A study on chemical characteristics and cytotoxicity of fine particulate matter in urban atmosphere

Abstract

It has been documented that airborne fine particulate matter (PM2.5) can enter the lungs deeply and has a significant negative impact on human health, including the occurrence of cancer and cardiovascular and respiratory diseases. Because different substances may have different levels of toxicity even with the same mass concentration, it is important to research both the chemical components determining toxicity and cell toxicity itself. Furthermore, due to the rapid hourly and daily variations in PM2.5 concentration and chemical composition, long-term daily data is essential for accurate identification. Evaluating cell viability is essential to understanding how cells respond to substances, providing insights into cell death, survival rates, and metabolic activity (Lee et al., 2011). This study assessed the chemical composition and cytotoxicity of PM2.5 in the urban Gwangju from April 6, 2022, to April 27, 2023. Gwangju exhibits both urban and rural characteristics, with the sampling area influenced by nearby residential and industrial regions and proximity to major highways. A total of 65 days of samples were selected, and PM2.5 was exposed to A549 cells. In order to compare intrinsic toxicity, Neutral Red Uptake (NRU) assay was used to measure cell viability, and mass was used to standardize the results. Additionally, ions, elements, OC, EC, WSOC, and WISOC were analyzed. Throughout the sampling duration, the average PM2.5 mass concentration was 20.3 ± 12.0 µg/m³, with the corresponding cell toxicitym value being 0.006 ± 32.8 %/µg, showing no significant seasonal differences. The cell toxicitym was highest in the summer, whereas the cell toxicityv was highest in the winter. The PM2.5 mass concentration was at its minimum level in June, yet cell toxicity was the highest in June. Compared to March, when cell toxicity was the lowest, June showed about 1.8 times higher cell toxicity, with the fractions of SO42-, WSOC, and WISOC being approximately 1.9, 2.3, and 1.6 times higher, respectively. Principal component analysis revealed that WSOC, WISOC, and traffic-related chemical components like copper and zinc were associated with cell toxicity. Multiple regression analysis suggested that WSOC and Zn are chemical components influencing cell toxicity. Accumulating data through further research and clarifying emission sources is expected to contribute to new understandings.