This work investigated six heavy metals (Pb, Cr, Zn, Cd, Ni and Cu) accumulation in five popular leafy vegetables: Telferia occidentalis (fluted pumpkin), Talinum triangulare (waterleaf), Ocimum gratissimum (scent leaves), Celosia argentea (plumed cockscomb), and Amaranthus viridis (slender amaranth) obtained from 4 popular markets in Lagos metropolis using an atomic absorption spectrophotometer (AAS), and evaluate the human health risks of their consumption. Heavy metals content in vegetables across the markets ranged as follow; Cd (0.05 -0.20 mg/kg); Pb (0.34 -5.44 mg/kg), .80 mg/kg), Cr (0.25 -1.51 mg/kg), Ni (0.13 -2.91 mg/kg) and Cu (2.34 -14.08 mg/kg). The concentrations of all metals are quite generally lower than the permissible levels by FAO/WHO in vegetables except for Pb. Statistical analysis of levels of the studied metals in A. viridis, T. occidentalis, C. argentea, and O. gratissimum in all the markets sample showed significant differences in levels of Zn, Cr, Cu and Ni (p<0.05). To assess the the health risk of the inhabitants of Lagos and the environs due to heavy metal intake from these vegetables consumption., the daily intake of metals (DIM), health risk index (HRI), and target hazard quotient (THQ) were calculated. The daily intake of metals in vegetables species for Zn (0.51 -1.46 mg/kg) and Ni (0.05 -0.22 mg/kg) are significantly lower than the recommended daily intake of metals and the upper tolerable daily intake level (UL). However, DIM of Cd (0.004 -0.017 mg/kg) and Pb (0.046 -0.182 mg/kg) exceed the recommended DIM but fall within the upper tolerable daily level. Cr (0.048 -0.082 mg/kg) is lower than the recommended oral reference dose (RFD) of 1.5 mg/kg (USEPA, 2010). The THQ values range showed that Cd was 0.048 -0.192, Pb was 0.150 -0.587, Zn was 0.021 -0.190, Cr was 0.0001 -0.001, Ni was 0.050 -0.120 and Cu was 0.148 -0.239. This result reflected the risk associated with exposure for the period of life expectancy considered, and the inhabitants are highly exposed to health risks associated to these metals in the order Pb > Cu > Cd > Ni > Zn > Cr. The THQ in all metals is less than 1 in all the vegetables species; therefore, it does not pose serious health risk concern. However, vegetable consumption was just one part of food consumption, the potential health risks for residents might actually be higher than in this study when other routes of heavy metals intake are considered. ©JASEM http://dx.doi.org/10.4314/jasem.v20i3.6

This study was conducted to evaluate nutritional composition and heavy metals concentration of smoked and raw edible fish species from Ologe lagoon (freshwater) and Lagos lagoon (marine). The fish species from Ologe include: Chrysichthys nigrodigitatus (Catfish), Monodactylus sebae (African moony), Pomadasys jubelini (Buro), Sphyraena barracuda (Great barracuda), and Pseudotolithus elongatus (Croaker), while that of Lagos lagoon include Chrysichthys nigrodigitatus (Catfish), Caranx hippos (Crevalle jack), Liza falcipinnis (Sicklefin mullet), Pomadasys jubelini (Buro), and Monodactylus sebae (African moony). The nutritional composition ranged in the following trend moisture (43.24 - 76.79 %) > carbohydrate (3.16 – 63.45 %) > protein (0.80 - 31.55 %) > fibre (1.07 – 2.8 %) > ash (0.81 – 1.88 %) > fat (0.40 – 1.30 %). In this study, these fishes are generally low in fats (lean fish), and fish smoking tend to reduces their nutritional composition. Heavy metals concentration trend thus Zn (2.4 – 7.75 mg/kg) > Ni (0.80 – 1.925 mg/kg) > Cr (0.20 – 0.550 mg/kg) > Pb (0.025 – 0.50 mg/kg). In all the samples, all the metals of interest were detected except cadmium which was not found in any of the samples analysed. Pb (0.025 - 0.5 mg/kg) values in the fishes were lower than the maximum standard level reported to be 0.5 mg/kg dry weight by FAO except in the raw Pomadasys jubelini where the value is 0.5mg/kg. The fresh water fishes showed higher concentration of heavy metals than marine water fishes but not statistically significant (p>0.05). Although, smoked fishes showed higher concentration of heavy metals than the raw fishes, it was only significant for zinc (p<0.05). In view of this study and the importance of fish in human diet, it is recommended that biological monitoring of fishes meant for consumption from these two water bodies be carried out regularly to ensure human safety.Keywords: Nutritional composition, heavy metals, fresh water fishes, marine water fishes, lagoons

The cytogenotoxic effects of emulsifiable concentrate of amitraz pesticides was evaluated using Allium cepa L. test. The root meristems of A. cepa L. were treated with five concentrations (1%, 5%, 10%, 20% and 40%) of the chemical pesticide at 48 h for cytogenetic analyses and 96 h for root length inhibition. Pesticide doses affected root length significantly (P<0.05) at 5% to 40%; with 50% effective concentration (EC50) value of 18% while there was no significant difference between control and 1% (p>0.05). The mean root length of the treated A. cepa for Amitraz pesticides in all concentrations was lower compared to the control showing the obvious mitodepressive effects of amitraz pesticides. A dose dependent reduction in the total mitotic dividing cells and mitotic index was observed in A. cepa treated with the pesticides. The values of mitotic index obtained for amitraz pesticides at 5% (5.20), 10% (4.0), 20% (2.30) and 40% (0.80) were lower than half of the negative control (7.25), which reflect its cytotoxicity. All the concentrations of the pesticides used in the present study induced important abnormalities during mitotic division. These aberrations were: chromosome stickiness, disturbed spindle, anaphase and telophase bridges, chromosome fragments, laggard chromosomes, and c-Mitosis. The highest abnormality number was observed in the root tips of Allium cepa (5%) while the least was at 40%. Frequencies of chromosome abnormalities were low at 20% and 40% concentration because of damaged cell and lower cell divisions. The present study, showed the inhibition of growth and induction of chromosomal aberrations by amitraz, this suggest their capability in inducing cytotoxicity and genome instability.