetylcholinesterase (AChE) inhibitory levels and their associated health effects in agricultural areas in Telangana, India. This cross-sectional included 341 exposed participants and 152 control participants from agricultural areas. A structured questionnaire was completed and blood and urine samples were collected to measure pesticides, dialkyle phosphate (DAP) metabolites, and AChE activity using liquid chromatography-tandem mass spectrometry and reversed-phase high-performance liquid chromatography. twenty-eight pesticides were detected in blood samples at concentrations ranging 0.42-45.77 ng/mL. Six DAP metabolites were also measured in urine, and all DAP metabolites were significantly higher in the exposed group. AChE activity is significantly reduced in individuals exposed for >10 years, raising concerns regarding possible neurological disorders. These results emphasise the urgent need to investigate the health effects of pesticides exposure, especially in agriculture.

Assessing IRS performance in a gender-integrated vector control programme on Bioko Island, Equatorial Guinea, 2010-2021

BACKGROUND

Indoor residual spraying (IRS) is a common vector control strategy in countries with high malaria burden. Historically, social norms have prevented women from working in IRS programmes. The Bioko Island Malaria Elimination Project has actively sought to reduce gender inequality in malaria control operations for many years by promoting women's participation in IRS.

METHODS

This study investigated the progress of female engagement and compared spray productivity by gender from 2010 to 2021, using inferential tests and multivariable regression. Spray productivity was measured by rooms sprayed by spray operator per day (RSOD), houses sprayed by spray operator per day (HSOD), and the daily productivity ratio (DPR), defined as the ratio of RSOD to HSOD, which standardized productivity by house size.

RESULTS

The percentage of women participating in IRS has increased over time. The difference in DPR comparing male and female spray operators was only statistically significant (p < 0.05) for two rounds, where the value was higher for women compared to men. Regression analyses showed marginal, significant differences in DPR between men and women, but beta coefficients were extremely small and thus not indicative of a measurable effect of gender on operational performance.

CONCLUSIONS

The quantitative analyses of spray productivity are counter to stigmatizing beliefs that women are less capable than male counterparts during IRS spray rounds. The findings from this research support the participation of women in IRS campaigns, and a renewed effort to implement equitable policies and practices that intentionally engage women in vector control activities.

GC-MS based untargeted metabolomics reveals the metabolic response of earthworm (Eudrilus eugeniae) after chronic combinatorial exposure to three different pesticides

In this study GC-MS-based untargeted metabolomics was used to identify the metabolic response of earthworm; Eudrilus eugeniae exposed to sub-lethal concentrations of chlorpyrifos-CHL, cypermethrin-CYP, Glyphosate-GLY, and Combined-C (all three pesticides) at the concentrations of 3, 6, and 12 mg/kg. Principal component analysis of the obtained datasets revealed a clear distinction between the control and treatment groups. The mean weight of the worms in the treated groups decreased significantly (p < 0.05). Among the identified metabolites, oleic acid (~ 93.47%), lysine (~ 92.20%), glutamic acid (~ 91.81%), leucine (~ 90.20%), asparagine (~ 94.20%), methionine (~ 92.27%), malic acid (~ 93.37%), turanose (~ 95.04%), maltose (~ 92.36%), cholesta-3,5-diene (~ 86.11%), galactose (~ 93.20%), cholesterol (~ 91.56%), tocopherol (~ 85.09%), decreased significantly (p < 0.05), whereas myoinositol (~ 83%) and isoleucine (78.09%) increased significantly (p < 0.05) upon exposure to the CHL, CYP, GLY, and C. Overall, the findings suggest that earthworms might be a new entry point for the pesticides into the food chain. The present study highlights that metabolomics can be a reliable approach to understand the effect of different xenobiotics including pesticides on the metabolic response of earthworms.

The impact of the use of personal-protective-equipment on the minimization of effects of exposure to pesticides among farm-workers in India

Introduction

Although excessive use of pesticides and unsafe agricultural practices may contribute to numerous intoxications, the role of PPE (personal-protective-equipment) in the minimization of toxicological effects due to pesticide exposure has not been addressed so far. The present study aimed to assess the impact of the use of PPE on the minimization of effects of exposure to pesticides among farm-workers.

