A prospective study of cancer risk among Agricultural Health Study farm spouses associated with personal use of organochlorine insecticides.

BACKGROUND: Organochlorine insecticides (OCs) have historically been used worldwide to control insects, although most have now been banned in developed countries. Evidence for an association between OC exposures and cancer predominantly comes from occupational and population based-studies among men. We evaluated the association between the use of specific OCs and cancer among the female spouses of pesticide applicators in the Agricultural Health Study. METHODS: At enrollment (1993-1997), spouses of private applicators in the cohort provided information about their own use of pesticides, including seven OCs (aldrin, chlordane, dieldrin, DDT, heptachlor, lindane, and toxaphene), and information on potential confounders. We used Poisson regression to estimate relative risks (RRs) and 95% confidence intervals (CIs) for cancers (n ≥ 3 exposed cases) reported to state cancer registries from enrollment through 2012 (North Carolina) and 2013 (Iowa), and use of the individual OCs, as well as use of any of the specific OCs. RESULTS: Among 28,909 female spouses, 2191 (7.58%) reported ever use of at least one OC, of whom 287 were diagnosed with cancer. Most cancers were not associated with OC use. Risk of glioma was increased among users of at least one OC (Nexposed = 11, RR = 3.52, 95% CI 1.72-7.21) and specifically among lindane users (Nexposed = 3, RR = 4.45, 95% CI 1.36-14.55). Multiple myeloma was associated with chlordane (Nexposed = 6, RR = 2.71, 95% CI 1.12-6.55). Based on 3 exposed cases each, there were also positive associations between pancreatic cancer and lindane, and ER-PR- breast cancer and dieldrin. No other associations with breast cancer were found. CONCLUSIONS: Overall, there were some associations with OC use and cancer incidence, however we were limited by the small number of exposed cancer cases. Future research should attempt to expand on these findings by assessing environmental sources of OC exposures, to fully evaluate the role of OC exposures on cancer risk in women.

Association between blood cholinesterase activity, organophosphate pesticide residues on hands, and health effects among chili farmers in Ubon Ratchathani Province, northeastern Thailand

Background: Use of pesticides has been documented to lead to several adverse health effects. Farmers are likely to be exposed to pesticides through dermal exposure as a result of mixing, loading, and spraying. Organophosphate pesticides (OPs) are widely used in most of the agricultural areas throughout Thailand. OPs are cholinesterase inhibitors and blood cholinesterase activity is used as a biomarker of OP effects. Objective: This study aims to determine the association between blood cholinesterase activity and organophosphate pesticide residues on chili farmer's hands and their adverse health effects. Materials and Methods: Ninety chili farmers directly involved with pesticide applications (e.g. mixing, loading, spraying) were recruited and were interviewed face to face. Both enzymes, erythrocyte acetylcholinesterase (AChE) and plasma cholinesterase (PChE), were tested with the EQM Test-mate Cholinesterase Test System (Model 400). Hand wipe samples were used for collecting residues on both hands and OP residues for chlorpyrifos and profenofos were quantified using gas chromatography equipped with a flame photometric detector (GC-FPD). Results: The average activity (±SD) of AChE and PChE was 2.73 (±0.88) and 1.58 (±0.56) U/mL, respectively. About 80.0% of the participants had detectable OP residues on hands. The median residues of chlorpyrifos and profenofos were found to be 0.02 and 0.03 mg/kg/two hands, respectively. Half of participants reported having some acute health symptoms within 48 hours after applying pesticides. When adjusted for gender, number of years working in chili farming, and frequency of pesticide use, AChE activity (Adjusted OR = 0.03, 95%CI: 0.01-0.13) and detected OP residues on hands (Adjusted OR = 0.15, 95%CI: 0.02-0.95) were significantly associated with having health effects, but no significant association was found in PChE activity (Adjusted OR = 2.09, 95%CI: 0.63-6.99). Conclusions: This study suggests that regular monitoring for blood cholinesterase and effective interventions to reduce pesticide exposure to prevent health effects should be provided to chili farmers.

Aldehydes in Relation to Air Pollution Sources: A Case Study around the Beijing Olympics.

This study was carried out to characterize three aldehydes of health concern (formaldehyde, acetaldehyde, and acrolein) at a central Beijing site in the summer and early fall of 2008 (from June to October). Aldehydes in polluted atmospheres come from both primary and secondary sources, which limits the control strategies for these reactive compounds. Measurements were made before, during, and after the Beijing Olympics to examine whether the dramatic air pollution control measures implemented during the Olympics had an impact on concentrations of the three aldehydes and their underlying primary and secondary sources. Average concentrations of formaldehyde, acetaldehyde and acrolein were 29.3±15.1 µg/m3, 27.1±15.7 µg/m3 and 2.3±1.0 µg/m3, respectively, for the entire period of measurements, all being at the high end of concentration ranges measured in cities around the world in photochemical smog seasons. Formaldehyde and acrolein increased during the pollution control period compared to the pre-Olympic Games, followed the changing pattern of temperature, and were significantly correlated with ozone and with a secondary formation factor identified by principal component analysis (PCA). In contrast, acetaldehyde had a reduction in mean concentration during the Olympic air pollution control period compared to the pre-Olympic period and was significantly correlated with several pollutants emitted from local emission sources (e.g., NO2, CO, and PM2.5). Acetaldehyde was also more strongly associated with primary emission sources including vegetative burning and oil combustion factors identified through the PCA. All three aldehydes were lower during the post-Olympic sampling period compared to the before and during Olympic periods, likely due to seasonal and regional effects. Our findings point to the complexity of source control strategies for secondary pollutants.

