Heavy metals toxicity in spinach (Spinacia oleracea) irrigated with sanitary wastewater in rural areas

Abstract

Heavy metal contamination harms soil and plant growth, making it a serious global environmental issue. Due to the scarcity of canal water, people have become more reliant on groundwater, but aquifers are expensive and of poor quality. Therefore, wastewater has become one of the essential sources of irrigation in developing countries and rural areas. In rural areas, sanitary, sewage, and municipal wastewater are the most common sources of irrigation. The objective was to analyze and compare the concentration of heavy metals in Spinach (Spinacia oleracea) collected from two different sites, i.e., one field irrigated using sanitary wastewater and another by tube well water through drainage ditches in a rural area of Faisalabad. AAS (Atomic Absorption Spectrophotometry) analyzed heavy metals from plants through irrigated water, soil, and the collected edible parts of plant samples. The samples were digested by using acids and AAS-analyzed metals. The concentration of Cd (0.051 ± 0.029) mg/l found higher than the recommended values by WHO (0.01 mg/l) in sanitary wastewater, as well as Cd concentration (0.478 ± 0.276) mg/kg in edible parts of spinach, also detected beyond the permissible limits (0.2) mg/kg of WHO (2007). These exceeding values of Cd in edible parts of spinach may cause serious human health risks.

Keywords

• Heavy metals
• Irrigation
• Soil
• Water
• Spinach