Pace of heavy metal pollution in the anthropogenically altered and industrialized Nakdong River Estuary, South Korea: Implications for the Anthropocene.

Estuaries, vital coastal ecosystems, face growing threats from industrialization. To understand the pace of sedimentary changes and heavy metal pollution at the anthropogenically altered and industrialized Nakdong River Estuary in South Korea, we used sediment coring to reconstruct environmental change. Estuarine dam construction in 1934 shifted the sedimentary system from sand to mud, coinciding with a post-1930s mercury increase due to coal burning. Mercury concentrations in other South Korean regions surged in the 1970s, indicating proximity to emission sources matters. However, most heavy metal levels (Cu, Cd, Zn, Ag) sharply rose in the 1960s and 1970s with regional industrialization. Modern heavy metal concentrations doubled pre-industrial levels, underscoring human activities as the primary driver of Nakdong Estuary environmental changes. This emphasizes the need for a balanced approach to development and environmental preservation.

Compound- and element-specific accumulation characteristics of persistent toxic substances and metals in sediments of the Yellow Sea.

This study investigated the large-scale distributions of persistent toxic substances (PTSs) and heavy metals in sediments of the Yellow Sea, collected from six transects between latitudes 32 and 37 degrees north (n = 35). Elevated concentrations of polychlorinated biphenyls (PCBs) were detected near the mainland, with a predominance of low-chlorinated congeners (di to tetra, ∼60%), indicative of atmospheric deposition. Analysis of traditional and emerging polycyclic aromatic hydrocarbons (t-PAHs and e-PAHs) revealed notable enrichment in the Central Yellow Sea Mud Zone (CYSM), attributing fossil fuel combustion as the significant source. Styrene oligomers and alkylphenols exhibited notable accumulation near the Han River Estuary in South Korea and the Yangtze River Estuary in China, respectively. The accumulation of heavy metals was predominantly observed in the CYSM, with element-specific distribution patterns. Cluster analysis revealed distinct distribution patterns for PTSs and metals, highlighting their source-dependent and grain size-dependent behaviors. In addition, the distribution and accumulation of PTSs tended to depend on their partitioning coefficients, such as the octanol-air partition coefficient (log KOA) and octanol-water partition coefficient (log KOW). This study offers valuable insights into the sources, transport, and fate of hazardous substances in the Yellow Sea, emphasizing the necessity for targeted environmental management strategies.

Spatiotemporal and multi-isotope assessment of metal sedimentation in the Great Lakes.

This study investigates spatiotemporal dynamics in metal sedimentation in the North American Great Lakes and their underlying biogeochemical controls. Bulk geochemical and isotope analyses of n = 72 surface and core sediment samples show that metal (Cu, Zn, Pb) concentrations and their isotopic compositions vary spatially across oligotrophic to mesotrophic settings, with intra-lake heterogeneity being similar or higher than inter-lake (basin-scale) variability. Concentrations of Cu, Zn, and Pb in sediments from Lake Huron and Lake Erie vary from 5 to 73 mg/kg, 18-580 mg/kg, and 5-168 mg/kg, respectively, but metal enrichment factors were small (<2) across the surface- and core sediments. The isotopic signatures of surface sediment Cu (δ65Cu between -1.19‰ and +0.96‰), Zn (δ66Zn between -0.09‰ and +0.41‰) and Pb (206/207Pb from 1.200 to 1.263) indicate predominantly lithogenic metal sourcing. In addition, temporal trends in sediment cores from Lake Huron and Lake Erie show uniform metal concentrations, minor enrichment, and Zn and Pb isotopic signatures suggestive of negligible in-lake biogeochemical fractionation. In contrast, Cu isotopic signatures and correlation to chlorophyll and macronutrient levels suggest more differentiation from source variability and/or redox-dependent fractionation, likely related to biological scavenging. Our results are used to derive baseline metal sedimentation fluxes and will help optimize water quality management and strategies for reducing metal loads and enrichment in the Great Lakes and beyond.

Seasonal and multi-decadal zinc isotope variations in blue mussels from two sites with contrasting zinc contamination levels.

