Health symptoms related to pesticide exposure and agricultural tasks among rice farmers from Northern Thailand

Organophosphate insecticide exposure and respiratory symptoms among school children in Northern Thailand: Interaction by biomass burning, dampness and season

The aim was to study associations between dialkylphosphates (DAPs), organophosphate (OP) metabolites in urine, biomarkers of OP insecticide exposure, and respiratory symptoms among children in upper northern Thailand. We recruited junior high school children in randomly selected schools in four cities (N = 337), with repeated data collection in wet and dry seasons. Urine was collected and analyzed for six OP metabolites, with creatinine adjustment. Total DAP was expressed as sum of DAPs. Data on respiratory symptoms was collected by a standardized questionnaire. Associations were analyzed by multiple logistic regression. Totally 11.3 % lived in farm families. Total DAPs concentration was higher in dry season (p = 0.002) but did not differ between farm and non-farm children. Total DAPs in wet season was associated with current wheeze (p = 0.019), current asthma attacks (p = 0.012) and attacks of breathlessness in last 12 months (p = 0.021). Total DAPs in dry season was associated with current wheeze (p = 0.042), and associations between DAPs and respiratory symptoms were stronger for dimethylphosphate metabolites (DMPs) than for diethylphosphate metabolites (DEPs). DMPs are produced by certain OP pesticides. Biomass burning inside or outside the home, and dampness or mold at home, enhanced the association between total DAPs and attacks of breathlessness. In conclusion, OP pesticide exposure, measured as urinary DAPs, was higher in dry season and similar in farm and non-farm children. OPs exposure, especially to DMP related pesticides, can increase asthmatic symptoms, especially in wet season. Combined exposure to OP and smoke from biomass burning, or dampness and mold, can further increase the prevalence of attacks of breathlessness. There is a need to reduce OP insecticide and biomass smoke exposure among Thai children. Since different pesticides can be used in different seasons, studies on respiratory health effects of OPs pesticide exposure should be done in different seasons.

Insecticide exposure and associated acute health effects in farmers in a rice growing district of India

This study investigated insecticide usage and associated acute health hazards in rice farming in Odisha, India. A retrospective cross-sectional study design was used to collect data from 139 participants, in the post-monsoon period, 2023. The participants were overwhelmingly male, mostly aged 30 and over, with basic literacy and a range of educational attainment, three-quarters ceasing education by 10th grade and a significant number never attending school. Most farmers/farmworkers used low or moderately toxic insecticides in low doses, typically 3 times/year. However, uptake of appropriate PPE was poor when mixing and applying insecticides. Almost two-thirds (63.4%) of participants reported discomfort/illness after insecticide exposure. Over 90% reported up to 3 symptoms, most experiencing skin irritation. The reported health symptoms were significantly higher among those who ate and drank during insecticide application, compared to those who did not. The number of symptoms reported was also significantly higher in participants who had seen or heard of community insecticide poisoning cases in the previous 12 months, compared with those who had not. Further research is needed on barriers to using effective PPE and on information and training on risks and controls of insecticide exposure that are appropriate for rice farmers in Odisha, India.

Biological Monitoring of Glyphosate Exposure among Knapsack Sprayers in Khon Kaen, Thailand

Sprayers' exposure to glyphosate was analyzed through detection of its biomarker in spot urine biological monitoring, and the health risk was assessed using the biomatrix model. Urine samples were collected from 15 sprayers after spraying, and the glyphosate concentration was determined by using the DLLME-HPLC method with a UV detector. The calibration curve for glyphosate was linear in the range of 0.4-100 µg/L, while the limits of detection and quantification were 0.1 µg/L and 0.4 µg/L, respectively. The human health risk was estimated using the hazard quotient (HQ) and the biomatrix of risk assessment. The internal dose ranged from 0.0001 to 0.0021 mg/kg b.w./day. The non-cancer HQ showed no potential health risk concerns (HQ < 1). The biomatrix of health risk assessment, based on urinary glyphosate concentration, exhibited a strong correlation with the health risk matrix model. This correlation was determined by considering the likelihood of exposure, calculated from the quantity of glyphosate used and the usage of personal protective equipment (r = 0.854, p < 0.001). Although low risk was observed in sprayers, proper PPE use and the application of more knowledge are required. The simplified health risk assessment can be used for easy self-assessment of risk in preventive action regarding health risk awareness among sprayers.

Acute health symptoms related to perception and practice of pesticides use among farmers from all regions of Thailand

Introduction

Occupational exposure to pesticides may cause acute health effects for farmers and agricultural workers. Therefore, this study aims to investigate the prevalence of poisoning symptoms related pesticide exposure among farmers from all regions of Thailand, as well as factors linked to poisoning symptoms of neurological and neuromuscular systems, the respiratory system, and eye and skin disorders.

Methods

A cross sectional study was conducted in 4,035 farmers who lived in four regions of Thailand. The samples were chosen using stratified random sampling, with 746 for the Central region, 2,065 for the North-East, 586 for the North, and 638 for the South.

Results

The results found that the highest prevalence of poisoning symptoms was found in association with neurological and neuromuscular systems (75%), followed by the respiratory system (60.4%), the eyes (41.2%), and skin (14.8%). The most prevalent symptoms were muscle pain (49%) for neurological and neuromuscular symptoms, burning nose (37.6%) for respiratory symptoms, itchy eyes (26.3%) for eye symptoms, and rashes (14.4%) for skin symptoms. The remarkable findings were that types of pesticide use, task on the farm, types of pesticide sprayers, and perception are the crucial factors affecting all poisoning symptoms.

Discussion

The findings are also beneficial to the Thai government and other relevant organizations for launching measures, campaigns, or interventions to lower modifiable risk factors, resulting in reducing health risks associated with pesticide exposure.

Relationship Between Pesticide Exposure Factors and Health Symptoms Among Chili Farmers in Northeast Thailand

OBJECTIVES

The unsafe use of pesticides in agriculture represents a major hazard to human health. This study was conducted to investigate the association between pesticide exposure and health symptoms among chili farmers in northeast Thailand.

METHODS

This cross-sectional analytic study included 141 chili farmers in Sakon Nakhon Province, in northeast Thailand. Data regarding health symptoms were gathered using a self-report questionnaire. A medical technician tested blood cholinesterase activity using an erythrocyte method, and an occupational medicine specialist at Ramathibodi Hospital in Bangkok, Thailand reviewed the results. Associations between personal characteristics, pesticide exposure factors, and health symptoms were analyzed using multiple logistic regression.

