Evaluating the pollution footprint of traffic-derived trace elements in roadside soil and the associated risks in a non-metropolitan city

A national-scale assessment of heavy metal contamination in urban road dust across China: a synthesis of data from 82 cities

Source identification and risk assessment of potentially toxic elements in surface soil of townships in the northwest Hebei region

Soil environmental quality in rural areas is not only crucial to the implementation of the rural revitalisation strategy, but also directly impacts the smooth progress of integrated urban-rural development. However, it faces an increasing risk of contamination from PTEs. Consequently, systematically identifying sources of contamination and assessing their ecological and health risks is essential to ensuring soil safety and sustainable development in rural areas. The results showed that the mean content of eight PTEs in the study area was lower than the background value of the soil environment in Hebei Province only for the elements As, Pb, Zn and Hg, and the exceeding rate of Cr, Cu, Cd and Ni was higher than 55%. APCS-MLR model identified five categories of pollution sources with the following sources and contributions: industrial pollution sources (47.1%), transportation sources (24.3%), natural sources (13.8%), agricultural sources (3.8%), and atmospheric deposition sources (11.0%). Ecological risks are mainly attributed to Cd and Hg, with high-risk areas concentrated in the central part of the study area. Probabilistic health risks indicate that adult and pediatric THI values are within the safe range at the 95% confidence interval and that 16.98% children have some significant carcinogenic risk. Source contribution to health risk indicates that industrial and transportation sources are important sources of control for cancer risk, yet elemental As are less enriched, so there is no need to pay much attention to the impact of natural sources on health risk. In conclusion, this study provides a reference for risk prevention and potential source identification of PTEs in the top soil of the township.

The Potential Heavy Metal Pollution Transfer to Surface Water and Groundwater in an Old Mining Area of Hubei, China

As a typical historical mining city, Daye, Hubei, faces potential heavy metal migration risks from legacy mining activities. This study conducted a grid-based survey in 2020, analyzing 389 soil and 137 water samples using the Nemerow Pollution Index (NPI) and spatial statistics to assess pollution and transfer mechanisms. Results show that soils were significantly contaminated (average NPI = 5.40), with 71.03% of samples exceeding the pollution threshold (NPI > 1), whereas surface water (0.18) and groundwater (0.11) maintained good quality. Despite limited direct soil migration, atmospheric wet deposition was identified as the probably dominant pathway driving higher concentrations of Cu, Cd, Pb, and As in surface water than in groundwater (e.g., on average, Cu and Cd levels in surface water were ~1.7-fold and ~5-fold those in groundwater, respectively, all well below Class III limits of national water quality standards). This study clarifies the mechanism protecting water bodies amid severe soil contamination and provides a scientific basis for integrated soil–water management in post-mining regions.

Priority control of potentially toxic elements in urban park soils through integrated source apportionment and health risk assessment

Multi-Compartment Pollution Assessment of Soil Metals and Air Pollutants in Lebanon’s Bekaa Valley: Integrating Geochemistry, Remote Sensing, and Multi-Scale Spatial Analysis

This study presents the first integrated multi-compartment assessment linking soil heavy- metal contamination and satellite-derived tropospheric air pollution in Lebanon’s Bekaa Valley. Six metals (Cd, Cr, Cu, Ni, Pb, Zn) were measured in 295 agricultural topsoils using DTPA extraction—which targets the labile, bioavailable pool most relevant to food-chain transfer in calcareous soils—and were compared with Sentinel-5P TROPOMI vertical columns of SO2, NO2 and HCHO extracted at point, 1000 m and 5000 m scales. Chromium was the dominant element, and composite pollution indices indicated overall good but transitional soil quality, with a majority of sites at warning level. Principal component analysis, spatial autocorrelation and land-use analysis converged on three plausible source groupings—predominantly geogenic (Cr, Ni), localized anthropogenic (Cd, Pb) and agricultural (Cu)—although, in the absence of isotopic or other direct source tracing, these assignments remain indicative rather than confirmed. Soil metals and atmospheric columns were largely uncorrelated (|r| < 0.3 for 17 of 18 pairs); this decoupling is consistent with the contrasting temporal integration and spatial support of the two compartments rather than with a single shared pathway. Multi-scale analysis supported a parsimonious dual-scale (point + 5000 m) sampling framework. The study offers a transferable assessment framework for other Mediterranean regions and underscores the need for locally calibrated, total-metal soil background values. Because these indices and threshold comparisons are computed from DTPA-extractable concentrations, they serve here as one-directional, bioavailability-based screening tools rather than regulatory determinations: an exceedance conservatively flags a site for confirmatory total-metal analysis, whereas a non-exceedance does not establish compliance.

Source apportionment and human health risk assessment of toxic trace elements in urban road dust