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There has been a lot of concern on the rate at which industrial and domestic wastes are discharged into River Delimi in north central Nigeria. This study was an attempt to assess the status of heavy metal pollutants (Cd, Cu, Pb and Zn) in sediment and water from River Delimi in Jos city, with a view to determining its ability to support aquatic life and suitability for use in vegetable crop irrigation. The study was conducted at three major irrigation sites at Gangare (station I), Farin Gada (station II) and main campus of University of Jos (station III) along River Delimi and one control site at Lamingo Dam (station IV) all within Jos city. The total metal contents in water and sediment were determined using Atomic Absorption Spectrophotometer (AAS) after extraction with Conc. HNO 3 and aqua-regia respectively. Results of the study revealed that the total metals content in water and sediment were generally higher at the study compared to the control site. At the study site, the mean Cd concentrations in water at stations I (0.14mg/L), II (0.381mg/L) and III (0.300mg/L), Cu at stations I (0.341mg/L) and II (0.371mg/L) were above the limits of 0.01mg/L and 0.20mg/L for Cd and Cu respectively for irrigation water recommended by FAO. Further analysis on the sediment pollution status using Contamination Factor (CF) revealed that Cd obtained from all the sampling sites showed considerable (3 ≤ CF ≤ 6) contamination while the other metals showed low (CF < 1) contamination. The use of Geoaccumulation Index (I-geo) also showed that only Zn at station IV (control site) attained unpolluted status (Class 0) It is recommended among others that measures should be put in place by relevant authorities to regulate the indiscriminate dumping of domestic waste and untreated industrial effluents into the river.

It is no doubt that soils are among the Earth's largest terrestrial reservoirs of carbon pool and hold potential for its sequestration and thus, soils can serve as potential way of mitigating the ever-increasing atmospheric CO 2 concentration. However, the stability and flux of soil organic carbon are affected in response to changes that are being driven by forms of environmental and anthropogenic factors. Therefore, to establish carbon sequestration potential of soils, an in-depth scientific evaluation that would provide mapping of and speciation of carbon chemical forms, as well as factors influencing the persistence of carbon in soils are key to the process which are beyond quantitative measurements that are conventionally implemented under different land use and/or soil management. This involves soil chemistry, physics, biology, and microbiology. Hence, this short review communication highlights portions of soil chemistry and physics as well as soil biology and microbiology that have not been given attention in determining and/or underpinning decisions on carbon sequestration potential of soils.

<p>This study was aimed at assessing the levels Persistent Organic Pollutant in Challawa River Basin of Kano State, Nigeria. The investigation was particularly plan to assess the presence of PCBs and PAHs in River Challawa and compare the concentrations of the pollutants with the acceptable limit set by Nigerian Standard and other international regulatory agencies. Data were collected using reconnaissance survey; laboratory experiment as well as other secondary data sources. A total of 26 water samples were collected through stratified and systematic random sampling. Three sampling points were chosen and designated A, B and C along the stretch of the river from Yan Danko Bridge to Tamburawa bridge. The result shows that Polychlorinated biphenyls were not detected but polycyclic aromatic hydrocarbons  were detected in all the samples analyzed using GCMS. The total concentrations of PAHs in the water samples range between 0.001 to 0.087mg/l. The analytical results revealed that most of the pollutants present in water were at significantly very high levels especially at Zamawa village situated very close to Challawa industrial estate - the major sources of effluent discharge point, making the drinking water around area is not fit for consumption. In conclusion, it can be said that industrial activities had impact on Challawa River basin and its environment. It is recommended among others that the industries should treat their effluents before releasing them into Challawa river basin. </p><p> </p><p>Keywords: persistent, organic, pollutant, challawa river, Nigeria</p>

The accumulation of heavy metals in agricultural soil is a source of concern because of food safety issues. The present study was aimed at evaluating the Transfer Factors(TFs) of potentially toxic metals (Cd, Cr, Cu, Pb and Zn) from soil into the food chain by assessing the levels of these metals in soils and vegetables (Carrot, Cabbage, Lettuce and Spinach) obtained from farmlands along River Delimi in Jos city. The metals content in soils and vegetables were determined using 210 VGP Model, Buck Scientific Atomic Absorption Spectrophotometer (AAS) after extraction with Aqua-regia. The data generated were analyzed using simple descriptive statistics followed by the determination of TFs calculated as the ratio of the concentrations of the metals in crops to the concentrations in soils. The results revealed that both the soil and crop samples collected at the study area contained more metals than those at the control site. Additionally, the metals generally had highest TFs values at the study area compared to the control site. The least TFs values for these metals in the crops at the control site could be attributed to the lower mean total metals content in the soils. This further suggests that plant absorption of these metals was mainly controlled by the content that is available in the soil. It is recommended that farmers should cultivate plant species (legumes, cereals, potatoes etc.) with low metal uptake and avoid the cultivation of crops such as carrots, spinach, lettuce that are known to accumulate high amount of metals. The metal transfer into food chain could also be reduced through cultivation of industrial crops such as Jatrophaand castor plants known for their high oil content. Furthermore Farm Yard Manure should be applied to the soil as it reduces the bioavailability of the heavy metals to the crops