RESULTS

Of the 141 chili farmers studied, 66.7% experienced pesticide poisoning, as indicated by below-normal cholinesterase levels. Fatigue was the most frequently reported symptom associated with pesticide exposure, affecting 37.6% of participants. This was followed by nausea and vomiting (31.9%), dizziness (14.9%), and dry throat (14.9%). Multivariate logistic regression analysis revealed that several factors were significantly associated with adverse symptoms: amount of work experience, volume of pesticides used, use of chemical pesticides, use of leaking containers during spraying, direct pesticide exposure while working, contact with pesticide-soaked clothing, consumption of food and drinks in the fields, and blood cholinesterase level indicating risk.

CONCLUSIONS

This study suggests potential health risks for chili farmers stemming from exposure to and contamination by pesticides used in agricultural practices. To mitigate these risks, it is essential to supply personal protective equipment and to implement educational programs aimed at improving protective behaviors among farmers.

Use of Pesticides and Health Risks to Chinese Water Chestnut Farmers in Suphanburi Province, Thailand

Background

We aimed to study the relationship between the use of pesticides and the health risks faced by Chinese water chestnut farmers in this country.

Methods

This cross-sectional survey was conducted among 425 farmers in Sriprachan district, Suphanburi Province, Thailand in 2021. Samples were recruited using the cluster sampling method, and data collection took place through questionnaires. The questionnaire consisted of 3 parts, 76 items, namely personal information of farmers (12 items checklist), the use of pesticides by chemical risk assessment was a 5-point rating scale (40 items), and health risk assessment exposure to pesticides was a 5-point rating scale (24 items). The content validity index for scale (S-CVI) was 0.963 and the reliability with Cronbach's alpha coefficient was 0.904. Data were analyzed using descriptive statistics, chi-square, relative risk, and 95% CI.

Results

The overall pesticide use among farmers was at a moderate level (Mean=3.26, SD=0.60). Farmers' signs and symptoms of exposure were compared to their use of pesticides. The pesticide use increased health risks by 15.57 (95% CI: 12.33 to 18.14). Hazard identification was 10.79 higher (95% CI: 8.19 to 13.40). Dose-response assessment was -16.23 higher (95% CI: -17.63 to -14.82). Exposure assessment was 11.49 higher (95% CI: 9.87 to 13.10) and the risk characteristic was -7.46 (95% CI: -8.49 to -6.44). It was statistically significant at <.001.

Conclusion

Careless and incorrect use of pesticides by Chinese water chestnut farmers can lead to health risks from exposure to toxic substances.

Risk evaluation of occupational exposure of southern Brazilian flower farmers to pesticides potentially leading to cholinesterase inhibition and metals exposure

This work presents a frequency matched observational study comparing flower farmers exposed to pesticides and unexposed individuals as controls. All subjects were interviewed before plasma and urine collection. Manganese and Zinc were measured in theses samples by using dynamic reaction cell inductively coupled mass spectrometry. Cholinesterase activity was analyzed through spectrophotometry by using a modified version of the Ellman method. Seventy-eight percent of subjects reported occupational contact with pesticides, from which 37% reported exposure for over 9 years. Flower farms farmers had increased odds of having headache and irritability, respectively, by factors of 6.2 and 2.4 than the control subjects. While the odds of exposed subjects to have insomnia was smaller than control subjects by a factor of 0.34. Exposure to pesticides had a significant effect regarding the plasmatic plasma and urinary manganese levels and whole blood cholinesterase activity (p < 0.05). High levels of plasma and urinary manganese, as well as cholinesterase inhibition in whole blood, were evident in the flower farmers who participated in the study.

Differences in Knowledge, Awareness, Practice, and Health Symptoms in Farmers Who Applied Organophosphates and Pyrethroids on Farms

OBJECTIVE

This cross-sectional study aimed to examine farmers' knowledge, awareness, practices regarding pesticide use, and prevalence of health symptoms related to pesticides exposure among farmers who applied organophosphates (OP) and pyrethroids (PY).

METHODS

Data regarding demographic variables and health symptoms pertinent to pesticide use was collected from 67 farmers who applied OP and 50 farmers who applied PY using interviews from January to March 2021.

RESULTS

The farmers who applied OP had lower knowledge, awareness, and prevention practices regarding pesticide use than those who applied PY. After adjustment of covariate variables, the farmers who applied OP had a significantly higher prevalence of respiratory conditions (OR = 8.29 for chest pain, OR = 6.98 for chest tightness, OR = 27.54 for dry throat, and OR = 5.91 for cough), neurological symptoms (OR = 10.62 for fatigue and OR = 6.76 for paresthesia), and neurobehavioral symptoms (OR = 13.84 for poor concentration, OR = 3.75 for short term memory, and OR = 8.99 for insomnia) related to pesticide exposure than those who applied PY.

CONCLUSION

Our findings suggest that OP had a more adverse effect on human health than PY, resulting in a higher prevalence of pesticide-related symptoms. The outcomes of this study have the benefit of providing vital information for all stakeholders with regard to the implementation of safe practices in the utilization of personal protective equipment (PPE) and pesticide use in a health intervention and health promotion program.

Evaluation of hematological indices among insecticides factory workers

Insecticides are commonly used pesticides in the world. Chronic exposure to insecticides has adverse effects on various human body organs. In this study, hematological findings were assessed in workers in an insecticide manufacturing plant. Hematological parameters and clinical symptoms were recorded in 99 workers exposed to insecticides and 107 workers not exposed to them in a cross-sectional study. Assessment of the hematological results showed a higher prevalence of thrombocytosis in the exposed group than the non-exposed group (P < 0.05). Mean white blood cell (WBC) and platelet counts, anisocytosis of red blood cells (RBCs), and neutrophils to lymphocytes ratio (NLR) were significantly higher in the exposed group compared to the non-exposed group (P < 0.05). Prevalence rates of headache, itchy skin, cough, and sleep disorders were higher in the exposed group than in the non-exposed group (P < 0.05). Chronic exposure to insecticides can alter hematological parameters in the normal range. Occupational exposure to insecticides may increase WBCs, platelet count, NLR, and red cell distribution width (RDW). It can also cause thrombocytosis. Complete blood count (CBC), as an inexpensive and accessible tool, can help monitor workers' health status exposed to insecticides properly.

