Non-carcinogenic health risk from carbamate pesticide exposure of toddlers living in agricultural areas of Thailand

Toddlers in agricultural areas may be athave risk from pesticide exposure . A cross-sectional study was conducted with 130 toddlers and their caregivers. Face-to-face interviews were done to gather information about exposure factors. A wipe sampling technique was used to collect carbamate residues on each toddler's hands and feet. Results showed that there were carbamate residues on all wipe samples (100%), with a median concentration of 30.47 micrograms per sample (hands and feet). Carbamate residues detected on toddlers' hands and feetwere significantly associated (p < 0.05) with many factors, including the toddlers' relationships with caregivers, the education level of caregivers, the household incomes, the gender of toddlers, the frequency of following caregivers to farms, the frequency of foot washing, daytime activities, and playing durations. The health risk from dermal carbamate exposurewas above the acceptable range (HI = 3.244). Preventive measures should be considered to reduce toddlers' pesticide exposure in agricultural areas.

An Evaluation of a Pesticide Training Program to Reduce Pesticide Exposure and Enhance Safety among Female Farmworkers in Nan, Thailand

BACKGROUND

Although exposure to chemical pesticides is known to cause negative effects on human health, farmers in Ban Luang, Nan, Thailand, continue to use them regularly to protect crops. This study focused on mothers who were engaged in farm tasks and had children between the ages of 0 to 72 months, with the objective of reducing pesticide exposure.

METHODS

This study was conducted from May 2020 to October 2020 in the Ban Fa and Ban Phi sub-districts in Ban Luang due to the high use of pesticides in these areas. A systematic random sampling technique was used to recruit 78 mothers exposed to pesticides. Thirty-nine mothers from Ban Fa district were randomly assigned to the intervention group and 39 from Ban Phi to the control group over a 3-month period. This study applied a pesticide behavioral change training program for the intervention group. To assess the effectiveness of the program, the study compared the results of a questionnaire regarding knowledge, attitude, and practice (KAP) and health beliefs related to pesticide exposure as well as the levels of acetylcholinesterase (AChE) and butyryl cholinesterase (BChE) enzymes, biomarkers of exposure to pesticides, before and after the intervention using ANCOVA statistical test. Furthermore, to evaluate the effectiveness of the intervention program, a paired t-test was used to investigate the in-home pesticide safety assessment.

RESULTS

After the intervention, we observed no significant change in AChE; however, a significant improvement in BChE (p < 0.05), a marker of short-term recovery, was observed. Pesticides can cause a reduction in AChE and BChE, however, after eliminating pesticides, BChE takes a shorter time (about 30-50 days) to recover than AChE (around 90-120 days). Therefore, increases in the measured concentrations of AChE and/or BChE suggest the presence of less chemicals from pesticides in the human body. The study also found a significant improvement in KAP and beliefs about chemical pesticide exposure after the intervention (p < 0.05). Furthermore, using a paired t-test, we found a significant increase in pesticide safety practices (p < 0.05) in the intervention group and a borderline significant increase regarding in-home safety (p = 0.051) in the control group.

CONCLUSIONS

Based on the results, the constructs of the intervention program were effective and could be applied in other agricultural areas in less developed countries. However, due to time limitations during the COVID-19 pandemic, further studies should be conducted to enable data collection over a longer time, with a larger number of subjects providing the ChE levels for the non-agricultural season.

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.

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.

Quantification and characterization of recovered materials in the cycle of the informal household electronic waste dismantling in Buriram province, Thailand: A challenge towards sustainable management and circular economy

The numerous amount of electronic waste (e-waste) has not been managed effectively resulting informal dismantling sites are being expanded in Thailand. The government attempts to improve the efficiency of an integrated e-waste management system, but baseline data of e-waste stream in informal sectors are insufficient. This research aimed to investigate the inflow and outflow of the materials throughout the informal e-waste dismantling processes at the well-known second-largest community in Buriram province during 2017-2018. To describe the quantities of dismantled materials, a material flow analysis was performed. The overall amount of e-waste taken to the community was estimated to be in the range of 1593-12,943 tonnes year^-1. Valuable materials could be recovered at more than 90% (by mass) from fans, refrigerators, washing machines, microwaves and air conditioners. The amount of e-waste residue that the local administrative organization had to handle was up to 1144 tonnes year^-1. The quantitative data retrieved from this study could provide a satisfactory equation for estimating the amount of separated valuable and non-valuable materials. Recyclable materials from dismantling have an economic incentive, e-waste dismantlers in a small and large household group that can earn approximately 798 and 1262 USD month^-1 income, respectively. The notable e-waste characterization and quantification of recovered materials would be useful for improving the potential circular flow of e-waste in Thailand.

Fine particulate matter and daily hospitalizations for mental and behavioral disorders: A time-series study in Ho Chi Minh City, Vietnam

Various adverse health outcomes caused by particulate matter (PM) exposure has been documented, while the evidence for the adverse effects of PM exposure on mental and behavioral disorders (MBDs) is limited. To date, few epidemiological studies, especially in developing countries, have focused on these adverse effects. In the past decade, air pollution sources in Vietnam have noticeably increased, resulting to the elevated concentrations of ambient air pollutants particularly fine PM or PM with an aerodynamic diameter ≤2.5 μm (PM_2.5). Hence, investigating the short-term association between PM_2.5 and MBDs is worthwhile. In this study, a quasi-Poisson time-series regression analysis was used to investigate the association between PM_2.5 exposure and daily hospitalizations for MBDs to the Ho Chi Minh City Mental Health Hospital during 2017-2020. A natural cubic spline smooth function for time was used to screen out long-term and seasonality trends. Stratified analyses were also performed by sex, age, and season. During study period, 9,986 hospitalizations for MBDs were recorded and included in the analysis. Results suggested that a 10 μg/m³ daily increase in PM_2.5 concentration was associated with a statistically significant 2.96% (95% confidence interval: 0.23%-5.76%) increase in hospitalizations for MBDs. The effects of PM_2.5 exposure on hospital admissions were more pronounced in female patients and the middle-age group (35-59 years). This finding could increase awareness regarding prevention and minimization of MBDs on the public.

Investigation of kidney function changes in sea salt workers during harvest season in Thailand

Background

The Thai government has been developing its Eastern Economic Corridor (EEC), which spans three provinces, with the aim of improving connections with other Asian nations. Since this strategic development, the number of trucks, private car, and passenger car registrations have continued to grow, with a corresponding increase in related to benzene, toluene, ethylbenzene, and xylene (BTEX).

Objectives

This study aims to compare the levels of trans, trans-muconic acid (t, t MA); toluene (TU); mandelic acid (MA); and methyl hippuric acid (MHA) in the urine of gas station employees, considering demographic and occupational factors.

Material and methods

These employees worked either near or away from the fuel dispenser, and there 100 people in each group. Data were collected using interviews and testing environmental air and urine samples for benzene, toluene, ethyl benzene, and xylene (BTEX).

Results

The results showed that BTEX concentrations were just detectable in all 200 cases (100%). The mean (±SD) urine level of t, t MA was 449.28 (±213.32) μg/g creatinine, while the median (min-max) was 428.23 (95.58-1202.56) μg/g creatinine. The mean TU was 0.011 (0.001) mg/L, while the median (min-max) was 0.011 (0.010-0.013) mg/L. MA levels were higher inside the pollution control zone than they were outside the zone (p=.009). Employees who practiced poor personal hygiene had relatively high urinary toluene and MHA levels (p=.009) and those who did not wear personal protective equipment (PPE) had relatively high MA levels (p=.040).

Conclusion

The results of this study revealed statistically significant biomarkers influencing the levels of t, t MA; TU; MA; and MHA in urine. The recommendations of this study are that employers should provide their employees with suitable PPE, check regularly to ensure that it is worn, and strongly encourage employees to take care of their sanitation. Employees should take appropriate breaks and days off to minimize their exposure to BTEX.

Investigation of Prenatal Pesticide Exposure and Neurodevelopmental Deficits in Northern Thailand: Protocol for a Longitudinal Birth Cohort Study

BACKGROUND

Prenatal exposure to pesticides has been linked to adverse neurodevelopmental outcomes. Gaps exist in the current literature about the timing and magnitude of exposures that result in these adverse outcomes.

