Benzene health risk assessment for neurological disorders of gas station employees in Rayong Province, Thailand.

Background: The main job of employees working in the area of fuel service stations is to provide refueling services to customers. Therefore, operators at petrol stations may be exposed to chemicals for long periods, potentially affecting their health in nervous system. Objectives: This study aims to assess the risk of benzene exposure to the nervous system in gas station operators. Data were collected from 100 fuel service personnel working at fuel dispensers and 100 employees working outside fuel dispensers, accounting to 200 cases. Material and methods: Data were collected using interview questionnaires. Urine samples were used for the analysis of t,t-muconic acid. Results: The results showed that t,t-muconic acid concentration is 431.23 ± 233.69 µg/g.cr (449.28 ± 213.32 µg/g.cr at fuel dispensers vs 413.18 ± 252.20 µg/g.cr outside fuel dispensers). The risk characterization results showed that most of the risks were at level 1 (low risk), as observed in 108 people (54.0%). The results of the analysis of the relationship between t,t-muconic acid concentrations classified by 3 levels of percentile and neurological disorders of the study group, the results showed that there was a statistically significant relationship (p-value <0.05). Conclusion: Therefore, the benzene neurotoxic risk assessment model could be utilized in field practice.

Comparison of monoamine oxidase and selected heavy metal levels in the blood and the workplace among e-waste sorting workers in Ubon Ratchathani Province, Thailand.

Background: E-waste sorting workers usually separate electronic waste. Therefore, they can be exposed to heavy metals. Objectives: This study compared monoamine oxidase (MAO) levels affected by the levels of lead (Pb), cadmium (Cd), and nickel (Ni) in the blood and their workplace among e-waste sorting workers (EWSW). Material and methods: The exposed group included 76 EWSW, and the non-exposed group included 49 village health volunteers. An interview form was used to assess the risk factors. We measured Pb, Cd, and Ni on the work surfaces and in the blood, and MAO levels as a neurological enzymes. Results: Among the EWSW, 42 were males (55.3%), and the mean age (SD) 48.0 (12.64) years, and income were 156.37 ± 88.08 USD. In the work areas of the exposed group, the concentration of Pb, Cd, and Ni were 245.042 (± 613.910), 0.375 (± 0.662), and 46.115 (± 75.740) µg/100 cm2, respectively, while the non-exposed group, the concentration of Pb, Cd, and Ni were 0.609 (± 0.934), 0.167 (± 1.171) and 1.020 (± 0.142) µg/100 cm2. Pb and Ni concentrations in the workplace of the exposed groups were statistically different from that of the non-exposed group. Pb, Cd, and Ni concentrations in serum were 6.411 ± 1.492 µg/dL, 0.9480 ± 0.350 µg/L, 2.568 ± 0.468 µg/L, respectively, while in the non-exposed group, the heavy metal concentrations were 6.411 ± 1.620 µg/dL, 0.909 ± 0.277 µg/L, 2.527 ± 0.457 µg/L. The MAO in the exposed group was 362.060 ± 97.981 U/L, while that in the non-exposed group was 369.771 ± 86.752 U/L. Moreover, MAO concentration was significantly different from Ni concentration (p < 0.05). Conclusion: The electronic waste sorting workers should clean their work areas to reduce the Pb, Cd, and Ni levels on the working surfaces, and health surveillance should be performed.

Comparison of urinary biomarkers concentrations in exposed and non-exposed petrol station workers in the Eastern Economic Corridor (EEC), 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.

The risk factors for occupational contact dermatitis among workers in a medium density fiberboard furniture factory in Eastern Thailand.

The aim of this study was to determine the occupational exposure to formaldehyde on the medium-density fiberboard (MDF) dust and allergic contact dermatitis among the workers at a furniture factory. Data were collected from 439 subjects using questionnaires and patch testing to evaluate allergic contact dermatitis resulting from formaldehyde on wood dust exposure in the workplace. The geometric mean concentration of formaldehyde on MDF dust that the workers in the production department were exposed to was 2.07 ppm (GSD 4.54). Patch test results revealed that some subjects developed allergy to various substances, including epoxy resin (16.7%) and formaldehyde (5.6%). The odds ratios (95% CI) for contact dermatitis were 3.6 (1.7-7.3) among those with a history of metal allergy, 1.8 (0.6-5.2) whose family members having a history of allergic contact dermatitis. Exposure to MDF dust in the workplace should be reduced, as the current levels of exposure exceed the permissible OSHA standard.