In silico prediction, characterization and molecular docking studies on Glutathione-S-transferase as a molecular sieve for toxic agrochemicals explored in survey of North Indian farmers

All across the globe, India is considered as an agricultural nation because its agro products drive the economy. An increase in population growth and a hike in food demands lead to the use of hazardous chemicals in farm fields. An in-depth field survey in Northern India was conducted to understand the types of agrochemicals that were used, farmers' knowledge about their safe handling, and their practices on its usage. Ninety-two responders (primarily farmers) from 37 districts of 12 states were interviewed to collect the information. The library containing 58 compounds as toxic spray constituents were developed and further screened in-silico for ADMET, drug-likeness, toxicity prediction, and molecular docking against their target actions in the human system. Glutathione S-transferases (GSTs) was selected as target protein showing the best-docked score with Bordeaux, Indoxacarb, Cyphenothrin, Deltamethrin, and Beta-cyfluthrin. The study revealed various adverse effects on human health and advocated provisions of alternative solutions such as using GST as a binding agents to hold the toxic chemicals out of living system and eventually saves valuable lives of the farmers.

Pesticide Spraying and Reduced Cholinesterase Activity among Hill Tribe Farmers in Thailand

BACKGROUND

Farming is an important occupation in Thai hill tribe communities, which are often remote, and lack other economic opportunities along with basic educational, health care, and occupational health and safety services. Additionally, these communities have a unique culture and language.

OBJECTIVES

The present study was conducted in northern Thailand to evaluate pesticide exposures and associated health impacts among hill tribe farmers, and to compare them to Thai farmers.

METHODS

Lahu hill tribe farmers in a mountain community were recruited by public health hospital staff, along with a reference group of lowland Thai farmers. Participants completed a survey on demographic factors and work practices, and blood and urine samples were collected by a trained nurse. Acetylcholinesterase activity (AChE) was quantified to assess pesticide exposure, whereas liver and kidney functions were evaluated using clinical biomarkers.

RESULTS

A large fraction (nearly 50%) of Lahu farmers were illiterate and could not speak Thai. Thai farmers worked fewer hours per week (39.4) than did Lahu farmers. Among Lahu farmers, AChE levels were significantly lower (worse) than those of Thai farmers. However, other health outcomes in these populations were similar. Formal education and language skills were not associated with pesticide exposures or health outcomes. Pesticide spraying was found to be a significant predictor of reduced AChE (OR=8.5, 95% CI 1.1-69.6).

CONCLUSIONS

Pesticide exposures are a significant occupational health hazard among Thai hill tribe farmers. Training, potentially delivered by community health volunteers, is needed to communicate safe pesticide work practices to these farmers.

PARTICIPANT CONSENT

Obtained.

ETHICS APPROVAL

The study protocol was approved by the Institutional Review Board of Mae Fah Luang University (REH-61080).

COMPETING INTERESTS

The authors declare no competing financial interests.

Factors Influencing Practice of Pesticide Use and Acute Health Symptoms among Farmers in Nakhon Sawan, Thailand

Information on knowledge (K), attitude (A), and practice (P) in terms of pesticide use is essential for an effective exposure control program. The objectives of this study were to survey the level of knowledge, attitude, and practice in terms of pesticide use, and the prevalence of acute health symptoms (AHSs) among farmers in Nakhon Sawan Province, Thailand. The study also tried to identify factors affecting the practice of pesticide use. Data from 680 farmers were collected using a face-to-face interview questionnaire. The relationship between safety practices and related factors was analyzed using ordinal logistic regression. This study found about 40% of the farmers had a good level of practice. Factors affecting practice were education, work experience, level of knowledge, or attitudes. Many participants experienced acute health symptoms in the past 24 h, and these symptoms were significantly associated with poor practice (p < 0.05). Public health organizations should provide farmers with more information, especially on chronic effects of pesticides.

Genetic Polymorphisms of Pesticide-Metabolizing Enzymes and Transporters in Agricultural Workers and Thyroid Hormone Levels

PURPOSE

Chronic exposure to pesticides has been associated with thyroid dysfunction owing to their endocrine disruption ability. Genetic variations in genes encoding phase I and II enzymes and phase III transporters are partly responsible for individual responses to chemical pesticides. This study investigated the association between variations in genes involved in pesticide metabolism and altered thyroid hormone concentrations.

METHODS

We assessed thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4) in organic agriculture workers (n = 216) and workers who used chemical pesticides (n = 229). A questionnaire was used to collect sociodemographic, pesticide exposure, and health status data. Blood samples were analyzed for TSH, FT3, and FT4. Genomic DNA was extracted and genotyped using the TaqMan real-time PCR genotyping assay and restriction fragment length polymorphism method for 15 metabolically related genes.

RESULTS

Significant differences in the TSH (1.58 vs 1.12 µIU/mL) and FT3 (0.34 vs 0.31 ng/dL) concentrations between the chemical and organic worker groups were observed. The frequencies of all single nucleotide polymorphisms were in Hardy-Weinberg equilibrium and were mostly consistent with Asian populations. The findings showed the association between SNPs of enzymes and transporters and TSH, FT3, and FT4. The odd ratio and adjusted odd ratio (with sex, age, smoking status, alcohol consumption and exposure parameters) for subclinical thyroid disease by the variant alleles CYP1A1 rs1048943, CYP2B6 rs2279343, CYP2C19 rs4244285, NAT2 rs1799931, and PON1 rs662 in the chemical workers compared with the organic workers were found (P values < 0.05).

CONCLUSION

This is the first study to assess gene-environment interactions in Thai agricultural workers by investigating disruptions of the hypothalamic-pituitary-thyroid axis. The investigated SNP profiles revealed several gene-thyroid hormone associations in which even low levels of pesticide exposure could disturb thyroid homeostasis. These findings provide a foundation for planning future studies investigating associations between complex diseases and occupational pesticide exposure.

