Knowledge, attitude and practices of pesticide use and acetylcholinesterase depression among farm workers in Nepal

The Survival and Physiological Response of Calliptamus abbreviatus Ikonn (Orthoptera: Acrididae) to Flavonoids Rutin and Quercetin

Insect-resistant substances from plants are important natural resources that human beings can potentially develop and use to control pests. In this study, we explored the adverse effects of rutin and quercetin on grasshopper (Calliptamus abbreviatus), as well as the insect's physiological response to these substances in laboratory and field experiments. These two plant compounds exhibited toxic effects on C. abbreviatus, with quercetin showing a stronger toxicity, indicated by a lower survival, slower development, and higher induced gene expression and activities of UDP-glucuronosyltransferase, cytochrome P450s, superoxide dismutase, peroxidase and catalase, compared to rutin. These compounds, especially quercetin, have the potential to be developed as biopesticides to control grasshoppers.

Occupational exposure to pesticides: DNA damage in horticulturist from Nativitas, Tlaxcala in Mexico

Mexico is a country where agricultural activity is of great importance, but biomonitoring data are still scarce. With more intensive pesticides use per unit area/surface in horticultural productivity, there is a higher impact on environmental contamination and workers' health. Considering that exposure to various pesticide and pesticide mixtures represents an additional genotoxic risk, the appropriate characterization of exposure, confounding factors and the risk itself are very much needed. We compared genetic damage in 42 horticulturists and 46 unexposed controls (Nativitas, Tlaxcala) using alkaline comet (whole blood) and micronucleus (MN) test with nuclear abnormalities (NA) (buccal epithelial cells). Workers demonstrated significantly higher levels of damage (TI%=14.02 ± 2.49 vs. 5.37 ± 0.46; MN=10.14 ± 5.15 vs. 2.40 ± 0.20), with more than 90% of them not using protective clothing nor gloves during application. Combined DNA damage techniques and periodic monitoring together with educational programs for safe pesticide application is the best strategy to assess and prevent workers' health risks.

Knowledge, perception, and pesticide application practices among smallholder cocoa farmers in four Ghanaian cocoa-growing regions

Pesticides are widely used in Ghana, especially in cocoa farming. However, the practice is suboptimal and unsupervised. Incorrect use of these chemicals can seriously harm human health, the environment, and economies that rely on these farmers' output. The study assessed cocoa farmers' pesticide knowledge, practices, and risk perception. Four hundred and four cocoa farmers were chosen randomly from 26 communities in four cocoa-growing regions of Ghana to answer questions about their risk knowledge, awareness, and practices, including personal protective equipment, storage and disposal of leftover pesticides, and used containers. The study revealed that 87% of the respondents belonged to cooperatives and certification groups. There was a significant positive relationship between group membership and benefits derived from inputs and training in pesticide use. About 70% of insecticides used were approved by the Ghana Cocoa Board, with neonicotinoids and pyrethroids being the most highly used insecticide classes in cocoa farms. Although farmers claimed adequate pesticide knowledge, this did not translate into practice, with the majority exhibiting improper pesticide storage, application, and disposal practices. Farmers appeared to know a lot but lacked the skills and attitude to put their knowledge to use. The improper practices appear to manifest in a variety of health symptoms experienced by farmers as a result of chemical exposure. The findings from this study suggest that cocoa farmers in Ghana require adequate practical training and support on pesticide use to reduce their associated health risks, protect the environment and ensure sustainable cocoa production in the world's second-largest cocoa bean exporter.

Video display terminal use and dry eye: preventive measures and future perspectives

BACKGROUND

Dry eye disease (DED) is a common cause of ocular pain and discomfort. Dry eye disease (DED) stems from a loss-of-tear film homeostasis and is frequently seen in video display terminal (VDT) users. Video display terminal (VDT) use reduces blink rates and increases incomplete blinks, leading to tear film instability and ocular inflammation, promoting DED.

PURPOSE

To assess and evaluate the methods for preventing VDT-associated DED and ocular discomfort.

METHODS

Studies were found using PubMed and Embase with the search terms: (digital visual terminal* OR computer use OR screen use OR smartphone OR display OR visual display terminal* OR computer vision syndrome OR tablet OR phone OR screen time) AND (dry eye OR DED).