Assessment of Sleep Deprivation and Fatigue Among Chemical Transportation Drivers in Chonburi, Thailand.

BACKGROUND: Fatigue and sleepiness are inter-related and common among road transport drivers. In this study, sleep deprivation and fatigue among chemical transportation drivers were examined. METHODS: A cross-sectional study surveying 107 drivers from three hazardous types of chemical production and transportation industries (nonflammable gases, flammable gases, and flammable liquids) was conducted. Data on sleep deprivation were collected using questionnaires of the Stanford Sleeping Scale and the Groningen Sleep Quality Scale. Fatigue was assessed using an interview questionnaire and a flicker fusion instrument. RESULTS: Chemical drivers had a mean sleeping scale (Stanford Sleeping Scale) of 1.98 (standard deviation 1.00) and had a mean score of 1.89 (standard deviation 2.06) on the Groningen Sleep Quality Scale. High-risk drivers had higher scores in both the Stanford Sleeping Scale and the Groningen Sleep Quality Scale with a mean score of 2.59 and 4.62, respectively, and those differences reached statistical significance (p < 0.05). The prevalence of fatigue, as assessed through a critical flicker fusion analyzer, subjective fatigue question, and either of the instruments, was 32.32%, 16.16%, and 43.43%, respectively. Drivers who slept <7 hours and had poor sleep quality were found to have more fatigue than those who slept enough and well. Drivers who had a more sleepiness score resulted in significantly more objective fatigue than those who had a less sleepiness score. CONCLUSION: Sleep quality and sleeping hour can affect a driver's fatigue. Optimization of work-rest model should be considered to improve productivity, driver retention, and road safety.

Access to Health Care by Migrant Farm Workers on Fruit Plantations in Eastern Thailand.

OBJECTIVES: This study was undertaken to elucidate factors that influenced access to health care for migrant farm workers from Cambodia employed on fruit plantations in eastern Thailand. METHODS: Data were collected from 861 participants via interview questions and focus group discussions. RESULTS: The results revealed that 58.2% of immigrant workers were male, averaged 30.4 years of age, and 56.3% had no formal education. In the past year, 28% reported back pain and 25% had joint pain. Most of the workers (89.8%) received health care services at a nearby government health promotion hospital (THPH). From the analysis of factors contributing to the access to health services among immigrant farm workers, the data indicate that the Cambodian workers had few concerns with their ability to access health care services, reporting high and medium levels of satisfaction (with odds ratios [ORs] of 6.19 and 3.94, respectively) versus being unsatisfied. The differences between those who reported significant minor illnesses and serious illness were important, as workers with significant complaints were 3.17 and 4.85 times more likely, respectively, to have sought medical treatment than those not reporting illness. CONCLUSION: The main recommendation resulting from this study is that factors leading to higher degrees of satisfaction with health care services by migrant farm workers for preventative care could be improved.

Pesticide Exposure and Cholinesterase Levels in Migrant Farm Workers in Thailand.