A global systematic review, meta-analysis and health risk assessment on the quantity of Malathion, Diazinon and Chlorpyrifos in Vegetables

It is widely believed that an increasing trend in the production and consumption of vegetables has led to a dramatic rise in the use of pesticides potentially threatening the health of consumers around the world. This systematic study along with meta-analysis has mainly centered on the evaluation of the quantity of three well-known pesticides namely, Malathion (MLT), Diazinon (DZN) and Chlorpyrifos (CPF) in vegetables. In this regard, a comprehensive literature search has been performed over the last decade (January 1, 2011 to June 21, 2020) within the scientific databases including PubMed, Web of Science, and Scopus. Of 1239 articles identified through the database screening, 22 plus 37 data report were retained and included in the meta-analysis phase. Additionally, the probabilistic human health risks for the consumers due to the intake of CPF, DZN and MLT from eating vegetables were estimated by the Monte Carlo Simulated (MCS) method. According to the findings, the maximum quantities of MLT, DZN and CPF in the vegetables were observed in Pakistan (222 μg/kg, 95%CI = 214.94-229.08), Thailand (245.00, 95% CI = 235.2-254.8) and South Korea (440 μg/kg, 95% CI = 437.19-442.81), while the lowest concentration levels were reported in China (1.7 μg/kg, 95% CI = 1.56-1.84), Poland (0.57, 95% CI = 0.46-0.68) and Poland (5.78 μg/kg, 95% CI = 4.40-7.12), respectively. The results of the Egger's and the Begg's tests revealed that no bias with regard to the potential publication was observed. Finally, non-carcinogenic risk assessment results demonstrated that the exposure to the studied pesticides thorough vegetables consumption could not threaten the health of consumers.

Insecticide Filtration Efficiency of Respiratory Protective Equipment Commonly Worn by Farmers in Thailand

Farmers are at a high risk of inhalation exposure when handling pesticides. Thai farmers usually protect themselves against pesticide exposure by wearing commercial respiratory protective equipment (RPE) available from rural community markets. However, scientific data regarding the pesticide filtration efficiency of RPE commonly worn by farmers is limited. Thus, this study aimed to investigate the efficiency of insecticide filtration of various RPE commonly worn by farmers in Thailand. The half facepiece respirator was used as a control to compare the results with other RPE. Ten types of RPE were selected for testing. The filtration efficiency of each RPE against insecticides was tested in a laboratory. The remarkable findings were that a surgical mask demonstrated the least filtration efficiency of all tested insecticides, with a range of 25.7-61.5%. The RPE available in rural markets of Thailand had a filtration efficiency within a range of 64.9-95.4%, whereas a half facepiece respirator was the most efficient in filtering insecticides, with a range of 96.5-98.9%. Therefore, our results suggest that the RPE most frequently worn by farmers may not provide adequate protection when compared with the respirator. However, considerations around RPE use in low-and middle-income countries and tropical climate conditions should be based on pesticide toxicity and practical use, ensuring balance between the risks from pesticide exposure and acceptance of PPE use.

Factors associated with respiratory symptoms among herbicide applicators and assistant applicators in maize field

A cross-sectional study was conducted with 3,291 maize farmers enrolled whose main roles were herbicide applicators and assistant applicators. This study aimed to compare the prevalence of respiratory symptoms and the use of personal protective equipment (PPE) between herbicide applicators and assistant applicators, and determine factors associated with respiratory symptoms. Our results suggest that wheeze and dyspnea were associated with the task on the farm (adj. OR = 10.33 for wheeze and 24.13 for dyspnea), amount of herbicide use (adj. OR = 1.95 for wheeze and 1.41 for dyspnea), frequency of herbicide use (adj. OR = 2.87 for wheeze and 4.08 for dyspnea), not always wearing a mask (adj. OR = 1.49 for wheeze and 3.17 for dyspnea), not always wearing gloves (adj. OR = 2.63 for wheeze and 2.44 for dyspnea), and not always wearing goggles (adj.OR = 2.01 for dyspnea) after adjusting for confounding factors.

Pesticide exposure and adverse health effects associated with farmwork in Northern Thailand

OBJECTIVES

To assess pesticide exposure and understand the resultant health effects of agricultural workers in Northern Thailand.

METHODS

This was a cross-sectional study. We quantified exposure to pesticides, including chlorpyrifos, methomyl, and metalaxyl, by air sampling and liquid chromatography/mass spectrometry. We estimated differences in self-reported health outcomes, complete blood counts, cholinesterase activity, and serum/urine calcium and creatinine concentrations at baseline between farmworkers and comparison workers, and after pesticide spraying in farmworkers only.

RESULTS

This study included 97 men between the ages of 22 and 76 years; 70 were conventional farmworkers; and 27 did not report any prior farmwork or pesticide spraying. None of the farmworkers wore standardized personal protective equipment (PPE) for the concentrated chemicals they were working with. Methomyl (8.4-13 481.9 ng/m3 ), ethyl chlorpyrifos (11.6-67 759 ng/m3 ), and metalaxyl (13.9-41 191.3 ng/m3 ) were detected via personal air sampling. When it came to reporting confidence in the ability to handle personal problems, only 43% of farmworkers reported feeling confident, which reflects higher stress levels in comparison to 78% of comparison workers (P = .028). Farmworkers also had significantly lower monocyte counts (P = .01), serum calcium (P = .01), red blood count (P = .01), white blood cell count (P = .04), and butyrylcholinesterase activity (P < .0001), relative to comparison workers. After adjusting for body mass index (BMI), age, and smoking, methomyl air concentrations were associated with a decrease in farmworker acetylcholinesterase activity (beta = -0.327, P = .016).

CONCLUSIONS

This population of farmworkers had significant alterations in stress measures and clinical biomarkers, including decreased blood cell counts and cholinesterase activity, relative to matched controls. These changes are potentially linked to occupational pesticide exposures. Improving PPE use presents a likely route for preventive intervention in this population.

The global distribution of acute unintentional pesticide poisoning: estimations based on a systematic review

BACKGROUND

Human poisoning by pesticides has long been seen as a severe public health problem. As early as 1990, a task force of the World Health Organization (WHO) estimated that about one million unintentional pesticide poisonings occur annually, leading to approximately 20,000 deaths. Thirty years on there is no up-to-date picture of global pesticide poisoning despite an increase in global pesticide use. Our aim was to systematically review the prevalence of unintentional, acute pesticide poisoning (UAPP), and to estimate the annual global number of UAPP.

