Health risk assessment of BTEX emissions in the landfill environment

This study focuses on a health risk assessment related to benzene, toluene, ethylbenzene, and m,p,o-xylene (xylenes) (BTEX) exposure via inhalation for workers at a landfill (LF) site. First, the landfill gas (LFG) samples were collected and analyzed accordance with US EPA method TO-17. The mean concentrations of benzene, toluene, ethylbenzene, and xylenes were determined as 140.3, 1271.7, 239.9, and 341.3 mu g/m(3), respectively. Then, a risk assessment methodology was employed to evaluate the potential adverse health effects of the individual BTEX compounds according to their carcinogenicities. The corresponding mean cancer risk for benzene was estimated to be 6.75E-05 that is lower than the designated acceptable risk level of 1.0E-04. With respect to mean non-carcinogenic risks for toluene, ethylbenzene, and xylenes, both individually and cumulatively, they were lower than the specified level of 1.0. These findings reveal that landfill BTEX emissions do not pose a health threat to workers at the landfill site. In addition, as far as the risks are concerned for the population in the neighborhood area of the landfill, air dilution of BTEX emitted from LF site is widely sufficient to guarantee their protection. (C) 2009 Elsevier B.V. All rights reserved.