Association of exposure to primary aromatic amines with health risks in China

Primary aromatic amines (PAAs) are a group of chemicals widely used in industrial processes, including the production of rubber, foams, dyes, plastics, and food packaging. Although some PAAs are known carcinogens, data on PAA exposure among the Chinese general population are scarce.

To that end, in a study published in the KeAi journal Environmental Chemistry and Ecotoxicology, a group of researchers from China reported a nationwide biomonitoring study they have conducted. It is the first comprehensive assessment of human exposure to primary aromatic amines (PAAs) across multiple cities in China, providing critical insights into potential health risks associated with PAA exposure.

In the study, the team of researchers analyzed 457 urine samples collected from residents across 16 cities in China, using ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS).

“We detected 25 PAAs with aniline (ANI), meta-toluidine(m-TD), ortho-toluidine (o-TD), para-toluidine (p-TD), 4-ethoxyaniline (4-EA), and 3,4-diaminoanisole (3,4-DAAS) that are most frequently found,” shares corresponding author  Tao Zhang. “The sum median concentrations of all PAAs ranged from 0.93 to 3.8 ng/mL across the cities.”

Notably, urinary PAA levels significantly varied depending on demographic, geographic, and socioeconomic factors, with higher concentrations observed among smokers, non-adults, and residents from industrialized or ethnically distinct cities.

“The urinary concentrations of ΣPAAs were also significantly correlated with gross domestic product (GDP) and GDP per capita of select Chinese cities,” adds Zhang.

One surprising finding was that although the overall exposure levels for all PAAs appearing low, with hazard quotients remaining below 1, several compounds including 4-EA, m-TD, o-TD and p-TD, showed significant associations with the oxidative DNA damage biomarker 8-OHdG.

“These associations were most evident among non-smokers, suggesting that chronic low-level exposure may still trigger oxidative stress and elevate long-term cancer risks in the general population,” says Zhang. “While our results indicate that the current exposure levels are not immediately alarming, the positive correlations with oxidative stress marker 8-OHdG cannot be ignored.

First author Yanan Yao adds, “Our work provides the first baseline data of PAA exposure for the Chinese general population and highlights that even low concentrations may contribute to DNA damage over time. This points the need to strengthen monitoring and implement targeted public health interventions, particularly for vulnerable groups such as non-adults and non-smokers.”

In sum, this study not only fills a critical knowledge gap but also lays the groundwork for future environmental health policies in China. By highlighting subtle but measurable biological effects, it offers new perspectives on the importance of routine biomonitoring and the potential risks of everyday chemical exposure.

Contact author details: Tao Zhang, Professor, School of Agriculture and Biotechnology, Shenzhen Campus of Sun Yat-sen University, Shenzhen, China, zhangt47@mail.sysu.edu.cn

Funder: This research was supported by the National Natural Science Foundation of China (42477295, 22306209, 22036004), the National Key Research and Development Program of China (No. 2023YFC3706800), and the Science and Technology Program of Guangzhou, China (2024A04J6442).

Conflict of interest: Kurunthachalam Kannan served as the editor-in-chief, Tao Zhang as the associate editor, and Jingchuan Xue as a member of editorial board of Environmental Chemistry and Ecotoxicology. None of them were involved in the editorial review or the decision to publish this article. All authors declare that there have no competing interests.

See the article: Yao, Y., Xue, J., Wang, Y., Kannan, K., Zhang, T., Exposure to carcinogenic primary aromatic amines and associated health risks among the Chinese general population: A nationwide biomonitoring study, Environmental Chemistry and Ecotoxicology, Volume 7, 2025, Pages 1624-1633, https://doi.org/10.1016/j.enceco.2025.07.007.