Heavy Metals Health Risk Assessment through Consumption of Baobab Leaf Cultivated in Katsina State, North West Nigeria

Abstract

Vegetables play important roles in human nutrition and health. They can also contain some undesirable components that can be harmful, e.g. Pesticides and heavy metals. The objectives of the study were mainly to detect the presence of heavy metals (Cr, Cd, Fe, Ni, Mn, Pb and Zn) in sampled Baobab leaf in Katsina state Nigeria and assessed the human health risks associated with the consumption of the Baobab leaves. The content of these metals was assayed by the AAS method. The health risk to the local inhabitants was evaluated by estimating daily heavy metal intake and computing the Incremental Lifetime Cancer Risk (ILCR) and the Target Hazard Quotient (THQ) for cancer and non-cancer risks. The results were compared with the safety standards established by the WHO/FAO and USEPA. With the exception of the heavy metal Pb (0.526-0.981) the mean concentration (mg/kg) range values of Cr (0.116-0.352), Cd (0.041-0.054), Fe (1.016-1.951) and Zn (0.940-1.229) in the samples were generally lower than the USEPA, WHO/FAO maximum permissive limits. The risk level of Target Hazard Quotient (THQ < 1) was observed for all the evaluated heavy metals for both adults and children. The THQ for the samples was in the decreasing order Zn>Fe>Pb>Cr>Cd, for all the baobab leaf samples respectively. All the studied samples showed the risk level (HI < 1). ILCR for Cd violated the threshold risk limit (>10−4) and ILCR for Pb reached the moderate risk limit (>10−3) for cancer in all the studied samples in adults, While in children ILCR for Pb in samples from Dabai and Daura have reached the moderate risk limit (>10−3), while the ILCR for Pb in rest of the samples and ILCR for Cd of all the samples are beyond the moderate risk level (>10−2). The consumption of the Baobab leaf sample may contribute to the population cancer burden.

Non-carcinogenic and Carcinogenic Health Risk Evaluation from Fish Contaminated with Heavy Metals

“…Although a previous study from Katsina State, Nigeria [8] has reported the heavy metal Ni to be below detection level (BDL) in fish samples, with similar studies conducted in the state in legumes, cereals and vegetables corroborating the same finding [38][39][40][41][42][43]. The present study is among the few of such studies [44,13] that reported a detection of Ni in evaluated food samples.…”

“…The risk assessment for carcinogenic exposure effect has revealed that the incremental lifetime cancer risk (ILCR) and the cumulative lifetime cancer risks (∑ILCR) were all above the safe limit for cancer in the children population with the heavy metal Ni contributing the highest risk and the sample of the fish sample of Clarias gariepinus having the highest cancer risk (Tables 6). [38][39][40][41][42][43].…”

Illegal Mining and Armed Banditry in Katsina State, Nigeria: What is their Contribution to the Heavy Metal Pollution of a Popularly Consumed Vegetable?

“…From the Tables (2 and 3) the combined health risks for all the metals in the sample for the adults and children population represented as the HRI were below 1, an indication that the sample is safe for consumption. The current result is in agreement to what was previously reported in Katsina State [33][34][35][36][37][38][39].…”

“…As seen from the results, the heavy metal Pb concentration that was above permissible limit of Pb in vegetables offers the suggestion that the sample is not safe for human consumption because of the high risk potential. In addition, the Pb and Mn mean values of the sample were higher than the reported mean values in studies that evaluate heavy metals in various food samples that were earlier conducted in Katsina State, Nigeria [33][34][35][36][37][38][39]. The apparent higher values obtained may not be unconnected with the illegal mining sites that are located within the vicinity of the sampling area.…”

Health Risk Assessment of Heavy Metals in a Vegetable Cultivated on Land Polluted through Illegal Mining

“…The observation that the heavy metals Pb and Fe have values that were higher than the regulatory bodies permissible limits is a pointer that the consumption of sample by the population is not safe because of the potentially high health risk. Also, the mean heavy metals concentrations of the sample was higher than the reported mean heavy metals concentrations in studies that evaluate heavy metals in various food samples that were earlier conducted in Katsina State, Nigeria [33][34][35][36][37][38][39]. The Apparent higher value obtained may not be unconnected with the illegal mining and metal artisanal sites that are located within the vicinity of the sampling area.…”