RESULTS

Thirty-one relevant articles were found. Ten described single-visit studies, whereas 21 had a prolonged follow-up. Most preventive measures of VDT-associated DED aimed to increase blink rate or directly prevent tear film instability, ocular inflammation, mucin loss or ocular surface damage. Using an adjustable chair and ergonomic training, blink animations and omega-3 supplementation improved signs and symptoms of VDT-associated DED. Taking frequent breaks was associated with fewer symptoms, but no study assessed the commonly suggested 20-20-20 rule.

CONCLUSION

Preventive measures, such as blink animation programmes, oral intake of omega-3 fatty acids and improved ergonomics act on different parts of the vicious cycle of dry eye and could supplement each other. A comparison of the efficacy of the different interventions as well as more evidence of the effect of increased humidity, VDT filters and ergonomic practices, are required.

Attitudinal behaviour of agriculturalists towards pesticide use in Pir Panjal Range of Kashmir Himalayas

BACKGROUND

Attainment of safety during pesticide spraying relies on the farmer's knowledge of pesticide use, attitude and sense of safety. However, such investigations are insufficient in the current study area.

METHODS

The study is based on a primary survey of 384 orchardists about the myriad of aspects affecting the use of pesticides and their subsequent effects.

RESULTS

The study revealed that knowledge, attitude, and perception had a weighted average index (WAI) and a standard deviation (SD) of 2.85 ± 1.17, 3.55 ± 1.34, and 3.81 ± 0.98 correspondingly. The findings reflect the farmers have a low to moderate level of knowledge, a moderate attitude toward pesticides, and a favourable perception on their utilization. Thus, for farmer personal protective equipment (PPE) use, it scored 2.77 ± 0.90 on the WAI scale, indicating that most farmers use PPEs 'rarely to occasionally' and that none use full protective gear. Furthermore, attitude and PPE usage exhibited a negative relationship with age, as younger people use PPE more than older ones. The findings were consistent for both farming experience and PPE usage. Moreover, there exists a positive association between age with perception and farming experience, knowledge with perception and PPE use, and attitude with perception.

CONCLUSIONS

The coefficient of determination (R²) shows that 67.2% of the variability in farmers' PPE use was attributed to factors including knowledge, attitude, perception, and education. A favorable behavioral shift in pesticide usage may be achieved by enhancing farmers' knowledge, attitudes and perceptions, and adequate PPE usage.

Farmers' knowledge and practice regarding good agricultural practices (GAP) on safe pesticide usage in Indonesia

Synthetic pesticides are widely applied for pest and disease control in Indonesia. However, a lack of knowledge and use of Good Agricultural Practices (GAP) for safe pesticide usage among Indonesian farmers remains a problem. This study aims to investigate the gap between farmers' knowledge of GAP for safe pesticide usage and their application of it. This research was conducted in 2020 in five Indonesian provinces. Primary data collection was by means of a survey, in which 298 respondents answered structured questionnaires. The survey also identified the sources of the information recorded and the respondents’ experience of pesticide exposure. The analysis tools used were the Wilcoxon Signed Ranked Test and Importance-Performance Analysis (IPA). There were significant differences in the results of the first analysis. These results appear to confirm the results of further analysis using IPA, which show that a high level of knowledge does not mean that farmers will apply this knowledge in practice: this is particularly relevant to wearing gloves and masks, using tools to remove blockages, never clearing blocked nozzles by blowing into them, and disposing of empty containers properly. Nevertheless, in some cases high levels of knowledge do result in high levels of application. Cases of pesticide exposure affecting human health by causing symptoms such as dizziness, nausea, and vomiting confirm that GAP for pesticide usage are not being implemented properly by some farmers. It is therefore recommended that their knowledge should be enhanced through the series of technical training programs using participatory approaches, so that farmers accumulate knowledge which will drive them to adopt GAP for safe pesticide usage.