OBJECTIVE

The Study of Asian Women and their Offspring's Development and Environmental Exposures (SAWASDEE) cohort was established to investigate the impact of prenatal exposure to pesticides on early indicators of cognitive and motor skills, inhibitory control, emotion regulation, and memory that have been found to be important in the development of subsequent neurobehavioral and neurodevelopmental diseases. The overarching goal is to find earlier predictors of potential adverse neurologic outcomes in order to enable earlier interventions that could result in better outcome prognoses.

METHODS

Recruitment of this prospective, longitudinal birth cohort began in July 2017 and was completed in June 2019 in Chom Thong and Fang, 2 farming districts in Chiang Mai Province in northern Thailand. Follow-up of the study participants is ongoing. During pregnancy, 7 questionnaires were administered. Time-resolved biospecimen samples were collected monthly (for urine) and during each trimester (for blood) during antenatal care visits. Medical records were abstracted. Infants were administered the NICU Network Neurobehavioral Scale (NNNS) test at 1 month of age. A total of 322 mother-child pairs completed the NNNS test. All children will be followed until 3 years of age and undergo a series of neurodevelopmental tests. We will complete several additional exposure related analyses.

RESULTS

A total of 1298 women were screened, and of those, 394 (30.35%) women were enrolled. The mean gestational age at enrollment was 9.9 weeks (SD 2.6). Differences in literacy were observed between Chom Thong and Fang participants. In Fang, about 54 of 105 (51.4%) participants reported being able to read in Thai compared to about 206 of 217 (94.9%) participants in Chom Thong. The percentages were comparable for reporting to be able to write in Thai.

CONCLUSIONS

This longitudinal birth cohort study will inform risk assessment standards for pregnant women in Thailand and other countries. Building awareness of how insecticide exposure during specific windows of pregnancy affects the neurodevelopmental trajectories of children in developing countries is a specific need recognized by the World Health Organization.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/31696.

Urinary Concentrations of Dialkylphosphate Metabolites of Organophosphate pesticides in the Study of Asian Women and their Offspring's Development and Environmental Exposures (SAWASDEE)

BACKGROUND

Measurements of urinary dialkyl phosphate (DAP) metabolites are often used to characterize exposures to organophosphate (OP) insecticides; however, some challenges to using urinary DAP metabolites as an exposure measure exist. OP insecticides have short biological half-lives with measurement in a single urine sample typically only reflecting recent exposure within the last few days. Because of the field staff and participant burden of longitudinal sample collection and the high cost of multiple measurements, typically only one or two urine samples have been used to evaluate OP insecticide exposure during pregnancy, which is unlikely to capture an accurate picture of prenatal exposure.

METHODS

We recruited pregnant farmworker women in Chom Thong and Fang, two districts of Chiang Mai province in northern Thailand (N = 330) into the Study of Asian Women and their Offspring's Development and Environmental Exposures (SAWASDEE) from 2017 to 2019. We collected up to 6 serial urine samples per participant during gestation and composited the samples to represent early, mid, and late pregnancy. We measured concentrations of urinary DAP metabolites in the composited urine samples and evaluated the within- and between-participant variability of these levels. We also investigated predictors of OP insecticide exposure.

RESULTS

DAP metabolite concentrations in serial composite samples were weakly to moderately correlated. Spearman correlations indicated that composite urine samples were more highly correlated in Fang participants than in Chom Thong participants. The within-person variances (0.064-0.65) exceeded the between-person variances for DETP, DEP, ∑DEAP, DMP, DMTP, ∑DMAP, ∑DAP. The intraclass correlations (ICCs) for the volume-based individual metabolite levels (ng/mL) ranged from 0.10 to 0.66. For ∑DEAP, ∑DMAP, and ∑DAP the ICCs were, 0.47, 0.17, 0.45 respectively. We observed significant differences between participants from Fang compared to those from Chom Thong both in demographic and exposure characteristics. Spearman correlations of composite samples from Fang participants ranged from 0.55 to 0.66 for the ∑DEAP metabolite concentrations in Fang indicating moderate correlation between pregnancy periods. The ICCs were higher for samples from Fang participants, which drove the overall ICCs.

CONCLUSIONS

Collecting multiple (∼6) urine samples during pregnancy rather than just 1 or 2 improved our ability to accurately assess exposure during the prenatal period. By compositing the samples, we were able to still obtain trimester-specific information on exposure while keeping the analytic costs and laboratory burden low. This analysis also helped to inform how to best conduct future analyses within the SAWASDEE study. We observed two different exposure profiles in participants in which the concentrations and variability in data were highly linked to the residential location of the participants.

Effect of heat exposure on dehydration and kidney function among sea salt workers in Thailand

Background

Excessive heat exposure and dehydration among agricultural workers have been reported to reduce kidney function and lead to chronic kidney disease of unknown etiology (CKDu).

Objective

This cross-sectional study aimed to assess heat exposure, factors related to dehydration and the relationship between dehydration and biomarkers of kidney function among sea salt workers in Thailand.

Material and methods

Wet bulb globe temperature (WBGT) was used at the time workers started work outdoors on salt farms. Urine-specific gravity, urine osmolarity, and serum creatinine were collected from 50 workers after work.

Results

The results showed that more than 50% of the participants were dehydrated after work. The maximum hours spent working per day was 10. The average water intake was 1.51 L. Urine specific gravity was highly significant correlated with urine osmolality (rs = 0.400, p<0.01), and urine osmolality was significantly correlated with the estimated glomerular filtration rate (eGFR) (rs = 0.349, p<0.05). In bivariate analysis adjusted for age, sex, and current alcohol consumption, we found that a WBGTTWA ≥ 30°C (OR = 0.08, 95% CI = 0.01-0.44, p = 0.003) and hours spent working (OR=2.22, 95% CI = 1.42-3.47, p <0.001) were independently associated with dehydration. This suggests that workers should increase their time spent on breaks and increase water consumption.

Conclusions

Educational program on heat exposure and heat-related illness prevention strategies should be provided.

Related health risk assessment of exposure to arsenic and some heavy metals in gold mines in Banmauk Township, Myanmar

Exposure to heavy metals in mining activities is a health issue among miners. This study was carried out at three small-scale gold mining sites situated in Banmauk Township, Myanmar and aims to assess the occupational health risks of small-scale gold miners who are exposed to arsenic (As), cadmium (Cd), mercury (Hg) and lead (Pb) in the soil through the dermal route. Soil samples were analyzed through atomic absorption spectroscopy (AAS). The concentrations of the heavy metals in soils found As, ranged 1.04 mg/kg to 22.17 mg/kg, 0.13 mg/kg to 3.07 mg/kg for Cd, 0.15 mg/kg to 77.44 mg/kg for Hg, and 7.67 mg/kg to 210.00 mg/kg for Pb. In this study, 79% of the participants did not use any form of personal protective equipment (PPE) while working in gold mining processes. Regarding noncancer risk assessment, the results found all hazard quotient were lower than acceptable level (HQ < 1). In addition, all hazard index (HI) was lover than 1, the highest HI was found as 5.66 × 10⁻¹ in the amalgamation process. On the other hand, the result found cancer risk ranged from 8.02 × 10⁻⁸ to 1.75 × 10⁻⁶, and the estimated cancer risks for 9 years ranged from 4.78 × 10⁻⁷ to 1.04 × 10⁻⁵. Therefore, the cancer risks of the miners were greater than the United State Environmental Protection Agency (U.S. EPA) acceptable cancer risk level, 1 × 10⁻⁶, and the miners may be at risk of developing carcinogenic diseases. The suggestion is to educate miners about the health risks of heavy metals and to encourage the use of proper PPE all the time while working in gold mine.

