Monitoring and Modeling of Heavy Metals Contents in Vegetables Collected from Markets in Imo State, South-Eastern, Nigeria

Vegetable consumption is one major exposure route of heavy metal to humans, but few data exist for Imo State. We assessed the contamination levels and associated health risk of cadmium (Cd), cobalt (Co), copper (Cu), nickel (Ni), lead (Pb) and zinc (Zn) in vegetables (Telfairia occidentalis, Pterocarpus mildbraedii, Gongronenina latifolium and Vernonia amygdalina) that are consumed frequently from markets (n=16) in three zones of Imo State, Nigeria. After wet-digestion of samples, the supernatant were analyzed by using atomic absorption spectrophotometry. The mean concentrations in the four vegetables ranged from 0.006±0.003 mg/kg to 0.011±0.007 mg/kg for Cd, 0.064±0.012 mg/kg to 1.225±0.226 mg/kg for Co, 10.711±1.968 mg/kg to 25.088±13.975 mg/kg for Cu, 0.062±0.013 mg/kg to 0.307±0.210 mg/kg for Ni, 0.006±0.005 mg/kg to 0.012±0.002 mg/kg for Pb and 63.55±4.055 mg/kg to 104.126±24.080 mg/kg for Zn. Except for Zn, all heavy metals in the various vegetables were below the joint standard of Food and Agriculture Organization (FAO) and World Health Organisation (WHO). Although, overall heavy metal load was very low, Zn had the highest contamination factor in vegetables. Heavy metals concentrations in vegetables generally showed low to high variations and statistically different (p < 0.05). Average daily intake was below the provisional tolerance limit except for Zn. The individual hazard index of vegetables for both children and adults were below 1, indicating no potential risk to the public. Overall, heavy metals hazard index were below 1, indicating acceptable level of non-carcinogenic adverse health effect. However, potential multi-element contamination from ingestion is possible as revealed by the correlation profiling of heavy metals. </p

Trace metals analysis of soil and edible plant leaves from abandoned municipal waste dumpsite in Owerri, Imo state, Nigeria

Municipal refuse may increase heavy metal concentration in soil, even at low levels, and their resulting long-term cumulative health effects are among the leading health concerns all over the world. In this study, we investigated the concentration of heavy metals in soils and edible plant leaves grown in an abandoned dumpsite along Akachi road in Owerri municipality. The soil samples were collected at each plot using a soil auger at the depth of 0-10 cm. Leaves of dominant edible plant species were selected and collected from each sample plot. The samples were dried in an oven with forced air at 40 °C, milled to fine powder then digested with 10 ml concentrated HNO3 and 5 ml concentrated HClO4 and were analyzed for Cr, Cu, Fe, Mn, Al, and Zn, using an H183200 MultiParameter Bench Photometer. Result showed that metals in in the sampled soils included (in order of quantity) Cr: 150-280 >Fe: 116.50-203 >Cu: 12.4-18.8 >Mn: 0-20 >Al: 0.08-0.16 >Zn: 0-1.4 mg kg-1 Dw. Moreover, levels of metals in the edible plant leaves are in the order of: Zn>Fe>Cu>Al>Mn>Cr. Zn, in particular, was higher than FAO/WHO recommended limits. Still, application of Pollution Load Index and Ecological risk models showed that the area is unpolluted and safe for use. Daily Metal Intake estimates indicated that zinc is mostly consumed from the plant species. The trends in Transfer Factor for the heavy metal in vegetable samples studied were in order: Zn>Al>Cu>Mn>Fe>Cr. Therefore, abandoned solid waste dumpsites contained significant concentrations of heavy metals which are later absorbed and accumulated by plants growing it

Indirect exposure to novel coronavirus (SARS-CoV-2): an overview of current knowledge

This review chronicles the indirect transmission method which seems to be overlooked by most people and makes attempts to document the various transmission ways with a hope that such information may strengthen the knowledge base of researchers towards methods of eradicating the pandemic. Current knowledge of transmission and exposure of SARS-CoV-2 has been explained. Various researchers have put forward different ways of exposure and transmission.&nbsp; Literature does not reveal whether the indirect transmission route is the dominant one. However, total lockdown could be a veritable means to reduce both direct and indirect transmission routes. In many countries where the indirect transmission has been reduced, the scourge of the virus is less. The work creates awareness on the need to watch out for those routes of transmissions that may not be popular and suggested vital knowledge gaps that need to fill. &nbsp