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[en] This article highlights the disagreement between 2 scientific commissions about the maximal acceptable concentration of radon. 1000 or 400 becquerels for each cubic-meter of air (Bq/m3). Information about the average concentration of radon in the different French departments is given by means of a map. (A.C.)
[en] In the assessment of the quality of surface waters, the typical procedure is that the concentration of contaminants in the surface water is monitored and subsequently compared with their respective Maximum Permissible Concentrations (MPCs). If the MPCs are not exceeded the water quality is considered to be safe. But can we be certain that this is true? We compared MPCs to observed and calculated effects of measured contaminants in Dutch surface waters and showed that effects of mixtures can cause a daphnid population to go extinct within 30 h of exposure even when MPCs are not exceeded. We conclude that there are shortcomings underlying the concepts of the MPCs. And that the MPCs aim to protect 95% of all species is not met. - Daphnid populations can go extinct rapidly in surface waters if exposed to mixtures even if environmental quality standards are not exceeded.
[en] Attention has been focused on the issue of radon in drinking water by a European Commission recommendation proposing that surveys should be undertaken in Member States to determine the scale and nature of exposures caused by radon in domestic drinking water supplies. The Commission recommends 1000 Bq/l as the radon activity concentration in private drinking water supplies above which remedial action to reduce the concentration should be taken. The logic behind the proposed action level is that it would broadly correspond to the risk posed to an individual from exposure to radon in the home at the current Reference Level of 200 Bq/m3 in air. A pilot study to assess the distribution and concentrations of radon in private ground water supplies was recently completed in Co. Wicklow. County Wicklow was selected for the study primarily on the basis that the underlying geology is predominantly granite with elevated uranium content. Furthermore, there is an estimated 1200 to 5000 private ground water supplies in use in the county and high radon activity concentrations in air in a significant number of dwellings have previously been predicted. As part of the pilot study, a number of scientific issues were addressed in order to underpin the results obtained and these are also discussed in the report. Radon activity concentrations were measured in the private ground water supplies of 166 houses in Co. Wicklow. In all cases the ground water was the principal source of drinking water for the house occupants. Four supplies had activity concentrations in excess of the Recommended EC action level of 1000 Bq/l, fifteen had activity concentrations between 500 and 1000 Bq/l, 51 were between 100 and 500 Bq/l and 96 had activity concentrations below 100 Bq/l. The doses estimated for the ingestion of radon bearing water varies significantly with the quantity of drinking water consumed and the degree to which the water has been processed prior to consumption. However dose estimates based on measurements made in this study demonstrate that radon in drinking water may pose a significant additional health risk, in the longer term, to some consumers who depend on private ground water supplies as their primary source of drinking water. (author)
[en] Nowadays, one of the environmental problems is the pollution of the environment with heavy metals, the release of which leads to accumulation in the body of animals. The aim of the research was to study the content of heavy metals in the body of cows of different breeds in a separated agricultural enterprise. Researches were held in LLC "EIF Solyanskoe" of Krasnoyarsk region. The objects of research were the blood, urine and milk of cows Red-Motley breed and Black-Motley breed at the age of the second lactation. The result of research determined that concentration of Cu, Zn and Pb in milk and blood serum of Red-Motley cows was more than in Black-Motley cows; on the contrary, in urine the concentration of the studied metals was higher in Black-Motley cows. In general, the content of heavy metals in milk, blood serum and urine of cows of both breeds did not exceed the maximum permissible concentrations, with the exception of Pb in milk, the existence of which was slightly higher than the hygienic norm by 0.02–0.03 mg/kg. (paper)
[en] The Kuril Islands region is considered promising for development of salmon aquaculture. There are 41 salmon fish hatcheries in the Sakhalin Island and the Kuril Islands, 34 of them are hatcheries of the chum. Therefore, concentrations of six elements (Zn, Cu, Cd, Pb, As, and Hg) were determined in chum salmon were caught in this region. The contents of toxic elements (Cd, Pb, As, and Hg) don't exceed their maximum permissible concentrations (MPC) according to the Russian sanitary standards, but concentration of Pb are closely to MPC. Increased concentrations of Pb in wild chum have the natural origin. The unusual conditions of the Western Pacific are formed under the influence such factors as volcanism and upwelling. - Highlights: • High content of Pb, found in chum from the Kuril Islands, is caused by natural sources. • The content of elements do not exceed maximum permissible concentrations in Russia. • Kuril region is considered as promising zone for development of salmon aquaculture. - Kuril region is suitable for aquaculture development of Pacific salmon.
[en] The article is an analysis of air pollution for the period 2011-2013 by priority air pollution cities of Kazakhstan: Almaty, Ust-Kamenogorsk, and Pavlodar. In these cities revealed values of maximum permissible concentration (MPC) of pollutants in the air of populated areas, the magnitude of the integrated pollution index (API5), which was calculated using the five substances with the highest normalized values MPC considering their risk class, as well as estimated by the excess of MPC. The article also provides an analysis of lung cancer incidence in the last 3 years due to the identification of development with air pollution.
[en] The first two months of the third Advanced LIGO and Virgo observing run (2019 April-May) showed that distant gravitational-wave (GW) events can now be readily detected. Three candidate mergers containing neutron stars (NS) were reported in a span of 15 days, all likely located more than 100 Mpc away. However, distant events such as the three new NS mergers are likely to be coarsely localized, which highlights the importance of facilities and scheduling systems that enable deep observations over hundreds to thousands of square degrees to detect the electromagnetic counterparts. On 2019 May 10 02:59:39.292 UT the GW candidate S190510g was discovered and initially classified as a binary neutron star (BNS) merger with 98% probability. The GW event was localized within an area of 3462 deg2, later refined to 1166 deg2 (90%) at a distance of 227 ± 92 Mpc. We triggered Target-of-Opportunity observations with the Dark Energy Camera (DECam), a wide-field optical imager mounted at the prime focus of the 4 m Blanco Telescope at Cerro Tololo Inter-American Observatory in Chile. This Letter describes our DECam observations and our real-time analysis results, focusing in particular on the design and implementation of the observing strategy. Within 24 hr of the merger time, we observed 65% of the total enclosed probability of the final skymap with an observing efficiency of 94%. Here, we identified and publicly announced 13 candidate counterparts. S190510g was reclassified 1.7 days after the merger, after our observations were completed, with a "BNS merger" probability reduced from 98% to 42% in favor of a "terrestrial classification.
[en] Carbon nanotubes (CNT) can be chemically modified by doping or functionalization to change the chemical and surface properties. These characteristic makes to CNT candidates for multiple applications including medical field in cardiovascular area. A novel method to CNT functionalization by formation of two compounds: α-bromoacid and the organic compound 2-(methacryloyloxy) ethyl phosphorylcholine (MPC), will be discussed in this article. According to results, CNT are suggested like candidates to repel oxidized low-density lipoproteins (ox-LDL) to prevent restenosis. The electronegative character on surface of functionalized CNT (F-CNT) is shown by wettability analysis observing a repellent behaviour in contact with ox-LDL after functionalization route. Here we analyse the toxicity of CNT and F-CNT on HepG2 cell line and find no damage to the cell membrane of HepG2 cells in concentration at doses below 1 mg/ml. - Highlights: • Carbon nanotubes, materials suggested like candidates to repel ox-LDL causative of cardiovascular diseases. • MPC functionalized CNT, a new route to repel ox-LDL. • MPC functionalized CNT increased repulsive behaviour with angles up to 135 grades in contact with ox-LDL. • CNT could be considered to medical applications in concentrations < 1mg/ml and diameters up to 60 nm.