Human biomarkers associated with low concentrations of arsenic (As) and lead (Pb) in groundwater in agricultural areas of Thailand

Human biomarkers were used to evaluate the lead (Pb) and arsenic (As) exposure of local people who lived in an agricultural area with intense agrochemical usage and who consumed groundwater. Although the heavy metals/metalloids in the groundwater were at low concentrations, they could cause adverse effects due to a high daily water intake rate over the long term. Biomarkers (hair, fingernails and urine) were collected from 100 subjects along with the local shallow groundwater and tap water, which is the treated deep groundwater, and investigated for the concentrations of As and Pb. Shallow groundwater had an average pH of 5.21 ± 1.90, ranging from 3.77 to 8.34, with average concentrations of As and Pb of 1.311 µg/L and 6.882 µg/L, respectively. Tap water had an average pH of 5.24 ± 1.63, ranging from 3.86 to 8.89, with the average concentrations of As and Pb of 0.77 µg/L and 0.004 µg/L, respectively. The levels of both As and Pb in the hair, fingernails and urine of shallow groundwater-consuming residents were greater than those in the hair, fingernails and urine of tap water-consuming residents. Interestingly, the As level in urine showed a linear relationship with the As concentration in groundwater (R2 = 0.91). The average water consumption rate was approximately two-fold higher than the standard; thus, its consumption posed a health risk even at the low As and Pb levels in the groundwater. The hazard index (HI) ranged from 0.01 to 16.34 (average of 1.20 ± 2.50), which was higher than the acceptable level. Finally, the concomitant factors for As and Pb in the urine, hair and nails from both binary logistic regression and odds ratio (OR) analysis indicated that groundwater consumption was the major concomitant risk factor. This study suggested that direct consumption of this groundwater should be avoided and that the groundwater should be treated, especially before consumption. In conclusion, urine is suggested to be a biomarker of daily exposure to As and Pb, while for long-term exposure to these metals, fingernails are suggested as a better biomarker than hair.

Using the Socio-Ecological Model to Frame the Influence of Stakeholders on Cocoa Farmers' Pesticide Safety in Nigeria: Findings from a Qualitative Study

PURPOSE

The aim of this study was to explore the roles of stakeholders on cocoa farmers' safe pesticide use in Nigeria using the socio-ecological model as the theoretical framework.

METHODS

This was a cross-sectional qualitative study where participants were purposefully selected based on some criteria. Then, they were interviewed in-depth using a semi-structured interview approach. The interview guide was designed based on other literature and the study objectives. The interview transcripts were transcribed verbatim and analyzed using the content analysis technique.

RESULTS

In all, 57 participants were involved in the interview process across all the study locations. Five layers of influence (cocoa farmers, pesticide retailers, extension officers, pesticide importers and government agencies) were considered. At individual level, cocoa farmers complained about lack of information from other stakeholders regarding pesticide use except retailers due to the farmers' proximity to their stores. However, pesticide safety information from the retailers were found to be inadequate due to their interest in financial gains rather than a focus on human health and the environment. Additionally, most retailers had no understanding about the characteristics of products they sold as they could not read pesticide labels. Furthermore, lack of motivations, human resources and facilities hindered effective extension education in the rural communities. Also, pesticide importers took efforts to train the farmers within their network, but majority of these trainings focused on lead farmers who were expected to disseminate the information to others. Besides, the agencies did organize training or workshop sometimes, but it was inadequate due to budget constraint. Lastly, environmental or agri-policies relating to Nigerian cocoa farmers concerning safe pesticide use and disposal were also inadequate.

CONCLUSION

Generally, there was a large information gap with respect to pesticide safety between cocoa farmers and other stakeholders which undermined pesticide use safety. This study highlighted the need for government agencies in Nigeria to develop mechanisms to monitor information exchange among other stakeholders and cocoa farmers with respect to safe pesticide use and disposal.

Heavy Metals in the Soils of Placer Small-Scale Gold Mining Sites in Myanmar

BACKGROUND

Artisanal and small-scale mining activities are widely practiced globally. Concentrations of heavy metals associated with gold, such as copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd), mercury (Hg) and lead (Pb) can increase in the environment as a result of mining activities, leading to environmental pollution and pose toxicity risks to humans and animals.

OBJECTIVES

The aim of the present study was to investigate soil concentrations of toxic heavy metals in placer small-scale gold mining operations in Myanmar.

METHODS

Soil samples were collected from three placer small-scale gold mining sites: Site A located in the Hmawbon public protected forest, Site B and Site C, situated in the Nant-Kyin reserved forest around Nar Nant Htun village. At each site, soil samples were collected from four gold mining stages (ore processing, sluicing, panning, and amalgamation). Atomic absorption spectroscopy was utilized to examine the concentrations of As, Cd, Pb, and Hg.

RESULTS

The highest heavy metal concentrations were generally found in the amalgamation stages across all the gold mining sites. Across the three mining sites, the maximum heavy metal concentrations in the amalgamation stage were 22.170 mg.kg^-1 for As, 3.070 mg.kg^-1 for Cd, 77.440 mg.kg^-1 for Hg, and 210.000 mg.kg^-1 for Pb.

CONCLUSIONS

The present study examined the concentrations of As, Cd, Hg and Pb in the soil of several small-scale gold mining sites in Banmauk Township, Myanmar. The results demonstrated the presence of high concentrations of heavy metals in the soil of the gold mining sites. Miners in this area work without proper personal protective equipment, and frequent exposure to heavy metals in the soil may cause adverse health effects. The present study provides baseline data for future risk assessment studies of heavy metal contamination in gold mines.

COMPETING INTERESTS

The authors declare no competing financial interests.

Pesticide use in Thailand: Current situation, health risks, and gaps in research and policy

Agriculture in Thailand, which employs over 30 percent of the workforce and contributes significantly to the country's gross domestic product, is a key sector of its economy. Import and use of pesticides has increased over the past decade due to Thailand's major role as a leading exporter of food and agricultural products. The widespread and poorly regulated use of pesticides presents a potential risk to the health of farmers, farm families, the general population including children and the environment. This article is a result of the Southeast Asia GEOHealth Network Meeting of February 2019. It summarizes the current situation on pesticide use and regulation in Thailand and reports research findings on the potential health and environmental impacts of pesticide use, as well as highlighting gaps in research that could play an important and influential role in future policy initiatives on pesticides. Although Thailand has made remarkable progress in improving agricultural health and safety and similarly strong research and policy programs are being developed in other countries in the region, there are still significant gaps in research and policy that need to be filled.

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.

Musculoskeletal disorders among rice farmers in Phimai District, Nakhon Ratchasima Province, Thailand

Purpose

The purpose of this paper is to explore the prevalence of musculoskeletal disorders (MSDs) and determine factors influencing MSDs among rice farmers.

Design/methodology/approach

A cross-sectional study was carried out among 156 rice farmers from 14 villages in Tarnlalord sub-district, Phimai district, Nakhon Ratchasima province, Thailand, from February 2017 to March 2017. Face-to-face interviews, including demographics, work characteristics and musculoskeletal pain, were conducted using a modified standardized Nordic questionnaire.

Findings

The results revealed that both 78 males and 78 females participated in the study to which the average of age and body mass index (BMI) was 45.5±11.4 years and 24.9±4.0 kg/m2, respectively. All rice farmers reported MSDs in at least one body region during the six months preceding the interview. The highest prevalence of MSDs showed 86.5 percent in the lower back area, followed by 85.9 percent in the neck, and 80.7 percent in the shoulders. The analysis of binary logistic regression and Spearman’s rank correlation showed that factors such as gender, age, BMI, work experience and farm size influence MSDs’ occurrence, and pain severity in one or more body regions (p < 0.05).

Originality/value

Musculoskeletal injuries are a significant health problem in rice farmers. The study indicated that appropriate agricultural practices such as working posture, equipment size selection and carrying loads should be recommended to prevent MSDs. Thus, the occupational health and safety services in agricultural workers are needed.

Exposure of chlorpyrifos in toddlers living in an agricultural area in Sakon Nakhon province, North-East Thailand

Purpose

Children living in agricultural areas are exposed to pesticides in their living areas and through activities of daily living. These exposures may lead to adverse health effects. The purpose of this paper is to investigate household environmental and behavioural factors associated with chlorpyrifos exposure and resultant adverse health effects in children living in an agricultural community.

