Quantification of neurosteroids during pregnancy using selective ion monitoring mass spectrometry.

Analytical techniques used to quantify neurosteroids in biological samples are often compromised by non-specificity and limited dynamic range which can result in erroneous results. A relatively rapid and inexpensive gas chromatography-mass spectrometry (GC-MS) was developed to simultaneously measure nine neurosteroids, including allopregnanolone, estradiol, and progesterone, as well as 25-hydroxy-vitamin D3 in plasma samples collected from adult women subjects during and after pregnancy. Sample preparation involved solid-phase extraction and derivatization, followed by automated injection on a GC equipped with a mass selective detector (MSD) operated in single ion monitoring (SIM) mode to yield a run time of less than 11min. Method detection limits for all neurosteroids ranged from 30 to 200pg/mL (parts per trillion), with coefficients of variation that ranged from 3% to 5% based on intra-assay comparisons run in triplicate. Although concentrations of estradiol measured by chemiluminescent immunoassay (CIA) were consistent with values determined by GC-MS values, CIA yielded considerable higher values of progesterone, suggesting antibody cross reactions resulting from low specificity. Mean neurosteroid levels and representative time-course data demonstrate the ability of the method to quantify changes in multiple neurosteroids during pregnancy, including rapid declines in neurosteroid levels associated with delivery. This simplified GC-MS method holds particular promise for research and clinical laboratories that require simultaneous quantification of multiple neurosteroids, but lack the resources and expertise to support advanced liquid chromatography-tandem mass spectrometry facilities.

Characterizing the low wage immigrant workforce: a comparative analysis of the health disparities among selected occupations in Somerville, Massachusetts.

BACKGROUND: This study estimates job-related risks among common low wage occupations (cleaning, construction, food service, cashier/baggers, and factory workers) held by predominantly Haitian, El Salvadorian, and Brazilian immigrants living or working in Somerville, Massachusetts. METHODS: A community-based cross-sectional survey on immigrant occupational health was conducted between 2006 and 2009 and logistic regression was used to assess the job-related risks among the most common low wage occupations. RESULTS: Construction workers reported significantly higher health risks, and lower access to occupational health services than the other occupations. Compared to cashier/baggers, the reference population in this study, cleaners reported significantly lower access to health and safety and work training and no knowledge of workers' compensation. Factory workers reported significantly lower work training compared to cashier/baggers. Food service workers reported the least access to doctors compared to the other occupations. CONCLUSION: We found significant variability in risks among different low wage immigrant occupations. The type of occupation independently contributed to varying levels of risks among these jobs. We believe our findings to be conservative and recommend additional inquiry aimed at assuring the representativeness of our findings.

Occupational health outcomes among self-identified immigrant workers living and working in Somerville, Massachusetts 2006-2009.

This study examines the burden of occupational health risks among a convenience sample of three immigrant worker populations (Brazilian, Haitian, and El Salvadoran) in Somerville, Massachusetts. In this community based research initiative (n = 346), logistic regression is used to analyze immigrant occupational health survey data collected from 2006 to 2009. In this study, injuries at work were significantly associated with lower English proficiency (OR = 1.8, 95 % CI 1.1-3.0), workers between the ages of 46 and 65 (OR = 2.7, 95 % CI 1.0-7.0), service workers (OR = 13.8, 95 % CI 1.8-105.2), production workers (OR = 10.8, 95 % CI 1.3-90.1), construction workers (OR: 21.7, 95 % CI 2.8-170.9) and immigrants with no health insurance (OR = 1.8, 95 % CI 1.0-3.1). Injuries were negatively associated with years in the US with more established immigrants in the US >15 years reporting more injuries at work. Older immigrants who have been in the US longer but are less proficient in English, and are still employed in low-wage occupations with no health insurance suffered more injuries than recent immigrants. Further validation of this result is required.

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.

Exposure to fuel-oil ash and welding emissions during the overhaul of an oil-fired boiler.

The health effects of exposure to vanadium in fuel-oil ash are not well described at levels ranging from 10 to 500 microg/m(3). As part of a larger occupational epidemiologic study that assessed these effects during the overhaul of a large oil-fired boiler, this study was designed to quantify boilermakers' exposures to fuel-oil ash particles, metals, and welding gases, and to identify determinants of these exposures. Personal exposure measurements were conducted on 18 boilermakers and 11 utility workers (referents) before and during a 3-week overhaul. Ash particles < 10 microm in diameter (PM(10), mg/m(3)) were sampled over full work shifts using a one-stage personal size selective sampler containing a polytetrafluoroethylene filter. Filters were digested using the Parr bomb method and analyzed for the metals vanadium (V), nickel (Ni), iron (Fe), chromium (Cr), cadmium (Cd), lead (Pb), manganese (Mn), and arsenic (As) by inductively coupled plasma mass spectrometry. Nitrogen dioxide (NO(2)) was measured with an Ogawa passive badge-type sampler and ozone (O(3)) with a personal active pump sampler.Time-weighted average (TWA) exposures were significantly higher (p < 0.05) for boilermakers than for utility workers for PM(10) (geometric mean: 0.47 vs. 0.13 mg/m(3)), V (8.9 vs. 1.4 microg/m(3)), Ni (7.4 vs. 1.8 microg/m(3)) and Fe (56.2 vs. 11.2 microg/m(3)). Exposures were affected by overhaul time periods, tasks, and work locations. No significant increases were found for O(3) or NO(2) for boilermakers or utility workers regardless of overhaul period or task group. Fuel-oil ash was a major contributor to boilermakers' exposure to PM(10) and metals. Vanadium concentrations sometimes exceeded the 2003 American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value.

