Environmental study and health risk assessment of the particulate matter and heavy metal pollution near a small-scale industrial area in Thailand

<p dir="ltr">Rapid industrialization, urbanization, and agriculture have contributed to accumulation of heavy metals in ecosystems, particularly in soil and air, posing health risks from airborne particulate matter and contaminated soil, and highlighting the importance for understanding of the present trace metals for effective environmental management and health interventions. The study aimed to determine heavy element concentrations (Mn, Fe, Ni, Cu, Pb, Al, Zn, As, and Cr) in surface soils and PM_2.5in and around the small scale industrial area. Specifically, it focused on indoor and outdoor PM_2.5 levels at a childcare center near the small scale industry, examining potential health risks for children (2-6 years old) and adults (>21 years old). Additionally, the study investigated particle dispersion and assessed the efficacy of window screens in reducing indoor pollutants. During the cool dry season, Al concentrations were observed to be the highest across all investigation sites, with particularly elevated levels detected in the industrial area for both surface topsoil and PM_2.5_. In the industrial area, surface soil recorded a Pb concentration of 1176 mg/kg, while Pb in PM_2.5 measured 0.670 μg/m³, surpassing national standards and acceptable limits. Conversely, in the hot dry season, Zn concentrations were found to be the highest across all sites. The seasonal fluctuations in heavy metal concentrations are possibly significantly influenced by anthropogenic activities and environmental factors. Furthermore, during the cool dry season, PM_2.5 concentrations exceeded national standards, particularly in the industrial zone (46.4 μg/m³), near main roads (41.0 μg/m³), and childcare center (31.6 μg/m³) whereas in the hot dry season, the PM_2.5 concentration was found in the range of 8.9 μg/m³ to 28.7 μg/m³. The lower concentrations observed during the hot dry season could possibly be attributed to occasional rainfall events occurring during sample collection, which might have washed out some of the airborne pollutants. The indoor-outdoor relationship for PM_2.5 concentrations varied in the childcare center. Indoor childcare spaces exhibited the highest Pb concentration (0.79 ± 1.31 μg/m³) in both cool and hot dry seasons in all study sites, emphasizing the need for rigorous environmental monitoring. Principal component analysis revealed distinct factors linked to specific metals, implying contributions from industrial and transportation sources particularly in the vicinity of a childcare center. Using computational fluid dynamics (CFD) modelling, the study identified the most effective window screen with 0.8 mm pore size and 0.5 mm thickness, resulting in approximately 54.16% reduction in particle concentration within the childcare center. The study highlights the critical importance of pollution control measures, particularly for vulnerable groups, and emphasizes the significance of installing window screens in childcare centers located near industrial areas to improve indoor air quality.</p>