Design/methodology/approach

A cross-sectional study was conducted including 65 toddlers (age of 12–36 months) and their parents were face-to-face interviewed from January to February 2016. Toddler’s hands and feet, toys and floors were wiped for chlorpyrifos residue analysis. The wipes were extracted and analysed by gas chromatography with a flame photometric detector, and blood cholinesterase activity was measured by the EQM Test-mate (model 400).

Findings

The average age (± standard deviation) of children was 19.9 (±5.9) months. Chlorpyrifos detections were 61.5 per cent (hands), 57.1 per cent (toys), 53.8 per cent (floors) and 30.8 per cent (feet). The highest chlorpyrifos residue concentration was detected on toy surface (3.022 µg/m2). Chlorpyrifos residues on hands and feet were positively correlated with concentrations on floors and toys (Spearman’s ρ, p<0.01). Multiple linear regression analysis revealed that more frequent hand washing (β=−0.236, p=0.067) and showering (β=−0.240, p=0.056) was negatively associated with chlorpyrifos residue on children’s body. House cleaning frequency was significantly associated with an increase in haemoglobin-adjusted erythrocyte cholinesterase (β=0.251, p<0.05).

Originality/value

Chlorpyrifos exposures found in the children household area through their activities and behaviours can cause several adverse health effects. The circumstances associated with chlorpyrifos exposure should be mitigated and reduced to improve the household environment of children living agricultural areas.

The Healthy e-Elderly People Assessment (HEPA) application

Purpose

The purpose of this paper is to evaluate health effects and determine the factors associated with health effects from smartphone and tablet use among the elderly in Thailand.

Design/methodology/approach

This study was a cross-sectional descriptive study. The participants comprised 490 elderly people. A self-administered questionnaire was used for data collection via the Healthy e-Elderly People Assessment mobile application in the Android operating system by Google which consists of five parts of a questionnaire. The variables were analyzed using SPSS such as frequency, percentage, mean and binary logistic regression.

Findings

Altogether, the participants were 223 males and 267 females; mean age=64.9±5.4. The average time spent using a mobile device was 2.8±1.9 h/day. Participants recorded that after use of either device, 59.0 percent experienced eye pain, 52.7 percent experienced dim eyes, 30.2 percent experienced tiredness, and 28.0 percent experienced moodiness. Socially, 26.8 percent recorded changes in social interaction. Periods of time using devices, time consumed in device usage (hours/day), the type of application, and the difference in times of use, place of usage and time spent in rest breaks from smartphone or tablet usage were significantly associated with health effects (p<0.05).

Originality/value

The elderly users may be at risk of several health effects from smartphone and tablet use. The potential gap in knowledge conceals some of the risk factors for the current health effects. Practical intervention to reduce health effects from the use of smartphones and tablets should be considered.

Effects of pesticide exposure on reproductivity of male groundnut farmers in Kyauk Kan village, Nyaung-U, Mandalay region, Myanmar

INTRODUCTION

Kyauk Kan village of Nyaung-U, Mandalay region, Myanmar is one of the most famous groundnut-growing zones and has been exposed to pesticides.

METHODS

This study design provided evaluation of within-person changes in the season across growing and nongrowing periods. A cross-sectional study was performed to identify health problems related to organophosphate pesticide (OP) exposure, to explore the protected use of this pesticide among 400 participants in the community by face-to-face interviews, and to determine the reproductive effects of OP exposure by using biomarkers of 100 male groundnut farmers aged 18-49 years.

RESULTS

The mean age of the participants was 37.5±9.45 years. Analysis revealed statistically significant differences in seminal parameters (P<0.05 for pH, viscosity, motility, morphology, and sperm count) and in a reproductive hormonal assay (P<0.05 in follicle-stimulating hormone and testosterone) between the growing and nongrowing periods. Blood-cholinesterase levels of plasma cholinesterase in the growing period were significantly higher than those in the nongrowing period (P<0.05).

CONCLUSION

Our results suggest that chronic exposure related to OP dose may reduce potential male reproductivity.

Using hair and fingernails in binary logistic regression for bio-monitoring of heavy metals/metalloid in groundwater in intensively agricultural areas, Thailand

In this study, the hair and fingernails of the local people in an intensively cultivated agricultural area in Ubon Ratchathani province, Thailand, were used as biomarkers of exposure to arsenic (As) and heavy metals. The study area has shallow acidic groundwater that is contaminated with As and heavy metals. The local people often consume this shallow groundwater; thus, they are exposed to As and heavy metals. Hair and fingernail samples were collected to characterize the differences between shallow groundwater drinking (SGWD) and tap water drinking (TWD) residents. The concentrations of As and the heavy metals Cd, Pb and Hg were significantly higher in the hair samples from the SGWD group than those from the TWD group, especially for As (0.020-0.571 vs. 0.024-0.359µg/g) and Cd (0.009-0.575 vs. 0.013-0.230µg/g). Similarly, the concentrations of As and the heavy metals in the fingernail samples collected from the SGWD group were larger than those of the TWD group, especially for As (0.039-2.440µg/g vs. 0.049-0.806µg/g). The χ² statistic and binary logistic regression were used to find the associated factors and assess the associated probabilities. The regression results show that the factors associated with the concentrations of As and the heavy metals in the hair samples were drinking water source, rate of water consumption, gender, bathing water source, education, smoking and underlying disease, whereas the factors associated with the concentrations of these species in the fingernail samples were drinking water source, gender, occupation, work hours per day, alcohol consumption, and the use of pesticides.

Using urine as a biomarker in human exposure risk associated with arsenic and other heavy metals contaminating drinking groundwater in intensively agricultural areas of Thailand

Urine used as a biomarker was collected and compared between two groups of participants: (1) a groundwater-drinking group and (2) a non-groundwater-drinking group in intensively agricultural areas in Ubon Ratchathani province, Thailand. The statistical relationship with the metal concentration in shallow groundwater wells was established with urine data. According to the groundwater data, the health risk assessment results for four metals appeared to be higher for participants who drank groundwater than for the other group. The carcinogenic risk and non-carcinogenic risk of arsenic (As) were found in 25.86 and 31.03% of participants, respectively. For lead (Pb), 13.79% of the participants had a non-carcinogenic risk. Moreover, 30 of the 58 participants in the groundwater-drinking group had As urine higher than the standard, and 26, 2 and 9 of the 58 participants had above-standard levels for cadmium (Cd), Pb and mercury (Hg) in urine, respectively. Both the risk assessment and biomarker level of groundwater-drinking participants were higher than in the other group. The results showed an average drinking rate of approximately 4.21 ± 2.73 L/day, which is twice as high as the standard. Interestingly, the As levels in the groundwater correlated with those in the urine of the groundwater-drinking participants, but not in the non-groundwater-drinking participants, as well as with the As-related cancer and non-carcinogenic risks. The hazard index (HI) of the 100 participants ranged from 0.00 to 25.86, with an average of 1.51 ± 3.63 higher than the acceptable level, revealing that 28 people appeared to have non-carcinogenic risk levels (24 and 4 people for groundwater-drinking participants and non-groundwater-drinking participants, respectively). Finally, the associated factors of heavy metals in urine were the drinking water source, body weight, smoking, sex and use of personal protective equipment.

Assessment of ambient dust pollution status at selected point sources (residential and commercial) of Mingaladon area, Yangon region, Myanmar

Purpose

Dust (particulate matters) is very dangerous to our health as it is not visible with our naked eyes. Emissions of dust concentrations in the natural environment can occur mainly by road traffic, constructions and dust generating working environments. The purpose of this paper is to assess the ambient dust pollution status and to find out the association between PM concentrations and other determinant factors such as wind speed, ambient temperature, relative humidity and traffic congestion.

Design/methodology/approach

A cross-sectional study was conducted for two consecutive months (June and July, 2016) at a residential site (Defence Services Liver Hospital, Mingaladon) and a commercial site (Htouk-kyant Junction, Mingaladon) based on WHO Air Quality Reference Guideline Value (24-hour average). Hourly monitoring of PM2.5 and PM10 concentration and determinant factors such as traffic congestion, wind speed, ambient temperature and relative humidity for 24 hours a day was performed in both study sites. CW-HAT200 handheld particulate matters monitoring device was used to assess PM concentrations, temperature and humidity while traffic congestion was monitored by CCTV cameras.

