Granulometric Insights into PAH Concentrations and Health Risks: A Study of Urban Street Dust in Warsaw, Poland

The study investigated the total concentrations, toxicity, and health risks of 16 carcinogenic priority polycyclic aromatic hydrocarbons (PAHs) in street dust collected from urban areas in Warsaw, Poland. Samples were analyzed across six granulometric fractions. Dust was collected from 149 sampling points divided between Area 1 (central Warsaw districts, left bank of the Vistula River, dominated by traffic-related pollution) and Areas 2 and 3 (suburban residential areas, right bank of the river).

Street dust was assessed both as a whole (“all”) and after separation into five size fractions: (1–0.8 mm, “0.8”), (0.8–0.6 mm, “0.6”), (0.6–0.4 mm, “0.4”), (0.4–0.2 mm, “0.2”), and (below 0.2 mm, “<0.2”). The average ΣPAH concentration was 3.21 mg/kg in Area 1 and 0.89 mg/kg in Areas 2 and 3. Collectively for all areas, the ΣBaPTPE values were 318.3, 83.5, 131.1, 81.4, 164.3, and 339.7 ng/g for “all”, “0.8”, “0.6”, “0.4”, “0.2”, and “<0.2”, respectively. Notable differences in ΣBaPTPE values were observed among the fractions and areas, with the “<0.2” fraction showing the highest values: 339.7 ng/g across all areas, 318.9 ng/g in Area 1, and 531.6 ng/g in Areas 2 and 3. Coarser fractions (“0.8”, “0.6”, and “0.4”) consistently had the lowest average ΣBaPTPE values.

Cancer risk levels for children and adults were comparable for dermal contact and ingestion, ranging from 10⁻⁵ to 10⁻⁴, while risks from inhalation were significantly lower, ranging from 10⁻¹⁰ to 10⁻⁸. Thus, inhalation of resuspended street dust poses negligible risk compared to other exposure pathways.

These findings suggest a pressing need for both scientific and governmental interventions to mitigate the health risks posed by PAHs in urban street dust. Specifically, the spatial analysis of PAH concentrations revealed that areas with high-density development and traffic exhibit the greatest pollution, further emphasizing the need for targeted strategies to reduce emissions in such locations.

Future research should extend this investigation across different seasons to capture potential temporal variations in PAH concentrations due to seasonal activities and environmental conditions. Additionally, refining health risk assessments through the incorporation of locally specific exposure scenarios could provide more precise estimates of the carcinogenic and non-carcinogenic risks to Warsaw's residents. Such efforts will not only deepen our understanding of urban pollution but also inform policies aimed at safeguarding public health from the adverse effects of PAHs in street dust.

Acknowledgments

This research was funded in whole by the National Science Centre (Poland), grant number 2021/43/D/ST10/00996. This work was supported by a subsidy from the Polish Ministry of Education and Science for the Institute of Geophysics, Polish Academy of Sciences. The authors would like to thank Dominika Kwiecień, a student who participated in the field and laboratory and Klaudia Tetfejer for contributing her technical expertise and for assisting with data collection.