title: Exposure to fuel-oil ash and welding emissions during the overhaul of an oil-fired boiler.
abstract: 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.
authors.affiliation: Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, USA. youcheng.liu@yale.edu
authors.forename: Youcheng
authors.initials: Y
authors.lastname: Liu
authors.forename: Mark A
authors.initials: MA
authors.lastname: Woodin
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Smith
authors.forename: Robert F
authors.initials: RF
authors.lastname: Herrick
authors.forename: Paige L
authors.initials: PL
authors.lastname: Williams
authors.forename: Russ
authors.initials: R
authors.lastname: Hauser
authors.forename: David C
authors.initials: DC
authors.lastname: Christiani
mesh_terms: D000328:Adult; D000395:Air Pollutants, Occupational / Q000009:adverse effects / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods*; D005648:Fuel Oils / Q000032:analysis* / Q000633:toxicity; D006801:Humans; D019570:Inhalation Exposure / Q000009:adverse effects / Q000032:analysis*; D008875:Middle Aged; D009585:Nitrogen Dioxide / Q000032:analysis; D016273:Occupational Exposure / Q000009:adverse effects / Q000032:analysis*; D010126:Ozone / Q000032:analysis; D010316:Particle Size; D011210:Power Plants / Q000295:instrumentation; D012134:Respiratory Protective Devices; D018570:Risk Assessment / Q000379:methods*; D020711:Threshold Limit Values; D014639:Vanadium / Q000032:analysis* / Q000633:toxicity; D014896:Welding
chemical_list: D000395:Air Pollutants, Occupational; D005648:Fuel Oils; D014639:Vanadium; D010126:Ozone; D009585:Nitrogen Dioxide