Health risk assessment and heavy metal bioaccumulation in vegetables irrigated with waste water in Kano State, Nigeria

Abstract

DOI: 10.15835/nsb13110890
 Intake of vegetables grown in heavy metals contaminated soils is one of the most common food chain routes for exposure of human. For this purpose, this research aimed at evaluating the concentration of heavy metals (cadmium-Cd, lead-Pb and zinc-Zn) in vegetables such as spinach (S), lettuce (L), and onion (O), irrigated with two different wastewater sources in Kano State Nigeria. Atomic Absorption Spectrophotometric analysis (AAS) was used in this research to determine the metal levels. Zn (0.17-0.12 mg/l) was detected in the wastewater, as well as in the irrigated soil (8.36-33.64 mg/kg), while Cd and Pb were not detected in both the wastewater and irrigated soils. Furthermore, between (1.50-27.05 mg/kg) of Zn was detected in the assayed vegetables (S, L and O). However, there was no significant difference (p<0.05) between the Zn content of the two wastewater sites. Lactuca sativa was observed to have the highest Zn concentration (27.5 mg/kg) in site A, while Spinacia oleracea had the lowest Zn concentration (1.5 mg/kg). Zn levels in all the samples analysed in this study were below the permissible limit of 100 mg/kg in vegetables, 50 mg/kg in soil and 5mg/l in wastewater set by FAO/WHO. However, Pb and Cd were not detected in all the samples. Bioaccumulation factor was found ranging from 0.32-41.17 mg/kg and the pollution index ranged from (0.46-1.80 µg g-1). This indicated potential health risk from Zn in people who are consuming these vegetables for long period of time due to biomagnification. This research suggested that frequent test should be carried out to monitor the accumulation and, farmers should be sensitized on the importance of treating irrigation water before agricultural usage.

Oxidative Stress Biomarkers Activities and Histological Changes in African Catfish (Clarias gariepinus) Exposed to Carwash Wastewater

“…Important indicators for controlling physiological processes and the dispersion of aquatic biota are the physicochemical characteristics of water (Jamila and Sule, 2020). Many metabolic processes in an organism are influenced by the temperature of the water (Habu et al, 2021). The wastewater was somewhat alkaline, as indicated by the pH value of 8.9 in the current study, which may affect a variety of physiological activities in the exposed experimental fish (FAO/WHO, 2018).…”

Risk assessment of heavy metals bioaccumulation in Clarias gariepinus tissues from Jakara Reservoir, Kano, Nigeria

“…Heavy metals have been reported as potent toxic compounds due to their slow degradation rate and non-biodegradable nature (Abdullahi et al, 2021). Variations in BAF rely on many conditions, such as age of the fish, physiology of the fish, migratory ability of fish, differential exposure and health conditions (Abdullahi et al, 2021;Habu et al, 2021). The BAF recorded is lower than 5.76 reported by Ahmad et al (2018) in Kafinchiri reservoir, Kano State.…”

“…Pollutants discharge into water bodies such as industrial, domestic and agricultural wastes results in various detrimental effects on the aquatic biota such as fish (Abubakar et al, 2012). Pollutants from these activities were reported to contain heavy metals such as Cu, Cr and Pb which invariably, affects the entire aquatic ecosystem (Habu et al, 2021). Due to their toxic nature, non-biodegradable and accumulative potential, heavy metals constitute a core group of aquatic pollutants (Jamila and Sule, 2020).…”

Heavy Metals Accumulation in Lettuce and Cherry Tomatoes Cultivated in Cities

“…Even though lettuce and cherry tomato were grown in the same conditions the heavy metal content were different in the EP and NEP of the plants, which according with [12] is due to the difference in morphology and physiology of vegetables for heavy metal usage.…”

“…The soil-root system is not the only means by which heavy metals and metalloids enter; access is also via the leaves and the cuticle and through the stoma, so there is a need for quantification of human risk assessment of consuming vegetables in urban areas [12]. Work on this topic in Mexico is scarce and refers to a specific medium such as soil, water or air.…”