Findings

The baseline PM2.5 and PM10 concentrations of Mingaladon area were (28.50±11.49)µg/m3 and (52.69±23.53)µg/m3, means 61.48 percent of PM2.5 concentration and 54.92 percent of PM10 concentration exceeded than the WHO reference value during the study period. PM concentration usually reached a peak during early morning (within 3:00 a.m.-5:00 a.m.) and at night (after 9:00 p.m.). PM2.5 concentration mainly depends on traffic congestion and temperature (adjusted R2=0.286), while PM10 concentration depends on traffic congestion and relative humidity (adjusted R2=0.292). Wind speed played a negative role in both PM2.5 and PM10 concentration with r=−0.228 and r=−0.266.

Originality/value

The air quality of the study area did not reach the satisfiable condition. The main cause of increased dust pollution in the whole study area was high traffic congestion (R2=0.63 and 0.60 for PM2.5 and PM10 concentration).

Job safety analysis and hazard identification for work accident prevention in para rubber wood sawmills in southern Thailand

OBJECTIVE

We utilized job safety analysis (JSA) and hazard identification for work accident prevention in Para rubber wood sawmills, which aimed to investigate occupational health risk exposures and assess the health hazards at sawmills in the Trang Province, located in southern Thailand.

METHODS

We conducted a cross-sectional study which included a walk-through survey, JSA, occupational risk assessment, and environmental samplings from March through September 2015 at four Para rubber wood sawmills.

RESULTS

We identified potential occupational safety and health hazards associated with six main processes, including: 1) logging and cutting, 2) sawing the lumber into sheets, 3) planing and re-arranging, 4) vacuuming and wood preservation, 5) drying and planks re-arranging, and 6) grading, packing, and storing. Working in sawmills was associated with high risk of wood dust and noise exposure, occupational accidents injuring hands and feet, chemicals and fungicide exposure, and injury due to poor ergonomics or repetitive work.

DISCUSSION

Several high-risk areas were identified from JSA and hazard identification of the working processes, especially high wood dust and noise exposure when sawing lumber into sheets and risk of occupational accidents of the hands and feet when struck by lumber. All workers were strongly recommended to use personal protective equipment in any working processes. Exposures should be controlled using local ventilation systems and reducing noise transmission. We recommend that the results from the risk assessment performed in this study be used to create an action plan for reducing occupational health hazards in Para rubber sawmills.

Relationship Between Noise-Related Risk Perception, Knowledge, and the Use of Hearing Protection Devices Among Para Rubber Wood Sawmill Workers

Background

The understanding of the relationship between risk perception, knowledge, and protective behaviors could play a major role in occupational risk control and management. Research exploring how workers perceive, recognize, and react to risks in different occupational settings is scarce in Thailand. The aim of this study was to assess the relationship of noise-related risk perceptions and knowledge to the use of hearing protective devices (HPDs) among sawmill workers in Thailand.

Methods

Sawmill workers (n = 540) from four factories in Trang, Southern Thailand, participated in a questionnaire interview from December 2015 to January 2016. Descriptive statistics and linear regression models were used to explore the risk factors related to HPD use. Path diagram analysis was demonstrated and used to evaluate associations.

Results

Risk perception was significantly correlated with HPD use (p < 0.01), HPD training (p = 0.01), and the number of years of work experience (p = 0.03). Sawmill workers were likely to use HPDs based on their risk perception and HPD training. However, HPD training was inversely correlated with age and the number of years of work experience.

Conclusion

The study highlights the importance of risk perceptions and knowledge, and these factors should be emphasized in the design and implementation of any personal safety intervention program for sawmill workers.

Environmental arsenic exposure and risk of diabetes type 2 in Ron Phibun subdistrict, Nakhon Si Thammarat Province, Thailand: unmatched and matched case-control studies

Background

There are inconsistent findings on associations between low-to-moderate level of arsenic in water and diabetes risk from previous epidemiological reports. In Ron Phibun subdistrict, Nakhon Si Thammarat Province, Thailand, a low level of arsenic exposure among population was observed and increased diabetes mellitus (DM) rate was identified.

Objectives

We aimed to investigate the association between determinants (including low-level water arsenic exposure) of DM type 2 risk among residents of three villages of Ron Phibun subdistrict, Nakhon Si Thammarat Province.

Materials and methods

Secondary data from two previous community based-studies, conducted in 2000 and 2008, were utilized. Data on independent variables relating to arsenic exposure and sociodemographic characteristics were taken from questionnaires and worksheets for health-risk screening. Water samples collected during household visit were sent for analysis of arsenic level at certified laboratories. Diabetes cases (N=185) were those who had been diagnosed with DM type 2. Two groups of controls, one unmatched to cases (n=200) and one pair matched on age and gender (n=200), were selected for analysis as unmatched and matched case–control studies, respectively. A multiple imputation technique was used to impute missing values of independent variables. Multivariable logistic regression models, with independent variables for arsenic exposure and sociodemographic characteristics, were constructed. The unmatched and matched data sets were analyzed using unconditional and conditional logistic analyses, respectively.

Results

Older age, body mass index (BMI), having a history of illness in siblings and parents, and drinking were associated with increased DM type 2 risk. We found no convincing association between DM type 2 risk and water arsenic concentration in either study.

Conclusion

We did not observe meaningful association between diabetes risk and the low-to-moderate arsenic levels observed in this study. Further research is needed to confirm this finding in the study area and elsewhere in Thailand.

Effectiveness of the multidimensional ergonomic intervention model to reduce musculoskeletal discomfort among street sweepers in Chiang Rai Province, Thailand

The aim of this study was to evaluate the effectiveness of multidimensional ergonomic intervention (MEI) model to reduce musculoskeletal discomfort (MSD) among street sweepers. A quasi-experimental study was conducted in Chiang Rai Province. The MEI model was designed on the basis of four core components: cognitive behavior therapy, ergonomic education training, stretching exercise, and the foam sleeve broom handle grip. Seventy-five street sweepers volunteered for the screening process on MSD of having level score ≥4 by physiotherapist. Face to face interviews were used mainly in order to diagnose MSD. Physical examination was performed by physiotherapist and physical performance by sports scientist. The findings showed that the MEI model among the intervention group significantly reduced MSD compared with that among control group at exit model and follow-up (P<0.01). This research suggests that the MEI model was appropriate to reduce MSD associated with repetitive movement and awkward postures on task.

Occupational noise-induced hearing loss in auto part factory workers in welding units in Thailand

Objectives:

Most workers in auto part factories in Thailand are usually exposed to excessive noise in their workplace. This study aimed to assess the level of occupational noise-induced hearing loss and investigate risk factors causing hearing loss in auto part factory workers in the welding units in Thailand.

Methods:

This was a cross-sectional study. One hundred eighty subjects were recruited from 356 workers in the welding unit of three factories. Sixty eligible subjects in each factory were selected by systemic random sampling. The subjects were interviewed using a face-to-face questionnaire. Noise exposure levels and audiograms were measured by a noise dosimeter and an audiometer, respectively.

Results:

The findings confirmed that noise exposure levels of 86-90 dB (A) and exceeding 90 dB (A) significantly increased the risk of hearing loss in either ear. A noise exposure level exceeding 90 dB (A) significantly increased the prevalence of hearing loss in both ears. Regarding, a 10-pack-year smoking history increased the prevalence of hearing loss in either ear or both ears. In addition, subjects with employment duration exceeding 10 years significantly developed hearing loss in either ear.

Conclusions:

The engineering control or personal control by wearing hearing protection device should be used to decrease noise exposure levels lower than 85 dB (A) for 8 h. Moreover, if the exposure level reaches 85 dB (A) for 8 h, the employer needs to implement a hearing conservation program in the workplace.

Salivary cotinine levels as a biomarker for green tobacco sickness in dry tobacco production among Thai traditional tobacco farmers

BACKGROUND

Dry Thai traditional tobacco (Nicotiana Tabacum L.) production involves a unique process: (a) picking tobacco leaves, (b) curing tobacco leaves, (c) removing stems of tobacco leaves, cutting leaves and putting on a bamboo rack, (d) drying in the sun, reversing a rack, spraying a tobacco extract to adjust the tobacco's color, storing dried tobacco and packaging. These processes may lead to adverse health effects caused by dermal absorption of nicotine such as Green Tobacco Sickness (GTS).