Urinary metal and polycyclic aromatic hydrocarbon biomarkers in boilermakers exposed to metal fume and residual oil fly ash.

BACKGROUND: Boilermakers are occupationally exposed to known carcinogens. METHODS: The association of urinary 1-hydroxy-pyrene (1-OHP), a biomarker of polycyclic aromatic hydrocarbon (PAH) exposure, with biomarkers of metal exposure (vanadium, chromium, manganese, nickel, copper, and lead) in boilermakers exposed to metal fume from welding and dust particulates from residual oil fly ash (ROFA) was examined. A repeated measures cohort study was conducted during the overhaul of an oil-fired boiler. Twice-daily urine samples were obtained for 5 days and analyzed for cotinine, 1-OHP, and metals. Generalized estimating equations (GEE) were used to model the multivariate relationship of 1-OHP to the explanatory variables. RESULTS: Metal and 1-OHP levels were determined for 165 urine samples from 20 boilermakers and these levels increased during the workweek. However, the 1-OHP level was not significantly associated with any individual metal level at any time point. CONCLUSION: This suggests that boilermakers were occupationally exposed to PAH and metals, but 1-OHP as a PAH biomarker was unable to serve as a surrogate marker of metal exposure for the metals measured in this study.

Estimation of personal exposures to particulate matter and metals in boiler overhaul work.

OBJECTIVE: We sought to develop an algorithm and estimate unmeasured exposures to particulate matter (PM) and metals in an epidemiologic study of boilermakers. METHODS: The algorithm was based on limited measurements and workers' task and time activity patterns. Half of the measurements were used to develop exposure estimates for unmeasured person days. The other half was used for method validation. RESULTS: The validation demonstrated good approximations of actual exposures with differences less than 5% for PM and vanadium (V). Average estimated exposures to PM (mg/m3) and V (microg/m3) were significantly higher for workers doing boiler repair than utility work (0.36 vs. 0.09 for PM and 5.99 vs. 0.38 for V). CONCLUSIONS: This algorithm provided reasonably accurate exposure indices for our epidemiologic study in this population. It also is likely applicable to similar exposure scenarios in other studies.

Smoking status and occupational exposure affects oxidative DNA injury in boilermakers exposed to metal fume and residual oil fly ash.

Epidemiologic studies demonstrate increased cancer incidence among workers exposed to polycyclic aromatic hydrocarbons (PAH) and metals, probably through cumulative oxidative DNA damage in response to carcinogens. Boilermakers are exposed to particulates of residual oil fly ash (ROFA) and metal fume that contain carcinogenic PAH and metals. We conducted a repeated-measures cohort study in boilermakers during the overhaul of an oil-fired boiler to determine a possible association between the level of 8-hydroxy-2'-deoxyguanosine (8-OH-dG; an oxidative injury biomarker) and biomarkers of PAH (1-hydroxypyrene; 1-OHP) and metal exposure. Preshift and postshift urine samples were analyzed for 8-OH-dG, cotinine, 1-OHP, and metals. Generalized estimating equations were used to model the multivariate relationship of 8-OH-dG to the explanatory variables of interest. Biomarker levels were determined for 181 urine samples from 20 male subjects (mean age 45 years, 50% smokers). Metal and 1-OHP levels increased cross-week and were affected by smoking status. Levels of 8-OH-dG were higher in nonsmokers at the start of the workweek yet declined after occupational exposure to similar levels as in smokers. Multivariate analysis indicated that metal x cotinine interaction terms for nickel, vanadium, chromium, and copper were significantly associated with the 8-OH-dG level, but there were differential effects depending on the metal. This study suggests that oxidative DNA damage in boilermakers is influenced by the interaction between occupational exposures and smoking status. In addition, boilermakers may have reduced ability to repair damaged DNA after ROFA and metal fume exposure. This finding has clinical relevance because these exposures may increase the cancer susceptibility of boilermakers.

Association of expired nitric oxide with urinary metal concentrations in boilermakers exposed to residual oil fly ash.

BACKGROUND: Exposure to metal-containing particulate matter has been associated with adverse pulmonary responses. Metals in particulate matter are soluble, hence are readily recovered in urine of exposed individuals. This study investigated the association between urinary metal concentrations and the fractional concentration of expired nitric oxide (F(E)NO) in boilermakers (N = 32) exposed to residual oil fly ash (ROFA). METHODS: Subjects were monitored at a boiler overhaul site located in the New England area, USA. F(E)NO and urine samples were collected pre- and post-workshift for 5 consecutive workdays. Metals investigated included vanadium (V), chromium (Cr), manganese (Mn), nickel (Ni), copper (Cu), and lead (Pb). RESULTS: The median F(E)NO was 7.5 ppb (95% CI: 7.4-8.0), and the median creatinine-adjusted urinary metal concentrations (mug/g creatinine) were: vanadium, 1.37; chromium, 0.48; manganese, 0.30; nickel, 1.52; copper, 3.70; and lead, 2.32. Linear mixed-effects models indicated significant inverse exposure-response relationships between log F(E)NO and the log-transformed urinary concentrations of vanadium, manganese, nickel, copper, and lead at several lag times, after adjusting for smoking status. CONCLUSIONS: Urine samples may be utilized as a biomarker of occupational metal exposure. The inverse association between F(E)NO and urinary metal concentrations suggests that exposure to metals in particulate matter may have an adverse effect on respiratory health.