1 Vol.:(0123456789) Scientifc Reports | (2022) 12:8972 | https://doi.org/10.1038/s41598-022-12345-8 www.nature.com/scientificreports Sources, toxicity potential, and human health risk assessment of heavy metals‑laden soil and dust of urban and suburban areas as afected by industrial and mining activities Hamed A. Al‑Swadi 1,2* , Adel R. A. Usman 1,3 , Abdullah S. Al‑Farraj 1 , Mohammad I. Al‑Wabel 1 , Munir Ahmad 1 & Abdulelah Al‑Faraj 4 Sources and levels of heavy metals (HMs) in soil and dust of urban and suburban areas in Riyadh (industrial city) and Mahad AD’Dahab (mining area) cities in Saudi Arabia were reported in this study. Additionally, the concentrations of HMs in diferent soil particle size fractions (> 250, 63–250 and < 63 µm) were reported. Pollution extent, and ecological and human health risks associated with collected soil and dust samples were explored. Contamination levels of HMs were higher in dust as compared to soil samples at all sites. The average integrated potential ecological risk in dust samples of urban area of Mahad AD’Dahab was 139, and thus characterized as a very‑high‑risk criterion. Enrichment factor (EF), correlation analyses, and principal component analysis showed that aluminum (Al), cobalt (Co), chromium (Cr), iron (Fe), manganese (Mn), nickel (Ni), titanium (Ti), and zinc (Zn) had mainly the lithogenic occurrence (EF < 2). However, Zn, copper (Cu), and lead (Pb) in Riyadh, and cadmium (Cd), Cu, Zn, and Pb in the Mahad AD’Dahab were afected by industrial and mining activities, respectively, that were of anthropogenic origins (EF > 2). The hazard index values of dust and soil (< 63 µm) samples in both urban and suburban areas in Mahad AD’Dahab were > 1, suggesting non‑carcinogenic risk. Therefore, the dust and soil samples from the mined area of Mahad AD’Dahab had a higher pollution levels, as well as ecological and human health risks than those from Riyadh. Hence, the pollution of such residential environments with HMs (especially Cd, Cu, Zn, and Pb) needs to be monitored. Interest in the characterization of urban soils and dust has increased greatly in the last two decades. Owing to the rapid growth of urban zones accompanied by increase in residential areas, streets, commercial, and industrial zones, increasing pollution levels have been recorded in urban environments 1–3 . Prompt industrialization has resulted in the contamination of terrestrial environments with various pollutants such as heavy metals (HMs). Various sources are responsible for very high concentrations of HMs in diferent environmental compartments of urban and suburban areas. Te elevated levels of HMs in soil could be either of lithogenic or anthropogenic origin 4 . Anthropogenic activities including emissions from vehicles, industrial waste, atmospheric deposition of dust and aerosols, and incinerators have introduced HMs into environments at signifcant levels 5,6 . Tus, anthropogenic activities are the main reason for HMs contamination of soil as well as airborne dust 7 . Dust storms are a natural phenomenon in desert ecosystems and their frequency have increased in some parts of the world since 1950s 8 . Te dust can be contaminated with HMs from industrial and vehicle emissions 9 . OPEN 1 Soil Science Department, College of Food and Agriculture Sciences, King Saud University, PO Box: 2460, Riyadh 11451, Saudi Arabia. 2 Department of Soil, Water and Environment, Faculty of Agriculture, Food and Environment, Sana’a University, Sana’a, Yemen. 3 Department of Soils and Water, Faculty of Agriculture, Assiut University, Assiut 71526, Egypt. 4 Agriculture Engineering Department, College of Food and Agriculture Sciences, King Saud University, Riyadh, Saudi Arabia. * email: halswadi@ksu.edu.sa