PM_2.5 exposure estimates for college students and health risk assessment

As students spend the bulk of their time indoors, the study’s goals were to estimate the daily personal exposures of students to PM_2.5, estimate contributions to personal exposure from different micro-environments, and allocate the contributions of PM_2.5 sources to the outdoor and indoor environment. Between July and October 2019, college students aged 16 to 20 were personally monitored for PM_2.5 concentrations. PM_2.5 personal concentrations for college students ranged from 215.6 to 121.4 µgm^-3, with an average of 137.5 ± 41.9 µgm^-3. Personal environmental monitors (PEM) were used to test PM_2.5 and its metal compositions of Zn, Pb, Ni, Fe, Cr, Cd, Mn, Ba, Cu, and Hg. Using the positive matrix factorization along with geo-accumulation index and enrichment factor analysis, other sources responsible for the production of particle pollution have also been identified. According to the findings of the factor analysis, anthropogenic activities, traffic emissions, tobacco or cigarette smoke, and metal processing, all play a significant role in the production of metal-bound PM_2.5 particle pollution emissions. Based on the non-cancer risk findings for metals, ingestion of metals via inhalation was not a potentially high chronic risk. But the carcinogenic risks of metals like Cd, Ni, and Cr represent a health risk. Future studies should focus more on investigating the specific epidemiological effects of exposure to heavy metals in fine particles.