Seasonal quimiometric study of formaldehyde and acetaldehyde atmospheric levels and health risk assessment, in urban areas of Salvador-Bahia, Brazil

Abstract

Air pollution affects the health of the population in a number of ways. In 2015, it was responsible for 6.4 million deaths worldwide. Among the aldehydes present in the atmosphere, formaldehyde (HCHO) and acetaldehyde (CH3CHO) are the most abundant ones and they are considered carcinogenic and probably carcinogenic to humans, respectively. The objective of this work was to correlate the concentrations of HCHO and CH3CHO in urban areas of the city of Salvador, in the northeast of Brazil, with levels of concentrations of conventional pollutants and meteorological parameters, and to calculate the risks of the atmospheric levels of these aldehydes to the health of the population. Formaldehyde and acetaldehyde were passively sampled in the air, with 7 days of exposure, using the AnalyzeAr kit in 9 sampling points, in rainy and dry periods. The samples were analyzed by high performance liquid chromatography (HPLC) with UV–Vis detection at 360 nm. The data were submitted to multivariate analysis, applying the principal component analysis (PCA). Formaldehyde and acetaldehyde concentrations ranged from 2.80 to 18.2 μg m−3 from to ≤ LQ (1.19) -16.8 μg m−3, not exceeding in only two places, during the rainy season, the short-term exposure limit (3.3 μg m−3) indicated by the Texas Environmental Quality Commission (USA), which limits this compound in the air at a lower level comparing with other international organizations. The variances of the first three main components together (PC1, PC2 and PC3) described 70.7% of the total data variance, with a tendency to separate the samples according to the seasonality. The average risk of cancer calculated for the local population was (7.2 ± 1.2) × 10−6 and (1.4 ± 0.81) × 10−5 for HCHO and (4.0 ± 1.0) × 10−7 and (2.2 ± 0.16) × 10−6 for CH3CHO, in the rainy and dry periods, respectively, which are above the safety limit established by the US Environmental Protection Agency (1.0 × 10−6) for HCHO in both periods, as well as for CH3CHO in the dry period.