Partitioning of inorganic and organic mercury in cockles Cardium edule (L.) and C. glaucum (Bruguiére) from a chronically polluted area: influence of size and age

Partitioning of inorganic and organic mercury was studied in the cockles Cardium edule and C. glaucum sampled in a chronically polluted area in the Western Limfjord, Denmark. The proportion of organic mercury in the cockles was linearly correlated to age (and weight) but not to total mercury concentration in the cockles. In 2-, 3- and 4-year-old cockles organic mercury constituted c. 30%, 60%, and 90% of total mercury, respectively. The age correlated proportion of organic mercury is discussed in a food chain context.     

A 10-year survey, 1980–1990, of prenatally diagnosed small supernumerary marker chromosomes,identified by fish analysis. Outcome and follow-up of 14 cases diagnosed in a series of 12 699 prenatal samples

A cytogenetic survey and follow-up studies were made of 14 cases with supernumerary marker chromosomes, identified among 12 699 prenatal samples, investigated at our institution over a 10-year period from 1980 to 1990. FISH (fluorescence in situ hybridization) techniques were employed to identify the chromosomal origin of the marker chromosomes. Five cases were familial, all derived from acrocentric chromosomes, and all without apparent phenotypic effects in the children. Nine cases represented de novo aberrations. In two cases (one with a marker from chromosome 14 or 22, the other with a ring-like marker derived from chromosome 17), the pregnancies continued and apparently normal babies were delivered at term, but the child with a marker derived from chromosome 17 showed slight psychomotor retardation at 2 years of age. All other pregnancies with de novo markers were terminated. In three cases, significant abnormalities were found at autopsy. One of these had an isochromosome 12p and the phenotype was consistent with Pallister-Killian syndrome. In conclusion, marker chromosome identification, as well as clinical follow-up, is essential for the purpose of improving genetic counselling.     

Air pollution exposure monitoring and estimation. Part IV. Urban exposure in children

In the winter of 1994, 2300 school-age children in Oslo participated in a panel study of the role of traffic pollution on the exacerbation of diseases of the respiratory system and other symptoms of reduced health and well being in children. The children filled out a diary daily with information for five time points over six weeks. In order to quantify exposure-effect relationships for the symptoms, individual exposure to NO2 and particulate matter (PM2.5) was estimated, using the DINEX method a combination of information from the diary as to the children's whereabouts during the five time points each day, coupled with continuous dispersion modelling. An individual exposure estimate for each time point for each child was defined. Individual exposure estimated using dispersion modelling can be used to examine patterns of exposure such as isolating geographic areas with higher concentrations or describing concentrations of pollution by time of day. The diary allowed the time-use of the children to be described.     

Practical experience with the management of a cholera outbreak in a refugee cAMP in eastern Sudan, 1985

From May to November 1985 most refugee camps in Eastern Sudan were affected by cholera. This article summarizes the experience from the refugee camp Wad Sherife with the emphasis on the practical aspects of management of cholera in a refugee context. Paramedical personnel from the refugee community were used to a great extent both in curative and preventive measures. The home visitors played an important role in the early detection of the cases and in trying to prevent the spread of cholera in the camp. A total of 1793 cases were admitted during a three month period. The results show a case fatality rate of 1.8%. A significantly higher number of women were affected in the age group 15–44. As seen in other refugee camps in Eastern Sudan, there was a relatively high intravenous fluid consumption with an average of about 6 litres in adults.     

Baseline survey of concentrations of toxaphene congeners in fish from European waters

The European Union project "Investigation into the monitoring, analysis and toxicity of toxaphene"(MATT) began in 1997 involving participants from the Netherlands, Ireland, Norway and Germany. Concentration information, analytical methodology and statistical interpretation of 207 samples covering 23 different fish species from European waters are presented for three toxaphene indicator congeners: CHBs 26, 50 and 62 (CHB = chlorobornane). Concentrations for the Sigma3CHBs were more elevated in fish from more northern latitudes, such as the Barents and Norwegian Sea, compared to fish from Irish, Dutch and German waters. Concentrations were lowest in shellfish and in fish species having low lipid content and were highest in medium/high lipid species. Females from a number of fish species were shown to contain significantly higher concentrations than those observed in male fish. Overall no samples were shown to exceed existing German MRL legislation, with only one Greenland halibut sample shown to exceed Canadian TDI recommendations.     

Classification of particles from the farm environment by automated sizing, counting and chemical characterisation with scanning electron microscopy-energy dispersive spectroscopy

About 60,000 particles in 288 aerosol samples collected during farm work have been characterised with automated particle analysis using scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDS). Based on EDS-analysis of materials with known composition (potato flour, alpha-quartz, K-feldspar and beta-wollastonite), criteria were developed for classification of particles as: (1) organic, (2) silicon-rich (silica), and (3) other inorganic particles. The reproducibility of the relative mass proportions in dust samples collected during farm work was 0.078 when approximately 200 particles were characterised per sample. Field samples from the farm environment showed clear differences in composition. Generally, inorganic particles dominated the particle mass. The proportion of the organic particle mass was highest for tending of swine and poultry, 55 and 38% respectively. Silica particles amounted to 10 to 20% of the total mass during handling crops, e.g. grain, straw, hay, potatoes, and onions. It seems likely that the results can be used in etiologic studies, but further validation would be needed for quantitative purposes.     

Scanning electron microscopy of metamorphosis in four species of barnacles (Cirripedia Thoracica Balanomorpha)

Metamorphosis and early juvenile development was followed in the laboratory in Balanus amphitrite and B. improvisus (family Balanidae) and in Semibalanus balanoides and Elminius modestus (family Archaeobalanidae) from cyprid settlement until 24 h after ecdysis. Stages of development were studied in vivo and with scanning electron microscopy. Events in metamorphosis and early juvenile development are very similar in all four species and can be interpreted in terms of a highly modified moult. Notably, there was no indication whatsoever of the amorphous decorticated settler previously described from metamorphosis of B. amphitrite. The shape of a juvenile barnacle with cirri and incipient shell plates is apparent immediately after the shedding of the cypris carapace, and rudimentary peduncle can be distinguished below the developing wall plates. A basal row of cuticular hairs encircles the peduncle in all species except S. balanoides. These hairs seem to serve a restraining function during early development, when the juvenile barnacle is only attached by the initially secreted cyprid cement. Similarly situated hairs are also present in very young juveniles of the lepadomorph Scalpellum scalpellum. In Semibalanus balanoides nothing indicates that the rostrum originates from the fusion of two latera as previously claimed, since this plate is single as soon as it can be distinguished.