Improving human health outcomes with a low-cost intervention to reduce exposures from lead acid battery recycling: Dong Mai, Vietnam.

This study details the first comprehensive evaluation of the efficacy of a soil lead mitigation project in Dong Mai village, Vietnam. The village's population had been subject to severe lead poisoning for at least a decade as a result of informal Used Lead Acid Battery (ULAB) recycling. Between July 2013 to February 2015, Pure Earth and the Centre for Environment and Community Development (Hanoi, Vietnam) implemented a multi-faceted environmental and human health intervention. The intervention consisted of a series of institutional and low-cost engineering controls including the capping of lead contaminated surface soils, cleaning of home interiors, an education campaign and the construction of a work-clothes changing and bathing facility. The mitigation project resulted in substantial declines in human and environmental lead levels. Remediated home yard and garden areas decreased from an average surface soil concentration of 3940mg/kg to <100mg/kg. One year after the intervention, blood lead levels in children (<6 years old) were reduced by an average of 67%-from a median of 40.4µg/dL to 13.3µg/dL. The Dong Mai project resulted in significantly decreased environmental and biological lead levels demonstrating that low-cost, rapid and well-coordinated interventions could be readily applied elsewhere to significantly reduce preventable human health harm.

Improving exposure estimates by combining exposure information.

OBJECTIVES: Any exposure estimation technique has inherent strengths and limitations. In an effort to improve exposure estimates, this study developed and evaluated the performance of several hybrid exposure estimates created by combining information from individual assessment techniques. METHODS: Construction workers (n = 68) each completed three full-shift noise measurements over 4 months. Three single exposure assessment techniques [trade mean (TM), task-based (TB), and subjective rating (SR)] were used to estimate exposures for each subject. Hybrid techniques were then developed which incorporated the TM, SR, and TB noise exposure estimates via arithmetic mean combination, linear regression combination, and modification of TM and TB estimates using SR information. Exposure estimates from the single and hybrid techniques were compared to subjects' measured exposures to evaluate accuracy. RESULTS: Hybrid estimates generally were more accurate than estimates from single techniques. The best-performing hybrid techniques combined TB and SR estimates and resulted in improvements in estimated exposures compared to single techniques. Hybrid estimates were not improved by the inclusion of TM information in this study. CONCLUSIONS: Hybrid noise exposure estimates performed better than individual estimates, and in this study, combination of TB and SR estimates using linear regression performed best. The application of hybrid approaches in other contexts will depend upon the exposure of interest and the nature of the individual exposure estimates available.

Iron-deficiency anaemia in rural Cambodia: community trial of a novel iron supplementation technique.

BACKGROUND: More than 3.5 billion people are affected by iron-deficiency anaemia (IDA). Previous studies have shown that the use of iron pots in daily cooking ameliorates IDA. We report a study on the use of a novel treatment to address IDA in rural women in Cambodia, where the use of iron pots is not common. METHODS: A community-wide randomized controlled trial was conducted in the village of Preak Ruessei, Kandal Province, Cambodia. Rural women (n = 189) were enrolled and randomly assigned by household to one of three groups: (i) control, (ii) iron treatment with no follow-up and (iii) iron treatment with follow-up visits to provide IDA education. Haemoglobin, serum iron and C-reactive protein concentrations were measured at baseline, 3 and 6 months. A reusable fish-shaped iron ingot was distributed to the two treatment groups and participants were directed to use them daily for cooking. We hypothesized that iron from the ingot would leach iron into food providing an effective iron source. RESULTS: Blood iron levels were higher in women in the iron fish plus follow-up at 3 months compared with controls, but this was not maintained. At 6 months, haemoglobin and serum iron had fallen in all groups and the proportion of anaemic women had increased. CONCLUSIONS: This study shows that the iron ingot was effective in the short but not longer-term against IDA. Though a novel treatment option, further research is warranted to determine bioavailability of leached iron and whether or not the surface area is large enough for sufficient iron leaching.

