Distribution of dissolved oxygen and causes of maximum concentration in the Bering Sea in July 2010

According to data obtained in the Bering Sea during the 4th Chinese National Arctic Research Expedition, the distribution of dissolved oxygen （DO） was studied, causes of its maximum concentration were discussed, and the relationships between DO and other parameters, such as saliniW, temperature, and chlorophyll a were analyzed. The results showed DO concentration ranged from 0.53 to 12.05 mg/L in the Bering Sea basin. The upper waters contained high concentrations and the maximum occurred at the depth range from 20 to 50 m. The DO concentration decreased rapidly when the depth was deeper than 200 m and reached the minimum at the depth range from 500 to 1000 m, and then increased slowly with the depth increasing but still kept at a low level. On the shelf, the DO concentration ranged from 6.53 to 16.63 mg/L with a mean value of 10.75 mg/L, and showed a characteristic of decreasing from north to south. The DO concentration was higher in the area between the Bering Sea and Lawrence Island and was lower in the southeast and southwest of Lawrence Island at the latitude of 62°N. The formation of maximum DO concentration was concerned with phytoplankton photosynthesis and formation of the themocline. To the south of Sta. B07 in the Bering Sea basin, the oxygen produced by photosynthesis permeated to the deeper water and the themocline made it difficult to exchange vertically, and to the north of Sta. B07, the maximum DO concen- tration occurred above the themocline due to phytoplankton activities. On the shelf, the oxygen produced by phytoplankton photosynthesis gathered at the bottom of the thermocline and formed the DO maximum concentration. In the Bering Sea basin, the DO and salinity showed a weak negative correlation （r=0.40） when the salinity was lower than 33.1, a significant negative correlation （r=-0.92） when the salinity ranged from 33.1 to 33.7, and an irregular reversed parabola （r=0.95） when the salinity was greater than 33.7. Key words： Bering Sea, dissolved oxygen, maximum concentration, stratification, chlorophyll a

Studies on the Hazardous Effects and the Maximum Allowable Concentration of Pyrophyllite Dust

Pyrophyllite (H2Al2,Si4 O22, ) dust (P-dust) is a mixture of silica (10-40% ), differentproportions of a luminium oxide (Al2O3 ), and various metal compounds. People with occupa-tions known to be associated with exposure to P-dust include miners, other industrial workersand persons engaged in artistic carving. Currently, little is known about pyrophyllite pneumo-coniosis from P-dust. This study was designed to investigate the hazardous effects of P-dustand to suggest a maximum allowable concentration (MAC) of the dust.This.study included four parts: (i) Occupational epidemiology surveys in 781 workersfrom 1 pyrophyllite mine (PM) and four pyrophyllite carving mills (PCM), with a registra-tion rate of 98 %. (ii) In vitro studies: Six groups of rats were expeed to different levels ofP-dust; the cytotoxicity of P-dust on rat alveolar macrophages (AM) was investigated by de-termining the potassium'content of AM and the activity levels of lactate dehydrogenase (LDH)in AM culture fluid. (iii) Mineralogical analysis of P-dust: The contents of silica (SiO2 ), alu-minium (Al), ferrum (Fe), niikel (Ni), zinc (Zn) and copper (Cu) in hath PM-dust andPCMdust were determined. (iv ) Determination of P-dust MAC: Using the life-talbemethod, an investigation of the hygiene standard of P-dust was carried out in 625 workers ex-POSed to either PM-dust or PCM-dust, uPon whom routine radiographs were Performed.The results suggest that the risk of developing pneumoconiosis from pyrophyllite dust issignificantly higher for PM workers than for PCM workers. The prevalence rate of PCM-dustpneumoconiosis is significantly higher in men than in women. The content of SiO2 and AlO3in the mixture of P-dust is the most important factor in the etiology of pyrophyllitosis. De-pending on the different P-dust MAC values, we suggest that 2 rng/m3 and 4 mg/m' shouldbe considered as the MAC for PM-dust and PCM-dust, respectively, and 3 mg/m' fOr P-dust. We believe that establishing different hygiene standards is more accurate even thoughworkers are exposured to the 'same' dust

