Human risk assessment of benzene after a gasoline station fuel leak.

Abstract

To assess the health risk of exposure to benzene for a community affected by a fuel leak. Data regarding the fuel leak accident with, which occurred in the Brasilia, Federal District, were obtained from the Fuel Distributor reports provided to the environmental authority. Information about the affected population (22 individuals) was obtained from focal groups of eight individuals. Length of exposure and water benzene concentration were estimated through a groundwater flow model associated with a benzene propagation model. The risk assessment was conducted according to the Agency for Toxic Substances and Disease Registry methodology. A high risk perception related to the health consequences of the accident was evident in the affected community (22 individuals), probably due to the lack of assistance and a poor risk communication from government authorities and the polluting agent. The community had been exposed to unsafe levels of benzene (> 5 μg/L) since December 2001, five months before they reported the leak. The mean benzene level in drinking water (72.2 μg/L) was higher than that obtained by the Fuel Distributer using the Risk Based Corrective Action methodology (17.2 μg/L).The estimated benzene intake from the consumption of water and food reached a maximum of 0.0091 μg/kg bw/day (5 x 10-7 cancer risk per 106 individuals). The level of benzene in water vapor while showering reached 7.5 μg/m3 for children (1 per 104 cancer risk). Total cancer risk ranged from 110 to 200 per 106 individuals. The population affected by the fuel leak was exposed to benzene levels that might have represented a health risk. Local government authorities need to develop better strategies to respond rapidly to these types of accidents to protect the health of the affected population and the environment.