OBJECTIVES

The aim of this study was to determine the correlation between GTS resulting from dry Thai traditional tobacco production and salivary cotinine levels among Thai traditional tobacco farmers in Nan Province, Thailand.

MATERIALS AND METHODS

A prospective cohort study was conducted with 20 tobacco farmers and 20 non-tobacco farmers in Praputtabath Sub-District and Phatow Sub-District. The participants were randomly selected and interviewed using in person questionnaires with bi-weekly follow-up for 14 weeks. During each contact, the cotinine concentration was measured by NicAlert(TM) Saliva strip tests (NCTS). Descriptive statistics and Spearman's correlation (Spearman's rho) was used to examine the relationship between the variables at both 0.01 and 0.05 significant probability levels.

RESULTS

This study indicated that GTS from dry tobacco production has the potential to be considered a common occupational disease. This study demonstrated the usefulness of salivary cotinine level measurements by NCTS. The levels were well correlated with farmers who were employed in the dry Thai tobacco production industry. Salivary cotinine levels were also significantly correlated with the prevalence of GTS in the group of tobacco farmers at any given time within a crop season. However, the production process of dry Thai traditional tobacco is different from that evaluated in our previous studies where GTS and salivary cotinine level were correlated in workers working in humid conditions.

CONCLUSIONS

The long-term effects of such exposure should be investigated and health education programs with health risk exposure studies to increase awareness amongst farmers is recommended.

Organophosphate pesticide exposure in school-aged children living in rice and aquacultural farming regions of Thailand

Organophosphate pesticides (OPs) are widely used in agricultural sectors in Thailand. Previous studies have documented that children residing in agricultural areas have higher exposure to OPs than children living in other residential areas. The objective of this study was to quantify urinary biomarkers of OP exposure and determine the environmental conditions and activities that predict their levels among children living in Central Thailand farming regions. In October 2011, 53 6-8-year-old participants were recruited from Pathum Thani Province, Thailand. Twenty-four lived in rice farming communities at Khlong Luang District where OPs are the pesticides used frequently. Twenty-nine participants, living in aquacultural farming communities at Lum Luk Ka District where OPs are not used, were recruited to serve as controls for pathways of exposure (e.g., residential, dietary) other than occupational/paraoccupational exposures encountered in rice farming. Household environments and participants' activities were assessed using a parental structured interview. Urine samples (first morning voids) were collected from participants for OP urinary metabolite (i.e., dialkylphosphates [DAPs] and 3,5,6-trichloro-2-pyridinol [TCPy]) measurements. The levels of most urinary OP metabolites were significantly higher in participants who lived in a rice farming community than those who lived in an aquacultural farming community (P < .05). The results from linear regression analysis revealed that the frequency of OP application on rice farms (∑DAP: P = .001; TCPy: P = .001) and living in a rice farming community (∑DAP: P = .009; TCPy: P < .001) were significant predictors of urinary DAP metabolite levels in participants. Increasing TCPy levels were significantly related to proximity to rice farm (P = .03), being with parent while working on a farm (P = .02), playing on a farm (P = .03), and the presence of observable dirt accumulated on the child's body (P = .02). In conclusion, OP metabolite levels among children who live in rice farming communities were strongly influenced by farming activity, household environments, and child behaviors, suggesting that these are the primary pathways in which children living in these agricultural communities in Thailand were exposed to OPs.

Green Tobacco Sickness among Thai Traditional Tobacco Farmers, Thailand

BACKGROUND

Traditional Thai tobacco (Nicotiana abacus L.) is known as a non-Virginia type whose mature leaf contains three to four times more nicotine than that of a Virginia type. As such, the process of Thai traditional tobacco production may lead to adverse health effects such as green tobacco sickness (GTS).

OBJECTIVE

To investigate the prevalence of GTS and risk factors related to GTS among Thai traditional tobacco farmers in Nan province, northern Thailand.

METHODS

473 Thai traditional tobacco farmers from rural areas in Nan province were randomly selected and interviewed in person by means of questionnaires and environmental survey. Statistical analyses were used to identify potential risk factors for GTS.

RESULTS

The prevalence of GTS was 22.6% (95% CI 19.1% to 26.6%). Multivariate analysis showed various risk factors associated with GTS including gender of the farmer (ORadj 0.44, 95% CI 0.26 to 0.73), smoking (ORadj 4.36, 95% CI 1.41 to 13.47), skin rash (ORadj 0.36, 95% CI 0.19 to 0.68), wearing a wet suit (ORadj 1.91, 95% CI 1.12 to 3.23), process of curing tobacco leaves (ORadj 0.06, 95% CI 0.02 to 0.16), and watering tobacco plants (ORadj 0.42, 95% CI 0.25 to 0.72).

CONCLUSION

The process of traditional Thai tobacco production can result in increased dermal exposure and can be considered a major risk factor for GTS. Body soaking during watering may further increase adverse health effects related to GTS.

Neurobehavioral effects of exposure to organophosphates and pyrethroid pesticides among Thai children

The use of pesticides for crop production has grown rapidly in Thailand during the last decade, resulting in significantly greater potential for exposure among children living on farms. Although some previous studies assessed exposures to pesticides in this population, no studies have been conducted to evaluate corresponding health effects. Twenty-four children from a rice farming community (exposed) and 29 from an aquaculture (shrimp) community (control) completed the study. Participants completed a neurobehavioral test battery three times at 6 month intervals: Session I: preliminary orientation; Session II: high pesticide use season; Session III: low pesticide-use season. Only sessions II and III were used in the analyses. High and low pesticide use seasons were determined by pesticide use on rice farms. Urinary metabolites of organophosphates (OPs) and pyrethroids (PYR) were analyzed from first morning void samples collected the day of neurobehavioral testing. Rice farm participants had significantly higher concentrations of dialkylphosphates (DAPs) (common metabolites of OPs) and TCPy (a specific metabolite of chlorpyrifos) than aquaculture farm children during both seasons. But, TCPy was significantly higher during the low rather than the high pesticide use season for both participant groups. Rice farm children had significantly higher DCCA, a metabolite of PYR, than aquaculture participants only during the high exposure season. Otherwise, no significant differences in PYR metabolites were noted between the participant groups or seasons. No significant adverse neurobehavioral effects were observed between participant groups during either the high or low pesticide use season. After controlling for differences in age and the Home Observation for Measurement of the Environment (HOME) scores, DAPs, TCPy, and PYR were not significant predictors of adverse neurobehavioral performance during either season. Increasing DAP and PYR metabolites predicted some relatively small improvement in latency of response. However, due to the small sample size and inability to characterize chronic exposure, any significant differences observed should be regarded with caution. Moreover although not statistically significant, confidence intervals suggest that small to moderate adverse effects of pesticide exposure cannot be ruled out for some indicators of neurobehavioral performance.

An association between organophosphate pesticides exposure and Parkinsonism amongst people in an agricultural area in Ubon Ratchathani Province, Thailand

BACKGROUND

Parkinson's disease (PD) is a ubiquitous disease. However, PDs prevalence in the population of agricultural communities lacks understanding and there has been no epidemiological study on the association between pesticides exposure factors and risk for PD.

OBJECTIVES

To investigate the potential association between organophosphate pesticides exposure and Parkinsonism by using a screening questionnaire in agricultural areas.

MATERIAL AND METHODS

Ninety elderly people living in agricultural areas participated in a cross-sectional study conducted at Tambon Hua-Rua Health Promoting Hospital in April 2014. Screening questionnaires for Parkinson's disease, Test-mate ChE (Model 400) for blood cholinesterase (ChE) levels of both blood enzymes erythrocyte cholinesterase (AChE), and plasma cholinesterase (PChE) were used as measurement tools. Descriptive statistics for frequencies and percentage distributions were used primarily to summarize and describe the data. Sensitivity, specificity, positive and negative predictive values were calculated.

