Nitrate, nitrite, and lead contamination in leafy vegetables collected from local market sites of Go Vap district, Ho Chi Minh City

Abstract

Lead, nitrate, and nitrite are among the major contaminants of vegetables. These concentrations appraise the quality characteristic of vegetables. Governments and regulators has control the level of nitrate, nitrite, and lead in vegetables to protect the human health. The present study was initiated to investigate the levels of these contaminants in five leafy vegetables in local market (Brassica juncea, Brassica integrifolia, Lactuca sativa, Ipomoea aquatica, and Nasturtium officinale). The vegetable species can be listed by decreasing nitrate content as follows: Lactuca sativa > Nasturtium officinale > Ipomoea aquatica > Brassica integrifolia > Brassica juncea. The nitrite content in leafy vegetables was significantly lower than nitrate content. Among observed vegetables, highest concentration of lead is in Ipomoea aquatica (0.200±0.011 mg/L), whereas lead content in Lactuca sativa and Nasturtium officinale were not detected. In addition, the Pb levels in the leafy vegetables were not correlated with nitrate concentration. Based on the results of our investigation, the approximate daily intake (DI) of NO3–, NO2– and Provisional Tolerable Weekly Intake (PTWI) of lead were assessed to human health in consuming the observed leafy vegetables.