Zinc (Zn) isotope compositions in soft mussel tissues help identify internal biological processes and track coastal Zn sources in coastal environments, thus aiding in managing marine metal pollution. This study investigated the seasonal and multi-decadal Zn isotope compositions of blue mussels (genus Mytilus) from two French coastal sites with contrasting Zn environmental contamination. Concurrently, we characterized the isotope ratios of sediments and plankton samples at each site to understand the associations between organisms and abiotic compartments. Our primary objective was to determine whether these isotope compositions trace long-term anthropogenic emission patterns or if they reflect short-term biological processes. The multi-decadal isotope profiles of mussels in the Loire Estuary and Toulon Bay showed no isotope variations, implying the enduring stability of the relative contributions of natural and anthropogenic Zn sources over time. At seasonal scales, Zn isotope ratios were also constant; hence, isotope effects related to spawning and body growth were not discernible. The multi-compartmental analysis between the sites revealed that Toulon Bay exhibits a remarkably lower Zn isotope ratio across all studied matrices, suggesting the upward transfer of anthropogenic Zn in the food web. In contrast, the Zn isotope variability observed for sediments and organisms from the Loire Estuary fell within the natural baseline of this element. In both sites, adsorptive geogenic material carrying significant amounts of Zn masks the biological isotope signature of plankton, making it difficult to determine whether the Zn isotope ratio in mussels solely reflects the planktonic diet or if it is further modified by biological homeostasis. In summary, Zn isotope ratios in mussels offer promising avenues for delineating source-specific isotope signatures, contingent upon a comprehensive understanding of the isotope fractionation processes associated with the trophic transfer of this element through the plankton.

Copper and lead isotope records from an electroplating activity in sediments and biota from Sepetiba Bay (southeastern Brazil).

An old electroplating plant in Sepetiba Bay discharged metal-enriched wastes into the surrounding mangroves for 30 years (from the 1960s to 1990s), resulting in a hotspot zone of legacy sediments highly concentrated in toxic trace metals. This study applies Cu and Pb isotope systems to investigate the contributions of past punctual sources relative to emerging modern diffuse sources. The electroplating activity imprinted particular isotopic signatures (average δ65CuSRM-976: 0.4 ‰ and 206Pb/207Pb: 1.14) distinct from the natural baseline and urban fluvial sediments. The isotopic compositions of tidal flat sediments show intermediate isotope compositions reflecting the mixing of Cu and Pb from the hotspot zone and terrigenous materials carried by rivers. Oyster isotope fingerprints match legacy sediments, attesting that anthropogenic Cu and Pb are bioavailable to the biota. These findings confirm the interest in combining two or more metal isotope systems to discriminate between modern and past metal source emissions in coastal environments.

Isotopic (Cu, Zn, and Pb) and elemental fingerprints of antifouling paints and their potential use for environmental forensic investigations.

Antifouling paints (APs) are one of the important sources of Cu and Zn contamination in coastal environments. This study applied for the first-time a multi-isotope (Cu, Zn, and Pb) and multi-elemental characterization of different AP brands to improve their tracking in marine environments. The Cu and Zn contents of APs were shown to be remarkably high ∼35% and ∼8%, respectively. The δ65CuAE647, δ66ZnIRMM3702, and 206Pb/207Pb of the APs differed depending on the manufacturers and color (-0.16 to +0.36‰, -0.34 to +0.03‰, and 1.1158 to 1.2140, respectively). A PCA analysis indicates that APs, tires, and brake pads have also distinct elemental fingerprints. Combining isotopic and elemental ratios (e.g., Zn/Cu) allows to distinguish the environmental samples. Nevertheless, a first attempt to apply this approach in highly urbanized harbor areas demonstrates difficulties in source apportionments, because the sediment was chemically and isotopically homogeneous. The similarity of isotope ranges between the harbor and non-exhaust traffic emission sources suggests that most metals are highly affected by urban runoff, and that APs are not the main contributors of these metals. It is suspected that AP-borne contamination should be punctual rather than dispersed, because of APs low solubility properties. Nevertheless, this study shows that the common coastal anthropogenic sources display different elemental and isotopic fingerprints, hence the potential for isotope source tracking applications in marine environments. Further study cases, combined with laboratory experiments to investigate isotope fractionation during releasing the metal sources are necessary to improve non-traditional isotope applications in environmental forensics.

Characteristics of metal pollution and multi-isotopic signatures for C, Cu, Zn, and Pb in coastal sediments from special management areas in Korea.