Methods

A community-based follow-up study with questionnaire-based survey and field observations was undertaken among farm-workers (n = 180) of Rangareddy district, Telangana, India. Biomarkers of exposure such as cholinesterase activity, inflammatory markers (TNF-α, IL-1β, IL-6, cortisol, and hs-C reactive protein), nutrients (vitamins A, E), liver function (total protein and A/G ratio, AST and ALT levels) were investigated in the laboratory by following the standard protocols.

Results

Farm-workers who had a mean farming exposure of 18 years of and who neither followed safe pesticide handling practices nor used PPE and also showed reluctance to obey good agricultural practices (GAPs). Inhibition of AChE (acetylcholine esterase) with increased inflammation was found among farm-workers as compared to their respective normal values when they have not used PPE. Linear regression statistical analysis revealed a profound effect on inhibition in the AChE activity and various inflammatory markers with the increase in the duration of pesticide exposure. Further, there was no effect of the duration of pesticide exposure on the levels of vitamins A, E, ALT, AST, total protein, and A/G ratio. Further, intervention studies carried out on the use of PPE provided (commercially available and cost-effective) for 90 days showed a significant reduction in the biomarker levels (p < 0.01).

Conclusion

This study demonstrated the importance of the use of PPE during pesticide applications and other agricultural tasks to minimize pesticide-associated adverse health effects.

Pesticide Residues in Fresh Fruit and Vegetables from Farm to Fork in the Kampala Metropolitan Area, Uganda

This study assessed concentrations of pesticide residues in fruits and vegetables from farm-to-fork in Kampala Metropolitan Area, Uganda. A total of 160 samples of fruit and vegetables collected from farms, markets, streets, restaurants and homes were analysed using liquid chromatography-tandem mass spectrometry; and Gas Chromatograph-Mass Spectrometer for dithiocarbamates. Multiple pesticide residues were detected in majority of the samples (95.6%). The proportions of the most frequently detected pesticides residue classes were organophosphates (91.3%), carbamates (67.5%), pyrethroids (60.0%) dithiocarbamates (48.1%) and neonicotinoids (42.5%). Among organophosphates, propotamophos, acephate, fonofos, monocrotophos and dichlorvos were the most detected active ingredients; aminocarb, methomyl and pirimicarb were the commonly detected carbamates; while imidacloprid, a neonicotinoid and lambda-cyhalothrin, pyrethroid were also highly detected. Twenty-seven pesticide were tested at all stages, of which the concentrations either decreased or increased along the chain. Multiple pesticide residues occurred in commonly consumed fruit and vegetables with decreasing or increasing concentrations from farm-to-fork.

Adverse Health Effects in Women Farmers Indirectly Exposed to Pesticides

Farmers are among the most vulnerable populations because of the exposure to low levels of pesticides. Acetylcholinesterase and butyrylcholinesterase activities are considered as biomarkers of pesticides poisoning. However, biomarkers of oxidative stress are also playing an important role in toxicity of these contaminants. Further, increased activities of gamma-glutamyltransferase, alanine aminotransferase, urea and creatinine have been linked with hepatic and nephrotoxic cell damage, respectively. The aim of this study was to ascertain if the indirect exposure to pesticides leads to some biochemical parameter changes. Thus, cholinesterase activities, oxidative stress status (lipid and protein oxidation), hepatic function (AST and ALT levels), hormonal function (TSH, T4, FSH, LH and AMH), renal function (serum creatinine and urea), as well as possible subclinical kidney damage (urinary proteins and biomarkers of early kidney damage) were evaluated in farmer women who collect fruits and vegetables comparing with a group of women non-occupational exposed to pesticides but living in the same rural environment. Samples were taken periodically along one year to relate the observed effects to a chronic exposure. Our main results showed for the first time a subclinical kidney damage in a rural setting with indirect chronic exposure to pesticides.

