Impact of environmental heat exposure on the health status in farmworkers, Nakhon Ratchasima, Thailand.

Background: Thailand is a tropical developing country which has a serious increase in health risk due to hot weather exposure among outdoor workers. Objectives: The aims of this study were to compare the factors related to environmental heat exposure in three different seasons, and to assess the relationship between environmental heat and dehydration status in each season among farmworkers in Nakhon Ratchasima, Thailand. Methods: A semi-longitudinal study was carried out in 22 male farmworkers throughout a year of farming. The primary data were collected in farmworkers for socio-demographic information, clinical assessments, and heat-related illnesses. Results: Average of environmental heat index (Median, SD) were severe in summer (WBGT=38.1, 2.8°C), rainy season (WBGT=36.1, 2.1°C), and winter (WBGT=31.5, 2.7°C). Average urine Sp. Gr. in summer, rainy season, and winter were 1.022, 1.020, and 1.018 respectively. The third sentence should be corrected as follows: The Friedman analysis revealed a statistically significant difference between the three different seasons in WBGT (wet bulb globe temperature), body temperature, heart rate (P<0.01), and respiratory rate (P<0.05). There was a statistically significant difference between the three different seasons for skin rash/itching, dizziness, muscle cramp dyspnea (P<0.05), and weakness (P<0.01). Wilcoxon signed-ranks analysis found a significant difference in the medians of the paired sets of urine Sp. Gr. values between baseline and summer (P<0.05). Spearman's rank correlation coefficient did not find a relationship between WBGT and urine Sp. Gr. in the three different seasons. Conclusions: This study demonstrated that farmworkers had exposure to environmental heat stress which was expressed through physical changes. Therefore, there is a need for either interventions or guidelines to prevent dehydration for outdoor workers in this region.

Risk factors, erythrocyte acetylcholinesterase inhibition, and self-reported symptoms of pesticide intoxication among farmers in Thailand: A cross-sectional study.

Background: Organophosphate and carbamate pesticides are widely used, and their adverse health effects remain a serious problem. Objectives: This investigation aimed to describe risk factors, erythrocyte acetylcholinesterase (AChE) inhibition, and self-reported symptoms and to derive an association between influence factors and erythrocyte AChE inhibition among farmers in Thailand. Methods: A cross-sectional study was conducted on 71 farmers from August to October 2022. General characteristics and pesticide exposure factors were elicited via a questionnaire-based interview. The erythrocyte AChE inhibition was assessed using the EQM Test-mate Cholinesterase (Model 400) instrument. Data were presented descriptively and analyzed statistically using Chi-square and binary logistic regression. Results: Most farmers were over 50 years old and had an abnormal body mass index (BMI) without alcohol consumption and smoking. Aprons (18.31%) and protective eyewear (12.68%) as personal protective equipment (PPE) were found to be used less often. The level of hemoglobin-adjusted erythrocyte AChE (Q) was considered normal when it was 59.15% and abnormal when it was 40.85%. Self-reported symptoms were confirmed to be associated with lower erythrocyte AChE levels. The Chi-square analysis showed that shortness of breath, irritation, headache, dizziness, sleep fragmentation, and memory problems were significantly associated with erythrocyte AChE (p < 0.05). The bivariate analysis revealed that farmers who consumed alcohol while using pesticides (mixing, loading, and spraying) (OR=35.821, 95% CI=4.591-279.490), who did not wear a mask while using pesticides (OR=11.898, 95% CI=1.061-133.440), and who did not wear boots while using pesticides (OR=0.166, 95% CI=0.031-0.890) had an increased likelihood of having a severe inhibition of erythrocyte AChE. Conclusions: These findings suggest that the promotion of risk prevention practices must be imposed on appropriate pesticide handling and PPE use among farmers.

Pesticide toxicity assessment and geographic information system (GIS) application in small-scale rice farming operations, Thailand.

The objectives of the study were to evaluate the impact of pesticide exposure on farmer health during non-active rice farming and active rice farming periods and present the change in the individual cholinesterase activities (%reduction) on the geographic information system (GIS) mapping in Nakhon Ratchasima Province, Thailand. Acetyl- and butyryl-cholinesterase (AChE and BuChE) activities were monitored during both study periods using Test-mate ChE (Model 400). The location of paddy fields was specified using Garmin geographic positioning system MAP 62s. Fifty-eight farmers who participated in this study had an average age of 49.2 ± 6.9 years. Higher prevalence of all health symptoms was observed among farmer participants during the active rice farming period comparing to the non-active rice farming period (p < 0.01). Furthermore, farmers had significantly lower activities of AChE and BuChE during the active rice farming period comparing to the non-active rice farming period (p < 0.01). Our findings indicate that the GIS mapping indicate that the cases with a significant enzyme inhibition have dispersed across the agricultural and the nearby residential areas. This, investigation can be used to promote safer use of pesticides among farmers and mitigate pesticide exposure among residents living in close proximity to a rice field.