The impact of vehicular fallout on the Pra estuary of Ghana (a case study of the impact of platinum group metals (PGMs) on the marine ecosystem)

It is increasingly being recognised and environmental measurements have demonstrated that Platinum (Pt) (and potentially Rhodium (Rh) and Palladium (Pd)) is released with the ageing of catalytic converters. Platinum is a particular concern as it has a known mutagenic and toxic effect, even at exceedingly low concentrations, in urban air (affecting human health) and urban water (affecting ecosystem health). In the context given above and given the still keen lack of reliable experimental data on the levels of Pd, Pt and Rh in water and sediment, this study determined the concentration of such elements in water and sediment of the Pra estuary in the Western Region of Ghana where it is estimated that more than two thousand cars pass over the bridge under which the river flows to join the sea each day. Elevated concentrations of platinum (Pt), palladium (Pd) and Rhodium (Rh) were found to be associated with water and soils from areas of high traffic densities (Beposo) suggesting that vehicles also contribute heavy metals (PGMs) to the environment. The result showed elevated levels of these metals in river bank, waterbed and in the water. There is therefore the tendency of possible accumulation of these metals in plant and animals along these areas.     

Assessment of dry season surface, ground, and treated water quality in the Cape Coast municipality of Ghana

This aim of this monitoring was to assess water quality in a dry season for the Cape Coast municipality in Ghana, which has been experiencing chronic water shortages. Fifteen different sampling stations—four surface, five ground, and six tap water samples—were analyzed for physicochemical and microbiological parameters during January to April 2005. Levels or trends in water quality that may be deleterious to sensitive water uses, including drinking, irrigation, and livestock watering have been noted with reference to well-established guidelines. Exceedances to some health-based drinking water guidelines included positive coliform for various water samples; pH for all groundwater samples (pH 5.9 ± 0.3); conductivity for 50% groundwater; color for about a third of groundwater and tap water; Mn for 44% tap water, 67% groundwater, and 50% surface water samples. The World Health Organization laundry staining Fe guideline of 0.3 mg/l was exceeded by 75% of surface water, 44% tap water, and 53% groundwater samples. The corresponding Mn guideline of 0.1 mg/l was exceeded by all the water samples. Respectively, all surface water samples and also 75% of the surface water exceeded some known Cu and Zn guideline for the protection of aquatic life. Compared to some historic data for Fosu Lagoon, the current study shows a lowering of ~1 pH unit, increase of ~65% $\text{NH}_{3}$ , one to two orders of magnitude increase in PO $_{4}^{{3}^{-}}$ , and more than two orders of magnitude increase in NO $_{3}^{-}$ . In several instances, tap water samples collected at the consumers’ end of the distribution system did not reflect on the true quality of the treated water. Mn, SO $_{4}^{{2}^{-}}$ , PO $_{4}^{{3}^{-}}$ , Cu, and Zn were among the chemical contaminations observed to occur in the distribution system.     

Bioaccumulation of platinum group metals on some fish species ( Oreochromis niloticus,Penaeus laspisulcates,Scylla serrate,Galaxias brevipinnis and Mollusc ) in the Pra estuary of Ghana

Catalytic converters have been designed to solve the problem of pollution from automobiles. However, recent studies have shown that the platinum group metals (PGMs) that are used in the design are being deposited alongside highways. The objective of this study was to measure the levels of PGMs that bioaccumulate in Oreochromis niloticus, Penaeus laspisulcates, Scylla serrate, Galaxias brevipinnis and Mollusc in the river Pra estuary along a major highway in Ghana. Chemical analysis using neutron activation analysis showed accumulation of the PGMs in all the biota species analysed. The S. serrate and mollusc showed higher accumulation than the other species. The mollusc and the other fish species in the estuary are consumed in Ghana, and therefore there is the need to educate the population on the effect of the PGMs on their health.