The effect of mass concentration, heavy metal content and oxidative potential of ambient air particulate matters (PM۲.۵) on biomarkers related to the cardiovascular system function in East Azerbaijan Province

Abstract

Introduction: Further investigation is required to gain a more comprehensive understanding of the adverse effects of PM components, their association with biomarkers, and their impact. Given the dearth of available data, it is imperative to examine the influence of PM2.5 contents on cardiovascular biomarkers. The primary objective of this study is to investigate the impact of PM2.5 mass concentration, heavy metal composition, and oxidative potential in ambient air on biomarkers that assess cardiovascular function in healthy adults residing in two distinct regions: high-traffic and industrial areas. This research is being conducted in Tabriz city, and the findings will be compared using a cross-sectional study design. Methods: The investigation was conducted on adults from October 12 to November 24, 2021. The initial selection of locations was based on the premise that they would serve as representative samples of high-traffic and industrial zones. The Shahid Yahivi health center in the Maralan region and the Kojaabad rural health center were thus selected as the most suitable sites for the study. Subsequently, in order to ascertain the general information and health status of the residents of the two locations, we collaborated with both centers and referred them to the Sib system. A simple random sampling method was utilized to select the participants. The number of individuals selected in the initial survey was approximately five times the number determined by the sample size in each region. Subsequently, contact was made with the individuals in question, after which a questionnaire was administered encompassing both general and health-related information. Should a subject meet all the requisite criteria and complete the questionnaire, they would be invited to participate further. A total of 89 healthy individuals, aged between 35 and 60 years, were selected as research participants. The aforementioned individuals were residents of two distinct localities. A total of 45 individuals were selected from the Maralan district of Tabriz, and 44 individuals were selected from the Kojaabad region. Blood samples were collected from the participants on a designated day and at a specified time of the week. Biomarkers include hemodynamic markers and cardiovascular markers such as NO, sICAM-1, SVCAM-1, MDA, and CRP. Prior to the collection of biological samples, the concentration of PM2.5 suspended particles from the surrounding health centers was monitored over a seven-day period. The concentrations of metals, PAHs, and oxidative potential (OP) were determined using ICP-MS, GC-MS, and dithiothreitol (DTT), respectively. A generalized linear model was used to examine the association between PM2.5 toxicity and each health endpoint. Results: The findings indicated that the daily concentrations of PM2.5 exceeded the WHOrecommended level by approximately sevenfold. A correlation was identified between PM2.5 exposure and adverse cardiovascular outcomes. Furthermore, exposure to PM2.5 mass, total PAHs, and specific trace metals (Ni, Fe, V, As, and Pb) was associated with a reduction in serum NO levels. At lag 3, exposure to PM2.5 mass resulted in a significant decrease in NO levels (1.32%, 95% CI: -2.27, -0.12) and total PAHs (2.05%, 95% CI: -3.93, -0.12). In contrast, OP exhibited a mild correlation with NO level increases at the same time point, with an increase of 16.19% (95% CI: -1.46, 40.69), p < 0.1. Moreover, positive associations were observed between PM2.5 and its chemical constituents (PAHs, As, Cu, OP) and adhesion molecules at different lag times. An increase of 0.16 ppb in PAH concentrations at an interquartile range was associated with a 4.74% decline (95% CI, -7.80, -0.55) in the sVCAM-1 level. However, no significant trend was observed between pollutants and other biomarkers (sICAM-1, MDA, and CRP) in the present study. Conclusion:The results of the study indicate that the chemical composition of PM2.5 has a significant impact on biological responses.Our findings suggests that exposure to PM2.5 and its compounds may potentially stimulate cardiovascular-related biomarkers in healthy populations.