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

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

Ecological risk assessment of pesticide residues in soils from vegetable production areas: A case study in S-Nepal

Pesticides pose a serious risk to ecosystems. In this study, we used European Food Safety Authority methods, such as risk quotient (RQ) and toxicity exposure ratios (TER), to assess the potential ecological risks of 15 pesticide residues detected in agricultural soils in the Gaidahawa Rural Municipality of Nepal. The mean and maximum concentrations of the detected pesticide residues in the soil were used for risk characterization related to soil organisms. RQ_mean, TER_mean and RQ_maximum, TER_maximum were used to determine general and the worst-case scenarios, respectively. Of all the detected pesticides in soils, the no observed effect concentration (NOEC) for 27% of the pesticides was not available in literature for the tested soil organisms and their TER and RQ could not be calculated. RQ threshold value of ≥1 indicates high risk for organisms. Similarly, TER threshold value of ≥5, which is acceptable trigger point value for chronic exposure, indicates an acceptable risk. The results showed that the worst-case scenario (RQ_maximum) indicated a high risk for soil organisms from chlorpyrifos [RQ_maximum > 9 at depths (cm) of 0-5, 15-20 and 35-40 soil layer]; imidacloprid (1.78 in the 35-40 cm soil layer) and profenofos (3.37 in the 0-5 cm and 1.09 in the 35-40 cm soil layer). Likewise, for all the soil depths, the calculated TER for both the general and worst-case scenarios for chlorpyrifos ranged from 0.37 to 3.22, indicating chronic toxicity to F. candida. Furthermore, the risk of organophosphate pesticides for soil organisms in the sampling sites was mainly due to chlorpyrifos, except for two study sites where the risk was from profenofos. Ecological risk assessment (EcoRA) of the pesticide use in the study area indicated that the EFSA soil organisms were at risk at some of the localities where farmers practiced conventional farming.

Small-scale Farmer Pesticide Knowledge and Practice and Impacts on the Environment and Human Health in Ethiopia

BACKGROUND

Inappropriate use and application of pesticides in Ethiopia pose a major threat to the health of farmers and the environment.

OBJECTIVE

The present study aimed to assess the level of knowledge, attitudes, and practices of small-scale vegetable farmers towards the use of pesticides in Ethiopia along the Lake Ziway watershed.

METHODS

This was a cross-sectional study involving a total of 210 farmers randomly selected during a period of pesticide application from a purposively selected village located in the immediate vicinity of Lake Ziway, Ethiopia. Data were generated through structured in-depth interviews and on-site observations on farms. A Chi-square test was applied to evaluate whether the collected data and their probable associations were significant.

RESULTS

World Health Organization (WHO) class II pesticides (moderately toxic) were the most frequently used pesticides in the study area. There was no reported use of WHO classes 1a and 1b and banned or restricted pesticides such as dichlorodiphenyltrichloroethane (DDT) and endosulfan. Most (92%) farmers reported indiscriminately disposing of empty containers in the field, while 86.7% applied the leftover pesticides to other crops. More than 90% of small-scale farmers did not use any personal protective equipment (PPE) when handling pesticides. About 95% of farmers had poor knowledge regarding pesticides. A significant association (p < 0.001) was observed between the knowledge of farmers and their practices related to pesticides.

CONCLUSIONS

Generally, the knowledge of small-scale farmers on pesticides was poor. Moreover, the inappropriate disposal of pesticides and pesticide containers poses a risk to the environment. The findings of the present study underline the need to train farmers concerning the safe and proper use of pesticides to mitigate hazards to human health and the environment.

PARTICIPANT CONSENT

Obtained.

ETHICS APPROVAL

The study was granted an exemption from requiring ethics approval from the Hawassa University College of Natural and Computational Science, Research and Review Committee.

COMPETING INTERESTS

The authors declare no competing financial interests.

Pesticide practices in coastal agricultural farms of Lebanon

The agricultural sector in Lebanon relies heavily on agrochemicals for crop protection; thus exposing humans and the environment to the harmful effects of pesticides. This study investigated Lebanese farmers' pesticide use practices and explored the underlying factors associated with farmers' choices. Of the 104 surveyed farmers, around 87% were willing to use pesticides that are less toxic to humans and the environment than those currently using, if available. The majority of these farmers (92%) planted their crops in greenhouses. Willingness to use less toxic pesticides was significantly associated with farmers using greenhouses as opposed to open fields, after adjusting for demographic and behavioural characteristics (OR = 7.50; p = 0.010). There was no association between willingness to use less toxic pesticides and perceptions of pesticides' health effects. Policies banning the import and sale of internationally banned pesticides must be enforced. Farmers must be supported to make informed choices about pesticides and their use.

