Potential exposure to metals-bound particulate during open burning of different waste materials

Smoke caused by open waste burning (OWB) contains metal-bound particulates that can harm human health. This study aimed to understand the differences in the exposure of particulate matter 10 and 2.5 µm (PM₁₀ and PM_2.5) concentrations in several distances and investigated potential health impacts of metal-bound particulates. Observations were made based on laboratory and field studies consisting of multiple open burning practices, PM capture, and inductively coupled plasma optical emission spectrometry (ICP-OES) analysis. Moreover, the potential health risks in terms of respiratory deposition dose (RDD), carcinogenic risk (CR), and non-carcinogenic risks were determined. The results showed that the exposure levels in the distance range of 1 - 5 m were not significantly different (0.419 - 0.607 mg/m³ for PM₁₀ and 0.289 - 0.399 mg/m³ for PM_2.5). During the day, RDD values were higher for adults (2.58 - 5.79 µg/min), with adults facing greater short-term exposure risk (2.45 - 5.79 µg/min) than children (2.22 - 3.90 µg/min). It was found that the highest CR from the ingestion pathway was caused by arsenic (As) from textile burning (1.41 × 10^-6), and that caused by chromium (Cr) through the inhalation pathway from backyard waste burning (7.43 × 10^-9). However, the CR values for both the pathways were below the acceptable threshold. In addition, the hazard index (HI), for both adults and children were less than 1 for all metal concentrations in all types of waste burning. The higher HI value in children indicates that they are most vulnerable to long-term exposure to OWB. Preventive actions to reduce OWB activity are necessary to reduce the adverse health effects.