The concentrations and isotopic compositions of carbon (C), copper (Cu), zinc (Zn), and lead (Pb) in coastal sediments were analyzed to identify potential pollution sources. High concentrations of total organic carbon (TOC) and metals were found close to cities and industrial areas. The isotopic compositions of C, Cu, Zn, and Pb tended to decrease as their concentrations increased. Bi-plots between δ65Cu and δ66Zn showed that the isotopic compositions in most coastal sediments, except sediments around a smelter, were similar to the isotopic compositions of road dust in urban and industrial areas of Korea. Our results suggest that heavy metal pollution in coastal sediments is greatly influenced by the pollution source, such that most metals originate from traffic and industrial activities in the urban environment. This analysis of multiple isotopes provides insights concerning the transport mechanisms and clarifies potential sources of metal contamination in coastal environments.

Pollution and ecological risk assessments for heavy metals in coastal, river, and road-deposited sediments from Apia City in Upolu Island, Samoa.

This study was the first to investigate the pollution and ecological risks of heavy metals in coastal, river/stream and road-deposited sediments (RDS) from Apia in Samoa. Cr and Ni concentrations in sediment samples were higher than those of other metals. River sediments and RDS had relatively high EF values around the intensive commercial areas, with a moderate to significant enrichment of Cu, Zn, Cd, and Pb. The results indicate that Cr and Ni have a natural origin from volcanic parent materials, while Cu, Zn, Cd, and Pb originated from anthropogenic activities, such as traffic emissions and the discharge of municipal wastewater. The assessments of pollution and ecological risk revealed that coastal sediments adjacent to the river are anthropogenically contaminated and present a moderate ecological risk. This study demonstrates that metals that have accumulated in the urban impermeable layer and river/stream bed have flowed into the coastal environment through runoff.

Pollution and Health Risk Assessments of Potentially Toxic Elements in the Fine-Grained Particles (10−63 µm and <10 µm) in Road Dust from Apia City, Samoa

Fine road dust is a major source of potentially toxic elements (PTEs) pollution in urban environments, which adversely affects the atmospheric environment and public health. Two different sizes (10−63 and <10 µm) were separated from road dust collected from Apia City, Samoa, and 10 PTEs were analyzed using inductively coupled plasma mass spectrometry (ICP-MS). Fine road dust (<10 µm) had 1.2−2.3 times higher levels of copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd), antimony (Sb), lead (Pb), and mercury (Hg) than 10−63 µm particles. The enrichment factor (EF) value of Sb was the highest among PTEs, and reflected significant contamination. Cu, Zn, and Pb in road dust were also present at moderate to significant levels. Chromium (Cr), cobalt (Co), and nickel (Ni) in road dust were mainly of natural origins, while Cu, Zn, Sb, and Pb were due to traffic activity. The levels of PTEs in road dust in Samoa are lower than in highly urbanized cities, and the exposure of residents in Samoa to PTEs in road dust does not pose a noncarcinogenic health risk. Further studies of the effects of PTEs contamination in road dust on the atmosphere and living organisms are needed.

Source apportionment and health risk assessment for potentially toxic elements in size-fractionated road dust in Busan Metropolitan City, Korea.

Potentially toxic elements' (PTEs; V, Cr, Co, Ni, Cu, Zn, As, Cd, Sb, Pb, and Hg) pollution level was investigated in size-fractionated road dust in Busan Metropolitan City. Health risks to humans (adult and children) were also evaluated in fine particle fraction (< 63 µm) of road dust. PTE concentrations in the fine particles (< 63 µm) were ranked as follows (unit: mg/kg): Zn (2511) > Cu (559) > Cr (531) > Pb (385) > Ni (139) > V (83.8) > Sb (31.6) > Co (21.6) > As (17.2) > Cd (4.1) > Hg (0.38). The PTE concentrations in fine particles (< 63 µm) were significantly higher than those in coarse particles except for V, Co, and As. The mean PTE loadings of fine particle fraction (< 63 µm; 233 mg/m2) in road dust were up to 4.5 times higher than other particle fractions. Igeo values of Sb were higher than 5 except for > 1000-µm fraction, indicating extremely polluted status. PCA results and elemental ratios indicated that most of the PTEs in road dust were derived from non-exhaust traffic-related sources such as brake pads and tires. Cr, Pb, and Sb had higher HI values than other metals for both adults and children. Sampling sites of heavy traffic and industrial areas showed that the carcinogenic risk exceeded the maximum threshold level (10 - 4). Especially in children, the mean carcinogenic risk (ingestion pathway) of As (6.8 × 10 - 4) Cd (2.0 × 10 - 4), and Ni (4.1 × 10 - 4) exceeded the maximum threshold level, indicating that continuous exposure to road dust may pose a high cancer risk to children. Therefore, continuous monitoring and management of these metals are needed to protect human health and the urban environment.

