Abstract

Health risk has been linked significantly with the presence of heavy metals in vegetables. Consumption of contaminated vegetables is a primary source for the intake of heavy metals into the human body and the production of reactive oxygen species which induce oxidative stress causing cellular damage in plants. This study aimed to investigate the health risks of arsenic, lead, and chromium, as well as the oxidative stress status of fluted pumpkin leaf (Telfairia occidentalis) collected from Ikpoba -Hill and Oba Market in Benin City, Nigeria. The samples of vegetables were collected, air dried, digested, and analyzed for heavy metal concentrations through the procedure of an atomic absorption spectrophotometer. The concentrations of Chromium (0.52± 0.22 mg/kg) and Lead (0.06±0.03 mg/kg) obtained from Ikpoba-Hill Market were higher than the concentrations of Chromium (0.26±0.11 mg/kg) and Lead (0.05± 0.02 mg/kg) obtained from Oba Market. The concentrations of heavy metals were below the FAO/WHO permissible limits. Arsenic was not detected in the two markets.  There was no significant difference in heavy metals concentration between the two markets. To assess the health risks, the daily intake, target hazard (THQ), hazard index (HI), and lifetime cancer risk (LCR) were calculated. The daily intake of metals fell below the recommended and upper-tolerable levels. The target hazard and Hazard Risk Index suggest an insignificant cancer risk to consumers, with all values below one. However, chromium levels in Ikpoba-Hill Market pose a potential cancer risk. The oxidative stress status was determined using the oxidative stress markers Glutathione peroxide (GPx), catalase (CAT), malondialdehyde (MDA) and superoxide dismutase (SOD). The oxidative stress marker activities were generally higher in Oba market (CAT = 0.10 ± 0.01, SOD =3.09 ± 0.18, GPX = 6.09 ± 0.37, MDA = 0.81 ± 0.10) than in Ikpoba-Hill market (CAT = 0.07 ± 0.00, SOD = 2.46 ± 0.12, GPX = 2.86 ± 0.12, MDA = 0.68 ± 0.04). However, a significant relationship was not determined between the heavy metals and oxidative stress markers. Therefore, further study is required to determine the cause of the activity level of the oxidative stress markers present in the fluted pumpkin leaf.

Keywords: Health risk, Heavy metals, Oxidative stress, Telfaria occidentalis