Personal exposure to benzene from fuel emissions among commercial fishers: comparison of two-stroke, four-stroke and diesel engines.
Commercial fishers are exposed to unburned hydrocarbon vapors and combustion products present in the emissions from their boat engines. The objective of this study was to measure personal exposure to benzene as a marker of fuel exposure, and to predict exposure levels across categories of carbureted two-stroke, four-stroke and diesel engines. A self-monitoring approach, employing passive monitors, was used to obtain measurements of personal exposure to benzene over time. Mixed-effect linear regression models were used to predict exposure levels, identify significant effects and determine restricted maximum likelihood estimates for within- and between-person variance components. Significant fixed effects for engine type and refueling a car or truck were identified. After controlling for refueling, predicted benzene exposure levels to fishers on boats equipped with two-stroke, four-stroke and diesel engines were 58.4, 38.9 and 15.7 microg/m3, respectively. The logged within-person variance component was 1.43, larger than the between-person variance component of 1.13, indicating that the total variation may be attributable to monitor placement, environmental conditions and other factors that change over time as well as differences between individual work practices. The health consequences of exposure to marine engine emissions are not known. The predicted levels are well below those at which health effects have been attributed, however.
Kirrane
Ellen
E
RTI International, Research Triangle Park, North Carolina 27709-2194, USA. ekirrane@rti.org
Loomis
Dana
D
Egeghy
Peter
P
Nylander-French
Leena
L
D000818:Animals; D015331:Cohort Studies; D004781:Environmental Exposure / Q000032:analysis; D004784:Environmental Monitoring / Q000379:methods; D005398:Fisheries; D006801:Humans; D019570:Inhalation Exposure / Q000032:analysis*; D016013:Likelihood Functions; D016014:Linear Models; D016273:Occupational Exposure / Q000032:analysis*; D012767:Ships; D011795:Surveys and Questionnaires; D001335:Vehicle Emissions / Q000032:analysis*
D001335:Vehicle Emissions