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Biomedical subjects

H Muntau

Publications and source records attributed to H Muntau.

4 recordsLinked to original sources

Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in the sediments of an Italian drinking water reservoir.

The concentration of 9 polychlorinated biphenyls (PCB 28, 52, 101, 151, 153, 170, 180, 183 and 194) and of 6 micropollutants commonly classified as organochlorine pesticides, or OCPs (alpha-HCH, beta-HCH, gamma-HCH, p,p'-DDT, p,p'-DDE and p,p'-DDD), was determined in 22 sediment samples of lake Simbirizzi, an artificial reservoir supplying drinking water to the city of Cagliari (Sardinia, Italy). The quantification was performed by analysing purified sediment extract with HRGC-ECD. The average concentrations proved to be relatively low. In the case of p,p'-DDE, the contaminant with the highest concentration, a mean value of 0.84 ppb (micrograms/kg d.m.) was found. These relatively low concentrations and the comparison with data relating to other lakes suggest that, as far as PCBs and the majority of OCPs are considered, atmospheric inputs are likely to be the main source of contamination. Only for lindane (gamma-HCH) it is possible to assume a contribution from agricultural activities. The presence of its isomers (alpha-HCH and beta-HCH) was attributed to natural occurring reactions of the gamma-form.

Agriculture

Toxicity identification evaluation of Lake Orta (Northern Italy) sediments using the Microtox system.

Pore waters extracted by centrifugation from Lake Orta (Northern Italy) sediments were studied with a modified Toxicity Identification Evaluation (TIE) procedure using the Microtox bacterial luminescence toxicity test system. The most toxic pore water samples were from stations near a rayon factory, known as a source of copper and ammonium discharges. The TIE manipulations used were filtration, EDTA chelation, and C18 solid-phase resin adsorption. The most effective treatments to remove toxicity were the EDTA and C18, indicating that both metals and nonpolar organic compounds contribute to the observed toxicity.

Ammonia

[Reference materials and trace element analysis].

The use of appropriate reference materials allows the accuracy of analytical determinations to be assessed. The present availability of certified reference materials not always can adequately meet the needs of research in the field of trace and ultratrace element analysis, in particular as regards complex matrices, such as biological and environmental materials. In this context the various definitions of a reference material are discussed. Planning and certification of novel certified reference materials cannot disregard the exigency of obtaining more qualified information on the analytes, especially in so far as their different chemical species are concerned.

Animals

Sources of cadmium, its distribution and turnover in the freshwater environment.

Cadmium enters the aquatic environment from numerous sources, e.g., via the atmosphere, from which the cadmium released by combustion, mainly of fossil fuels, is deposited. Since some fertilizers contain up to 40 mg/kg cadmium, wash-out from agricultural land is another source. Zinc ores contain up to several percent of cadmium, and there may be high concentrations in raw zinc, zinc alloys and zinc compounds, so that cadmium may enter the aquatic environment from mining residues, solid wastes and wastewater discharges. Once in the aquatic environment, cadmium is highly mobile. Its dissolved species are extremely labile, and are the first to be released, e.g., when salinity increases in estuaries. Sediments reflect the metal loading in the past, and their analysis can be the key to an understanding of the fate of anthropogenic discharges into the hydrosphere. The internal cadmium loading of aquatic systems can be estimated from the remobilization rates of cadmium from sediments.

Animals