Association of weight at enlistment with enrollment in the Army Weight Control Program and subsequent attrition in the Assessment of Recruit Motivation and Strength Study.

The ongoing obesity epidemic has made recruiting qualified Army applicants increasingly difficult. A cohort of 10,213 Army enlisted subjects was enrolled in the Assessment of Recruit Motivation and Strength (ARMS) study from February 2005 through September 2006. Overweight recruits obtained a waiver for enlistment (n = 990) if they passed a screening physical fitness test. Recruits were evaluated for enrollment into the Army Weight Control Program (AWCP) and discharged during the 15 months following enlistment. Enrollment was higher among overweight recruits than recruits who met entrance standards (men: adjusted OR = 13.3 [95% CI: 10.3, 17.2]; women: adjusted OR = 3.6 [3.3, 3.9]). Although the discharge frequency was higher in the waiver group than in those who met standards (25.4% versus 19.9%, p < 0.001), there were only 10 (0.5% of total) discharges directly attributed to weight. Granting overweight waivers through the ARMS program increases enrollment to the AWCP but has little effect on weight-related attrition.

Comparison of perceived and quantitative measures of occupational noise exposure.

OBJECTIVES: Characterization of highly variable noise exposures over long periods of time presents a major challenge. Common exposure assessment strategies such as assignment of exposure levels based on job title information may not provide adequate exposure contrast or precision for variable exposures. Subjective exposure data may offer an alternative or complementary exposure assessment strategy. This study evaluated the relationship between perceived and quantitatively measured exposure. METHODS: Twenty subjects were recruited at each of three worksites with different noise environments (continuous, intermittent and highly variable). Full-shift quantitative measurements (n = 206) were made on each subject during four workshifts over 2 weeks. Perceived exposure data were collected via surveys on subjects' first (n = 58) and last (n = 57) monitored shifts, as well as through timeline logs completed by subjects during each monitored shift. The first survey focused on the first shift only, while the second survey covered the whole 2-week period. RESULTS: Timeline log data suggested that subjects could differentiate between different noise levels and degrees of noise variability. Survey items on perceived exposure variability and impulsiveness performed well at the continuous and highly variable sites. Analyses of contrast between exposure grouping strategies showed that job title generally did not produce statistically distinct exposure groups and that several survey items provided greater contrast than job title. The precision of exposures predicted from survey items was comparable to, or slightly better than, that of job title for several survey items, and the addition of survey items to prediction models which included job title improved model fit and precision. CONCLUSIONS: Supplemental perceived noise exposure information appears to offer promise for improving exposure estimates, particularly for individuals with highly variable exposures.

Predictors of hearing protection use in construction workers.

OBJECTIVES: Although noise-induced hearing loss is completely preventable, it remains highly prevalent among construction workers. Hearing protection devices (HPDs) are commonly relied upon for exposure reduction in construction, but their use is complicated by intermittent and highly variable noise, inadequate industry support for hearing conservation, and lax regulatory enforcement. METHODS: As part of an intervention study designed to promote HPD use in the construction industry, we enrolled a cohort of 268 construction workers from a variety of trades at eight sites and evaluated their use of HPDs at baseline. We measured HPD use with two instruments, a questionnaire survey and a validated combination of activity logs with simultaneous dosimetry measurements. With these measurements, we evaluated potential predictors of HPD use based on components of Pender's revised health promotion model (HPM) and safety climate factors. RESULTS: Observed full-shift equivalent noise levels were above recommended limits, with a mean of 89.8 +/- 4.9 dBA, and workers spent an average of 32.4 +/- 18.6% of time in each shift above 85 dBA. We observed a bimodal distribution of HPD use from the activity card/dosimetry measures, with nearly 80% of workers reporting either almost never or almost always using HPDs. Fair agreement (kappa = 0.38) was found between the survey and activity card/dosimetry HPD use measures. Logistic regression models identified site, trade, education level, years in construction, percent of shift in high noise, and five HPM components as important predictors of HPD use at the individual level. Site safety climate factors were also predictors at the group level. CONCLUSIONS: Full-shift equivalent noise levels on the construction sites assessed were well above the level at which HPDs are required, but usage rates were quite low. Understanding and predicting HPD use differs by methods used to assess use (survey versus activity card/dosimetry). Site, trade, and the belief that wearing HPD is not time consuming were the only predictors of HPD use common to both measures on an individual level. At the group level, perceived support for site safety and HPD use proved to be predictive of HPD use.

