Purpose Heavy metal contamination derived from smelter emissions poses significant risks to soil health. Microorganisms serve as key drivers of soil biogeochemical cycling, and understanding their responses to long-term metal accumulation warrant further investigation. This study aimed to evaluate the degree and health risks of heavy metal contamination in soils, and to assess the responses of soil microbial community structure and diversity to prolonged contaminant exposure. The findings emphasize the necessity of integrated soil remediation strategies that simultaneously address metal immobilization and soil quality restoration to mitigate health hazards. Materials and methods Surface soil samples (0–20 cm) were collected from the vicinity of a zinc smelting plant. Soil physicochemical properties were characterized, and the horizontal distributions and associated health risks of cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) were determined. Soil microbial community structure was investigated using quantitative real-time PCR (qPCR) and high-throughput sequencing. Comprehensive analyses were then conducted to elucidate the interactions between microbial communities and environmental variables. Results and discussion Concentrations of Cd, Cu, Zn, and Pb in the collected soil samples were 2.82 ~ 109.95, 35.89 ~ 125.73, 299.36 ~ 2389.86, and 53.25 ~ 341.70 mg⋅kg− 1, respectively. On average, these values were 421.30, 3.28, 20.80, and 8.72 times the background levels for Liaoning Province. Health risk assessment indicated the carcinogenic risk of Cd was within an acceptable range, whereas the non-carcinogenic risk followed the order Pb > Cd > Zn > Cu, with hazard index exceeding 1 for Cd and Pb at several sampling sites. Bacterial communities displayed consistent patterns at the phylum level despite site‑specific variations, with Actinobacteria (36.60%), Proteobacteria (23.23%), Chloroflexi (15.29%), and Acidobacteria (10.90%) being dominant. Actinobacteria exhibited overwhelming predominance across most of the samples, with relative abundances ranging from 25.74% to 53.59%. Conclusion The contaminated farmland soil presented potential human health risks and adversely affected indigenous microbial taxa. Further analysis revealed that microbial composition and diversity were influenced by a combination of heavy metals and pivotal soil properties, with pH, organic carbon and total nitrogen being particularly significant.

Contamination and microbial community composition in soil around a zinc smelting plant

期刊论文
发表日期：

2026年5月16日

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Yaqi Li,
Mingyi Shi,
Zhanhua Ji,
Meihua Lian,
Xiaoman Yu

摘要

Purpose

Heavy metal contamination derived from smelter emissions poses significant risks to soil health. Microorganisms serve as key drivers of soil biogeochemical cycling, and understanding their responses to long-term metal accumulation warrant further investigation. This study aimed to evaluate the degree and health risks of heavy metal contamination in soils, and to assess the responses of soil microbial community structure and diversity to prolonged contaminant exposure. The findings emphasize the necessity of integrated soil remediation strategies that simultaneously address metal immobilization and soil quality restoration to mitigate health hazards.

Materials and methods

Surface soil samples (0–20 cm) were collected from the vicinity of a zinc smelting plant. Soil physicochemical properties were characterized, and the horizontal distributions and associated health risks of cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) were determined. Soil microbial community structure was investigated using quantitative real-time PCR (qPCR) and high-throughput sequencing. Comprehensive analyses were then conducted to elucidate the interactions between microbial communities and environmental variables.

Results and discussion

Concentrations of Cd, Cu, Zn, and Pb in the collected soil samples were 2.82 ~ 109.95, 35.89 ~ 125.73, 299.36 ~ 2389.86, and 53.25 ~ 341.70 mg⋅kg^− 1, respectively. On average, these values were 421.30, 3.28, 20.80, and 8.72 times the background levels for Liaoning Province. Health risk assessment indicated the carcinogenic risk of Cd was within an acceptable range, whereas the non-carcinogenic risk followed the order Pb > Cd > Zn > Cu, with hazard index exceeding 1 for Cd and Pb at several sampling sites. Bacterial communities displayed consistent patterns at the phylum level despite site‑specific variations, with Actinobacteria (36.60%), Proteobacteria (23.23%), Chloroflexi (15.29%), and Acidobacteria (10.90%) being dominant. Actinobacteria exhibited overwhelming predominance across most of the samples, with relative abundances ranging from 25.74% to 53.59%.

Conclusion

The contaminated farmland soil presented potential human health risks and adversely affected indigenous microbial taxa. Further analysis revealed that microbial composition and diversity were influenced by a combination of heavy metals and pivotal soil properties, with pH, organic carbon and total nitrogen being particularly significant.