Pilot Educational Intervention to Promote Safe Pesticide Use Practices Among Farmworkers in Nepal

OBJECTIVES

The misuse of pesticides among farmworkers in Nepal is commonplace. To address this, we implemented a pilot educational intervention (three modules delivered over 3 days and lasting approximately 3 h each) in Kavre District of Nepal. Modules included: (i) health and environmental effects of pesticides, (ii) use of personal protective equipment, and (iii) label literacy and behavioral factors that influence pesticide exposure. In addition, 10 posters with key messages from each of the modules were hung throughout communities.

METHODS

Surveys were administered to cross-sectional convenience samples of farmworkers at baseline (n = 106) and 1 year later (n = 98). Practices relating to pesticides at baseline and endline were compared using multivariable logistic regression to adjust for differences in demographic and socioeconomic characteristics between the samples.

RESULTS

Compared with the baseline sample, farmworkers in the endline sample were significantly more likely to report: getting information regarding the amount of pesticides to use from experts or pesticide labels (versus personal judgment); wearing gloves while mixing pesticides; wearing boots while working in the field; using personal hygiene practices after handling pesticides such as bathing or washing hands and feet; changing clothes after handling pesticides; checking the wind direction before spraying; and delaying entry for a longer period of time after spraying.

CONCLUSIONS

These results suggest that a simple educational intervention can improve pesticide handling practices among farmworkers in Nepal. Future research should explore the impact of such interventions on pesticide exposure levels and health outcomes, and the potential to scale up these programs nationally.

Key Risk Factors Affecting Farmers' Mental Health: A Systematic Review

Recently, concern has increased globally over farmers' mental health issues. We present a systematic review of the outcomes, locations, study designs, and methods of current studies on farmers' mental health. In particular, this review aims to fill an important gap in understanding of the potential key risk factors affecting farmers' mental health around the world. 167 articles on farmer mental health were included in a final systematic review using a standardized electronic literature search strategy and PRISMA guidelines. The four most-cited influences on farmers' mental health in the reviewed literature respectively were pesticide exposure, financial difficulties, climate variabilities/drought, and poor physical health/past injuries. The majority of studies were from developed countries, most specifically from the United States, Australia, and the United Kingdom. Comparative studies on the mental health of farmers and other occupational workers showed mixed results, with a larger portion identifying that psychological health disturbances were more common in farmers and farm-workers. Knowledge of farmer psychological disorder risk factors and its impacts are essential for reducing the burden of mental illness. Further research will be required on climate change impacts, developing country farmers' mental health, and information on how to reduce help-seeking barriers amongst farmers.

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.

Pesticide residues in Nepalese vegetables and potential health risks

We conducted this study in order to assess the pesticide residues in vegetables and examine the related human health risk. Therefore, residues of 23 pesticides (organophosphates, organochlorines, acaricides, fungicides, and insecticides of biological origin) were analysed in the three main vegetable crops grown in Southern Nepal: 27 eggplant, 27 chilli and 32 tomato samples representing (i) conventional (N = 67) and ii) integrated pest management (IPM) fields (N = 19). Pesticide residues were found in 93% of the eggplant samples and in all of the chilli and tomato samples. Multiple residues were observed in 56% of the eggplant samples, 96% of chilli samples and all of the tomato samples. The range (µg/kg) of total detected pesticide residues in eggplants, chillies and tomatoes was 1.71-231, 4.97-507, 13.1-3465, respectively. The most frequently detected pesticides in these vegetables were carbendazim and chloropyrifos. Pesticide residues in 4% of the eggplant, 44% of the tomato and 19% of the chilli samples exceeded the EU maximum residue limits (MRLs). The residues of triazophos, omethoate, chloropyrifos and carbendazim exceeded the EU MRLs. Compared to chilli and eggplant crops, more carbendazim was sprayed onto tomato crops (p < 0.05). We assessed adolescent and adult dietary exposure using hazard quotient (HQ) and hazard index (HI) equations for the identified pesticides. HQ> 1 was observed for chloropyrifos, triazophos and carbendazim in eggplants; profenofos, triazophos, dimethoate, omethoate, chloropyrifos and carbendazim in tomatoes; and dichlorvos and chloropyrifos in chillies. Of all of the HQs, the highest acute HQ (aHQ) was for triazophos (tomato) in adolescents (aHQ=657) and adults (aHQ=677), showing the highest risks of dietary exposure. The cumulative dietary exposure showed a higher HI for organophosphates (HI>83) and a lower HI for organochlorines, acaricides and biological insecticides (HI<1). The concentration of pesticide residues in the vegetable crops from the IPM field was considerably lower, suggesting a greater ability of IPM systems to reduce the dietary risks from exposure to pesticides.