Work-related carpal tunnel syndrome in Washington State workers' compensation: utilization of surgery and the duration of lost work.

BACKGROUND: Work-related carpal tunnel syndrome (CTS) is a leading cause of lengthy disability. METHODS: This population-based retrospective cohort study used Washington State workers' compensation claims for CTS to characterize associations between utilization of CTS surgery and duration of lost work. The sample included all claims (n = 8,224) filed during 1990-1994 (followed through 2000) and receiving lost-work compensation. RESULTS: Sixty-four percent of studied workers had CTS surgery. Among workers with >1 month of lost work, the total duration was much shorter when workers had surgery, versus those who did not (median 4.3 and 6.2 months, respectively; P < 0.001); there was no difference when disability extended >6 months. When workers had surgery, disability was less likely to end before 6 months if non-CTS conditions were present, surgery occurred >3 months after claim filing, or employment was in an industry with high incidence of CTS; disability was more likely to end if the diagnosing provider and operating surgeon had higher CTS claims volume. Physical and rehabilitation medicine services were associated with lower probability of returning to work, with or without surgery. CONCLUSIONS: There is a need to scrutinize the role of surgery and physical-rehabilitation medicine modalities in the management of CTS covered by workers' compensation. The findings suggest disability can be minimized by establishing the CTS diagnosis as early as possible and, if surgery is appropriate, conducting surgery without substantial delay and maximizing post-operative efforts to facilitate return to work. Use of surgery >6 months after filing should be considered with great caution.

Residual methamphetamine in decontaminated clandestine drug laboratories.

This pilot cross-sectional study examined three previously decontaminated residential clandestine drug laboratories (CDLs) in Washington State to determine the distribution and magnitude of residual methamphetamine concentrations relative to the state decontamination standard. A total of 159 discrete random methamphetamine wipe samples were collected from the three CDLs, focusing on the master bedroom, bathroom, living room, and kitchen at each site. Additional samples were collected from specific non-random locations likely to be contacted by future residents (e.g., door knobs and light switches). Samples were analyzed for methamphetamine by EPA method 8270 for semivolatile organic chemicals. Overall, 59% of random samples and 75% of contact point samples contained methamphetamine in excess of the state decontamination standard (0.1 micro g/100 cm(2)). At each site, methamphetamine concentrations were generally higher and more variable in rooms where methamphetamine was prepared and used. Even compared with the less stringent standard adopted in Colorado (0.5 micro g/100cm(2)), a substantial number of samples at each site still demonstrated excessive residual methamphetamine (random samples, 25%; contact samples, 44%). Independent oversight of CDL decontamination in residential structures is warranted to protect public health. Further research on the efficacy of CDL decontamination procedures and subsequent verification of methods is needed.

Indicators of hearing protection use: self-report and researcher observation.

Hearing protection devices (HPD) are commonly used to prevent occupational noise-induced hearing loss. There is a large body of research on hearing protection use in industry, and much of it relies on workers' self-reported use of hearing protection. Based on previous studies in fixed industry, worker self-report has been accepted as an adequate and reliable tool to measure this behavior among workers in many industrial sectors. However, recent research indicates self-reported hearing protection use may not accurately reflect subject behavior in industries with variable noise exposure. This study compares workers' self-reported use of hearing protection with their observed use in three workplaces with two types of noise environments: one construction site and one fixed industry facility with a variable noise environment, and one fixed industry facility with a steady noise environment. Subjects reported their use of hearing protection on self-administered surveys and activity cards, which were validated using researcher observations. The primary outcome of interest in the study was the difference between the self-reported use of hearing protection in high noise on the activity card and survey: (1) over one workday, and (2) over a 2-week period. The primary hypotheses for the study were that subjects in workplaces with variable noise environments would report their use of HPDs less accurately than subjects in the stable noise environment, and that reporting would be less accurate over 2 weeks than over 1 day. In addition to noise variability, other personal and workplace factors thought to affect the accuracy of self-reported hearing protection use were also analyzed. This study found good agreement between subjects' self-reported HPD use and researcher observations. Workers in the steady noise environment self-reported hearing protection use more accurately on the surveys than workers in variable noise environments. The findings demonstrate the potential importance of noise exposure variability as a factor influencing reporting accuracy.

