Mark Woodin

Acute respiratory symptoms in workers exposed to vanadium-rich fuel-oil ash

BACKGROUND Occupational exposure to fuel-oil ash, with its high vanadium content, may cause respiratory illness. It is unclear, however, what early acute health effects may occur on the pathway from normal to compromised respiratory function. METHODS Using a repeated measures design, we studied prospectively 18 boilermakers overhauling an oil-fired boiler and 11 utility worker controls. Subjects completed a respiratory symptom diary five times per day by using a 0-3 scale where 0=symptom not present, 1=mild symptom, 2=moderate symptom, and 3=severe symptom. Daily symptom severity was calculated by using the highest reported score each day for upper and lower respiratory symptoms. Daily symptom frequency was calculated by summing all upper or lower airway symptom reports, then dividing by number of reporting times. Respiratory symptom frequency and severity were analyzed for dose-response relationships with estimated vanadium and PM(10) doses to the lung and upper airway by using robust regression. RESULTS During the overhaul, 72% of boilermakers reported lower airway symptoms, and 67% reported upper airway symptoms. These percentages were 27 and 36 for controls. Boilermakers had more frequent and more severe upper and lower respiratory symptoms compared to utility workers, and this difference was greatest during interior boiler work. A statistically significant dose-response pattern for frequency and severity of both upper and lower respiratory symptoms was seen with vanadium and PM(10) in the three lower exposure quartiles. However, there was a reversal in the dose-response trend in the highest exposure quartile, reflecting a possible healthy worker effect. CONCLUSIONS Boilermakers experience more frequent and more severe respiratory symptoms than utility workers. This is most statistically significant during boiler work and is associated with increasing dose estimates of lung and nasal vanadium and PM(10).

Native and foreign born as predictors of pediatric asthma in an Asian immigrant population: a cross sectional survey

BackgroundAsthma prevalence is lower in less developed countries and among some recent immigrant populations in the US, but the reasons for this are not clear. One possibility is that early childhood infections are protective against asthma.MethodsWe surveyed Asian immigrant children (n = 204; age 4–18) to assess the relationship between asthma and native or foreign place of birth. We included questions about environmental exposures, demographic variables and family history of asthma to test whether they might explain effects of place of birth on asthma.ResultsThe native and foreign born groups were similar in most respects. Analysis of association with diagnosed asthma for all ages together resulted in two logistic regression models. Both retained born in the US (ORs were 3.2 and 4.3; p < 0.01) and family history of asthma (ORs were 6.4 and 7.2; p < 0.001). One model retained living near heavy motor traffic (OR = 2.6; p = 0.012). The other retained language (OR = 3.2; p = 0.003). However, for older children (11–18 years of age) being born in the US lost some of its predictive power.ConclusionOur findings are consistent with early childhood infections that are prevalent outside the US protecting against asthma.

Effective control of Schistosoma haematobium infection in a Ghanaian community following installation of a water recreation area.

Background Urogenital schistosomiasis caused by Schistosoma haematobium was endemic in Adasawase, Ghana in 2007. Transmission was reported to be primarily through recreational water contact. Methods We designed a water recreation area (WRA) to prevent transmission to school-aged children. The WRA features a concrete pool supplied by a borehole well and a gravity-driven rainwater collection system; it is 30 m2 and is split into shallow and deep sections to accommodate a variety of age groups. The WRA opened in 2009 and children were encouraged to use it for recreation as opposed to the local river. We screened children annually for S. haematobium eggs in their urine in 2008, 2009, and 2010 and established differences in infection rates before (2008–09) and after (2009–10) installation of the WRA. After each annual screening, children were treated with praziquantel and rescreened to confirm parasite clearance. Principal Findings Initial baseline testing in 2008 established that 105 of 247 (42.5%) children were egg-positive. In 2009, with drug treatment alone, the pre-WRA annual cumulative incidence of infection was 29 of 216 (13.4%). In 2010, this incidence rate fell significantly (p<0.001, chi-squared) to 9 of 245 (3.7%) children after installation of the WRA. Logistic regression analysis was used to determine correlates of infection among the variables age, sex, distance between home and river, minutes observed at the river, low height-for-age, low weight-for-age, low Body Mass Index (BMI)-for-age, and previous infection status. Conclusion/Significance The installation and use of a WRA is a feasible and highly effective means to reduce the incidence of schistosomiasis in school-aged children in a rural Ghanaian community. In conjunction with drug treatment and education, such an intervention can represent a significant step towards the control of schistosomiasis. The WRA should be tested in other water-rich endemic areas to determine whether infection prevalence can be substantially reduced.

