The Metropolitan Region of Rio de Janeiro is the second largest urban and industrial region in Brazil. While the south and south-east areas are affected by vehicular emissions, the districts and cities located in the northern area are subjected to industrial emissions and have the poorest air quality of the region. In this study, BTEX concentrations were determined in the District of Irajá, a residential area located in the north of the city of Rio de Janeiro, approximately 25 km from the industrial zone, as well as in the District of Jardim Primavera, in the city of Duque de Caxias. The mean values for total BTEX concentrations were 38.4 ± 11.7 and 44.6 ± 29.3 μg m⁻³, in Irajá and Jardim Primavera, respectively, which are higher than those previously reported for other areas. The benzene/toluene rates, (approximately 0.5 for both sampling sites), were also higher than typical values that were determined for diesel and gasoline emissions through dynamometer experiments.

里约热内卢都会区是巴西第二大城市和工业区。虽然南部和东南部地区受到车辆排放的影响，但位于北部地区的地区和城市受到工业排放的影响，空气质量是该地区最差的。在这项研究中，BTEX 浓度在 Irajá 区（位于里约热内卢市北部的一个住宅区，距离工业区约 25 公里）以及该市的 Jardim Primavera 区进行了测定卡西亚斯公爵。BTEX 总浓度的平均值为 38.4 ± 11.7 和 44.6 ± 29.3 μg m ^-3，分别在 Irajá 和 Jardim Primavera，高于之前报告的其他地区。苯/甲苯比率（两个采样点约为 0.5）也高于通过测功机实验确定的柴油和汽油排放的典型值。