Evaluation of a healthcare safety climate measurement tool.

PROBLEM: Psychometrically validated measurement tools are needed to evaluate an organization's safety climate. In 2000, Gershon and colleagues published a new healthcare safety climate measurement tool to determine its relationship to safe work behavior (Gershon, R., Karkashian, C., Grosch, J., Murphy, L., Escamilla-Cejudo, A., Flanagan, P., et al. (2000). Hospital safety climate and its relationship with safe work practices and workplace exposure incidents. American Journal of Infection Control, 28, 211-21). The present study evaluated the psychometric properties of the Gershon tool when modified to address respiratory rather than bloodborne pathogen exposures. METHOD: Medical practitioners, nurses, and nurse aides (n=460) were surveyed using the modified Gershon tool. Data were analyzed by factor analysis and psychometric properties of the tool evaluated. RESULTS: Eight safety climate dimensions were extracted from 25 items (Cronbach's alpha range: 0.62 - 0.88). Factor extractions and psychometric properties were reasonably consistent with those of the Gershon tool. IMPACT ON INDUSTRY: The Gershon safety climate tool appears to have sufficient reliability and validity for use by healthcare decision makers as an indicator of employee perceptions of safety in their institution.

Blood Lead Levels and Risk Factors for Lead Exposure in a Pediatric Population in Ho Chi Minh City, Vietnam.

Although lead recycling activities are a known risk factor for elevated blood levels in South East Asia, little is known regarding the prevalence of and risk factors for elevated blood lead levels (BLL) among the general pediatric population in Vietnam. This study is a cross-sectional evaluation of 311 children from Children's Hospital #2 in Ho Chi Minh City, Vietnam. Capillary blood lead testing was performed using the LeadCare II. Mean BLLs were 4.97 µg/dL (Standard Deviation (SD) 5.50), with 7% of the participants having levels greater than 10 µg/dL. Living in Bing Duong province (OR 2.7, 95% CI 1.4-5.6.1) or the Dong Nai province (OR 2.3, 95% CI 1.0-5.1) and having an age greater than 12 months (OR 6.0, 95% CI 3.1-11.8) were associated with higher BLLs. The prevalence of elevated BLLs in Vietnam is consistent with other SE Asian countries. Mean BLLs in Ho Chi Minh City are markedly less than those seen in a separate study of children living near lead recycling activities. Additional evaluation is necessary to better detail potential risk factors if screening is to be implemented within Vietnam.

Occupational accidents and injuries in Thailand.

The Workers' Compensation Fund (WCF) represents only a limited fraction of work-related injuries in the Thai workforce. This cross-sectional study examined 258,986 records from the Thai National Injury Surveillance (NIS) system collected during 2001-2004, focusing on 17,538 injuries coded as work-related. NIS records provided information generally not represented in WCF statistics, such as construction and agriculture. The reported mechanisms in 129 work-related fatalities were particularly informative, including electrical current (27%), transport accidents (20%), and falls (15%). Mortality in transport accidents was dramatically higher when seat belts or motorcycle helmets were not used, whether work-related or not. The findings emphasize the need to use multiple sources of information for a complete picture of work-related injuries in Thailand, and possibly in other countries. The mechanisms of fatal injury indicate areas where focused efforts are warranted.

Assessment of Environmental Contamination with Pathogenic Bacteria at a Hospital Laundry Facility.

