Human Health Risk Assessment and Early Warning of Heavy Metal Pollution in Soil of a Coal Chemical Plant in Northwest China

ABSTRACT

In this paper, 153 samples of heavy metals in the soil of a coal chemical plant in Northwest China were collected in the study area to predict and evaluate the human health risks of arsenic (As), cadmium (Cd), chromium (Cr(VI)), lead (Pb), and mercury (Hg) in the soil of the plant area in 2021, 2026, and 2031 and their change laws by referring to the “Soil Environmental Capacity Model,” “Technical Guidelines for Risk Assessment of Contaminated Sites” and USEPA recommended model. In addition, Kriging interpolation method is introduced to generate the plant risk assessment map from the risk assessment of limited points. The assessment study showed: the carcinogenic risks of As, Cr(VI), and Cd will all exceed the acceptable risk limit of 1.00E-06 at the year of 2021, and their average risk level will reach 2.300E-05, 4.878E-06, and 7.455E-05, respectively, at the year of 2031; the non-carcinogenic risk of As has already exceeded the acceptable risk limit of 1.0, while the hazard quotients of Cr(VI), Cd, Pb, and Hg are within the limit; the plant area should focus on the harm of the accumulation of As and Cd to the human body, and prevent the pollution of groundwater by Cr (VI); the health risk map shows that the Power Unit and its downwind direction (open space in southeast area) are the core high-risk areas of the entire plant, including the Logistics Exits and Coal Transportation Corridor. The highest carcinogenic risk value of the core area in 2031 is 8.572E-05, which is caused by Cr (VI); the oral intake is the main exposure pathway of the heavy metal pollution. Personnel working in Power Units, Logistic Exits, Coal Transportation Corridors and nearby vehicle corridors should wear specialized protective clothing and masks to reduce or block potential health risks. No doubt the clarification made in this research on the change rule and risk distribution of heavy metals can provide a scientific basis of theoretical reference for the prevention and protection of heavy metals in soil of the coal chemical plant.

KEYWORDS:

• Heavy metal pollution in soil
• human health risk assessment
• prediction and early-warning
• kriging

Acknowledgments

This work was co-supported by the Yue Qi Young Scholar Project, China University of Mining & Technology, Beijing and National Key Research and Development Program of China (2018YFC0406404) and the Fundamental Research Funds for the Central Universities (2018QH03)

Additional information

Funding

This work was supported by the National Key Research and Development Program of China [2018YFC0406404]; the Yue Qi Young Scholar Project, China University of Mining & Technology, Beijing [2019QN08]; the Fundamental Research Funds for the Central Universities [2018QH03].