OBJECTIVES: In this study, we examined the effects of pesticides in migrant farm workers from Cambodia after workplace exposure on fruit plantations in eastern Thailand. METHODS: We studied 891 migrant farm workers employed on pineapple, durian, and rambutan plantations in Thailand. Data were collected via a detailed questionnaire survey and measurements of serum cholinesterase level (SChE). RESULTS: The majority of subjects was male (57.7%), with an average age of 30.3 years. Most subjects (76.8%) were moderately aware of good industrial hygiene practices. SChE level was divided into four groups based on the results. Only 4.4% had normal levels of cholinesterase activity, 20.5% had slightly reduced levels, 58.5% had markedly reduced levels and were "at risk," and 16.6% who had highest levels of cholinesterase inhibition were deemed to be in an "unsafe" range. SChE was classified into two groups, SChE value of 87.5 was "normal" and <87.5 units/mL "abnormal." For the multiple logistic regression analysis of the abnormal SChE levels, the variables entered in the model included gender, period of insecticide use, the total area of plantation, frequency of spraying, period of daily insecticide spraying, and insecticide spraying method. The results indicated that the aOR (adjust odds ratio) for male migrant farm workers (95% confidence interval [CI]) was 1.58 (1.14, 2.17). The OR for farm migrant workers who worked on larger plantations of more than 39.5 acres (95% CI) was 2.69 (1.51, 4.82). Finally, the OR for the migrant farm workers who used a backpack sprayer (95% CI) was 2.07 (1.28, 3.34). CONCLUSIONS: These results suggest that health screening should be provided to migrant farm workers, especially those who spray pesticides on plantations of >39 acres, use a backpack sprayer, or have a low level of compliance with accepted industrial hygiene practices. These three classes of workers are at increased risk of chemical exposures and developing acute or chronic illness from pesticide exposures.

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.

Factors affecting the musculoskeletal disorders of workers in the frozen food manufacturing factories in Thailand.

The purpose of this research was to study factors affecting musculoskeletal disorders. The sample population of the study was 528 factory workers from the frozen food industry, as well as a controlled group of 255 office workers. The samples were collected during interviews using the Nordic questionnaire to assess musculoskeletal disorders, and to assess the risk by the rapid upper limb assessment and rapid entire body assessment techniques. The findings of the study were that most symptoms were found in the dissecting department, higher than in the controlled group. The details of the symptoms were, accordingly: elbow pain (adjusted odds ratio, 35.1; 95% CI [17.4, 70.9]). Regarding the risk of alcohol drinking, workers were exposed to more risks when alcohol was consumed. It is suggested that workers' health should be monitored regularly. People who work in a cold environment should be encouraged to wear body protection and to avoid drinking.

Neuropsychological Symptoms among Workers Exposed to Toluene and Xylene in Two Paint Manufacturing Factories in Eastern Thailand.

The study analyzed the exposure factors that may lead to neuropsychological symptoms among 92 workers who were exposed to xylene and toluene and 100 workers who were not exposed to the solvents. The airborne concentration of xylene and toluene was evaluated with personal passive badges. The levels of methyl hippuric acid and hippuric acid in urine were assessed, and interviews were performed to observe the neuropsychological symptoms that may result from exposure to the solvents. The result showed that the average concentration for the exposed group of xylene in the paint company working environment was 2.7 (SD = 2.4) ppm and the average concentration of toluene was 9.5 (SD = 10.4) ppm. The average level of methyl hippuric acid in urine was 78 (SD = 74.7) mg/g creatinine. Factors that affected the neuropsychological symptoms included the following. (1) The impact of age: the risk (adjusted odds ratio) for getting psychosomatic symptoms in persons over 40 and exposed to xylene was 9.5 and the aOR of those exposed to toluene was 8.3. (2) The impact of not providing personal protective equipment was found to be sleep disturbance; it was found that the aOR of those exposed to xylene was 3.9, and the aOR of those exposed to toluene was 4.4. In summary, periodic examination of workers by occupational physician is needed for detection of early neuropsychological effects, especially psychosomatic symptoms, and sleep disturbances.

Cold exposure and health effects among frozen food processing workers in eastern Thailand.