Little is known about exposure to pathogenic bacteria among industrial laundry workers who work with soiled clinical linen. To study worker exposures, an assessment of surface contamination was performed at an industrial laundry facility serving hospitals in Seattle, WA, USA. Surface swab samples (n = 240) from the environment were collected during four site visits at 3-month intervals. These samples were cultured for Clostridium difficile, methicillin-resistant Staphylococcus aureus (MRSA), and vancomycin-resistant enterococci (VRE). Voluntary participation of 23 employees consisted of nasal swabs for detection of MRSA, observations during work, and questionnaires. Contamination with all three pathogens was observed in both dirty (laundry handling prior to washing) and clean areas (subsequent to washing). The dirty area had higher odds of overall contamination (≥1 pathogen) than the clean area (odds ratio, OR = 18.0, 95% confidence interval 8.9-36.5, P < 0.001). The odds of contamination were high for each individual pathogen: C. difficile, OR = 15.5; MRSA, OR = 14.8; and VRE, OR = 12.6 (each, P < 0.001). The highest odds of finding surface contamination occurred in the primary and secondary sort areas where soiled linens were manually sorted by employees (OR = 63.0, P < 0.001). The study substantiates that the laundry facility environment can become contaminated by soiled linens. Workers who handle soiled linen may have a higher risk of exposure to C. difficile, MRSA, and VRE than those who handle clean linens. Improved protocols for prevention and reduction of environmental contamination were implemented because of this study.

Ethanol-induced increase in the metabolic clearance of 1,1,1-trichloroethane in human volunteers.

This study evaluated the effect of moderate doses of ethanol over a short period of time on the toxicokinetics of an organic solvent, 1,1,1-trichloroethane. A group of 10 moderate drinkers were recruited and exposed via inhalation for 2 h to a low concentration of 1,1,1-trichloroethane (175 ppm) on two separate occasions. Subjects were administered ethanol (0.35 g/kg body weight) on each of the 7 days preceding one of the exposures. Blood and urine samples were collected during and following each exposure, with blood analyzed for 1,1,1-trichloroethane and urine analyzed for the metabolites of 1,1,1-trichloroethane: trichloroethanol and trichloroacetic acid. Prior ethanol consumption resulted in a significant increase in apparent metabolic clearance of 1,1,1-trichloroethane (mean increase = 25.4%). The results of this study demonstrate that ethanol consumption over time can affect the rate at which an organic solvent is cleared through metabolism in humans. For chemicals with toxic metabolic products, this inductive effect of ethanol consumption on the rate of biotransformation could be potentially harmful to exposed individuals. Metabolic clearance of compounds with high hepatic extraction may not be affected by enzyme induction as it is likely that these compounds are essentially completely metabolized while passing through the liver.

Migrant Workers in Agriculture: A View from Thailand.

There has been a dramatic increase in the global movement of workers during the last few decades. As Thailand has developed rapidly over the past 20 years, it has attracted laborers (both authorized and unauthorized) from the neighboring countries of Myanmar, People's Democratic Republic of Lao (Lao PDR), and Cambodia. Given that agriculture has been Thailand's most important industry, its continued growth has been dependent on migrant workers. Both crop agriculture and animal-production agriculture have employed migrant labor. Migrants have been hired to plant, weed, fertilize, spray pesticides, and harvest crops such as rice, corn, sugar cane, and cassava. They have worked at rubber and coffee plantations, as well as in the production of ornamental crops. Also, migrants have labored on pig, beef, and duck farms. There have been numerous documented health problems among migrant workers, including acute diarrhea, malaria, and fever of unknown causes. Occupational illness and injury have been a significant concern, and there has been limited health and safety training. This article reviewed the demographic changes in Thailand, studied the agricultural crops and animal production that are dependent on migrant labor, discussed the health status and safety challenges pertaining to migrant workers in agriculture, and described several recommendations. Among the recommendations, the conclusions of this study have suggested that addressing the cost for health care and solutions to health care access for migrant labor are needed.

