Assessment of concentrations of heavy metals in three leafy vegetables irrigated with wastewater in Hadnet district, Mekelle, Ethiopia

Urban Farm DB summary

A study in Hadnet district, Mekelle, Ethiopia, assessed heavy metal concentrations in wastewater, spring water, and three leafy vegetables (lettuce, spinach, cauliflower). Wastewater samples from four experimental sites exceeded permissible limits for 4 out of 10 heavy metals (Cd, Cr, Cu, Mn), and spring water from a comparison site also exceeded limits for 4 metals (Al, As, Cd, Cu). Leafy vegetables grown in the least contaminated experimental site showed high concentrations for 6-7 out of 10 heavy metals, with lettuce and spinach having elevated levels of As and Al, respectively. The study concluded that the wastewater used for irrigation is not safe, the farm soils may have accumulated significant heavy metals, and the cultivated vegetables are highly contaminated, necessitating regulation of wastewater use for irrigation.