Occupational health risk assessment of benzene and toluene at a landfill site in Johannesburg, South Africa

In developing countries land-filling is the most common form of waste management that is practiced. Landfills are known to be anthropogenic sources of air pollutants that have a negative impact on both environmental and human health. People who work on landfill sites are particularly at risk of adverse health effects associated with the inhalation of hazardous air pollutants (HAPs), such as volatile organic compounds (VOCs). Although VOCs only make up between 0.5% and 1% of total landfill gas, they are important due to the high level of toxicity associated with them. Regular air quality monitoring and hazard risk assessments provide important information that can be used in an effort to protect the health and safety of people working in a landfill environment. This is especially important within a developing context as relevant information is limited. In this study an occupational health risk assessment of benzene and toluene was conducted at a landfill in Johannesburg, South Africa. Applying an approach of modelling (using LandGEM) results indicated a significant increase in emission rates over a 90 year period. In addition, ambient air concentrations of BTEX, 100 meters from the landfill, were found to be unacceptable by US EPA air quality recommended standards. Additionally, cancer risk and hazard index calculations of benzene and toluene, of employees on-site, indicated that occupational exposures were above US EPA recommended standards. Thus, it was shown that employees were significantly at risk to adverse health effects associated with inhalation exposure to these HAPs.