Seagrass and green macroalgae Halimeda as biomonitoring tools for metal contamination in Chuuk, Micronesia: Pollution assessment and bioaccumulation.

In this study, we evaluated metal accumulation in different species and tissues of seagrasses and green macroalgae Halimeda and assessed metal pollution levels in Chuuk, Micronesia. In seagrass, the concentrations of Ni, Cu, Zn, Cd, Pb, and Hg were higher in leaves than in roots, whereas Cr and As concentrations were higher in roots. Halimeda had higher concentrations of Ni than of the other metals, and the mean Ni concentration was approximately 2.1 times higher in Halimeda than in seagrass leaves. The concentrations of Cr, As, Cu, Pb, and Hg in Halimeda were similar to those in seagrasses, whereas the Zn and Cd concentrations in Halimeda were very low. Significant correlations in metal concentrations between sediment and both seagrasses and Halimeda were observed for Cr, Ni, Cu, Zn, and Pb. This study suggests that seagrasses and Halimeda are useful indicators for monitoring metal pollution in coastal environments.

Effects of particulate matter (PM2.5) on life history traits, oxidative stress, and defensome system in the marine copepod Tigriopus japonicus.

Particulate matter (PM2.5) generated in large cities creates new problems in marine ecosystems and may adversely affect its inhabitants. However, the mechanisms underlying the same remain unclear; hence, we investigated the effects of PM2.5 on life history traits (e.g., mortality, development, and fecundity), cellular reactive oxygen species (ROS) levels, antioxidant enzyme (e.g., glutathione peroxidase [GPx], superoxide dismutase [SOD], and catalase [CAT]) activities, and the transcript levels of detoxification-related genes (cytochrome P450s [CYPs]) and antioxidant (glutathione S-transferases [GSTs]) in the copepod Tigriopus japonicus. Among the life history traits, developmental time was the only trait to significantly deviate (P < 0.05) in response to PM2.5 (compared to that in the controls). Significant changes in ROS levels and antioxidant enzymatic activities (P < 0.05) in response to PM2.5, suggested that PM2.5 can induce oxidative stress, leading to adverse effects on the T. japonicus life history. In addition, PM2.5 induced a differential regulation of various CYP and GST genes, particularly CYP307E1, GST-kappa, and GST-sigma were significantly upregulated (P < 0.05), suggesting that these genes likely play crucial roles in detoxification mechanisms and could be useful as reliable biomarkers for PM2.5 toxicity. Overall, the results of this study provide new insights into the potential toxicity of PM2.5.

Characteristics of potentially toxic elements and multi-isotope signatures (Cu, Zn, Pb) in non-exhaust traffic emission sources.

Non-exhaust emissions (e.g., particles from brake pads, asphalt, curb, road paint, tire) are important sources of potentially toxic elements (PTEs) pollution in urban environments and are potential causes of PTEs pollution in road dust. We present the PTEs concentrations (Cr, Ni, Cu, Zn, As, Cd, Sn, Sb, Pb) of non-exhaust emission sources and pollution degree of PTEs. Isotopic signatures of Cu, Zn, and Pb were also analyzed to distinguish these sources. Among PTEs, the Cu concentration in all brake pads was significantly high and brake pads from Korea showed remarkably high Sb concentrations. Asphalt had a higher Pb concentration than other non-exhaust emission sources. Mean of δ65CuAE647, δ66ZnIRMM3702, and 206Pb/207Pb values of non-exhaust emission sources in this study ranged from -0.49‰ to +0.19‰, -0.24‰ to +0.16‰, and 1.1535 to 1.4471, respectively. Non-exhaust emission sources could be discriminated by plotting the concentration and isotopic composition of Cu. Cu isotopic compositions (δ65CuAE647) were clearly distinguished between brake pads including domestic and imported products and tires. Zn isotope values (δ66ZnIRMM3702) of brake pads, tires, and asphalt overlapped, but discriminated from road paint and curb. Our results indicate that the combination of Cu and Zn isotopic signatures can distinguish various non-exhaust traffic emissions, especially brake pads and tires.

