Assessment of health risks of PAHs from rural cooking emissions: Neighborhood diffusion and the impact of village settlement characteristics

Abstract

Solid fuel cooking in rural areas has led to substantial emissions of air pollutants, notably polycyclic aromatic hydrocarbons (PAHs), especially in developing countries such as China. The potential health risks associated with outdoor exposure of residents to PAHs from fugitive cooking exhaust within rural settlements also merit consideration. Consequently, this study employs computational fluid dynamics (CFD) techniques to evaluate the neighborhood diffusion of benzo[a]pyrene (B[a]P), a carcinogenic PAH congener, in a cluster shape rural settlement. Subsequently, the health risks associated with outdoor exposure to neighborhood-diffused PAHs were quantified using the incremental lifetime cancer risk (ILCR) for the susceptible population. The simulations encompass four settlement characteristics, including the angle between approaching wind and streets (θ), street width (SW), slit distance (SD), and building arrangement, to analyze their influence on the neighborhood diffusion of PAHs. The results demonstrate that the highest ILCR resulting from outdoor PAHs exposure within the main activity areas of neighboring buildings exceeds the United States Environmental Protection Agency (USEPA)'s limit of 1×10−6 across all simulated cases. Additionally, settlement characteristics significantly affect the neighborhood diffusion of cooking-generated B[a]P. Smaller θ and staggered arrangement lead to a reduction in the affected area by B[a]P, but result in higher concentrations and ILCR near the source building. Meanwhile, wider street width proves to be an effective strategy for reducing concentrations and ILCR for both neighboring buildings and entire settlement. These findings offer valuable insights for policymakers and urban planners to develop environmentally sustainable rural communities that minimize health risks associated with cooking activities.