Cholinesterase homozygous genotype as susceptible biomarker of hypertriglyceridaemia for pesticide-exposed agricultural workers

PURPOSE

Dyslipidemia is an emerging metabolic disorder among pesticide-exposed agricultural workers, and this study was aimed to explore biomarkers of hypertriglyceridaemia susceptibility.

METHODS

This cross-sectional study recruited 72 pesticide-exposed subjects and 78 non-exposed controls. Lipid profile, cholinesterase activity, and thyroid hormones were analysed with routine assays. Six loci, including rs11206244 and rs2235544 for deiodinase 1, rs12885300 and rs225014 for deiodinase 2, rs1803274 for butyrylcholinesterase, and rs3757869 for acetylcholinesterase were genotyped using an improved multiplex ligation detection reaction technique.

RESULTS

Pesticide-exposed subjects showed higher levels of triglyceride than controls (p = 0.009), although there were comparable cholinesterase activity and genotype frequencies of all six loci between pesticide-exposed subjects and controls. Pesticide-exposed subjects with homozygous genotype of cholinesterase had increased triglyceride levels than controls (p < 0.05). The percentage of hypertriglyceridaemia was 28.6% and 8.8% for pesticide-exposed subjects and controls with homozygous butyrylcholinesterase genotype (p = 0.007) and 20.8% and 14.3% with homozygous acetylcholinesterase genotype (p = 0.792), respectively. Multivariate logistic regression analyses found that odds ratio of hypertriglyceridaemia is 21.92 and 4.56 for pesticide-exposed subjects with homozygous genotype of butyrylcholinesterase (p = 0.001) and acetylcholinesterase (p = 0.036), respectively.

CONCLUSIONS

Cholinesterase homozygous genotype might be a potential susceptible biomarker in screening pesticide-exposed agricultural workers vulnerable to hypertriglyceridaemia.

Measuring butyrylcholinesterase activity and hematological parameters in farmers exposed to pesticides: a case and control study from Morocco

The Farmers are exposed to a wide range of pesticides. The application of these pesticides has been documented to lead to several adverse health effects. This aim of this case-control study was to estimate risks linked to pesticide exposure among farmers in the Souss region of Morocco through the analysis of serum butyrylcholinesterase (BChE) activity and hematological parameters. This prospective study included 98 participants (49 farmers and 49 controls). A questionnaire was used to collect socio-demographic data, technical information regarding the application of pesticides, previous poisonings by pesticides, and training on the use of pesticides. The blood samples were collected for hematological parameters and BChE analysis, and the activity of BChE was measured spectrophotometrically by the butyrlthiocholine method. The results showed no significant differences in hemoglobin (HB), hematocrit, mean corpuscular volume, platelets, red blood cell, and leukocyte cell counts between both the exposed farmer and the control group. In contrast, a significant decreased in mean corpuscular HB, mean corpuscular HB concentration, eosinophils, and basophils counts were observed. In addition, the exposed group showed a significant decrease in the BChE activity (p < .001) compared to the control group. Farmers exposed to pesticides in the Souss Massa region may be at risk of hematological alterations as well as neurotoxicity, characterized by inhibition of BChE enzyme activity.

Oxidative stress and DNA damage in agricultural workers after exposure to pesticides

BACKGROUND

Recent epidemiological studies on workers describe that exposure to pesticides can induce oxidative stress by increased production of free radicals that can accumulate in the cell and damage biological macromolecules, for example, RNA, DNA, DNA repair proteins and other proteins and/or modify antioxidant defense mechanisms, as well as detoxification and scavenger enzymes. This study aimed to assess oxidative stress and DNA damage among workers exposed to pesticides.

METHODS

For this purpose, 52 pesticide exposed workers and 52 organic farmers were enrolled. They were assessed: the pesticide exposure, thiobarbituric acid reactive substances (TBARS), total glutathione (TG), oxidized glutathione levels (GSSG), and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), levels.