RESULTS

The age range of the participants was 50 to 59 years old, with an average age of 53.9±2.87 years. The majority of the participants were female (62.2%), 82.2% of respondents were farmers. Most of participants (76.7%) reported that they applied insecticides in their farms. Ninety persons participated and completed the 11-item questionnaire. Of these, 17 (18.9%) felt that they lost balance when turning or that they needed to take a few steps to turn right around and 16.7% of participants indicated that they felt the need to move slowly or stiffly. The study found the prevalence of abnormal AChE levels was 28.9% (95%CI=19.81-39.40) and 17.8% of PChE levels (95%CI=10.52-27.26). To predict Parkinsonism, AChE, and PChE level, with a cutoff score of 5 or higher there had to be a sensitivity of 0.31, specificity of 1.00, positive predictive value (PPV) of 1.00 and negative predictive value (NPV) of 0.78 for AChE. While PChE, the score value of 5 or more had a sensitivity of 0.19, specificity of 0.93, PPV of 0.38 and NPV of 0.84.

CONCLUSIONS

This study described an association between pesticides exposure and Parkinsonism. The questionnaire appears to be useful for Thai agriculturists as a screening tool for Parkinsonism and cholinesterase levels regarding to pesticides exposure.

Pyrethroid insecticide exposure in school-aged children living in rice and aquacultural farming regions of Thailand

BACKGROUND

Pyrethroid insecticides (PYR) are commonly used in rice farms and household pest control in Thailand. No investigative study has yet been made regarding factors associated with PYR exposure among Thai children.

OBJECTIVE

This study aimed to compare the levels of PYR exposure between children living in rice farms (high-intensity PYR used) and aquacultural areas (low-intensity PYR used) during the wet and dry seasons in Thailand, during which different amounts of PYR are applied. Environmental conditions and common activities of children were used to identify factors associated with PYR exposure.

METHODS

A cross-sectional study was done during the wet and dry seasons, respectively. A total of 53 participants aged between 6 and 8 years old were recruited from rice farms and aquacultural areas. A parental-structured interview was used to gather information about PYR use, household environments, and participants' activities. First voided morning urine samples were collected for PYR urinary metabolites (ie, 3-phenoxybenzoic acid [3-PBA] and cis/trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid [DCCA]) measurements. Hand wipe samples were collected during home visits, to measure PYR residues on the hands.

RESULTS AND DISCUSSION

The concentrations of urinary PYR metabolites were not significantly different between participants who lived in rice farming and those who lived in aquacultural areas, during both wet and dry seasons. Both participant groups had slightly increased urinary PYR metabolites during the wet season compared with the dry season. The results from linear regression analysis revealed that some environmental conditions and activities or practices may be used to predict trends of PYR exposure. Frequency of PYR use in farms (β=0.004) and households (β=0.07), proximity to rice farms (β=0.09), playing in rice farms (β=0.11), and oral exposure from objects exposed to PYR (β=0.08) were likely to be related to increased concentrations of PYR metabolites. These findings suggest that PYR use in rice farms and households may be significant sources of PYR exposure among children living in agricultural areas. However, a bigger sample size may be necessary in a subsequent study, to explore the association between long-term exposure to pesticide and its health effects on children.

Incense and joss stick making in small household factories, Thailand

BACKGROUND

Incense and joss stick are generally used in the world. Most products were made in small household factories. There are many environmental and occupational hazards in these factories.

OBJECTIVE

To evaluate the workplace environmental and occupational hazards in small household incense and joss stick factories in Roi-Et, Thailand.

METHODS

Nine small household factories in rural areas of Roi-Et, Thailand, were studied. Dust concentration and small aerosol particles were counted through real time exposure monitoring. The inductively coupled plasma optical emission spectrometry (ICP-OES) was used for quantitative measurement of heavy metal residue in incense products.

RESULTS

Several heavy metals were found in dissolved dye and joss sticks. Those included barium, manganese, and lead. Rolling and shaking processes produced the highest concentration of dust and aerosols. Only 3.9% of female workers used personal protection equipment.

CONCLUSION

Dust and chemicals were major threats in small household incense and joss stick factories in Thailand. Increasing awareness towards using personal protection equipment and emphasis on elimination of environmental workplace hazards should be considered to help the workers of this industry.

Effects of an injury and illness prevention program on occupational safety behaviors among rice farmers in Nakhon Nayok Province, Thailand

The objective of this study was to determine the effects of an Injury and Illness Prevention (IIP) program intervention on occupational safety behavior among rice farmers in Nakhon Nayok Province, Thailand. This was a quasi-experimental study in an intervention group and a control group. It was carried out in two rice farming communities, in which most people are rice farmers with similar socio-demographic characteristics. Multistage sampling was employed, selecting one person per rice farming household. The intervention group was 62 randomly selected rice farmers living in a rural area; another 55 rice farmers served as the control group. A structured face-to-face interview questionnaire was administered to participants to evaluate their safety behaviors in four areas: equipment use, pesticide use, ergonomics, and working conditions. The 2-week intervention program consisted of four elements: 1) health education, 2) safety inspection, 3) safety communication, and 4) health surveillance. Data were collected at baseline and 4 months after the intervention (follow-up). We used a general linear model repeated-measures analysis of variance to assess the mean difference between baseline and follow-up occupational safety behavior points between the intervention and control groups. Pesticide safety behaviors significantly increased in the intervention group compared with the control group. Ergonomics and working conditions points also increased in the intervention group, but not significantly so. The equipment use score decreased in the intervention group. It is necessary to identify and develop further measures to improve occupational safety behaviors. Some methods, such as effective risk communication, could be added to increase risk perception.

Heavy metal contamination and human health risk assessment in drinking water from shallow groundwater wells in an agricultural area in Ubon Ratchathani province, Thailand

Most local people in the agricultural areas of Hua-ruea sub-district, Ubon Ratchathani province (Thailand), generally consume shallow groundwater from farm wells. This study aimed to assess the health risk related to heavy metal contamination in that groundwater. Samples were randomly collected from 12 wells twice in each of the rainy and the dry seasons and were analyzed by inductive coupled plasma spectrometry-mass spectrometry (ICP-MS). The concentration of detected metals in each well and the overall mean were below the acceptable groundwater standard limits for As, Cd, Cr, Cu, Hg, Ni and Zn, but Pb levels were higher in four wells with an overall average Pb concentration of 16.66 ± 18.52 μg/l. Exposure questionnaires, completed by face-to-face interviews with 100 local people who drink groundwater from farm wells, were used to evaluate the hazard quotients (HQs) and hazard indices (HIs). The HQs for non-carcinogenic risk for As, Cu, Zn and Pb, with a range of 0.004-2.901, 0.053-54.818, 0.003-6.399 and 0.007-26.80, respectively, and the HI values (range from 0.10 to 88.21) exceeded acceptable limits in 58 % of the wells. The HI results were higher than one for groundwater wells located in intensively cultivated chili fields. The highest cancer risk found was 2.6 × 10(-6) for As in well no. 11. This study suggested that people living in warmer climates are more susceptible to and at greater risk of groundwater contamination because of their increased daily drinking water intake. This may lead to an increased number of cases of non-carcinogenic and carcinogenic health defects among local people exposed to heavy metals by drinking the groundwater.

Organophosphate pesticide exposure and dialkyl phosphate urinary metabolites among chili farmers in northeastern Thailand

BACKGROUND

Chlorpyrifos and profenofos are organophosphate pesticides (OPPs), we studied exposure and urinary metabolites in an agricultural area in the northeastern of Thailand during the chili-growing season (March - April) in 2012.

OBJECTIVE

This study was designed to assess pesticide exposure concentration through dermal and inhalation pathways and to find and depict a relationship between urinary metabolites and means of exposure.

MATERIALS AND METHODS

To estimate the pesticides exposure concentration, dermal wipes (hand, face, and feet), dermal patches and air samples were collected from 38 chili farmers. The morning void of pre and post application urine samples was an indicator of biological monitoring in the study which derived from 39 chili farmers.