Frozen food processing workers work under a cold environment which can cause several adverse health effects.This study explored factors affecting workers' health in the frozen food industry in Thailand. Participants comprised 497 workers exposed to a cold working environment and 255 office workers who served as the controls. Data were collected by a survey on the work environment, and the interview of workers for abnormal symptoms. The exposed group had the following characteristics: 52.7% male, overall average age of 27 (SD 6.6) years old, attained elementary education (Grade 4 and Grade 6) (54.1%), married (48.9%), smokers (21.3%), alcohol consumption (31.0%), duration of work was between 1 and 5 years (65.2%), working 6 days a week (82.7%), 1-5 hours of overtime per week (33.8%), office workers (33.9%); work category: sizing (6.9%), peeling (28.3%) dissecting (22.2%), and in the warehouse (8.6%). The temperature in the work environment ranged from 17.2°C to 19.2°C in most sections, -18.0°C in the warehouse, and 25°C in the office areas. Warehouse workers had more abnormal symptoms than controls including repeated pain in the musculoskeletal system (OR 11.9; 95% CI 6.12-23.45), disturbance throughout the body (OR 4.60; 95% CI 2.00-10.56), respiratory symptoms (OR 9.73; 95% CI 3.53-26.80), episodic finger symptoms (OR 13.51; 95% CI 5.17-35.33). The study results suggest that workers' health should be monitored especially with regard to back and muscle pain, respiratory symptoms, episodic finger symptoms, and cardiovascular symptoms. Health promotion campaigns such as antismoking and reduction of alcohol consumption should be established because smoking and alcohol consumption are contributing factors to the pathogenesis of Raynaud's phenomenon and peripheral vascular disorders such as hypertension and heart disease.

Factors influencing poisoning symptoms: a case study of vegetable farmers exposed to mixed insecticides in Prek Balatchheng Village, Cambodia.

This study aimed to identify factors influencing poisoning symptoms among 153 mixed insecticide-exposed vegetable farmers in one Cambodian village, where 153 factory workers were selected as a comparative nonexposed group. The research instruments were questionnaires and reactive-paper test kits. The majority of vegetable farmers were male, with approximately 87% of the total participants with an average age of 34 years. The personal hygiene scores of most vegetable farmers (108; 70.8%) were moderate, and knowledge scores were at poor level (131; 85.6%). Abnormally low cholinesterase (ChE) levels were detected among 119 (77.8%) farmers. Multiple logistic regression analysis was used to identify factors associated with possible poisoning symptoms. This study found that mixing an average of four to six types of insecticides (odds ratio [OR] = 4.6; P = .03) and abnormal ChE level (OR = 4.09; P = .004) was associated with central nervous system (CNS) symptoms. Age group >45 years (OR = 2.8; P = .04) and type of vegetable "other" (OR = 2.73; P = .02) were associated with gastrointestinal symptoms. Type of insecticide, organophosphates (OPs) and carbamates (CMs) (OR = 3.2; P = .04), was associated with respiratory symptoms. It is recommended that farmers should reduce insecticide spraying times, increase their use of personal protective equipment (PPE), and undergo training on insecticide use. These combined measures should improve the insecticide-related health status of vegetable farmers in this area.

Time to update and quantitative changes in the results of cochrane pregnancy and childbirth reviews.

BACKGROUND: The recommended interval between updates for systematic reviews included in The Cochrane Library is 2 years. However, it is unclear whether this interval is always appropriate. Whereas excessive updating wastes time and resources, insufficient updating allows out-of-date or incomplete evidence to guide clinical decision-making. We set out to determine, for Cochrane pregnancy and childbirth reviews, the frequency of updates, factors associated with updating, and whether updating frequency was appropriate. METHODOLOGY/PRINCIPAL FINDINGS: Cochrane pregnancy and childbirth reviews published in Issue 3, 2007 of the Cochrane Database of Systematic Reviews were retrieved, and data were collected from their original and updated versions. Quantitative changes were determined for one of the primary outcomes (mortality, or the outcome of greatest clinical significance). Potential factors associated with time to update were assessed using the Cox proportional hazard model. Among the 101 reviews in our final sample, the median time before the first update was 3.3 years (95% CI 2.7-3.8). Only 32.7% had been updated within the recommended interval of 2 years. In 75.3% (76/101), a median of 3 new trials with a median of 576 additional participants were included in the updated versions. There were quantitative changes in 71% of the reviews that included new trials (54/76): the median change in effect size was 18.2%, and the median change in 95% CI width was 30.8%. Statistical significance changed in 18.5% (10/54) of these reviews, but conclusions were revised in only 3.7% (2/54). A shorter time to update was associated with the same original review team at updating. CONCLUSIONS/SIGNIFICANCE: Most reviews were updated less frequently than recommended by Cochrane policy, but few updates had revised conclusions. Prescribed time to update should be reconsidered to support improved decision-making while making efficient use of limited resources.