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.

Factors affecting pesticide safety behaviour: The perceptions of Nepalese farmers and retailers

Indiscriminate use of pesticides in vegetable farming is an emerging problem resulting in increasing health and environmental risks in developing countries including Nepal. As there are limited studies focusing on farmers' and retailers' knowledge related to pesticide use and associated risks as well as safety behaviour, this study assesses their perceptions of pesticide use, associated impacts on human and environmental health and safety behaviours. This study is also intended to quantify pesticide use in vegetable farming. We used the Health Belief Model (HBM) to evaluate farmers' and retailers' safety behaviour associated with pesticides. We interviewed 183 farmers and 45 retailers. The study revealed that farmers applied pesticides at an average of 2.9kga.i./ha per crop per season; and insecticides, especially pyrethrins and pyrethroids as well as organophosphate, were the most frequently used. Retailers were more aware of the threats surrounding pesticide use and were thus more aware of the risks to their own health as well as to the health of animals, birds, fishes, and honey bees. Headache (73.8%) was the most commonly reported acute health symptom of pesticide use. Farmers often did not adopt the appropriate safety measures when handling pesticides sighting the constrained perceived barriers (direct path coefficient, DPC=-0.837) such as feeling uncomfortable and the unavailability of safety measures. Likewise, retailers lacked the incentive (direct path coefficient, DPC=0.397) to adopt the necessary safety measures while handling pesticides. Training and awareness programs addressing safe handling practices and safety measures as well as education concerning the long-term risks of pesticide exposure on health and the environment, through radio, television and posters, may improve the safety behaviour of farmers and retailers.

Aziz FS. Factors influencing farmer’s perceptions and behavior toward pesticide use in Malaysia

Purpose

The purpose of this paper is to examine the factors believed to influence the behavior of 1,042 rice farmers in Malaysia regarding the overuse of pesticides. Frequent overuse of pesticide will have an impact on human health and the environment, which lead to greater expenditure on health care.

Design/methodology/approach

The theoretical models of compliance behavior tested include the basic deterrence model, which focuses on the enforcement of regulation as a key determinant of compliance. The models integrate economic theory with theories of social behavior to account for motivations expected, influencing individuals’ decisions on whether to follow the regulation on using pesticides.

Findings

Significance tests reported that the information regarding the danger of using pesticides, the perception toward the impact on the environment and the expected impact on health influences the compliance behavior of using pesticides.

Research limitations/implications

These findings highlight the necessity for the policy makers to design an effective program which gives more information and provide training related to the risk and the safe handling of pesticides.

Practical implications

The farmers who receive information and training related to handling of pesticides become more cautious in the use of pesticides. Countries involved in agriculture and the use of pesticides widely by their farmers need to emphasize continuous training and periodic information dissemination.

Social implications

The implication drawn is rice farmers should be encouraged to practice new methods in rice planting, especially in the integrated pest management method.

Originality/value

These research findings suggest that the overuse of pesticides in the rice farming continues to be an important problem.

Changes in Perceptions and Practices of Farmers and Pesticide Retailers on Safer Pesticide Use and Alternatives: Impacts of a Community Intervention in Chitwan, Nepal

Unsafe use of hazardous pesticides is a neglected public health problem in developing countries. This survey evaluates the effects of a training program to increase awareness on harmful effects of pesticides and to enhance capacity for safe handling involving 57 trained farmers, 98 neighboring farmers, 94 control farmers, and 23 pesticide retailers from villages in Chitwan, Nepal. Knowledge and attitude-related variables improved in all 3 farmer groups, with a significant trend of better knowledge and attitude from trained to neighboring to control farmers (in 14/16 [87.5%] variables). In practice, there were significant differences among the groups with a trend from trained to neighboring to control farmers (in 10/26 [38.5%] variables).The pesticide retailers also improved on knowledge and practice. In conclusion, training farmers and pesticide retailers improved their knowledge and practice, with possible positive effect on neighboring farmers and control villages as well. An improved extension service to farmers is recommended.

