Risk assessment of inhalation exposure to polycyclic aromatic hydrocarbons in Taiwanese workers at night markets

To examine the inhalation exposure of cooks at night markets in Taiwan to PAHs and to estimate the corresponding potential human health risks posed by the inhalation of carcinogenic PAHs. Eight-hour personal air samples collecting particle-bound PAHs and XAD-2 retaining PAHs in the gas phase were taken by personal PM2.5 cyclones with cooks carrying the sampler on the shoulder while cooking at selected food stalls at four night markets in Taipei, and the concentrations of 16 priority PAHs in both particulates and air were measured with GC/MS. The total identified PAHs in both gas and PM2.5 phases exposed by cooks during cook hours ranged from 233,995 to 44,166 ng m(-3). Total exposed PAHs in cooks, as well as the percentage of PAHs in PM2.5, were the highest at the barbecue stall F3. The fractions of gaseous PAHs (97%) in the four food stalls were consistently higher than the fractions of particulate PAHs (3%). The diagnostic ratios of PAHs fell within the range of those found in other studies related to cooking. At all typical food stalls in night markets except for F2, the excess lifetime cancer risk (ELCR) of cooks are beyond the acceptable target risk range of 10(-6) to 10(-4) for occupational workers set by USEPA. The PAHs measured in the night markets originated from combustion due to food cooking. The control of gaseous PAH emissions would be more important than the fractions of particulate PAH emissions. Occupational exposure to cooking emissions in Taiwanese workers at night markets is of health concern. Thus, effective protective measures are therefore suggested to minimize cooks' exposure to such emissions, such as wearing mask of activated carbon, evacuating the exhaust into water tank with bio-surfactant to improve PAH removal, installing effective mechanical exhaust vacuum or building high exhaust fume hood above cooking ovens.