Serum estimate of benzene, naphthalene and pyrene as measure of occupational exposure to vehicular air pollution

Abstract

BACKGROUND AND AIM: Exacerbation in respiration tract infections (RTI) and asthma is associated with exposure to vehicular emission in urban environment. Urban occupational exposure to dust and particulate matter has been shown to increase infections inside airway of human epithelial cells and evidence about rising asthma among occupations working on roadsides were reported. METHODS: Hence, we studied 89 workers directly exposed to vehicular emission such as fuel-station attendants, construction workers, traffic police wardens and bus-drivers with an aim to assess RTI and asthma prevalence resulting from inhalation of air containing dust and vehicular pollutants. Unexposed office workers (n=44) were recruited as control cohort. Exposure was characterized as daily work hours and years associated with current profession. RESULTS:Serum benzene, naphthalene and pyrene median concentrations were 4.5, 12.6, and 2.04 μg/L in exposed group and 0.54, 0.77, and 0.14 μg/L in unexposed cohort, respectively. Compared to self-reported dermal contact, the estimated concentrations were higher in fuel-station attendants related to spills of gasoline (p0.05). After adjusting long work hours, 39% of exposures estimates exceeded the benzene threshold limit value for an 8-h time-weighted average of 1.6 mg/m3. Smokers appeared highly vulnerable to naphthalene (r=0.49, p0.01) and pyrene (r=0.38, p0.05) body burden among traffic police wardens and bus-drivers. Results of regression analysis showed asthma highly prevalent in construction workers (R2=0.53) followed by bus-drivers (R2=0.41). Compared to unexposed control group, RTI was found in 67% of the fuel-station attendants. CONCLUSIONS:We conclude that except construction workers, inhalation and frequent skin exposure to naphthalene and pyrene is unavoidable in all occupational groups. Reducing working hours and job rotation coupled with use of protective equipment are suggested as intervention measures to reduce exposure for vehicular air pollution. KEYWORDS: Air pollution; pyrene, benzene, road-side workers; biomonitoring