An overview of benzene contamination in the second-largest metropolis in Southeastern Brazil

Benzene is a highly volatile monoaromatic hydrocarbon and genotoxic carcinogen. In Brazil, it is considered a priority for the National Health System. However, although this compound is targeted by health surveillance in Brazil, scarce data are available on occupational or environmental exposure. This review contributes to an overview regarding benzene levels in the second-largest metropolis in Southeastern Brazil, Rio de Janeiro, and associated risks. A decreasing trend has been noted in the city of Rio de Janeiro, in the last decades, due to more stringent vehicular emission legislations and advances in vehicular technology, although adulterated gasoline is still a concern. Future actions regarding reductions of benzene emissions in the city include regulatory and surveillance programs concerning adulterated gasoline, substitution of raw materials to reduce benzene input to production processes, implementing changes in operating conditions to minimize benzene formation or volatilization and equipment modification to avoid benzene escaping into the environment. Finally, the increasing use and further construction of alternative transportation can significantly contribute to lowering benzene emissions in Rio de Janeiro and other metropolis worldwide and should be implemented as soon as possible.