Source Analysis and Environmental Health Risk Assessment of Metals in Shallow Groundwater in the Eastern Hebei Plain

In recent years, human activities have affected the groundwater environment, posing potential risks to human health. To investigate the effects of metal elements in groundwater on human health, a total of 64 shallow groundwater samples were collected from the plain area of Tangshan City, Hebei Province. 10 metal elements, such as Fe and Mn, were detected, and their concentration characteristics were analyzed. The main sources of metal elements in the shallow groundwater area were analyzed by combining the geostatistical method and positive matrix factorization (PMF). Based on the source analysis, a health risk assessment model was applied to evaluate the health risk status of the study area. The results showed that: (1) The metal element with the highest exceedance rate in the groundwater of the study area was Mn, with a maximum content of 8.66mg/L, primarily found near the coastal plain. (2) The areas with high metal exceedance rates in shallow groundwater were primarily located in the coastal plain, and their sources can be classified into four categories. Type 1 was characterized by Fe, primarily influenced by geological environment and industrial activities. Type 2 was characterized by Mn, mainly influenced by the geological environment. Type 3 was characterized by Al, mainly influenced by industrial activities and mining. Type 4 was characterized by Zn and Cr⁶⁺, mainly influenced by industrial activities. (3) The health risk evaluation indicated that the primary concern for metallic elements in shallow groundwater was carcinogenic risk for the receptor population. The main exposure route was oral ingestion, with Cr⁶⁺ as the primary carcinogen and Mn as the main non-carcinogen. The total health risk for children was higher than for adults, with high spatial concordance between the two receptors, and higher risk areas concentrated in urban regions. To ensure the safety of the receptor population in the study area, efforts should focus on controlling Mn and Cr⁶⁺ levels in shallow groundwater.