The use of self-reported symptoms as a proxy for acute organophosphate poisoning after exposure to chlorpyrifos 50% plus cypermethrin 5% among Nepali farmers: a randomized, double-blind, placebo-controlled, crossover study

BACKGROUND

Previous studies stating a high prevalence of occupational acute pesticide poisoning in developing countries have mainly relied on measurements of the rather non-specific self-reported acute pesticide poisoning symptoms. Only a few studies have measured the biomarker plasma cholinesterase (PchE) activity, in addition to the symptoms, when assessing occupational acute pesticide poisoning. This study evaluated self-reported symptoms as a proxy for acute organophosphate poisoning among Nepali farmers by examining self-reported acute organophosphate poisoning symptoms and PchE activity in response to occupational acute organophosphate exposure.

METHODS

We performed a randomized, double-blind, placebo-controlled, crossover trial among 42 Nepali commercial vegetable farmers. The farmers were randomly assigned (ratio 1:1) to a 2-h organophosphate (chlorpyrifos 50% plus cypermethrin 5%: moderately hazardous) spray session or a 2-h placebo spray session, and after 7 days' washout, the farmers were assigned to the other spray session. Before and after each spray session farmers were interviewed about acute organophosphate poisoning symptoms and PchE activity was measured. Analyses were conducted with a Two Sample T-test and Mann Whitney U-test.

RESULTS

We found no difference in the symptom sum or PchE activity from baseline to follow up among farmers spraying with organophosphate (symptom sum difference -1, p = 0.737; PchE mean difference 0.02 U/mL, p = 0.220), placebo (symptom sum difference 9, p = 0.394; PchE mean difference 0.02 U/mL, p = 0.133), or when comparing organophosphate to placebo (symptom p = 0.378; PchE p = 0.775). However, a high percentage of the farmers reported having one or more symptoms both at baseline and at follow up in the organophosphate spray session (baseline 47.6%, follow up 45.2%) and placebo spray session (baseline 35.7%, follow up 50.0%), and 14.3% of the farmers reported three or more symptoms after the organophosphate spray session as well as after the placebo spray session.

CONCLUSION

We found a general presence of acute organophosphate symptoms among the farmers regardless of organophosphate exposure or poisoning. Thus, self-reported acute organophosphate symptoms seem to be a poor proxy for acute organophosphate poisoning as the occurrence of these symptoms is not necessarily associated with acute organophosphate poisoning.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02838303 . Registered 19 July 2016. Retrospectively registered.

Modulatory role of GSTM1 null genotype on the frequency of micronuclei in pesticide-exposed agricultural workers

In this study, we aimed to investigate the extent of genotoxic risk and the association between null GSTM1/GSTT1 and GSTP1 Ile105Val variants and cellular DNA damage, as measured by micronucleus (MN) assay in a group of agricultural workers from Denizli, Turkey. Peripheral blood samples were collected from 116 subjects, including 58 workers who were occupationally exposed to pesticides and 58 healthy unexposed controls. The MN frequencies of each individual were assessed by cytokinesis-blocked micronuclei assays on lymphocytes. Genotypes for different GST variants were determined using polymerase chain reaction-based methods. A significant 3.4-fold increase in MN frequency was observed in workers compared with the controls ( p < 0.001). Among the GST genotypes, only the GSTM1 null genotype was found to be significantly associated with an increased MN frequency in workers ( p = 0.01). Individuals with a concomitant null GSTM1/GSTT1 genotype demonstrated a significant ( p = 0.01) increase in MN frequency compared with those with functional isozymes in the exposed worker group. The association of the GSTM1 null genotype with higher MN frequency suggests that it may be a modifier of genotoxic risk in individuals exposed to pesticides and may thus be a candidate susceptibility biomarker for human biomonitoring studies.

Patterns of Pesticide Use and Associated Factors Among the Commercial Farmers of Chitwan, Nepal

Farmers in developing countries are exposed to pesticide hazards due to unsafe handling. This study was conducted to identify the prevailing practices of pesticide use and factors affecting the handling of pesticides among the farmers of Chitwan, Nepal. A cross-sectional study was conducted among 125 farmers. None of the farmers completely followed all the protective measures. About 59% disposed the empty pesticide containers to a nearby water source and 62% preferred house ceilings as a storage place. Males (aOR = 3.99, CI = 1.63-9.78) and older farmers (aOR = 6.18, CI = 2.59-14.72) were more likely to smoke or chew tobacco during the process of spray. Males (aOR = 2.42, CI = 1.03-5.67), literate farmers (aOR = 3.56, CI = 1.51-8.33), and farmers aware of color coding (aOR = 2.67, CI = 1.13-5.67) were more likely to read the labels on pesticide bottles. In spite of an extensive use of pesticides, the farmers were not following proper and safe handling practices, exposing them and the community to a potential pesticide hazard.

