Assessment of urinary aromatic amines in Brazilian pregnant women and association with DNA damage: Influence of genetic diversity, lifestyle, and environmental and socioeconomic factors

Abstract

Aromatic amines (AAs) are polar organic chemicals with a wide environmental distribution originating from various sources, such as tobacco smoke, diesel exhaust, and dermal absorption from textile products with azo dyes. The toxicity profile of AAs is directly related to the amino group's metabolic activation and the generation of the reactive intermediate, forming DNA adducts and potential carcinogenicity. Urinary levels of 8-hydroxy-2′-deoxyguanosine (8OHdG) are an important biomarker of DNA damage. Since AAs have been shown to cross the placental barrier, being a risk factor for adverse birth outcomes, prenatal exposure is a great public health concern. The present study aimed to measure the urinary levels of 58 AAs in Brazilian pregnant women (n = 300) and investigated the impact of this exposure on DNA damage by quantifying 8OHdG levels. The influence of tobacco smoke exposure and dermal absorption of AAs by clothes on urinary levels was also assessed. The results showed a 100% detection rate for eight AAs, two of them regulated by the European Union (2,6-dimethylaniline and 2,4-diaminotolune). Hundreds of AAs may be derived from aniline, which here showed a median of 1.38 ng/mL. Aniline also correlated positively with 2,6-dimethylaniline, p-aminophenol, and other AAs, suggesting exposure to multiple sources. The present findings suggest that both tobacco smoke and dermal contact with clothes containing azo dyes are potential sources that might strongly influence urinary levels of AAs in Brazilian pregnant women. A multiple regression linear model (R2 = 0.772) suggested that some regulated AAs (i.e., 2-naphthylamine and 4-aminobiphenyl), nicotine, smoke habit, age, and Brazilian region could induce DNA damage occurrence, increasing the levels of 8OHdG. Given the limited available data on human exposure to carcinogenic AAs, as well as the lack of toxicological information on those non-regulated, further studies focused on measuring their levels in human fluids and the potential exposure sources are clearly essential.