Air pollution and anemia as risk factors for pneumonia in Ecuadorian children: a retrospective cohort analysis.

BackgroundAmbient air pollution and malnutrition, particularly anemia, are risk factors for pneumonia, a leading cause of death in children under five. We simultaneously assessed these risk factors in Quito, Ecuador.MethodsIn 2005, we studied two socioeconomically similar neighborhoods in Quito: Lucha de los Pobres (LP) and Jaime Roldos (JR). LP had relatively high levels of air pollution (annual median PM2.5 = 20.4 μg/m3; NO2 = 29.5 μg/m3) compared to JR (annual median PM2.5 = 15.3 μg/m3; NO2 = 16.6 μg/m3). We enrolled 408 children from LP (more polluted) and 413 children from JR (less polluted). All subjects were aged 18-42 months. We obtained medical histories of prior physician visits and hospitalizations during the previous year, anthropometric nutrition data, hemoglobin levels, and hemoglobin oxygen saturation via oximetry.ResultsIn anemic children, higher pollution exposure was significantly associated with pneumonia hospitalization (OR = 6.82, 95%CI = 1.45-32.00; P = 0.015). In non-anemic children, no difference in hospitalizations by pollution exposure status was detected (OR = 1.04, NS). Children exposed to higher levels of air pollution had more pneumonia hospitalizations (OR = 3.68, 1.09-12.44; P = 0.036), total respiratory illness (OR = 2.93, 95% CI 1.92-4.47; P < 0.001), stunting (OR = 1.88, 1.36-2.60; P < 0.001) and anemia (OR = 1.45, 1.09-1.93; P = 0.013) compared to children exposed to lower levels of air pollution. Also, children exposed to higher levels of air pollution had significantly lower oxygen saturation (92.2% ± 2.6% vs. 95.8% ± 2.2%; P < 0.0001), consistent with air pollution related dyshemoglobinemia.ConclusionsAmbient air pollution is associated with rates of hospitalization for pneumonia and with physicians consultations for acute respiratory infections. Anemia may interact with air pollution to increase pneumonia hospitalizations. If confirmed in larger studies, improving nutrition-related anemia, as well as decreasing the levels of air pollution in Quito, may reduce pneumonia incidence.

Evidence for the healthy immigrant effect in older Chinese immigrants: a cross-sectional study

BackgroundPrevious work has found that first-generation immigrants to developed nations tend to have better health than individuals born in the host country. We examined the evidence for the healthy immigrant effect and convergence of health status between Chinese immigrants (n = 147) and U.S. born whites (n = 167) participating in the cross-sectional Community Assessment of Freeway Exposure and Health study and residing in the same neighborhoods.MethodsWe used bivariate and multivariate models to compare disease prevalence and clinical biomarkers.ResultsDespite an older average age and lower socioeconomic status, Chinese immigrants were less likely to have asthma (OR = 0.20, 95% CI = 0.09–0.48) or cardiovascular disease (OR = 0.44, 95% CI = 0.20–0.94), had lower body mass index (BMI), lower inflammation biomarker levels, lower average sex-adjusted low-density lipoprotein (LDL) cholesterol, and higher average sex-adjusted high-density lipoprotein (HDL) cholesterol. However, there was no significant difference in the prevalence of diabetes or hypertension. Duration of time in the U.S. was related to cardiovascular disease and asthma but was not associated with diabetes, hypertension, BMI, HDL cholesterol, LDL cholesterol, socioeconomic status, or health behaviors.ConclusionsThe lower CVD and asthma prevalence among the Chinese immigrants may be partially attributed to healthier diets, more physical activity, lower BMI, and less exposure to cigarette smoke. First generation immigrant status may be protective even after about two decades.

Community-level data suggest that asthma prevalence varies between U.S. and foreign-born black subpopulations.

For Mexican and Chinese immigrants it has been reported that foreign born children have a lower prevalence of asthma than U.S.-born children. Inner-city black populations have a high prevalence of asthma. However, despite growing populations of black immigrants, we are aware of no previous studies that have looked at the effect of nativity on their asthma prevalence. We report data collected from a convenience sample in the Dorchester neighborhood of Boston for black respondents. The survey was conducted by medical students and community residents using a community-based participatory research approach. For adult respondents (n = 290) there was a strong negative association between being born outside the United States and reporting asthma (OR = 0.39; p = 0.033) that was retained in our multivariate model. For children (n = 157, reported by their parents) there was also a strong association with being born outside the United States (p < 0.05 using χ2 tabular analysis); however, there were no foreign-born children with asthma so an OR could not be calculated and this association could not be carried forward into multivariate analyses. For children, but not adults, there were also strong associations between asthma and environmental factors. These findings point to the need for further research into nativity and asthma in black U.S. populations. Future studies should seek to obtain a representative sample, gather more demographic data than we did and seek a larger sample of children. It makes sense to ask about nativity in asthma prevalence studies in order to distinguish these two apparently very different subpopulations.