Changes in the characteristics of organic matter associated with hydrodynamics and phytoplankton size structure in the central-eastern Yellow Sea.

The central-eastern Yellow Sea is an important region for transporting organic matter (OM) to the Pacific Ocean, however, there is limited information available regarding the characteristics and sources of OM in this area. The present study investigated the concentrations and stable isotopic compositions of carbon (δ13C) and nitrogen (δ15N) for particulate matter and sediment in the central-eastern Yellow Sea during April 2019. The physicochemical properties (i.e., salinity, temperature, fluorescence, and nutrients), size-fractionated phytoplankton biomass (Chl-a), and concentration and fluorescence characteristics of dissolved organic matter (DOM) were also determined. The satellite SST and Chl-a data indicated that mixing cold and warm water masses were observed. Phytoplankton blooms occurred a few days before our sampling campaign. Considering the high concentration of suspended solids in the bottom layer, resuspended sediment caused by tidal currents could be a major source of OM in coastal areas. The δ13C values of particulate organic matter (POM) in the coastal area were higher (-23 to -22‰) than those of OM from terrestrial sources (approximately -28 to -27‰). Instead, the lowest δ13C values were observed in the central part of our study area, where the relative abundance of picophytoplankton was high. These results indicated that phytoplankton-derived OM after phytoplankton spring blooms in the coastal area could be the primary source of OM rather than terrestrial origins. In addition, the source of OM that presented low δ13C values could be picophytoplankton-derived OM. The characteristics of DOM were related to biological processes (mediated by phytoplankton and bacteria) and resuspension of sedimentary organic matter. We did not detect an influx of large amounts of terrestrial OM in coastal sediments. Overall, the source and characteristics of OM appeared to be influenced by the hydrodynamics and the distribution properties of lower trophic-level organisms in the central-eastern Yellow Sea during the spring season.

A nationwide survey of trace metals and Zn isotopic signatures in mussels (Mytilus edulis) and oysters (Crassostrea gigas) from the coast of South Korea.

Thirteen trace metals and Zn isotopic signatures were investigated in mussels and oysters collected from the coast of South Korea to evaluate their bioavailability in bivalve mollusks. The average Cu, Zn, and Cd concentrations were 2.6-17.7 times higher in oysters than mussels, and high biota sediment accumulation factors (>30) were observed for these metals in oysters. Except for Pb in mussels, most metals had no correlation with total sediment concentrations. In oysters, Fe, V, Cu, Zn, Sn, and Pb concentrations were significantly correlated with sediments. The average values of δ66ZnIRMM3702 in mussels, oyster, and sediments were +0.09‰, +0.12‰, and -0.06‰, respectively. Soft tissues of mussels and oysters with high Zn concentrations tended to contain lighter Zn isotopes. The results indicate that oysters are a better biomonitoring organism for metal contamination than mussels and can be used in the monitoring and management of coastal environments and ecosystems.

Potentially toxic elements pollution in road deposited sediments around the active smelting industry of Korea.

Potentially toxic elements (PTEs) were investigated in the different sizes of road deposited sediments (RDS) around the active smelting industry to understand their sources and to assess the pollution and ecological risk levels. The highest PTEs concentrations was shown near the raw materials import port and the smelting facilities. The fine particles of RDS showed extremely high PTEs concentrations. Zn has the highest mean concentration in the < 63 µm particle size of RDS, followed by Pb > Cu > As > Cr > Ni > Cd > Hg. The PTEs concentrations of this study were the highest values compared to the soils around the smelter and the RDS in urban and industrial areas in the world. This indicates that these PTEs pollution in RDS were mainly attributed to the transportation of raw materials for the smelting industry. According to nemerow pollution index calculation, RDS at all sampling sites with particles of less than 250 mm was seriously polluted with PTEs. The ecological risk was also found to be very high in all RDS fractions and highly toxic elements such as Cd, Pb and Hg pose extremely risk. Given the total amounts PTEs in the road surface, it is necessary to apply RDS removal management plan to reduce the PTEs pollution.

Heavy metal pollution assessment in coastal sediments and bioaccumulation on seagrass (Enhalus acoroides) of Palau.