METHODS

We carried out a systematic review of the scientific literature published between 2006 and 2018, supplemented by mortality data from WHO. We extracted data from 157 publications and the WHO cause-of-death database, then performed country-wise synopses, and arrived at annual numbers of national UAPP. World-wide UAPP was estimated based on national figures and population data for regions defined by the Food and Agriculture Organization (FAO).

RESULTS

In total 141 countries were covered, including 58 by the 157 articles and an additional 83 by data from the WHO Mortality Database. Approximately 740,000 annual cases of UAPP were reported by the extracted publications resulting from 7446 fatalities and 733,921 non-fatal cases. On this basis, we estimate that about 385 million cases of UAPP occur annually world-wide including around 11,000 fatalities. Based on a worldwide farming population of approximately 860 million this means that about 44% of farmers are poisoned by pesticides every year. The greatest estimated number of UAPP cases is in southern Asia, followed by south-eastern Asia and east Africa with regards to non-fatal UAPP.

CONCLUSIONS

Our study updates outdated figures on world-wide UAPP. Along with other estimates, robust evidence is presented that acute pesticide poisoning is an ongoing major global public health challenge. There is a need to recognize the high burden of non-fatal UAPP, particularly on farmers and farmworkers, and that the current focus solely on fatalities hampers international efforts in risk assessment and prevention of poisoning. Implementation of the international recommendations to phase out highly hazardous pesticides by the FAO Council could significantly reduce the burden of UAPP.

Knowledge, attitude and practice of pesticide use and serum cholinesterase levels among rice farmers in Nakhon Nayok Province, Thailand

Purpose

The study purposes were to investigate the knowledge, attitude and practice of pesticide use and to determine the levels of serum cholinesterase among rice farmers in Nakhon Nayok province, Thailand.

Design/methodology/approach

A cross-sectional study was carried out in communities in Nakhon Nayok Province, Thailand. Multistage random sampling was employed, selecting one person per each rice farmer household. Data was collected from 188 rice farmers using a structured face-to-face interview questionnaire. A reactive-paper finger-blood test was used to determine SChE levels. Chi-square test was used to determine the relationship between the practice of pesticide use and SChE levels.

Findings

The results indicated that the rice farmers had a fairly good knowledge and a neutral attitude toward the practice of pesticide use. Most of the respondents had a fairly proper practice of pesticide use. However, serum cholinesterase levels of the farmers were unsafe and risky. It signified that 68.1% of the farmers had a health risk from using pesticides. The prevalence of abnormal SChE levels among rice farmers with improper use was significantly higher than that among rice farmers who had a proper use.

Research limitations/implications

The result provided a guideline for operational planning and control and prevention of health effects from pesticides use in farmers or other agriculturists who use pesticides in cultivation.

Practical implications

Concerned local agencies especially health-related agencies are able to conduct a training to educate and build safety awareness including monitoring continuously the safety behaviors toward pesticides use. It can be implemented by establishing leaders from health promoting hospitals led by village health volunteers, community leaders and participation from farmers to collaboratively monitor proper use of pesticides beginning with health surveillance in the abnormal SChE group to be screened for pesticide exposure every six months or one year.

Social implications

Farmers gained knowledge and understanding of pesticides use and used it properly, which resulted in a reduction of pesticide residues in body as well as in the environment. In addition, the government policy should legislate measures for related agencies to promote proper use of pesticides. For instance, Department of Agriculture, Minister of Agriculture and Cooperatives should regularly supervise, monitor and inspect the production and distribution of pesticides in local shops and also systematically encourage agriculturists to adopt using pesticides that are less harmful.

Originality/value

Having knowledge, understanding and proper practices toward pesticides use, farmers can reduce health effects of pesticides use in themselves and family members.

Biological variation in kidney injury and kidney function biomarkers among farmers in Lamphun province, Thailand

Frequent and long-term exposure to pesticides can induce acute kidney injury and subsequent chronic kidney diseases. In this study, we aimed to investigate the correlation between kidney injury, kidney function biomarkers, and pesticide use in farmers from the Pasang district, Lamphun province, Thailand. A cross-sectional study was performed in 59 farmers occupationally exposed to various types of pesticides. The levels of urinary neutrophil gelatinase-associated lipocalin (uNGAL), serum creatinine (sCr), urinary microalbumin-to-creatinine ratio (ACR), serum cystatin C (sCys-C), estimated glomerular filtration rate (eGFR), and exposure intensity index (EII) were evaluated. Spearman's correlation and a linear regression analysis were carried out to investigate the association between age, pesticide use, EII, kidney injury markers, and kidney function biomarkers. The most common pesticide used in this study area was glyphosate, followed by paraquat and iprodione. Urinary NGAL levels showed a significant correlation with sCys-C levels, EII, and eGFR Cr-Cys. In addition, the sCr levels were associated with glyphosate use (B = 0.08) and EII (B = 0.01). In conclusion, occupation exposure to pesticides is likely to be linked to kidney injury and dysfunction. Pesticide mix status, pesticide application method, equipment repair status, and personal protective equipment (PPE) use are all involved in changes in kidney markers.

DNA damage and adverse neurological outcomes among garlic farmers exposed to organophosphate pesticides

Garlic farmers used organophosphate pesticides to control insects, resulting in an increased risk for adverse health outcomes. Thus, we investigated exposure to organophosphate pesticides, DNA damage, nerve conduction, and neurological symptoms among 134 garlic farmers. They were interviewed, measured nerve conduction, and collected blood and urine for determining DNA damage and dialkylphosphate metabolites. Total dialkylphosphate levels of farmers who began cultivating garlic in October were significantly higher than those of non-farmers and the farmers who began cultivating in November and December. Farmers showed significantly longer comet tail lengths and tail moments than non-farmers. However, their mean compound motor and sensory nerve action potential amplitudes of the median, ulnar, and common peroneal nerves were within normal ranges. Measurement of DNA damage is useful as a biomarker of long-term and low-level exposure to organophosphate pesticides; however, electromyography might be not sufficiently sensitive to detect nerve conduction effects in farmers exposed to pesticides.