Pulmonary function in workers exposed to low levels of fuel-oil ash.

Previously, we reported significant lung function changes after exposure to fuel-oil ash during a boiler overhaul in which median PM10 and vanadium concentrations were 2.9 mg/m3 and 11.9 micrograms/m3, respectively. In this study, we examined prospectively 18 boilermakers involved in the short-term, partial overhaul of a large, oil-fired boiler where occupational exposures to PM10 and metals were relatively low. Vanadium and PM10 exposure levels were measured before and during boiler work. For PM10, median exposure before and during boiler work was 0.5 and 0.6 mg/m3, respectively. For vanadium, median exposure before and during boiler work was 1.0 and 12.7 micrograms/m3, respectively, comparable with the results of our previous study. Spirometric (PFT) testing was done three times: first day on the job (PFT1), end of overhaul (PFT2), and 2 weeks post-overhaul (PFT3). Spirometry results were analyzed using repeated measures analysis of variance. No significant differences were found. Boilermakers working on a short-term overhaul of an oil-fired boiler exhibited no significant change in any lung function parameter comparing pre-, during, and 2 weeks post-exposure. The comparatively low levels of exposure to PM10 and vanadium observed during boiler work, the short duration of the overhaul, and the healthy worker effect are possible explanations for these results.

Occupational Health and Safety Experiences among Self-Identified Immigrant Workers Living or Working in Somerville, MA by Ethnicity, Years in the US, and English Proficiency

In this community based research initiative, we employed a survey instrument predominately developed and administered by Teen Educators to assess occupational health risks for Haitian, Salvadoran, and Brazilian immigrants (n = 405) in Somerville, MA, USA. We demonstrate that a combined analysis of ethnicity, years in the US, and English proficiency better characterized the occupational experience of immigrant workers than considering these variables individually. While years in the US (negatively) and English proficiency (positively) explained the occurrence of health risks, the country of origin identified the most vulnerable populations in the community. Brazilians, Salvadorans, and other Hispanic, all of whom who have been in the US varying length of time, with varying proficiency in English language had twice the odds of reporting injuries due to work compared to other immigrants. Although this observation was not significant it indicates that years in the US and English proficiency alone do not predict health risks among this population. We recommend the initiation of larger studies employing c community based participatory research methods to confirm these differences and to further explore work and health issues of immigrant populations. This study is one of the small number of research efforts to utilize a contemporaneous assessment of occupational health problems in three distinct immigrant populations at the community level within a specific Environmental Justice context and social milieu.

Developing Methods to Compare Low-Education Community-Based and University-Based Survey Teams

We compared the quality of low-education community-based survey teams to college educated graduate students. Our approach was to develop methods, conduct a pilot survey, and report lessons. Community and university teams conducted surveys from non-overlapping random samples of addresses at a public housing development in Boston, Massachusetts. The two types of teams make a similar number of attempts (122 and 124, respectively), and there was no statistically significant difference between the teams in terms of response rate or amount of missing data. Similarly, there was no statistically significant difference in refusal rate or in responses to questions in the survey. There was, however, evidence that the community teams used data tracking forms improperly. This study suggests that it is possible to study the relative quality of community and university-based teams in terms of data collection. The findings also suggest that the two types of teams may be roughly comparable.

Method to screen urine samples for vanadium by inductively coupled plasma mass spectrometry with cryogenic desolvation

The determination of vanadium by inductively coupled plasma mass spectrometry is complicated by ClO+ ions from chlorine matrices. Cryogenic desolvation reduces the amount of chloride reaching the plasma by condensing it as hydrogen chloride and reduces the amount of oxide formation by removing water vapor. Urine samples are screened for vanadium at the 12 ppb level using scandium as an internal standard. The V+ and Sc+ signals are affected by the matrix in the same way, so the V+/Sc+ signal ratio corrects for signal suppression by the matrix, as well as drift. Cryogenic desolvation also removes ArCl+, which should facilitate measurement of arsenic and selenium.