The contamination characteristics and health risk of barium (Ba), cobalt (Co), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), vanadium (V), zinc (Zn), arsenic (As), mercury (Hg), and cadmium (Cd) in samples of dust gathered from squares and parks of Baotou city, an industrial city situated in a semi-arid location of the northwest China were investigated. The contents of Ba, Co, Cr, Cu, Mn, Ni, V, Pb, and Zn in the collected dust samples were determined using X-ray fluorescence spectrometry, while the contents of As and Hg in the dust were investigated by use of the ICP-MS. Further, cadmium was quantified through the atomic absorption spectrometry. Levels of contamination of heavy metals analyzed in the dust samples were evaluated using the Geo-Accumulation index (I_geo) as well as through a Pollution Load Index (PLI). Their health risks to children and adults were evaluated based on the US EPA model of health risk. The findings portrayed that the mean concentrations of Ba, Co Cr, Cu, Pb, V, Cd, and Hg were elevated as compared with their local soil background values. Mean values of I_geo illustrate the order of Co > Cr> Cd > Hg > Pb > Cu > Ba > V > Ni > Mn > Zn > As. It was evident that dusts from the parks and squares were “unpolluted” to “moderately polluted”. Assessment of health risk depicts that ingestion is the foremost route of exposure in regard to the heavy metals, then the dermal adsorption follows. Hg exposure from dust might also set impending health threats to children. Besides, the cancer risks of Co, Cr, Ni, Cd, and As are considered to be within the presently tolerable range.

During the first two decades of the 21st century, the level of polycyclic aromatic hydrocarbon (PAH) pollution in urban atmospheric particulate matter (PM) in China significantly increased. By combining data from more than 6,695 individual samples covering 89 typical cities (population > 0.5 million people) across China, this study focuses on evaluating the health risks to urban residents and the ecological risks to the surrounding environment from PAHs in PM using the methods of the United States Environmental Protection Agency and sediment quality standards. The PAH contents and contamination levels in Central China (CC) were lower than those in South China (SC) and North China (NC). NC exhibited the most severe PAH pollution and greatest ecological risk, while CC had the highest population density and gross domestic product. The incremental lifetime cancer risk and hazard index values for people in NC were greater than those for people in CC and SC, and the health risk increased with increasing latitude. Based on ecological risk criteria and standard assessment methods, PAHs in PM in China pose a potential ecological risk, and the risk of harmful biological effects follows the order of NC > CC > SC. Given the significant risks of PAHs to people, animals and plants at both the national and global scales, under the guidance of the One Health concept of the World Health Organization, it is necessary to comprehensively manage PAHs in PM and reduce their threats to humans and ecosystems.