Differences among Thai Agricultural Workers' Health, Working Conditions, and Pesticide Use by Farm Type

More than 11 million Thai people (38%) work in agriculture, but since most are in the informal sector, government enforcement and support are very limited. As a result, working conditions on Thai farms vary greatly, putting the health of many agricultural workers at risk. A cross-sectional study in three Thai provinces collected information on the work activities and conditions of 424 farmers representing five farm types: rice, vegetable, flower, rice/vegetable, and flower/vegetable. The agricultural workers were mainly women (60%); their average age was 53 but ranged from 18 to 87 years. More than 64% worked more than 5 days/week. Seventy-four percent of them had only primary school education. A number of the health and hazardous working conditions surveyed were significantly different by farm type. Rice farmers were found to have the highest prevalence of allergies, nasal congestion, wheezing, and acute symptoms after pesticide use, while flower farmers had the lowest prevalence of these health outcomes. Rice farmers reported the highest prevalence of hazardous working conditions including high noise levels, working on slippery surfaces, sitting or standing on a vibrating machine, spills of chemicals/pesticides, and sharp injuries. The lowest prevalence of these working conditions (except noise) was reported by flower farmers. Vegetable farmers reported the highest prevalence knee problems, while rice farmers had the lowest prevalence. Among these farmers, more than 27 different types of pesticides were reported in use during the past year, with the majority reporting use once a month. The flower/vegetable farming group reported the highest frequency of good exposure prevention practices during pesticide use. They were the most likely to report using cotton or rubber gloves or a disposable paper masks during insecticide spraying. Those farmers who only grew vegetables had the lowest frequency of good exposure prevention practices, including use of personal protective equipment. The economic cost of work-related injuries and illnesses among informal sector agricultural workers in Thailand is unknown and in need of study. Gaps in the regulations covering pesticide sales allow farmers to purchase pesticides without adequate training in their safe use. Training targeted to farm type regarding safe pesticide use and the prevention of accidents and musculoskeletal disorders is needed. Studies of chronic health effects among Thai farmers are needed, with special emphasis on respiratory, metabolic disease and cancer.

A longitudinal follow-up study of oxidative stress and DNA damage among farmers exposed to pesticide mixtures

Exposure to pesticides may have increased risk of oxidative stress and genetic damage and hence of development of chronic diseases. The aim of this longitudinal follow-up study is to compare oxidative stress and DNA damage between the pre- and post-pesticide application seasons among 56 male farmers. The study also investigated the factors associated with changes in oxidative stress, DNA damage, and health symptoms during the pesticide application season. The eligibility criteria for the subjects were men aged between 25 and 55 years, applied pesticide mixtures during May and June 2018, and healthy without current illness. Ten milliliters of venous blood samples was collected twice from each subject in the pre- and post-pesticide application seasons for determination of superoxide dismutase (SOD), 8-hydroxy-2'-deoxyguanosine (8-OHdG), comet tail length, and comet tail moment. The remarkable findings included a statistically significant increase in SOD activity during the pesticide application season (P < 0.001). However, there were no statistical differences in 8-OHdG, comet tail length, and comet tail moment. When we analyzed the factors associated with changes in SOD activity during the pesticide application season by using linear regression analysis, working hours on the farm (B ± SE. = 0.790 ± 0.341, P = 0.025) and planting activities (B ± SE. = 1.217 ± 0.504, P = 0.020) were associated with increase in SOD activity. Therefore, increase in SOD may be a consequence of oxidative damage induced by pesticide exposure and this marker may be used as an early warning for pesticide-induced acute and chronic toxicities.

Changes in lung function and respiratory symptoms during pesticide spraying season among male sprayers

Exposure to pesticides via inhalation might impair lung function and develop further severe respiratory symptoms and diseases. Thus, the purpose of the study was to compare lung function between pre- and post-pesticide spraying seasons among male sprayers. The study also evaluated the association of lung function changes and other factors with respiratory symptoms. The follow-up study was conducted on 58 male sprayers. The subjects were interviewed and measured lung function before and after pesticide spraying season. The results found that forced vital capacity (FVC), forced expiratory volume in one second (FEV₁), and peak expiratory flow rate in the post-spraying season were significantly lower than in the pre-spraying season. With regard to respiratory symptoms, cough symptoms were associated with changes in FEV₁/FVC [odd ratio (OR) = 1.29, 95% confidence interval (CI) = 1.01-1.67)] and smoking status (OR = 12.95, 95%CI = 1.35-124.34). Phlegm symptoms were also associated with changes in FVC (OR = 2.07, 95%CI = 1.01-4.25) and FEV₁ (OR = 0.41, 95%CI = 0.18-0.91). The study provides evidence that pesticide spraying may increase risks for significant alteration of lung function and respiratory symptoms.

Pesticide Use, Poisoning, and Knowledge and Unsafe Occupational Practices in Thailand

The agricultural system in Thailand has shifted from a traditional to a commercial agricultural system. Pesticides have been imported into Thailand to increase agricultural productivity, resulting in adverse health effects for farmers and consumers. However, the scientific data available in Thailand are limited and inconsistent. Thus, this article reviews research studies regarding pesticide use, poisoning, and knowledge and unsafe occupational practices in Thailand over the last decade. This article also makes recommendations for future policies. Research studies conducted in Thailand during 2006-2017 were reviewed and summarized. Overall, there are several solutions to address the pesticide problem, such as rigorous legislation and regulations, campaigns for reducing pesticide use, education, and training. The Thai government has an important role in making policies and regulations and encouraging all agricultural activities to be sustainable.

Emerging health risks from agricultural intensification in Southeast Asia: a systematic review

Background Agricultural intensification is having profound impacts on food security and rural livelihoods; however, concerns remain about the potential implications on public health. Objectives We aim to examine and synthesize the evidence for human health risks of agricultural intensification in Southeast Asia. Methods We conducted a systematic review of peer-reviewed articles published between January 2000 and December 2015 from two electronic databases (PubMed, CAB Direct). Results A total of 73 relevant studies were included and evaluated. More than half of the studies used epidemiological methods while others applied alternative methods to quantify or estimate risks. Studies mainly focused on occupational and consumer exposure to pesticides, without often specifying the actual health risk. Conclusion Overall, the current knowledge on health risks appears to be limited. More research on long-term health implications and a wider range of contaminants are needed if sustainable benefits are to be obtained from agricultural intensification.

