Heavy Metal Accumulation in Agricultural Soils: Environmental Risk Assessment and Remediation Strategies

Abstract

Heavy metal enrichment in agricultural soils raises severe environmental as well as health issues, especially where there is industrial activity alongside intensive agriculture. This study assessed the level of heavy metal contamination in five agricultural soil samples from Ludhiana District, Punjab, India. Cadmium (Cd), lead (Pb), arsenic (As), chromium (Cr), nickel (Ni), copper (Cu), and zinc (Zn) in soil samples were analyzed by inductively coupled plasma mass spectrometry (ICP-MS). Levels of pollution were measured in terms of contamination factor (CF), enrichment factor (EF), geo-accumulation index (I_geo), and ecological risk index (RI). The risks to human health were estimated using United States Environmental Protection Agency (USEPA) models based on ingestion, dermal contact, and inhalation exposure routes. The contents of Cd (1.2–3.4 mg/kg) and Pb (45.7–112.3 mg/kg) were higher than the WHO/FAO permissible limits in 60% of the sites. RI values were maximum at Sahnewal (355) and Doraha (312), showing significant ecological risk, with cadmium accounting for about 70% of the cumulative RI. High EF values for Cd, Pb, and Zn validated severe anthropogenic impact, mainly from industrial effluent and agrochemical application. Non-carcinogenic health risk assessment showed that children were exposed to greater non-carcinogenic risks (HI > 1), especially in the vicinity of industrial areas. Multivariate statistical analysis ascribed heavy metals to both industrial pollution and overuse of fertilizers and pesticides. Results confirm the immediate requirement for site-specific treatments like phytoremediation and organic amendments combined with regulatory actions for controlling pollution sources, maintaining soil health, and food safety.