Diatoms in maggots; a potential tool for drowning diagnosis - A preliminary study.

Advanced putrefaction causes extensive loss of soft tissue, rendering it difficult to use the diatom test as a reliable diagnostic tool for drowning investigations. A positive diatom test in carrion insect larvae may provide significant assistance in overcoming the challenge of decomposition. The studies determined the utility of diatom test in carrion larvae on severely decomposed bodies. A modified acid digestion method involving nitric acid, K2Cr2O7 and HCl, was used to digest the blowfly larvae feeding on piglet carrion previously drowned in freshwater and sea water, respectively. Extracted diatom frustules were analysed and characterised using light microscopy coupled to a digital camera. Diatoms recovered from maggots on sea-drowned piglets were similar to diatoms from sea water (drowning medium). Centric diatoms recovered in maggots were higher (200 ± 60 diatoms/ mL) than pennate diatoms (80 ± 20 diatoms/mL). Isolated diatoms common to both maggots and water samples included Coscinodiscus sp. and Navicular spp. Albeit, there were no diatoms recovered from maggots on freshwater-drowned piglets. The findings of this study suggest that the diatom test is still a reliable diagnostic tool to determine if drowning was involved in the death of a fully decomposed body. This is the first study that isolated diatoms from maggots feeding on drowned bodies. It serves as the basis for further research into the utility of maggots for drowning investigations.

Statistical evaluation of environmental contamination, distribution and source assessment of heavy metals (aluminum, arsenic, cadmium, and mercury) in some lagoons and an estuary along the coastal belt of Ghana.

An environmental pollution investigation was carried out to determine the concentrations of aluminum (Al), arsenic (As), cadmium (Cd), and mercury (Hg) (heavy metals) in the surface water and river water bed sediments of lagoons and estuaries along the coastal belt of Ghana. The study assessed the environmental pollution situation and evaluated their sources and distribution of these metals. The total concentrations of Al, As, Cd, and Hg were determined by the neutron activation analysis technique. Water and sediment samples were collected from the Benya, Fosu, and Narkwa lagoons in the Central Region and from the Pra estuary in the western part of Ghana. Some indices, such as contamination factor, pollution-load index, contamination degree, and geoaccumulation index, were used to assess eco-environmental quality of the sampling sites. The analysis indicated that the Fosu lagoon was fairly polluted with Cd. The investigation indicated a highly localized distribution pattern closely associated with the two pollution sources (garbage/solid waste dumps and industrial activities) along the coastal belt. The resulting environmental deterioration required a concerted evaluative effort by all stakeholders.

Levels of platinum group metals in selected species (Sarotherodon melanotheron, Chonophorus lateristriga, Macrobrachium vollenhovenii and Crassostrea tulipa) in some estuaries and lagoons along the coast of Ghana.

The use of some biota as bioindicators of heavy metal pollution has been demonstrated as particularly adequate due to their capacity of bioconcentration. This study evaluated the levels of platinum group metals (PGMs) in some selected species along the coastal belt of Ghana, using the neutron activation analysis (NAA) method. The result was processed to evaluate pollution indices in order to map the distribution of the metals in those species in the lagoons and estuaries along the costal belt of Ghana. The analysis showed significant levels of all PGMs in blackchin tilapia (Sarotherodon melanotheron Cichlidae), brown goby (Chonophorus lateristriga Gobiidae), shrimp (Macrobrachium vollenhovenii Palaemonidae), and mangrove oysters (Crassostrea tulipa Ostreidae) in the lagoons and river Pra estuary. However, the oysters showed an elevated mean concentration of 0.13 µg/g (dry weight) Pd. From the pollution indices, most of the sampling sites registered mean contamination factor (CF) values between 1.20 and 3.00 for Pt, Pd, and Rh. The pollution load index (PLI) conducted also gave an average pollution index between 0.79 and 2.37, indicating progressive contamination levels. The results revealed that anthropogenic sources, industrial and hospital effluent, etc., together with vehicular emissions, could be the contributing factors to the deposition of PGMs along the Ghanaian coast.

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 approximately 1 pH unit, increase of approximately 65% NH3, one to two orders of magnitude increase in PO4(3-), and more than two orders of magnitude increase in NO3-. 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, SO4(2-), PO4(3-), Cu, and Zn were among the chemical contaminations observed to occur in the distribution system.

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.