Metallic contamination in soils around a municipal solid waste incineration site: a case study in northeast China

An investigation of 45 soil samples collected from the surface soil around a municipal solid waste incinerator, in northeast China, was performed to understand the status of metallic contamination in the soil. Methods such as inverse distance weighting, pollution index, potential ecological risk, and statistical analysis were used to investigate metallic contamination in soils around municipal solid waste incineration sites. Both grade II and background concentrations were employed as reference standards to evaluate the levels of metallic contamination in soils. The results revealed that the metal concentrations and contamination levels were both the highest near the centre of the MSWI and decreased away from the centre of the MSWI. The source identification results demonstrated that the MSWI, natural sources and complicated sources represented the three primary sources, accounting for 59.08 %, 11.17 %, and 10.43 % of the contamination, respectively. The most heavily polluted samples were located to the south of the MSWI. When the grade II values were used as references, the metals in soils, except for Cd, Zn, and Cu in some samples, exhibited low contamination levels and ecological risks. Soils were polluted by the metals to various degrees based on the background reference values. Additionally, the potential ecological risk analysis further suggested that the study area was at considerable risk, especially for Cd pollution. These results are critical for protecting the environment in the vicinity of a MSWI and providing basic data for policy-makers to formulate viable regulations in the future.