LAUSR

This study aims to determine BTEX concentrations in the Metropolitan Region of Rio de Janeiro (MRRJ, Brazil) and evaluate potential health risks of benzene and ethylbenzene exposure based on the collected data, in 2015, the year before the Rio 2016 Olympic Games. Samples were collected and analyzed following method TO-15 (U.S.EPA). Toluene was the most abundant compound in all samples (mean concentration 16.72 ± 15.70 µg m −3 ). The average benzene concentration in ambient air (3.44 ± 3.14 µg m −3 ) was slightly lower than the yearly average “upper assessment threshold”, 3.5 µg m −3 , established by EU Directive 2008/50/EC. The calculated cancer risk values were > 1 × 10 −6 for all samples, clearly indicating a potential cancer risk and the importance of fixed measurements by the monitoring stations to assess ambient air quality in the urban areas of the MRRJ. Calculated ratios for the BTEX species indicate that these compounds are predominantly emitted from vehicular sources with a contribution from industrial sources.