Association of urinary 3-phenoxybenzoic acid levels with self-reported depression symptoms in a rural elderly population in Asan, South Korea

OBJECTIVES

This study aimed to evaluate the association between presence of depression symptoms and the exposure level to insecticides among aged population in rural area, determined via measured levels of urinary 3-phenoxybenzoic acid (3-PBA), after controlling for socioeconomic confounding factors.

METHODS

Using a cross-sectional study design, we randomly recruited participants for our study (161 male and 239 female) from rural areas of Asan, Chungnam, Korea. Environmental risk factor exposure was assessed using a questionnaire, and gas chromatography- mass spectrometry was used to analyze urinary 3-PBA levels. We used a logistic regression analysis to assess the association of urinary 3-PBA levels with the presence of self-reported depression symptoms.

RESULTS

After controlling for creatinine levels, the median (interquartile range) concentration of 3-PBA was approximately 1.5 times (p<0.05) higher among female (1.54 [0.90 to 2.35]) μg/g) than among male (1.06 [0.64 to 1.81] μg/g). Our study found that among female participants, the unit increase in 3-PBA levels exhibited a likely positive association (odds ratio, 1.12; 95% confidence interval, 1.00 to 1.25) with an increased risk of presence of self-reported depression symptoms, after adjusting for socioeconomic insurance type, daily physical condition, marital status, smoking status, and age.

CONCLUSIONS

Given our finding of a potential association between the presence of selfreported depression symptoms and 3-PBA levels, precautions should be considered to minimize exposure to insecticides and thus protect the health of aged residents in rural areas.

Pesticide use, erythrocyte acetylcholinesterase level and self-reported acute intoxication symptoms among vegetable farmers in Nepal: a cross-sectional study

BACKGROUND

As pesticide use is increasing and proper handling training is lacking, exposure to pesticides and intoxications are an important public health problems among farmers in developing countries. This study describes pesticide use among farmers and compares symptoms of possible acute intoxication and Erythrocyte Acetylcholinesterase(AChE) levels among vegetable farmers with a control group of blood donors in Nepal.

METHODS

A cross-sectional study was carried out among 90 pesticide-exposed farmers and a control group of 90 blood donors. Participants were randomly selected and data were gathered through questionnaires, observation and blood test. Chi-square test, logistic regression and Student's t-test were used for data analysis to describe pesticide use and compare symptoms and AChE levels between the two groups. This study was approved by Nepal Health Research Council.

RESULTS

The majority of pesticides used were WHO class II, classified as moderately hazardous. The mean numbers of personal protective equipment used by farmers were 2.22 (95% CI: 1.89; 2.54). Out of five hygienic practices asked, farmers followed 3.63 (95% CI: 3.40; 3.86) hygienic practices on the average. Farmers reported more symptoms of possible pesticide intoxication in the past month than did controls, mean 5.47 (95% CI: 4.70; 6.25) versus 2.02 (95% CI: 1.63; 2.40) (p < 0.05). The mean haemoglobin-adjusted AChE(Q) was significantly lower among farmers compared to controls, 28.92 (95% CI: 28.28; 29.56) U/g versus 30.05 (95% CI: 29.51; 30.60) U/g, (p = 0.01). The risk of a farmer having lower Q level was about 3 times (OR = 2.95; 95% CI: 1.16; 7.51) greater than controls.

CONCLUSION

Nepalese farmers exposed to pesticides have significantly more symptoms of possible pesticide intoxication than a control group of healthy individuals. A lower mean haemoglobin- adjusted AChE level was seen among farmers compared to the controls. The use of highly toxic pesticides, inadequate use of personal protective equipment and poor hygienic practices might explain the reason for symptoms of pesticide intoxication and a lower AChE level among farmers. Education and information of farmers should be undertaken to remediate these problems.