Aromatic amine exposure and bladder cancer: a review of recent advances in epidemiology, pathogenesis, and prevention

Aromatic amines are environmental and occupational pollutants found in industrial chemicals, tobacco smoke, hair dyes, and azo-dye-containing textiles. Epidemiological studies confirm that occupational settings and tobacco smoking are the primary sources of exposure, with inhalation and dermal absorption being the major routes of entry, significantly increasing bladder cancer risk. Mechanistically, aromatic amines undergo metabolic activation, leading to DNA adduct formation, oxidative stress, DNA double-strand breaks, and activation of oncogenic signaling pathways such as MAPK/AP-1. Genetic polymorphisms in metabolic enzymes modify individual susceptibility, and risk prediction models incorporating these markers show promise. However, controversies remain regarding low-dose combined exposures, differences in carcinogenic potency among aromatic amines, and inadequate control for confounders in epidemiological studies. Future research should use multi-omics technologies to elucidate complete molecular networks and establish integrated prevention strategies.