Pre-assessment of the speciation of 60Co, 125Sb, 137Cs and 241Am in a contaminated aquifer

A sample of contaminated groundwater was analyzed using a combination of wet techniques to obtain geochemical information on the mobile species of 60Co, 125Sb, 137Cs and 241Am. The techniques were combined in a scheme to determine the predominant character of the radionuclides in negative or positive fractions, size separation by ultrafiltration, and their association with natural organic matter (NOM). The analyses indicated that the radionuclides of interest were predominantly in the negative fraction. Most of the 60Co and 125Sb were in the small size fraction (<5000 Da), and 137Cs and 241Am were found with the larger, colloidal-sized material. Antimony-125 and 60Co were predominantly in the hydrophilic fraction, while 137Cs and 241Am were found in hydrophobic fractions. Our analysis indicated that 137Cs is found in the same fraction as the large-sized colloidal (hydrophobic) material, suggesting an association with NOM. The results suggested that 60Co and 241Am were associated with NOM, in different size fractions, suggesting that these two nuclides are bound to different sites. Finally, the 125Sb results were inconclusive, whether this nuclide is associated with NOM, or it is inorganic.     

Influence of oil contamination levels on hydrocarbon biodegradation in sandy sediment

The influence of oil concentration on hydrocarbon biodegradation in a sandy sediment was studied in polyvinyl chloride reactors (0.45 x 0.28 x 0.31 m) containing 76.8 kg of beach sand in natura, where the upper layer was artificially contaminated with petroleum. The oil-degrading microorganisms used consisted of a mixed culture named ND, obtained from landfarming and associated with indigenous microorganisms. On the 28th day of the process, the degradation in reactors containing sandy sediment contaminated with light Arabian oil and presenting an initial oil content of 14, 21 or 28 g kg-1 reached the following levels (%): 33.7, 32.9 and 28.9 for oil and grease; up to 88.3, 35.3 and 13.0 for C14-C26 n-alkanes; and 100, 61.3 and 59.4 for pristane, respectively. Phytane removal (37.1%) was only detected in the reactor contaminated with the lowest oil concentration studied. These results, together with the expressive bacterial growth observed (from 10(6) to 10(11) cfu g-1) give strong support to the argument that biodegradation was the dominant component of the remediation process. Susceptibility to biodegradation was inversely proportional to increasing oil contamination. The degradation of branched alkane: pristane was not repressed by the presence of n-alkanes.     

Reasons for women's non-uptake of amniocentesis

More than 10 years after a chromosomal anomaly screening programme was set up in France for pregnant women of advanced age, amniocentesis is still a controversial issue. The reasons why eligible women did not utilize the test and whether or not the existence of social welfare coverage determined women's access to prenatal diagnosis were studied. A group of 291 women aged ⩾35 years who recently gave birth to normal liveborns was interviewed by telephone. Among those aged 38 years and over, who automatically qualified for social security coverage, 75 per cent had undergone amniocentesis as opposed to 23 per cent in the 35 to 37-year-old non-covered age group who did not qualify for social security coverage. In both groups, access to amniocentesis was found to depend on the physicians', women's and male partners' attitudes towards prenatal diagnosis and abortion. Among the younger group, the uptake depended mainly on socio-economic factors. Institutional policies should ensure greater equality of access while allowing for individual preferences.     

Measuring total sustainable incomes from multifunctional management of Corsican Maritime Pine and Andalusian Cork oak Mediterranean forests

Enough advances have recently been made in income accounting theory to recommend that environmental services accruing either to the forest owner or to the general public should be included in the forest accounting system. In this study, the results of two case studies, one in Bonifatu, Corsica (France) and the other in Alcornocales, Andalusia (Spain), show that private environmental services provide the majority share of social total sustainable income in Alcornocales (29%), whereas public environmental services are the most relevant in Bonifatu (32%). The social total sustainable income measured by the agroforestry accounting system is, respectively, 1.6 and 2.4 times higher than the income estimated by economic accounts for forestry in Alcornocales and Bonifatu forests.     

Inter-laboratory validation of an ISO test method for measuring enzyme activities in soil samples using colorimetric substrates

Environmental Science and Pollution Research - The evaluation of soil quality requires the use of robust methods to assess biologically based indicators. Among them, enzyme activities are used for...     

Annealing Effect on Pla/Eva Blends Performance

Journal of Polymers and the Environment - PLA has aroused industrial and scientific interest in recent years, mainly due to its biodegradable character. However, PLA is brittle and displays low...