Setting of French indoor air quality guidelines for chronic exposure to benzene

Abstract : Indoor air quality guidelines (IAQGs) provide safe levels of indoor pollutant concentrations below which adverse health effects are not expected to occur in the general population, including susceptible groups. The development of French IAQGs has been on-going since 2005 in the framework of the National Environment and Health Action Plan (NEHAP, 2004-2008). According to toxicological and epidemiological data, benzene inhalation leads to acute and chronic effects. For long-term exposure, haematological effects and leukaemia have been observed in the Pliofilm cohort. Benzene is classified as carcinogenic for humans and its genotoxic effects have been demonstrated. Considering non carcinogenic effects and available toxicological reference values for benzene, the IAQG of 10 micro g.m-3 is proposed to protect the general population for long-term exposure. To protect from carcinogenic effects, the proposed IAQGs are based on WHO's potency slope factor: 2 and 0.2 micro g.m-3 respectively associated with an excess lifetime risk of 10-5 and 10-6.