Trace elements in the flesh and liver of two fish species from polluted and unpolluted areas of the Aegean Sea

Geochemical analyses of groundwater and streams flowing around abandoned and active dumpsites in Lagos, Southwestern Nigeria were carried out. Results show that water samples have generally low total dissolved solids with average values of 163.75 and 153.4 for abandoned and active dumpsites, respectively. pH ranges from 3.96-8.34 while total hardness varies from 10-220 mg/L calcium carbonate (soft to slightly hard). Average concentrations of the dominant ions for abandoned and active dumpsites were 57.8 and 25.86 mg/L (Na) representing 40.7 and 46.3 % of the total cations respectively and Nitrate (av. 96.89 and 61.51 mg/L) representing 49.1 % and 40 %, respectively of the total anions. The pH, coliform count and concentrations of nitrate iron, manganese and sodium in most of the water samples were above the national drinking water standards proposed by the United States Environmental Protection Agency. Trace elements like silver, arsenic, beryllium, bismuth, cerium, cobalt, chromium, lithium selenium, tellurium, titanium, uranium, vanadium, tin and yttrium were below detection level for all the water samples while tungsten, thallium, molybdenum and lead were only present in surface and groundwater close to the dumpsites and also display values higher than recommended standards while cupper, zinc, aluminum, barium and strontium were present in most of the samples. The pollution index among all sites varied from 0.009 to 1.26 and 0.106 to 6.25 for abandoned and active dumpsites, respectively while the water around most of the dumpsite areas exceeded the acute and chronic effect levels proposed by the United States Environmental Protection Agency in 2007.

Section: Introductionmentioning

confidence: 99%

Contamination assessment of surface and groundwater within and around two dumpsites

Odukoya

Abimbola

2010

“…This capacity is widely recognized as offering one way of monitoring the distribution of toxins in the environment. One of the reasons these toxins are so harmful is that they become more concentrated in successive trophic levels of a food web, a process called biological magnification (Woodwell, 1972;Grimanis et al,. 1978;Adams et al, 1992;Campbell, 1996;Manly, 1996).…”

Section: Introductionmentioning

confidence: 99%

Accumulation of lead, cadmium, manganese, copper and zinc by sludge worms; Tubifex tubifex in sewage sludge

Kaonga

Kumwenda

Mapoma

2009

ABSTRACT:Tubifex tubifex has been shown to survive in organic polluted environments, however, not much has been done on its inorganic pollution tolerance. Samples of T. tubifex and their respective sewage sludge were taken from Soche wastewater treatment plant in Blantyre City, Malawi during July 2007 to November 2008. The total number of sludge samples taken was fifty one which was made into seventeen composite samples. A total of seventeen T. Tubifex samples were also collected. The samples were analyzed for copper, lead, manganese, zinc and cadmium using standard methods from American Public Health Association and Association of Official Analytical Chemists. The concentrations of metals in sewage sludge and T. tubifex were on dry weight basis and the metals determined were acid extractable. In general, heavy metals concentration was lower in T. tubifex than in sewage sludge. The range of heavy metals concentrations were (in sludge and (T. tubifex)): zinc 275.3 -361.5 mg/kg (45.0 -82.2 mg/kg), manganese 293.7 -230.1 mg/kg (1.21 -3.69 mg/kg), copper 86.5 -120.1 mg/kg (1.6 -4.7 mg/kg), lead 11.2 -22.4 mg/kg (Below detection limit -0.95 ) and cadmium 1.12 -2.31 mg/kg (1.08 -2.18 mg/kg). The results showed significant differences between the concentrations of manganese, copper, lead and zinc in sewage sludge and T. tubifex (p < 0.05). However there was no significant difference between the concentrations of cadmium in sewage sludge and T. tubifex (p > 0.05). T. tubifex did not show the ability to accumulate heavy metals (attributed to its high defecation and metabolic rate) except for cadmium hence cannot be used as a bioindicator for heavy metal pollution in sludge.

“…Bioaccumulation is the process in which a chemical pollutant enters the body of an organism and is not excreted but rather collected in the organism' s tissues (Zweig, et al, 1999). Metals that are deposited in the aquatic environment may accumulate in the food chain and cause ecological damage while also posing a risk to human health (Grimanis, et al, 1978;. Taylor Creek, a non-tidal freshwater environmental unit, is situated in Gbarain clan in the Yenagoa Local Government Area of Bayelsa State in the Niger Delta.…”

Section: Introductionmentioning

confidence: 99%

Correlations, partitioning and bioaccumulation of trace metals between different segments of Taylor Creek, southern Nigeria

Okafor

Opuene

2006

ABSTRACT:Correlations between trace metals in dissolved and particulate phases, B. bayad and sediments were investigated in five selected sites along Taylor Creek, which lies between longitude 006°17I to 006°21 I E and latitude 05°01 I to 05°05 I N. The degree of correlation between the various metals was different in each of the investigated segments. Between segments, not many significant correlations were recognized. Only Ni and Cd, Mn and Cd, Mn and Ni, and Mn and Pb are correlated in the sediments and in the particulate phase, Fe and Cr, Pb and Cd, and Zn and Ni are correlated, which suggests that the sources are not common for both compartments. Partitioning coefficients (K d ) of trace metals between dissolved and particulate phases are generally low, which is typical for fresh water ecosystems and fairly stable over Taylor Creek all through the seasons. Furthermore, the bio-concentration factors (BCF) of B. bayad were low unlike those of other natural waters. Cluster analysis showed that metal accumulation in the particulate phase differed from those observed in sediments, which also confirms that the pollution of the Creek might be from different sources.