RESULTS

Chlorpyrifos and profenofos residues were detected on dermal patches, face wipes, and hand wipe samples, while no significant residues were found on the feet. Using a personal air sampling technique, all air samples detected pesticide residues. However, significant correlation between dermal pesticide exposure concentration and inhalation was not found (p>0.05). For urinary metabolite levels, there was a relationship between the first pre application morning void and post application morning void (p < 0.05); similar to the association between the first pre application morning void and the second post application morning void (p < 0.05). The main relationship between pesticide exposure and urinary metabolite was found to have been relevant to dermal exposure (r= 0.405; p < 0.05).

CONCLUSIONS

The results of this study could suggested that public health education training programs, including the use of appropriate personal protective equipment (PPE), should be offered for the chili growing farmers in order to improve their ability to properly use pesticides.

KEY WORDS

pesticide exposure, chili farmers, urinary metabolites, organophosphate pesticides.

Adaptation of a neurobehavioral test battery for Thai children

BACKGROUND

Exposure to neurotoxicants is a world wide problem with significant health implications for child development. In spite of higher neurotoxicant exposures, many developing countries do not have established neuropsychological instruments.

OBJECTIVE

This study evaluated the adaptation and reliability of a computer and examiner administered Behavioral Assessment and Research System (BARS) that includes tests of motor speed and dexterity, attention, memory, and visuospatial coordination for use in Thailand.

MATERIAL AND METHODS

To assess test-retest and alternate form reliability, BARS was administered to 24 healthy, 6-8 year old urban Thai children during two testing sessions two weeks apart. A comparison group of 29 healthy, rural Thai children of similar age and sex completed the BARS as part of another study and comprised a comparison group.

RESULTS

Test-retest reliabilities for tests without alternate forms ranged from 0.41 to 0.77, but reliabilities were lower for tests with alternate forms (0.11 to 0.83). Paired t-tests revealed few significant differences in group performance between test administrations. Performance of urban Thai participants was compared to 29 rural Thai participants of similar age and sex. Parental education was significantly greater for urban vs. rural participants, resulting in significant differences in performance on tests of motor speed.

CONCLUSIONS

This study supports the use of BARS for epidemiologic studies of neurotoxicants in Thailand, but highlights the sensitivity of these tests to differences in parental education and the need for improved alternate test forms.

Respiratory symptoms and patterns of pulmonary dysfunction among roofing fiber cement workers in the south of Thailand

OBJECTIVE

This study examined the associations between respiratory symptoms and patterns of pulmonary dysfunction of 115 male roofing cement workers compared with 134 unexposed subjects.

METHODS

A cross-sectional study was conducted. Environmental samplings and spirometry measurements were also collected.

RESULTS

The exposed workers had higher respiratory dust exposure levels (0.65 mg/m3) compared with the unexposed groups (0.32 mg/m3). The exposed group had significantly higher prevalence than the unexposed group for shortness of breath (OR=2.19). The exposed group also had higher but insignificant prevalence of chronic cough (OR=1.34), chest tightness (OR=1.64), and wheezing (OR=1.89). The ventilatory respiratory function values (FEV1 and FVC) were slightly lower for the exposed group.

CONCLUSION

An association between higher cement dust levels and a decline in ventilatory function among roofing fiber cement workers suggests that the respiratory health of roofing cement workers should be protected through policies or work standards.

Health Risk Behaviors Associated With Agrochemical Exposure Among Rice Farmers in a Rural Community, Thailand

The study objective was to evaluate health beliefs and behaviors associated with agrochemical exposure among rice farmers. We applied the Health Belief Model, community-based ethnography, and public health risk assessment for this study. Data were collected from 101 rice farmers in Khlong Seven community between January and June 2010. Data comprised observations, unstructured and semistructured interviews, and focus group discussions. We showed that farmers had moderate levels of perceived susceptibility to, severity of, benefits of, and barriers to using agrochemicals safely. The major risk factors related to agrochemical exposure resulted from the misuse of pesticides, including erroneous beliefs of farmers regarding pesticide toxicity, the use of faulty spraying equipment, the lack of proper maintenance of spraying equipment, or the lack of protective gear and appropriate clothing. An intervention program is necessary to improve safety with regard to agrochemicals in the rice Khlong Seven community.

Health risk reduction behaviors model for scavengers exposed to solid waste in municipal dump sites in Nakhon Ratchasima Province, Thailand

The aim of this study was to evaluate the effect of comprehensive health risk protection behaviors, knowledge, attitudes, and practices among scavengers in open dump sites. A control group of 44 scavengers and an intervention group of 44 scavengers participated in this study. Interventions included the use of personal protective equipment, health protection training, and other measures. The analysis showed significant differences before and after the intervention program and also between the control and intervention groups. These observations suggest that further action should be taken to reduce adverse exposure during waste collection. To reduce health hazards to workers, dump site scavenging should be incorporated into the formal sector program. Solid waste and the management of municipal solid waste has become a human and environmental health issue and future research should look at constructing a sustainable model to help protect the health of scavengers and drive authorities to adopt safer management techniques.

Multi-approach model for improving agrochemical safety among rice farmers in Pathumthani, Thailand

The large-scale use of agrochemicals has raised environmental and human health concerns. A comprehensive intervention strategy for improving agrochemical safety among rice farmers in Thailand is lacking. The objective of this study is to develop a model in order to improve farmers' health and prevent them from being exposed to agrochemical hazards, in addition to evaluating the effectiveness of the intervention in terms of agrochemical safety. This study was conducted between October 2009 and January 2011. It measures changes in the mean scores of agrochemical knowledge, health beliefs, agrochemical use behaviors, and in-home pesticide safety. Knowledge of agrochemical use constitutes a basic knowledge of agrochemicals and agrochemical safety behaviors. Health beliefs constitute perceived susceptibility, severity, benefits, and barriers to using agrochemicals. Agrochemical use behaviors include self-care practices in terms of personal health at specific times including before spraying, while spraying, during storage, transportation, waste management, and health risk management. Fifty rice farmers from Khlong Seven Community (study group) and 51 rice farmers from Bueng Ka Sam community (control group) were randomly recruited with support from community leaders. The participants were involved in a combination of home visits (ie, pesticide safety assessments at home) and community participatory activities regarding agrochemical safety. This study reveals that health risk behaviors regarding agrochemical exposure in the study area are mainly caused by lack of attention to safety precautions and the use of faulty protective gear. After 6 months, the intervention program showed significant improvements in the overall scores on knowledge, beliefs, behaviors, and home pesticide safety in the study group (P < 0.05). Therefore, this intervention model is effective in improving agrochemical safety behaviors among Khlong Seven Community rice farmers. These findings demonstrate that a multi-approach model for improving agrochemical safety behaviors can lead to sustainable prevention of agrochemical hazards for farmers.

Occupational exposure of gasoline station workers to BTEX compounds in Bangkok, Thailand

BACKGROUND

Gasoline station workers are exposed to volatile organic compounds such as benzene, toluene, ethylbenzene and xylene (BTEX).

OBJECTIVE

To determine the level of exposure to BTEX compounds among gasoline station workers and measure the roadside concentrations of these compounds in the inner and outer areas of Bangkok, Thailand.

METHODS

49 workers at 6 gasoline stations in the inner and outer areas of Bangkok participated in this study. Samples of ambient air were collected from the area near gas pumps at each station and at the roadside in front of the gas stations by charcoal tubes. All samples were analyzed for BTEX compounds by gas chromatography-flame ionized detector (GC-FID).

RESULTS

The mean BTEX concentration in gas stations was slightly higher than that of the roadside; there was no significant difference in the concentration between inner and outer areas. The mean lifetime cancer risks for workers exposed to benzene and ethylbenzene for 30 years were estimated at 1.75×10⁻⁴ and 9.55×10⁻⁷. The estimated hazard quotients for BTEX compounds were 0.600, 0.008, 0.007 and 0.002, respectively. The most prevalent symptoms of workers were headache (61%), fatigue (29%) and throat irritation (11%), respectively. Exposure to benzene and toluene was significantly associated with fatigue (p<0.05).

CONCLUSION

Exposure to BTEX compounds would increase the risk of cancer in gasoline station workers. Exposure to benzene and toluene may cause fatigue.