BTEX Atmospheric Levels and Health Risk in an Urban Site in Ciudad del Carmen, Campeche

Benzene, toluene, ethylbenzene, and xylenes (BTEX) were measured in ambient air in an urban site of Ciudad del Carmen, Campeche during spring 2022. Samples were collected during the morning (from 07:00 to 08:00 h), midday (from 14:00 to 15:00 h) and afternoon (from 18:00 to 19:00 h) using glass tubes packed with activated carbon, at a controlled air flow of 1.5 L/min. Samples were analyzed by gas chromatography with flame ionization detection. The relative abundance in ambient air of BTEX was the following: benzene (9.197 μg/m^3) > toluene (8.953 μg/m^3) > xylenes (7.789 μg/m^3) > ethylbenzene (7.538 μg/m^3). The statistical analysis revealed that BTEX compounds had strong correlations between each other, indicating that they were originated from common sources. From the meteorological analysis, it was found that the prevailing winds blew from the east and southeast, indicating that vehicular emissions coming from avenues located in these directions may have contributed to the BTEX levels in the study site. Principal component analysis and BTEX ratios (T/B and X/Ebz) revealed that vehicular emissions and fresh local air masses influenced the BTEX concentrations during the study period. From the health risk analysis, cancer risk coefficients exceeded the acceptable level (1 × 10 -6), thus exposed population may be at a possible risk of developing cancer in the lifetime due to the inhalation of BTEX at the measured concentrations. These results will be a useful tool for local authorities in order to establish control measures focused on the reduction of BTEX emissions and the improvement of the air quality in the study area.