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.

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.

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.

Teacher perspectives on implementing and sustaining a handwashing promotion intervention in Western Kenyan primary schools.

School-based handwashing programs are challenging to establish and sustain, especially in low-resource settings. This qualitative study described teacher perspectives associated with implementing and sustaining a handwashing program in primary schools participating in the Nyando Integrated Child Health and Education (NICHE) project. Structured key informant interviews were conducted with teachers. Prevalent concepts and themes were grouped into themes and topic areas using an iterative, open coding approach. Forty-one teacher respondents reported favorable expectations and benefits of handwashing programs. The importance of available resources (e.g., reliable water) was cited as a primary concern. Other challenges included time and personal or institutional financial commitment necessary to ensure program sustainability. Handwashing programs in low-income, rural schools, where infrastructure is lacking and "student ambassadors" extend the intervention to the surrounding community, hold great promise to improve community health. Teachers must have adequate support and resources to implement and sustain the programs.

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.

Enhancing a safe water intervention with student-created visual aids to promote handwashing behavior in Kenyan primary schools.

The Nyando Integrated Child Health Education (NICHE) project was a collaborative effort by the U.S. Centers for Disease Control and local partners to assess the effectiveness of multiple interventions for improving child survival in western Kenya. To increase handwashing in schools, NICHE trained teachers and installed handwashing stations with treated water and soap in 51 primary schools. This cluster-randomized trial evaluated an additional educational strategy (a poster contest themed, "Handwashing with Soap") to improve handwashing behavior in 23 NICHE primary schools. Pupils were engaged in the poster development. Pupil handwashing behavior was observed unobtrusively at baseline and after four months. Intervention schools displayed a significant increase in the number of handwashing stations and proportion of teacher-supervised stations over the study period. No significant between-group differences of intervention in handwashing frequency, soap availability, or visibility of handwashing stations was observed. Despite finding a limited effect beyond the NICHE intervention, the trial appeared to promote sustainability across some measures.

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.

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.

Opioid use for chronic low back pain: A prospective, population-based study among injured workers in Washington state, 2002-2005.

OBJECTIVES: To determine (1) the natural history of prescription opioid use, (2) the predictors of long-term opioid use, and (3) the association between opioid dose and pain and function in a large cohort of workers with recent back injuries. METHODS: Prospective cohort of workers with back injuries (N=1883) interviewed 18 days (median) and 1 year after claim submission. Detailed pharmacy data were obtained from computerized records of paid bills. RESULTS: Forty-two percent of workers (781/1843) received an opioid in the year after injury, most (694/781, 89%) at or shortly after the first medical visit for the injury. Of these, most (410/694, 59%) received opioids only within the first quarter after injury, whereas 16% (111/694) received opioids for 4 quarters. Among these long-term users, total morphine equivalent dose (MED) increased significantly (P<0.01) from the first (mean, 2364 mg; standard deviation, 4019 mg) to the fourth (mean, 3824 mg; standard deviation, 5998 mg) quarter. Improvement by at least 30% in pain and function measure scores occurred in only 26% (95% confidence interval 18%-36%) and 16% (95% confidence interval 10%-25%), respectively, of long-term users. Opioid doses increased substantially over time in all but those in whom function improved. After adjustment for baseline pain, function, and injury severity, the strongest predictor of longer term opioid prescription was total MED in the first quarter. Workers receiving at least 40 mg MED per day in the first quarter had 6-fold odds of receiving longer-term opioids. DISCUSSIONS: For the small group of workers with compensable back injuries who receive opioids longer-term (111/1843, 6%), opioid doses increase substantially and only a minority shows clinically important improvement in pain and function. The amount of prescribed opioid received early after injury strongly predicts long-term use. More research is needed to understand clinical decisions to continue or increase opioid therapy after back injury.

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.

Development and pilot test of hearing conservation training for construction workers.

BACKGROUND: Hearing conservation efforts in construction frequently rely on use of hearing protection devices (HPDs): however, training on HPDs is often not provided, and usage rates remain low. In this study, a hearing conservation training program was developed and pilot tested. METHODS: A theoretical model was selected as the basis for the program, and program contents and delivery methods were selected to optimize the effectiveness and flexibility of the training. Two evaluation measures were selected to assess training-related changes in self-reported HPD use. The first was a validated method using concurrent work-shift noise dosimetry, and the second was a survey concerning workers beliefs and attitudes towards HPDs and HPD use. RESULTS: The training program was pilot tested on a single construction site. Complete assessment data were available for 23 workers. The percent of time when hearing protection was used during noise levels above 85 dBA nearly doubled post-training, and the change was statistically significant. CONCLUSIONS: Pre- and post-training data from participating workers demonstrated that HPD use can be increased significantly with basic model-based training, even in industries with complex noise exposures such as construction.