Childhood Lead Exposure from Battery Recycling in Vietnam.

BACKGROUND: Battery recycling facilities in developing countries can cause community lead exposure. OBJECTIVE: To evaluate child lead exposure in a Vietnam battery recycling craft village after efforts to shift home-based recycling outside the village. METHODS: This cross-sectional study evaluated 109 children in Dong Mai village, using blood lead level (BLL) measurement, parent interview, and household observation. Blood samples were analyzed with a LeadCare II field instrument; highest BLLs (≥45 µg/dL) were retested by laboratory analysis. Surface and soil lead were measured at 11 households and a school with X-ray fluorescence analyzer. RESULTS: All children had high BLLs; 28% had BLL ≥45 µg/dL. Younger age, family recycling, and outside brick surfaces were associated with higher BLL. Surface and soil lead levels were high at all tested homes, even with no recycling history. Laboratory BLLs were lower than LeadCare BLLs, in 24 retested children. DISCUSSION: In spite of improvements, lead exposure was still substantial and probably associated with continued home-based recycling, legacy contamination, and workplace take-home exposure pathways. There is a need for effective strategies to manage lead exposure from battery recycling in craft villages. These reported BLL values should be interpreted cautiously, although the observed field-laboratory discordance may reflect bias in laboratory results.

Comparison of criteria for significant threshold shift in workplace hearing conservation programs.

The National Institute for Occupational Safety and Health (NIOSH) recommended that the Standard Threshold Shift (STS) be replaced as the sentinel indicator of hearing loss in workplace audiometric surveillance programs. We conducted a retrospective cohort study of 1220 workers followed for eight consecutive years in the hearing conservation program at the Hanford nuclear facility, to evaluate the relative accuracy of eight candidate threshold-shift criteria for detecting hearing loss over time, using two evaluation methods and comparing to NIOSH findings. The NIOSH-recommended criterion was one of the better criteria. However, the differences between better criteria were less evident using a different evaluation method than the one described by NIOSH. Also, when we compared our findings with those underlying the NIOSH recommendation, the between-database differences were large enough that the smaller between-criteria differences may have limited importance.

Aerobic residential onsite sewage systems: an evaluation of treated-effluent quality.

This retrospective cohort study used existing data to evaluate the quality of effluent from three of the most common types of onsite residential aerobic treatment sewage systems (Multi-Flo, Norweco, and Whitewater) installed in Kitsap County, Washington. Five-day biochemical oxygen demand (BOD5), total suspended solids (TSS), and fecal-coliform-bacteria parameters were used to determine performance. Although most (77 percent) of the systems were less than one year old at the time of sampling, over a third failed to meet NSF certification standards for BOD5 and TSS in effluent (< 30 milligrams per liter [mg/L]). Over two-thirds of systems failed to meet Washington State Board of Health Treatment Standard 2 criteria for BOD5 and TSS (< 10 mg/L). Furthermore, an average of 59 percent of the systems failed to meet state standards for fecal coliform (< 800 fecal coliform bacteria per 100 milliliters).

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.

Health impact assessment of urban waterway decisions.

Health impact assessments (HIA) promote the consideration of health in a wide range of public decisions. Although each HIA is different, common pathways, evidence bases, and strategies for community engagement tend to emerge in certain sectors, such as urban redevelopment, natural resource extraction, or transportation planning. To date, a limited number of HIAs have been conducted on decisions affecting water resources and waterfronts. This review presents four recent HIAs of water-related decisions in the United States and Puerto Rico. Although the four cases are topically and geographically diverse, several common themes emerged from the consideration of health in water-related decisions. Water resource decisions are characterized by multiple competing uses, inter-institutional and inter-jurisdictional complexity, scientific uncertainty, long time scales for environmental change, diverse cultural and historical human values, and tradeoffs between private use and public access. These four case studies reveal challenges and opportunities of examining waterfront decisions through a "health lens". This review analyzes these cases, common themes, and lessons learned for the future practice of HIA in the waterfront zone and beyond.