Neutron activation study of the natural elementary composition of edible sea urchins (Paracentrotus lividus Lamarck) in the National Park of Port-Cros (Mediterranean, France).

Neutron activation study of elementary composition was performed on edible sea urchins Paracentrotus lividus from the National Park of Port-Cros. The analysis allows the identification and quantification of 22 elements: antimony, arsenic, baryum, bromine, cerium, chromium, cesium, cobalt, gold, iron, lanthane, potassium, sodium, rubidium, samarium, scandium, selenium, silver, strontium, thorium, uranium and zinc. The concentration levels were higher in the soft organic parts (alimentary canals and gonads) for all the elements, except for strontium, which developed a strong affinity with calcareous hard parts (tests, spines, masticating apparatus). We also found high rates of baryum, arsenic, zinc, bromine and iron. The hypothesis on the origin of these elements is discussed. The data obtained on this referential zone will soon be used to appreciate the perturbation of the elementary composition of urchins by pollution in various parts of the French seashore.

Neutron activation study of the elementary composition of edible sea urchins (Paracentrotus lividus Lamarck) in marine creek area polluted by city sewages of Marseille (France).

Neutron activation study of elementary composition (Ag, As, Au, Ba, Br, Ce, Co, Cr, Cs, Fe, K, La, Na, Rb, Sb, Sc, Se, Sm, Sr, Th, U and Zn) was performed on edible sea urchins (Paracentrotus lividus Lamarck) from marine creek area polluted by city sewages from Marseille (France) after a purifying plant was brought into operation. Concentration levels were higher in soft organic parts (alimentary canals and gonads) for all the elements except for Sr which showed a strong affinity for calcareous parts (tests, spines and masticating apparatus). Certain elements present in the soft organic parts are rarely found in the hard parts. More than half the elements studied show higher concentrations in Marseille samples than in the referential region of Port-Cros National Park (France). That must be due to sewage rejection for a large number of them. This hypothesis is confirmed with regard to elements the values of which decrease significantly with the distance from the sewage emission point, e.g. Cr, Fe and Zn, and a little less for Ag, Ba, Ce, Rb, Sb, Sc, Se, Sm and Th. These results raise a question: has that artificial change on the elementary composition any toxicological effects on the urchin populations? This question is discussed.

Mercury, zinc and selenium bioaccumulation in tissues and organs of Mediterranean striped dolphins Stenella coeruleoalba meyen. Toxicological result of their interaction.

Neutron activation analysis of 13 Mediterranean striped dolphins Stenella coeruleoalba showed high mercury and selenium contaminations of main tissues and organs of these cetaceans. The mercuric contents were excessive, particularly in liver (from 68 to 2272 micrograms/g dry wt. basis), then in kidney, lung, muscle, heart and brain. The selenium concentrations were also high in liver (from 45 to 1320 micrograms/g dry wt. basis), then in kidney, lung, muscle, skin and heart. The main way of contamination seems to be the food through trophic network, but skin and lung are also able to play a part which must be elucidated. The average Hg/Se ratios in liver and kidney were respectively 1.82 and 1.59. Linear relationship between mercury and selenium concentrations in tissues and organs, particularly in liver and kidney, were confirmed. The mercury and selenium interaction on a toxicological point of view was established by a statistical approach; in the same way, intervention of zinc, metallothioneins and glutathiones have been discussed.

Transfer of toxic elements from the atmosphere to cattle and game animals.

Neutron activation analysis was used for determining trace element content in hair of herbivorous animals. Pollutant deposition from the air onto foliage must be considered as the main cause of contamination of the animals.

Production of 134Cs thermo-generated aerosols. Study of their behavior after deposition on spruce trees.

This paper presents observations made on the behavior of radioactive cesium in laboratory conditions. 134Cs-loaded aerosols are generated from UO2 pellets in an electric oven and allowed to deposit on small spruce trees. The transfer of radioactivity to the plants has been studied. In another series of experiments, trees are submitted to artificial rain contaminated by the radioactive aerosols. The two modes of contamination are compared.

Air quality status in Kinshasa as determined by instrumental neutron activation analysis, atomic absorption spectrometry, and ion-exchange chromatography.

Three independent analytical techniques: instrumental neutron activation analysis, atomic absorption spectrometry, and ion-exchange chromatography were applied to airborne particulates collected on filters, and to atmospheric acid gases collected in carbonate buffer solutions. Twenty trace elements and seven acid gases and acid aerosols were determined. Results were compared with those observed elsewhere and showed that air pollution is low in Kinshasa and should not cause anxiety. The main known sources of pollutants are vehicle exhaust and aeolian processes on stripped soils.