A comparison of "Train-the-Trainer" and expert training modalities for hearing protection use in construction.

BACKGROUND: Few assessments have been conducted on the impact of a "Train-the-Trainer" (T3) approach for training delivery. The present study compared the effectiveness of a noise induced hearing loss (NIHL) prevention training delivered using "Train-the-Trainer" and expert trainer modalities. METHODS: Participating construction companies were assigned to the Train-the-Trainer or expert trainer modalities. Workers were recruited from each company and then trained. The effectiveness of the modalities was assessed through the use of surveys. The accuracy of self-reported hearing protection device (HPD) use was also evaluated through on-site observation. RESULTS: Post-training scores for hearing conservation knowledge, perceived barriers, and current and intended future use of HPDs improved significantly for both training modalities. Subjects trained by T3 trainers significantly increased their beliefs regarding general susceptibility to NIHL, desire to prevent NIHL, and ability to recognize, and control hazardous noise exposures. The expert-trained groups significantly increased their beliefs regarding the benefits of HPD use and ability to ask for help with HPDs. The only changes that were significantly different between modalities were in general susceptibility to NIHL and effective use of HPDs. However, these beliefs differed significantly between subjects in the two-modality groups prior to training. Self-reported HPD use was poorly correlated with observed use, calling into question the validity of survey-based HPD use measures in this context. CONCLUSIONS: The training improved beliefs regarding HPD use, increased workers' hearing conservation knowledge, and increased self-reported HPD use. The effectiveness of the training was not found to be dependent on training modality.

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.

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.

Work-related carpal tunnel syndrome in Washington State workers' compensation: temporal trends, clinical practices, and disability.

BACKGROUND: Work-related carpal tunnel syndrome (CTS) is a leading cause of disability. There is a need for information about temporal trends, clinical practices, and treatment outcomes. METHODS: A population based, retrospective cohort study of Washington State workers' compensation claims for CTS was initiated focusing on claims filed during 1990-1994, followed through 2000 (n = 16,710). RESULTS: Half of the claims were filed for conditions other than CTS, but were eventually identified to be or include CTS. The first CTS diagnosis occurred more than 3 months after claim filing in 20% of claims. The longer that the CTS diagnosis occurred after claim filing, the more likely that CTS was accompanied by other problems, and disability tended to be longer. CONCLUSIONS: Making an accurate diagnosis of CTS and initiating appropriate actions earlier than might otherwise occur could reduce the disability and costs in a large fraction of claims that are ultimately determined to involve CTS.

Comparison of ergonomist, supervisor, and worker assessments of work-related musculoskeletal risk factors.

In primary prevention efforts to reduce the incidence of work-related musculoskeletal disease (MSD), many employers will use supervisor or worker assessments for initial evaluation of MSD risk factors. This cross-sectional study examined the ability of supervisors and workers to accurately assess the presence of MSD risk factors at four work sites in four different industries, examining five jobs that represented six primary categories of risk factors: posture, force, repetition, impact, lifting, and vibration. Thirty-seven supervisors and 55 workers assessed the jobs they oversee or perform through the use of a 14-item questionnaire. Their assessments were compared with detailed ergonomist job analyses to determine their accuracy in identifying the presence or absence of MSD risk factors. In assessing the absence or presence of all risk factors, agreement with the ergonomist was found 81% of the time for supervisors and 77% of the time for workers. Overall, supervisors and workers overestimated the presence of risk in assessing the jobs. Supervisors and worker assessments appear promising in recognizing risk in initial ergonomic assessments.

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).

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.

Increased reporting of occupational hearing loss: workers' compensation in Washington State, 1984-1998.

BACKGROUND: Workers' compensation claims for hearing loss increased two-fold during 1984-1991 in Washington State. METHODS: This population-based descriptive study examined 27,019 claims filed during 1984-1998 and accepted for hearing loss, in the workers' compensation jurisdiction that covers nearly all non-federal workers in Washington State. RESULTS: The number of claims increased 12-fold during 1984-1998. The annual incidence reached 2.6/1,000 workers statewide, and 70/1,000 in the most impacted industry. The increase involved all ages over 35 years, especially claimants over 65 years. Only 4% of providers accounted for 66% of claims. Most claimants (90%) received permanent partial disability compensation. In 1998, identifiable costs exceeded $57 million dollars. CONCLUSIONS: The striking increase in claims is probably largely due to reporting phenomena unrelated to current work circumstances. However, occupational hearing loss is probably much more common than usually recognized, and contemporary workers may still face substantial risk for hearing loss.