Heavy Metals Contamination of Agricultural Land and Their Impact on Food Safety

Aims: The aim of this study is to investigate the heavy metals pollution status and health risks assessment of the vegetables grown at Danbatta irrigation lands.

Study Design: The research involved the collection of soil, water and cultivated vegetable from irrigation lands as well as analyzing their heavy metals pollution status.

Place and Duration of Study: Samples were collected from Danbatta irrigation lands of Kano state, Nigeria. The research study covered a period of one year.

Methodology: This study investigates the prevalence of heavy metals pollution and related health risks associated with the vegetables grown at Danbatta local government of Kano state. This was achieved by collecting irrigation soil, water and vegetables (onion, spinach and lettuce) from the irrigation sites, which were subsequently assayed for several heavy metals such as; Pb, Mn, Cu, Fe, Zn and Co using atomic absorption spectrophotometry (AAS).

Results: The results obtained show that the concentrations of Pb, Cu and Zn in water samples to be 0.033, 0.8, and 0.89 mg/ml, respectively, while Mn and Co were not detected. Even though concentrations of these metals in water are within FAO/WHO limits, the soil was found to be contaminated with Cu (12.17 mg/kg), Fe (152.29 mg/kg) and Zn (55.75 mg/kg). Furthermore, both spinach, lettuce and onion were contaminated with Pb, and Mn. However, only lettuce and spinach were contaminated with Cu, Fe and Zn. Health risk assessment of both adults and children show that Pb, Mn, Co and Cu, posed a significant health risk to the population as their health risk index (HRI) is greater than one. The result shows that poor agricultural practices could be responsible for contaminating the soil with heavy metals, which eventually gets accumulated in the edible parts of the plants and posed a great risk to its consumers. Impacts of heavy metals pollution is on the rise across the globe. As such, it becomes necessary to monitor our environment to checkmate the threat of these contaminants and implement a reliable strategy and stable treatment of the pollution to ensure food safety.