Heavy metals in coastal sediments and seagrass (Enhalus acoroides) were studied to assess the pollution level and to understand the bioaccumulation of metals on different organs. The mean of metal concentrations in sediments were in the following order: Cr > Ni > As>Zn > Cu > Co > Pb > Cd > Hg. The results of principal component analysis indicate that Cr, Ni, Cu, Zn, As and Hg are derived from natural sources but Cd and Pb seems to be of anthropogenic sources. Cr, Ni, Cu, Zn, Cd and Pb in the coastal sediments were at low ecological risk level. As and Hg presented the highest ecological risk among all metals. The mean concentrations of Cr, Ni, Cu, Zn, Cd, and Hg were higher in leaves of E. acoroides than in roots. Significant correlations (p < 0.05) for Cr, Ni, Cu, Zn, and Pb in between sediments and in E. acoroides both leaves and roots. High bioconcentration factor (BCF) were calculated for Zn, Cd, and Hg.

Source identification and implications of heavy metals in urban roads for the coastal pollution in a beach town, Busan, Korea.

Heavy metals in the sediments of urban roads (RDS), storm drains (SDS), and marine areas (MS) were investigated to assess road pollution in a beach town adjacent to the coast in Busan and identify their relationships with the marine environment. RDS were considerably polluted with Zn, Cu, Cr, and Pb, with mean concentrations of 1090, 178, 171, and 199 mg/kg, respectively. MS were severely contaminated with Zn and Cu, exceeding the effects range median (ERM; Cu = 270, Zn = 410 mg/kg). PCA and HCA identified tire and brake wear in RDS as the major sources of Zn, Pb, Cu, and Cd, and that high levels of Zn, Cu, and Pb in RDS originating from traffic activities contaminated MS through the urban storm drain system. The results suggested that traffic-originated metals in RDS are potential pollutants in coastal environments, and further studies on their fate and management should be conducted.

Characterization of the contribution of road deposited sediments to the contamination of the close marine environment with trace metals: Case of the port city of Busan (South Korea).

We examined the concentrations of 12 trace metals in road-deposited sediments (RDS) and their contributions to the pollution of harbor/marine sediments in the port city of Busan, South Korea. The concentrations of Cr, Cu, Zn, Cd, Sn, Sb, and Pb in RDS affected by industrial and traffic activities were 6.7-25.7 times higher than those in marine sediments. The enrichment factors indicate that RDS are extremely polluted with Sb and moderately to strongly polluted with Cr, Cu, As, Sn, Pb, Zn, and Cd. The mean modified pollution index distinguished between unpolluted marine sediments, moderately to heavily polluted harbor sediments, and severely polluted RDS. Furthermore, harbor/marine sediments close to shipyards and the mouths of streams and rivers were found to be moderately polluted with Cu, Zn, Cd, Sb, and Pb. RDS containing trace metals accumulate on impervious surfaces and flow into the marine environment via untreated stormwater runoff.

Heavy metal pollution by road-deposited sediments and its contribution to total suspended solids in rainfall runoff from intensive industrial areas.

Understanding the relationship between road-deposited sediments (RDS) and total suspended solids (TSS) is essential for managing non-point pollution. Studying the heavy metal concentrations of RDS and TSS in rainfall is important to the development of RDS management strategies and to the design of effective stormwater management practices. We investigated the heavy metal (V, Cr, Mn, Co, Ni, Cu, Zn, As, Mo, Cd, Sn, Pb) in RDS and TSS in rainfall runoff to assess the metal pollution level and to evaluate the contribution of RDS heavy metal pollution in the TSS. The heavy metal pollution in RDS and TSS in industrial areas was relatively higher in small particles (<125 µm), while TSS had a higher heavy metal concentration than RDS. In addition, the concentration of heavy metals in TSS increased rapidly during the initial rainfall. The amount of particles larger than 125 µm also increased, suggesting that large metal particles accumulated in industrial areas were also discharged in the form of non-point pollution. The amount of RDS per unit of industrial area (g/m2) and the accumulation of heavy metals (Pb, Cu, and Zn) (mg/m2) were 15- and 8-54-fold higher than those of urban areas, respectively. Considering particles <125 µm, which can be easily transported or discharged during rainfall, the contribution rate of RDS to TSS was 41.3%, but the average contribution rate to heavy metals in TSS was 22.1%. The average load of heavy metals from industrial areas in TSS was 77.9%. The load of Cu, Ni, As, Cd, and Sn exceeded 90%, indicating that most of these metals were attributed to industrial activities related to metal processing. Our results suggest the importance of efficient road cleaning and rainfall runoff management strategies to solve the heavy metal pollution problem caused by non-point sources in industrial areas.