Urinary dialkylphosphate metabolites and health symptoms among farmers in Thailand

Using a cross-sectional study, we investigated urinary DAPs levels and health symptoms related to the type of crop cultivation and farm tasks among 84 farmers in Phayao Province of northern Thailand. The results showed that the average of ∑DAPs levels was 10.93 ± 19.64 μg/g creatinine (range 1.48-163.90 μg/g creatinine). The compound found the most was DEP, followed by DETP, DEDTP, DMP, DMTP, and DMDTP, respectively. The type of crop cultivation may be associated with an increasing prevalence of respiratory tract, muscle system, and skin irritation. Farm tasks were associated with an increasing prevalence of muscle system and skin irritation. It was difficult to assess adverse health symptoms associated with urinary DAPs in low levels of exposure; therefore, further investigation is needed using more sensitive biomarkers and more sensitive health symptom measurement.

Food safety in Thailand. 3: Pesticide residues detected in mangosteen (Garcinia mangostana L.), queen of fruits

BACKGROUND

For developing countries like Thailand, regulation of pesticide usage exists, but it is not fully enforced. Therefore, pesticide residues in vegetables and fruits have not been well monitored. This study aimed to determine the pesticide residues in mangosteen fruits sold in Thailand. The mangosteen samples (n = 111) were purchased and the contents of 28 pesticides were analysed by GC-MS/MS method.

RESULTS

Of the pesticides tested, eight were found in 100% of the mangosteen samples. However, in 97% of these samples, either chlorothalonil, chlorpyrifos, diazinon, dimethoate, metalaxyl or profenofos was detected exceeding their maximum residue limits (MRLs), representing a 97% rate of pesticide detection above the MRL. This rate is much higher than those found in other fruits sold in developed countries. However, this conclusion excludes the fresh Thai mangosteens grown for export, as these are generally cultivated and harvested to GAP standards. Since the edible part of the mangosteen is the pulp, washing the fruits with running water can reduce the risk of pesticide residues contaminating the pulp which would be eaten by the consumer.

CONCLUSION

The findings strongly suggest that routine monitoring of pesticide residues in fruits and vegetables is required to reduce the health risks associated with consuming contaminated food. © 2016 Society of Chemical Industry.

Association of health symptoms with low-level exposure to organophosphates, DNA damage, AChE activity, and occupational knowledge and practice among rice, corn, and double-crop farmers

Objectives:

This study aims to determine (1) total dialkylphosphate (ΣDAP) levels, occupational knowledge and practice, DNA damage, AChE activity, and health symptoms in rice, corn, and double-crop farmers; (2) the association of health symptoms with ΣDAP levels, occupational knowledge and practice, DNA damage, and AChE activity in farmers; and (3) the prevalence of health symptoms between farmers and non-farmers.

Methods:

A cross-sectional study was conducted by interviewing as well as analyzing urine and blood samples during July to August 2014.

Results:

There were no differences in ΣDAP levels, AChE activity, and occupational knowledge and practice scores among all farmer groups. In terms of health symptoms related to ΣDAP, AChE activity, DNA damage, and occupational knowledge and practice, pesticide-related symptoms were determined, including breathlessness, chest pain, dry throat, numbness, muscle weakness, cramp, headache, dizziness, eye irritation, white/red rash, and white/red pimple, which were classified as respiratory, muscle, nervous, and epithelial symptoms. A remarkable finding was that farmers had a significantly higher prevalence of muscle weakness (odds ratio (OR)=3.79) and numbness (OR=3.45) as compared with non-farmers.

Conclusion:

Our findings, therefore, suggest that a long-term low-level exposure to organophosphates (OPs) may be associated with an increasing prevalence of muscle symptoms. However, a further cohort study incorporating sensitive health outcomes and measurement of multiple pesticides monitoring on a larger scale is warranted.

Factors that contribute to insecticide poisoning among immigrant agricultural workers in Thailand

BACKGROUND

There has been a strong increase in the international movement of workers during the last few decades. As Thailand's economy has rapidly developed during the past 20 years, it has attracted growing numbers of laborers from the bordering countries of Myanmar, Lao PDR, and Cambodia. Numbers of migrant workers in Thai agriculture have risen to the extent that the sector's continued growth has become increasingly dependent on migrant workers.

OBJECTIVE

The purpose of this study was to explore the factors that contribute to the development of symptoms of insecticide poisoning among immigrant agricultural workers in the eastern region of Thailand.

METHODS

Data were collected via interviews (N = 891), and the levels of cholinesterase activity in the workers' blood were tested using reactive test strips.

RESULTS

Only 4.4% of the workers had normal levels of cholinesterase activity and 75.1% had levels that were abnormal. Regarding factors that affect gastrointestinal symptoms of poisoning, being aged 45 to 50 increased the risk of developing gastrointestinal symptoms (odds ratio (OR): 2.51; 95% CI: 1.41-4.46), as did using a backpack spraying technique (OR: 3.74; 95% CI: 2.16-6.49) and having only moderate levels of self-protection behavior while spraying the insecticides (OR: 2.23; 95% CI: 1.16-4.29). Having an at risk level of cholinesterase activity increased the risk of gastrointestinal symptoms (OR: 3.25; 95% CI: 1.05-10.04) and the risk of respiratory symptoms (OR: 2.75; 95% CI: 1.17-6.44).

CONCLUSION

It is recommended that insecticide self-protection measures should be promoted and health monitoring should be implemented for migrant workers affected by high-risk insecticide use.

Food safety in Thailand 4: comparison of pesticide residues found in three commonly consumed vegetables purchased from local markets and supermarkets in Thailand

Background

The wide use of pesticides raises concerns on the health risks associated with pesticide exposure. For developing countries, like Thailand, pesticide monitoring program (in vegetables and fruits) and also the maximum residue limits (MRL) regulation have not been entirely implemented. The MRL is a product limit, not a safety limit. The MRL is the maximum concentration of a pesticide residue (expressed as mg/kg) recommended by the Codex Alimentarius Commission to be legally permitted in or on food commodities and animal feeds (Codex Alimentarius Commission, 2015; European Commission, 2015). MRLs are based on supervised residue trial data where the pesticide has been applied in accordance with GAP (Good Agricultural Practice). This study aims at providing comparison data on pesticide residues found in three commonly consumed vegetables (Chinese kale, pakchoi and morning glory) purchased from some local markets and supermarkets in Thailand.

Methods

These vegetables were randomly bought from local markets and supermarkets. Then they were analyzed for the content of 28 pesticides by using GC-MS/MS.

