In this study, eleven soil samples and twenty-twoplants samples were collected in the vicinity of eleven industries and a thermal station was analyzed for zinc, copper, iron, lead and cadmium. Soil sample from Egbin thermal station had the highest concentration of Zn (141.06 mg/kg) and Cu (131.70 mg/kg). Soil from international textile had the highest level of Fe and the soil from Nichemtex had the highest concentration Pb and Cd was the highest in soil from Guinness (28.91 mg/kg, 59.80 mg/kg and 1.72 mg/kg respectively). The highest concentrations of the heavy metals were observed from different plants species. Analyses of variance (p < 0.05) showed that heavy metal variation in plant and soil samples were not significant (p > 0.5). There were positive correlations between the heavy metals in the soils and the plant samples indicated that the plants obtained the heavy metals from the soil. Plants having BCF values less than one had limited ability to accumulate, translocate and phytoextract heavy metals. These plants in this study with higher Bioconcentration Factor value especially those greater than one (Croton lobatus, Borreria sp., Cyathula prostrata, Lantana camara, Ficus sp., Mimosa pudica, Eclipta prostrata, Commelina sp. etc.) were suggested for further research and assessment on their bioaccumulation abilities and phytoremediation potential.

Twenty one sampling locations were assessed for carbon monoxide (CO), carbondioxide (CO 2 ), oxygen (O 2 ), sulphur dioxide (SO 2 ), nitrogen dioxide (NO 2 ), nitrogen oxide (NO), suspended particulate matter (SPM) and noise level using air pollutants measurement methods approved by ASTM for each specific parameter. All equipments and meters were all properly pre-calibrated before each usage for quality assurance. Findings of the study showed that measured levels of noise (61.4 -101.4 dBA), NO (0.0 -3.0 ppm), NO 2 (0.0 -3.0 ppm), CO (1.0 -42.0 ppm) and SPM (0.14 -4.82 ppm) in all sampling areas were quite high and above regulatory limits however there was no significant difference except in SPM (at all the sampling points), and noise, NO 2 and NO (only in major traffic intersection). Air quality index (AQI) indicates that the ambient air can be described as poor for SPM, varied from good to very poor for CO, while NO and NO 2 are very good except at major traffic intersection where they were both poor and very poor (D-E). The results suggest that strict and appropriate vehicle emission management, industrial air pollution control coupled with close burning management of wastes should be considered in the study area to reduce the risks associated with these pollutants.© JASEM http://dx.doi.org/10.4314/jasem.v20i1.21

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 investigated pesticide residue levels in the two vegetables commonly eaten in Lagos state Nigeria. The vegetables (Telfairia occidentalis and Celosia argentea) were purchased from six markets (Oyingbo, Mile 12, Mushin, Ajah, Agege and Festac) in Lagos. The pesticide residue levels were determined using gas chromatography/mass spectrometry. Data obtained were statistically analysed using graph pad prism 6.0 software and were compared with WHO limits. The vegetables from all the markets had pesticide residue level above the WHO lower limit (0.02 mg/kg). The two vegetables from Oyingbo and Mile 12 markets had total pesticide residue levels above the WHO upper limit (0.7 mg/kg). T. occidentalis from Oyingbo market had the highest total pesticide residue level (2.35mg/kg) and the highest number of pesticides while C. argentea from Agege market had the least total pesticide residue level (0.08mg/kg).Aladrin was found in the two vegetables from all markets and generally more pesticide residue was found in the tissues of T. occidentalis than in the tissues of C. argentea. Significant differences (P<0.05; P<0.01) were noticed between some pesticides in T. occidentalis from Oyingbo and some pesticides in the vegetables from the other markets.Although the hazard quotient and hazard index values (being less than 1 and 0.2 respectively) indicate that there will be no health risk in consuming the vegetable, some of pesticides residues were above the maximum residue levels. The presence of pesticides in the vegetables calls for strict regulation of the application of the pesticides in farms and preservation chambers. This will help in preventing some of the diseases and other problems associated with pesticide accumulation.

Sediments are complex environments, with varying physicochemical characteristics, such as composition and type of organic matter, particle size distribution, and pH. Contaminated sediment is a significant environmental problem affecting many marine, estuarine and freshwater environments throughout the world. Most assessments of water quality have historically focused on water-soluble compounds, with relatively little attention paid to sediment. The aim of this research is to assess the physical and chemical parameters of sediments from Nwaja Creek, Niger Delta, Nigeria. Monitoring of this sediment quality is an important part of preserving and restoring the biological integrity of water bodies as well as protecting aquatic life, wild life and human health. Sediment samples from Nwaja Creek were sampled from seven sampling stations along the creek for over three months May to July, 2015, rainfall peak period, for assessment of their physical and chemical characteristics, such as grain size, organic carbon, pH, conductivity, nitrate and phosphate. These parameters are known to influence the interactions and dynamics of pollutants within sediment matrix. Sediment particle size distribution indicates that they have higher proportion of clay (clay > silt > sand), the mean percentage composition of clay, silt and sand ranged between 64.28% ± 22.04%-72.36% ± 14.00%, 18.71% ± 12.03%-27.32% ± 22.17% and 8.40% ± 6.28%-9.76% ± 4.59% respectively. TOC in the study area is generally above 1% across all stations during the study period with a range between 0.98% and 4.58%. Minimal monthly and spatial variations are observed in particle distribution, pH (3.9-8.5) and phosphate (5.5-15.5 kg/mg) while significant variations are observed in conductivity (23.0-567.0 uS/cm), total organic carbon (0.98%-4.58%) and nitrate (0.45-11.9 mg/kg) concentration. It is concluded that physicochemical characteristics of the sediments from Nwaja Creek are influenced by anthropogenic sources

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The toxicity of crude oil on ten accessions of Sorghum bicolor Moench was evaluated in this study. The study used germination, shoot length, root length, chromosomal abnormalities, mitotic indices and EC 50 as bioassay parameters in the evaluation with 0% to 8% of crude oil as treatments. The percentage germination of seeds of the different accessions in the different treatments were significantly different (p<0.05; p<0.01 and p<0.001). Significant differences also existed in the rates at which the different accessions grew in the different treatment (p<0.05; p<0.01 and p<0.001). Chromosomal aberrations ranging from vagrant, bridged anaphase, c-metaphase amongst others were noticed in the cells of the seedlings exposed to the different treatments. The EC of the different accession ranged from 5.5% to 19% for germination, 4.4% to 13.8% for root length and 6.3% 50 to 16.7% for shoot length. The mitotic indices of the plants were also affected by the different treatments. The results of the study shows that although the different assay parameters show that crude oil can affect different plants in the different ways, 07/125 is more sensitive to crude oil pollution. Further studies can be carried out on the more resistant accessions to determine their suitability for remediation of crude oil contaminated sites.