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.

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.

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.

Microparticles of arsenic water treatment media and water softener resin observed in treated water at private wells.

Observation of arsenic water treatment adsorption media in the treated water of several homes with high arsenic private wells led to the hypothesis that treatment media was escaping the treatment systems and entering the plumbing and drinking water. Our research at 62 homes identified that microparticles of arsenic water treatment media and/or water softener resin had escaped the treatment system in 71% of the homes. This is a potential health hazard as ingesting arsenic treatment media or water softener resin may lead to an elevated ingestion exposure to arsenic and other contaminants. Potential causes of media escape from the treatment systems include media observed to be smaller in size than specifications and media breaking into smaller pieces. One interim solution to media escape is installation of a post-treatment sediment filter. New developments in media durability or treatment system design and maintenance may be needed to prevent media escaping into drinking water. PRACTITIONER POINTS: Arsenic in private wells is often treated with point-of-entry whole house adsorption systems. Arsenic adsorption treatment media and/or water softener resin was observed in treated water at 44 of 62 homes inspected. Water treatment media escaping into treated water is a potential hazardous exposure pathway. Potential causes and solutions are discussed.

Prevalence of Current Areca Nut Use and Its Associated Factors among Bhutanese Aged 15-69 Years: Analysis of the Nationally Representative STEPS Survey 2019.

BACKGROUND: Areca nut (AN) use receives less global attention than tobacco use. Studies have linked AN consumption to a range of adverse health effects, including oral cavity and pharyngeal cancers, periodontal diseases, cardiovascular diseases, diabetes, hypertension, and addiction. The masticatory use of AN is rampant in Bhutan. There is a paucity of local evidence and limited empirical studies to understand the factors associated with current AN use in Bhutan. METHODS: This analysis uses secondary data from the Bhutan STEPS Survey 2019 that included 5575 participants aged 15-69 years, selected using multistage stratified cluster sampling. The outcome variable of interest was current AN use. Weighted analysis was done to calculate the prevalence of AN use. Factors associated with AN use were assessed using multivariable logistic regression models. RESULTS: The prevalence of current AN use was 56.82% (95% confidence interval [CI]: 54.27-59.33). A significantly higher prevalence of 63.58% (95% CI: 60.58-66.48) was found in the age group of 25-39 years. Tobacco users were 17% more likely to use AN as compared to those who do not consume tobacco (adjusted odds ratio: 1.17, 95% CI: 1.08-1.26). Current alcohol consumers were 45% more likely to consume AN as compared to lifetime alcohol abstainers. CONCLUSIONS: Age, alcohol use, and tobacco use were associated with current AN use in Bhutan. There is a need to regulate access to AN while targeting young and middle-aged individuals with public health and behavioral interventions.

Pesticide Safety Behavior among Cocoa Farmers in Nigeria: Current Trends and Determinants.

BACKGROUND: There is a strong link between pesticide exposure risk and farmers' safety behavior. However, there is a lack of understanding of farmers' safety behavior in pesticide use and the psychological factors that influence it, especially in Nigeria. OBJECTIVE: This study aimed to identify safety behaviors in pesticide use and their determinants among cocoa farmers in Nigeria using the Health Belief Model (HBM). METHODS: We used a suitable questionnaire to retrieve data from 391 cocoa farmers across three major cocoa-producing belts in Nigeria. The data were analyzed using both descriptive and inferential statistics. RESULTS: Findings showed that cocoa farmers in this study sprayed insecticides, herbicides, and fungicides on their cocoa farms. The study revealed that most pesticides were not approved for cocoa production by the authority, but the farmers were still using them. The study participants overused surveyed pesticides as the quantities applied were beyond the recommended dosage by the manufacturers. Correlation analysis showed a relationship between education status, pesticide training, perceived susceptibility and cue to action, and the farmers' pesticide overuse. In all, 42.7% of the farmers showed unsafe behaviors, 49.1% showed intermediate behaviors, and just 8.2% reported safe behaviors in pesticide use. Multiple linear regression analysis showed that perceived barriers, susceptibility, self-efficacy, and cue to action were related to age, education status, and farm experience and accounted for 59.3% of the total variance in the farmers' pesticide safety behaviors. Perceived barriers had the most significant negative influence on the farmers' behaviors, while perceived susceptibility, self-efficacy, and cue to action positively influenced the farmers' behavior. CONCLUSION: Future intervention programs in Nigeria incorporating significant variables, especially perceived barriers, in their designs with proper implementation could be more effective.

Future challenges to protecting public health from drinking-water contaminants.

Over the past several decades, human health protection for chemical contaminants in drinking water has been accomplished by development of chemical-specific standards. This approach alone is not feasible to address current issues of the occurrence of multiple contaminants in drinking water, some of which have little health effects information, and water scarcity. In this article, we describe the current chemical-specific paradigm for regulating chemicals in drinking water and discuss some potential additional approaches currently being explored to focus more on sustaining quality water for specific purposes. Also discussed are strategies being explored by the federal government to screen more efficiently the toxicity of large numbers of chemicals to prioritize further intensive testing. Water reuse and water treatment are described as sustainable measures for managing water resources for potable uses as well as other uses such as irrigation.