Results

Types of pesticides detected in the samples either from local markets or supermarkets were similar. The incidence of detected pesticides was 100% (local markets) and 99% (supermarkets) for the Chinese kale; 98% (local markets) and 100% (supermarkets) for the pakchoi; and 99% (local markets) and 97% (supermarkets) for the morning glory samples. The pesticides were detected exceeding their MRL at a rate of 48% (local markets) and 35% (supermarkets) for the Chinese kale; 71% (local markets) and 55% (supermarkets) for the pakchoi, and 42% (local markets) and 49% (supermarkets) for the morning glory.

Discussion

These rates are much higher than those seen in developed countries. It should be noted that these findings were assessed on basis of using criteria (such as MRL) obtained from developed countries. Our findings were also confined to these vegetables sold in a few central provinces of Thailand and did not reflect for the whole country as sample sizes were small. Risk assessment due to consuming these pesticide contaminated vegetables, still remains to be evaluated. However, remarkably high incidence rates of detected pesticides give warning to the Thai authorities to implement proper regulations on pesticide monitoring program. Similar incidence of pesticide contamination found in the vegetables bought from local markets and supermarkets raises question regarding the quality of organic vegetables domestically sold in Thailand. This conclusion excludes Thai export quality vegetables and fruits routinely monitored for pesticide contamination before exporting.

Food safety in Thailand 2: Pesticide residues found in Chinese kale (Brassica oleracea), a commonly consumed vegetable in Asian countries

There is increasing public concern over human health risks associated with extensive use of pesticides in agriculture. Regulation of pesticide maximum residue limits (MRLs) in food commodities is established in many developed countries. For Thailand, this regulation exists in law but is not fully enforced. Therefore, pesticide residues in vegetables and fruits have not been well monitored. This study investigated the pesticide residues in Chinese kale, a commonly eaten vegetable among Asians. The Chinese kale samples (N = 117) were purchased from markets in Nakhon Pathom Province, Thailand, and analyzed for the content of 28 pesticides. Analysis was performed by the multiresidual extraction followed by GC-MS/MS. Of pesticides investigated, 12 pesticides were detected in 85% of the Chinese kale samples. Although carbaryl, deltamethrin, diazinon, fenvalerate and malathion were found in some samples, their levels were lower than their MRLs. However, in 34 samples tested, either carbofuran, chlorpyrifos, chlorothalonil, cypermethrin, dimethoate, metalaxyl or profenofos was detected exceeding their MRLs. This represents a 29% rate of pesticide detection above the MRL; a rate much higher than in developed countries. Washing vegetables under running water significantly reduced (p < 0.05) profenofos residues by 55%. The running water method did not significantly decrease cypermethrin residues in the samples but washing with vinegar did. Our research suggests that routine monitoring of pesticide residues is necessary to reduce the public health risks associated with eating contaminated vegetables. Washing vegetables before consumption is advisable as this helps to reduce the level of pesticide residues in our daily intake.

Pesticide poisoning and neurobehavioral function among farm workers in Jiangsu, People's Republic of China

Pesticides remain an integral part of agricultural activities worldwide. Although there have been a number of studies over the last two decades concerning the adverse effects of pesticide poisoning and chronic long term exposures on neurobehavioral function, the impact of recent pesticide poisoning and long term pesticide exposure on neurobehavioral function in Chinese farm workers has not been reported. China is the largest user of pesticides worldwide and figures suggest 53,300-123,000 Chinese people are poisoned every year. A case control study was conducted to examine the impact of recent pesticide poisoning on neurobehavioral function and the relationship between years worked in agriculture and lower performance on neurobehavioral tests. A total of 121 farm workers who self-reported recent pesticide poisonings within the previous 12 months (case group) and 80 farm workers who reported no pesticide poisoning in the previous 12 months (control group) were recruited from three areas of Jiangsu Province, China. The World Health Organization (WHO) recommended neurobehavioral core test battery (NCTB) was used to assess neurobehavioral functioning among cases and controls. Student's t tests and two-way covariance analysis (ANCOVA) were used to test for significant differences in the neurobehavioral test results between the groups. Scores on the Profile of Mood States (POMS) in the recently poisoned group were significantly higher for anger-hostility, depression-dejection, tension-anxiety and lower for vigor-activity compared to controls (p < .05). Digit span, digit symbol, Benton visual retention and pursuit aiming scores were all significantly lower among the recently poisoned group compared to the controls (p < .05). Two-way ANCOVA indicated significantly lower performance in correct pursuit aiming and higher error pursuit aiming amongst the recently poisoned group and those who had worked for more than 30 years in agriculture (p < .05). These findings provide important preliminary epidemiological evidence regarding the association between occupational pesticide exposure and neurobehavioral functioning in Chinese farm workers.

Organophosphorus pesticide residues in vegetables from farms, markets, and a supermarket around Kwan Phayao Lake of Northern Thailand

This study investigated organophosphorus (OP) residues in vegetables from 27 farms, 106 markets, and 1 supermarket around Kwan Phayao Lake, Northern Thailand, between August and September 2013. Types of vegetables sampled were all vegetables cultivated or sold around the study site. The most common OP pesticides detected in farm samples were chlorpyrifos (50 %), malathion (31.8 %), monocrotophos (31.8 %), diazinon (13.6 %), omethoate (13.6 %), and dicrotophos (9.1 %). The most common OP pesticides detected in market samples were chlorpyrifos (33.9 %), diazinon (18.6 %), parathion-methyl (3.4 %), profenofos (3.4 %), primiphos-ethyl (3.4 %), and fenitrothion (1.7 %). The OP pesticides detected in supermarket samples were chlorpyrifos (33.3 %), and diazinon (66.7 %). Among the compounds detected, chlorpyrifos was detected in most of the vegetable samples from all sources. The highest chlorpyrifos level in farm samples were found in lemon balm (2.423 mg/kg) followed by Vietnamese coriander (0.835 mg/kg), and cowpea (0.027 mg/kg). The highest level in markets samples were found in garlic (7.785 mg/kg) followed by Chinese cabbage (2.864 mg/kg) and Vietnamese coriander (1.308 mg/kg). Residues from supermarket samples were found only in parsley (0.027 mg/kg). The findings showed that 16 samples (59.3 %) from farms and 14 samples (13.2 %) from markets contained OP residues at or above the maximum residue limits established by the European Union. It is concluded that awareness, safety education, and strict regulation of pesticide use are necessary.