RESULTS

Correlation between pesticide exposure was positively associated with high TBARS and 8-oxodG levels (p <  0.001). A negative association was founded with TG and GSSG and pesticide exposure.

CONCLUSIONS

The present investigation results seem to indicate a mild augment in oxidative stress associated with pesticide exposure, followed by an adaptive response to increase the antioxidant defenses to prevent sustained oxidative adverse effects stress.

Oxidative stress and DNA damage in agricultural workers after exposure to pesticides

BACKGROUND

Recent epidemiological studies on workers describe that exposure to pesticides can induce oxidative stress by increased production of free radicals that can accumulate in the cell and damage biological macromolecules, for example, RNA, DNA, DNA repair proteins and other proteins and/or modify antioxidant defense mechanisms, as well as detoxification and scavenger enzymes. This study aimed to assess oxidative stress and DNA damage among workers exposed to pesticides.

METHODS

For this purpose, 52 pesticide exposed workers and 52 organic farmers were enrolled. They were assessed: the pesticide exposure, thiobarbituric acid reactive substances (TBARS), total glutathione (TG), oxidized glutathione levels (GSSG), and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), levels.

RESULTS

Correlation between pesticide exposure was positively associated with high TBARS and 8-oxodG levels (p <  0.001). A negative association was founded with TG and GSSG and pesticide exposure.

CONCLUSIONS

The present investigation results seem to indicate a mild augment in oxidative stress associated with pesticide exposure, followed by an adaptive response to increase the antioxidant defenses to prevent sustained oxidative adverse effects stress.

Pesticide handling practices and self-reported morbidity symptoms among farmers

Amid growing concern about the adverse effects of pesticides, a questionnaire-based cross-sectional study was conducted to evaluate farmers' knowledge on pesticides handling. Results of in-depth surveys (n = 217) with field observations revealed that participants had a mean 18 years of farming experience and knapsack-sprays were used for spraying. About 99% were not using any personal-protective-equipments during mixing, loading, application operations. Over 80% reentered the treated farms within two-days of application without following safety protocols and 39% admitted unsafe disposal of empty containers of pesticides. Statistical-analysis revealed a significant association between participant's pesticide handling practices and self-reported morbidity symptoms (p < 0.05). Despite awareness of toxicity, participants were mishandling the pesticides. Training on safe handling practices and incentives in form of personal-protective-equipments could be productive to ensure safety at work.

Oxidative Stress and Analysis of Selected SNPs of ACHE (rs 2571598), BCHE (rs 3495), CAT (rs 7943316), SIRT1 (rs 10823108), GSTP1 (rs 1695), and Gene GSTM1, GSTT1 in Chronic Organophosphates Exposed Groups from Cameroon and Pakistan

The detrimental effects of organophosphates (OPs) on human health are thought to be of systemic, i.e., irreversible inhibition of acetylcholinesterase (AChE) at nerve synapses. However, several studies have shown that AChE inhibition alone cannot explain all the toxicological manifestations in prolonged exposure to OPs. The present study aimed to assess the status of antioxidants malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH) (reduced), catalase, and ferric reducing antioxidant power (FRAP) in chronic OP-exposed groups from Cameroon and Pakistan. Molecular analysis of genetic polymorphisms (SNPs) of glutathione transferases (GSTM1, GSTP1, GSTT1), catalase gene (CAT, rs7943316), sirtuin 1 gene (SIRT1, rs10823108), acetylcholinesterase gene (ACHE, rs2571598), and butyrylcholinesterase gene (BCHE, rs3495) were screened in the OP-exposed individuals to find the possible causative association with oxidative stress and toxicity. Cholinesterase and antioxidant activities were measured by colorimetric methods using a spectrophotometer. Salting-out method was employed for DNA extraction from blood followed by restriction fragment length polymorphism (RFLP) for molecular analysis. Cholinergic enzymes were significantly decreased in OP-exposed groups. Catalase and SOD were decreased and MDA and FRAP were increased in OP-exposed groups compared to unexposed groups in both groups. GSH was decreased only in Pakistani OPs-exposed group. Molecular analysis of ACHE, BCHE, Catalase, GSTP1, and GSTM1 SNPs revealed a tentative association with their phenotypic expression that is level of antioxidant and cholinergic enzymes. The study concludes that chronic OPs exposure induces oxidative stress which is associated with the related SNP polymorphism. The toxicogenetics of understudied SNPs were examined for the first time to our understanding. The findings may lead to a newer area of investigation on OPs induced health issues and toxicogenetics.

