Seasonal variations, source apportionment, and health risk assessment of nitrosamines in inhalable particulate matter (PM10) in the atmosphere of Zonguldak, Türkiye

Abstract

The study presents seasonal changes in nitrosamine concentrations in inhalable particulate matter (PM₁₀) collected from the atmosphere of Zonguldak, Turkey, during heating and non-heating periods, possible source apportionment, and risk assessment of human health. The daily collected PM_2.5 and PM_2.5–10 samples were analyzed for nitrosodimethylamine, nitrosomethylethylamine, nitrosodiethylamine, nitrosopyrrolidine, nitrosodipropylamine, nitrosomorpholine, nitrosoethylbutylamine, nitrosopiperidine, mono-nitrosopiperazine, di-nitrosopiperazine, nitrosodibutylamine, and nitrosodiphenylamine by gas chromatography–mass spectrometry (GC–MS). The mean concentrations of total nitrosamines in PM₁₀ were found to be 19.04 ng/m³ in summer, 113.67 ng/m³ in winter, and 98.88 ng/m³ annually, with a peak of 253.56 ng/m³ occurring in winter. The source apportionment of the analyzed data was conducted using principal component analysis, resulting in two primary factors: “Coal-Fuel Oil Combustion-Cooking” and “Traffic Emissions-Secondary Atmospheric Reaction-Landfill.” These two factors collectively accounted for 82.944% of the total variance. In order to evaluate the health risks associated with the inhalation of mutagenic and carcinogenic nitrosamines present in airborne PM₁₀, cumulative lifetime cancer risks (LCR) were calculated for different age groups based on exposure time (ET) using annual mean concentrations. The average cumulative lifetime cancer risks, represented as the number of additional cancer cases per million exposed population, were in the range of 1.57–12.57 for the 0– < 1 age group, 4.18–33.52 for the 1– < 6 age group, 5.48–43.96 for the 6– < 21 age group, and 7.70–61.61 for the 21 < 70 age group. The estimated average cumulative lifetime cancer risks from inhalation exposure to nitrosamines in urban PM10 exceed the US Environmental Protection Agency’s guideline for a negligible risk level of 1 excess cancer case per 1 million exposed individuals across all age groups. LCRs exceed the maximum acceptable value of 10 at different exposure times in all age groups but do not exceed the intolerable value of 100 in any age group.