ABSTRACT
Trace amounts of water dissolved in minerals affect density, viscosity and melting behaviour of the Earth's mantle and play an important role in global tectonics, magmatism and volatile cycle. Water concentrations and the ratios of hydrogen isotopes in the mantle give insight into these processes, as well as into the origin of terrestrial water. Here we show the presence of molecular H2 in minerals (omphacites) from eclogites from the Kaapvaal and Siberian cratons. These omphacites contain both high amounts of H2 (70 to 460 wt. ppm) and OH. Furthermore, their ∂D values increase with dehydration, suggesting a positive H isotope fractionation factor between minerals and H2-bearing fluid, contrary to what is expected in case of isotopic exchange between minerals and H2O-fluids. The possibility of incorporation of large quantities of H as H2 in nominally anhydrous minerals implies that the storage capacity of H in the mantle may have been underestimated, and sheds new light on H isotope variations in mantle magmas and minerals.
ABSTRACT
On the basis of official statistics of 1995-2014 a comparative analysis of the dynamics of stillbirths of boys and girls in the Bryansk region and the Russian Federation was carried out. The study established exceeding of rate of stillbirths in boys over stillbirths in girls at 14.4% and 9.0% correspondingly both in the Bryansk Oblast and the Russian Federation that confirms the global trend of higher risk of stillbirth in boys by approximately to 10%. In case the stillbirth rate in the Bryansk Oblast will proceed established trend the ratio of stillbirths will increase relatively to the nationwide values in 2016 - 2021 and will reach 30% in 2021. At that, the gap between indices of boys and girls will increase up to 32,8%.
Subject(s)
Infant Mortality , Stillbirth , Female , Humans , Infant , Infant Mortality/trends , Infant, Newborn , Male , Pregnancy , Russia/epidemiologyABSTRACT
On the basis of official statistical data for 1999-2014 the authors assessed the frequency of polydactyly, reduction defects of limbs and multiple congenital malformations in newborns of the Bryansk region living in the areas with different densities of radioactive contamination by long-lived radionuclides cesium-137.(3.0 to 2523.4 kBq/m(2)) and strontium-90 (from 0.02 to 42.5 kBq/M(2)). The findings did not reveal statistically significant differences in the frequency of polydactyly, reduction defects of limbs and multiple congenital malformations in newborns in the South-Western Territories compared with medium-regional values, although the maximum value of the sum of congenital. developmental anomalies (polydactyly, reduction limb defects and multiple congenital malformations) are detected in the above-mentioned most contaminated areas.
Subject(s)
Abnormalities, Multiple/epidemiology , Chernobyl Nuclear Accident , Congenital Abnormalities/epidemiology , Polydactyly/epidemiology , Abnormalities, Multiple/etiology , Abnormalities, Multiple/physiopathology , Cesium Radioisotopes/toxicity , Congenital Abnormalities/etiology , Congenital Abnormalities/physiopathology , Female , Humans , Infant, Newborn , Male , Polydactyly/etiology , Polydactyly/physiopathology , Republic of Belarus/epidemiology , Strontium Radioisotopes/toxicityABSTRACT
On the basis of official statistics for 1999-2014 there was performed the comparative evaluation of the prevalence of congenital malformations de novo: polydactyly, reduction limb defects and multiple congenital malformations in newborns of radiation-contaminated areas of the Bryansk area residing in areas with the various density of radioactive contamination by long lived radionuclides cesium-137 (from 10.0 to 2523.4 kBq/m) and strontium-90 (from 0.7 to 42.5 kBq/m). The findings showed no statistically significant differences in the prevalence of polydactyly, reduction limb defects and multiple congenital malformations in newborns in the South-Western areas compared to medium regional values, although the maximum value of the amount of congenital malformations de novo is found in most radiation-contaminated areas.
Subject(s)
Congenital Abnormalities/epidemiology , Environmental Exposure/adverse effects , Radioactive Hazard Release/statistics & numerical data , Cesium Radioisotopes/analysis , Female , Humans , Infant, Newborn , Male , Prevalence , Russia/epidemiology , Strontium Radioisotopes/analysisABSTRACT
The use of the buccal mucosa cell micronucleus test for comparison of chemical, radiation, and radiation-chemical environmental pollution has been considered. The combined impact of chemical and radiation factors has been found to cause additive effects, synergism, and inhibition. It has been noted that the cytogenetic characteristics of the buccal epithelium may be used as a "biological dosimeter" of the total level of environmental pollution.
Subject(s)
Mouth Mucosa/cytology , Radioactive Pollutants/adverse effects , Water Pollutants, Chemical/adverse effects , Child , Female , Humans , Male , Mouth Mucosa/drug effects , Mouth Mucosa/radiation effectsABSTRACT
Comparative evaluation of the frequency of incidence of all forms of primary malignant tumors in the child population over the fourteen-year period (1995-2008.) is presented. Evaluation was carried out in ecologically unfavorable territories of the Bryansk region with varying density of radioactive (from 28.1 to 661.9 kBq/m2 for 137Cs), toxic (from 1.47 to 183.6 kg/person/year for gaseous toxic substances) and combined environment pollution. Statistically significant differences of incidence of malignant neoplasms in children in ecologically unfavorable areas have been established.