Co-exposure risks of pesticides residues and bacterial contamination in fresh fruits and vegetables under smallholder horticultural production systems in Tanzania

This study was carried out to investigate the risks of simultaneous exposure to pesticide residues and bacteria contaminants in locally produced fresh vegetables and vegetables in Tanzania. A total of 613 samples were analyzed for pesticide residues, out of which 250 were also analyzed for bacterial contamination. Overall, 47.5% had pesticide residues, 74.2% exceeded Maximum Residue Levels (MRLs). Organophosphorus (95.2%), organochlorines (24.0%), pyrethroids (17.3%), and carbamates (9.2%) residues dominated. MRL values were mostly exceeded in tomatoes, onions, watermelons, cucumbers, Chinese cabbage, and sweet paper. Tetramethrin (0.0329-1.3733 mg/kg), pirimiphos-methyl (0.0003-1.4093 mg/kg), permethrin (0.0009-2.4537 mg/kg), endosulfan (beta) (0.0008-2.3416 mg/kg), carbaryl (0.0215-1.5068 mg/kg), profenofos (0.0176-2.1377 mg/kg), chlorpyrifos (0.0004-1.2549 mg/kg) and dieldrin (0.0011-0.5271 mg/kg) exceeded MRLs. The prevalence of bacteria contamination was high (63.2%). Enterobacter (55.6%) Pseudomonas aeruginosa (32.4%), E. coli (28.2%), Citrobacter (26.8%), Klebsiella oxytoca (14.8%), and Salmonella (7.7%) were isolated. Furthermore, 46.4% tested positive for both pesticide residues and bacterial contaminants. Vegetables from farms (60.7%) contained more dual contaminants than market-based vegetables (41.8%). This may have resulted from excessive pesticide use and unhygienic handling of fresh fruits and vegetables at production level. Binary logistic regression showed that fresh fruits and vegetables with pesticide residues were 2.231 times more likely to have bacteria contaminants (OR: 2.231; 95% CI: 0.501, 8.802). The contamination levels of pesticide residues and bacterial contaminants could be perceived as a serious problem as most fresh fruits and vegetables recorded values of pesticide residues far above the MRLs with pathogenic bacteria isolated in higher proportions. MRLs was higher in most vegetables consumed raw or semi-cooked such as watermelons, carrots, cucumber, tomatoes, onion and sweet paper. There is an urgent need to develop pesticide monitoring and surveillance systems at farmer level, educating farmers and promoting the use of greener pesticides to mitigate the health effects of pesticides and bacterial contaminants.

Identification of markers of depression and neurotoxicity in pesticide exposed agriculture workers

Earlier, we reported that chronic exposure to pesticides causes a reduction in the acetylcholinesterase activity and hematological and biochemical alterations in agriculture workers. In continuation with that, the present study aimed to investigate the pesticide-induced neurochemical imbalance and its association with behavior alterations in agricultural workers. A significant increase in depressive symptoms, assessed by the Beck Depression Inventory-II was observed in pesticide exposed workers as compared to the unexposed. A decrease in the level of dopamine in plasma and levels of dopamine, 3,4-dihydroxyphenylacetic acid, homovanillic acids, norepinephrine, serotonin, and hydroxyindoleacetic acid in urine was also observed. An increase in the levels of MAO-A and MAO-B has also been observed in these individuals. The decreased levels of neurotransmitters in the blood and urine have been linked with increased levels of MAO and pesticide residues in plasma and urine. Furthermore, these changes were associated with a higher incidence of depression in agricultural workers.