Mercury May Pose Higher Ecological and Human Health Risks than Lead in Vegetables Cultivated on Solid Wastes...

Vegetable cultivation on solid wastes dumpsites (SWD) soils is very common in developing countries though unsafe due to heavy metals pollution. In order to evaluate the ecological and human health risks of this practice, Talium triangulare and Lycopersicon esculentum were grown in a greenhouse on soils from two abandoned and active SWD, and control site. The SWD soils were acidic (pH 6.4-6.8), rich in organic matter (10.15%-15.35%) and the heavy metals content patterned Zn > Mn > Hg > Cu > Pb > Ni > Cd. Ecological risk was very high ([Formula: see text] = 396.40; RI = 400) for waterworks dumpsite (WWD) and was > 99% attributable to Hg. Pb was not accumulated in either vegetable but Hg levels exceeded FAO/WHO limits. HQ was mostly < 1 except for Hg (0.47-3.42) and Co (0-1.33) while THQ > 1 for T. triangulare and cancer risks exceeded 10^-6-10^-4 acceptable limits. Regular monitoring and outlawing of vegetable cultivation on SWD is advocated to avert Hg toxicity.