Monitoring Ambient Air Quality in the Carpathian Region of Ukraine

Ivano-Frankivsk oblast is located in the south-western part of Ukraine, close to the geographical center of Europe at the junction of the two major geographic units, the East European Plain and the Eastern Carpathians （the Carpathian region of Ukraine）. Between September 2013 and September 2015, the expert group of the Department of Organic and Analytical Chemistry of Vasyl Stefanyk Precarpathian National University conducted the mobile monitoring of air cleanliness in Ivano-Frankivsk region; the authors monitored the level of air contamination with seven gases： carbon monoxide and dioxide, sulfur dioxide, nitrogen dioxide, hydrogen sulfide, ammonia, formaldehyde, beta-particles, and gamma radiation. For this purpose, there were used six automatic analyzers ＂Dozor-C-P＂, the formaldehyde Gas Analyzer ＂MIC-98170＂, and the radiometer ＂TERRA＂. The monitoring resulted in the making of three maps of Ivano-Frankivsk region, on which the average levels of concentration of three particular gases （CO2, SO2, and CH20） throughout all the districts of the oblast were marked. There was registered the excess of CH20 limits--the consequences of the presence of the chipboard and wood-fiber production, for which formaldehyde is used as a raw material. Also there was observed the excess of SO2 in the air caused by gas fumes from vehicles and thermal power stations.

Development of the Program of Monitoring of Composition of Atmospheric Air

To settle the indicators of air pollutions at the industrial enterprises is very important. For this purpose, authors analyzed and developed a program for monitoring atmospheric composition in Borland Delphi 7 for the calculation of the hazard class and the average daily maximum allowable concentration of air. Results of calculations on this program will allow operating composition of air by regulation of operating modes of filtering devices.

Geological and Geochemical Investigation of Low Grade Basement Rocks: Implication to Human Health in and around Asgeda Tsimbla, Western Tigray, Northern Ethiopia

The increase in the number of liver related disease patients from north western region of Ethiopia has been an environmental health issue of national concern. As the disease is restricted to a specific geographical terrain, particularly to Shire area, northwestern dry zone of the country, detail research studies are required to identify possible etiology and risk factors. The aim of the study is to determine the level of trace element and heavy metal concentrations and distributions in water and stream sediments of the area and identify the possible sources in relation to human health. During the study, geochemical sampling (20 water, 20 stream sediment and 6 rock samples) was carried out in March 2011. The collected samples were analyzed for their major and trace element contents using ICP-MS, ICP-OES, Ion Chromatography (IC), and XRF. Analytical data were organized and treated using Excel, SPSS, ArcGIS and Aquachem softwares. Analytical data results with respect to trace element contents in surface and ground waters are compared with the Maximum Acceptable Concentration or Maximum Allowable Concentration (MAC) of World Health Organization (WHO) and Ethiopian standards for drinking water. The comparison reveals that there are problematic elements that pass over the quality standards set for drinking water. One of these is: Bromine (Br), for which 100% all samples have value above 0.01 mg/l and up to 1.475 mg/l. Other problematic elements including aluminum (Al)—30%, fluorine (F)—20%, arsenic (As)—10%, and nitrate (NO3)—10% are examples of elements which have above WHO-MAC for drinking water. Selenium (Se) deficiency may be the other problematic element in the area for its deficiency is associated with liver damage and heart muscle disorder. The metal contaminations (i.e. heavy metals) were also evaluated by world geochemical background value in average shale and sediment quality guideline proposed by US EPA. The concentration of Co and Cr exceeded average shale value at most sample stations indicated that these stations ware in potential risk. Geochemical factors are mostly considered to explain the etiology of this liver related disease.

Biosorption of mercury and lead by aqueous Streptomyces VITSVK9 sp. isolated from marine sediments from the bay of Bengal, India

Toxic heavy metals are increasingly accumu- lating in the environment worldwide and are considered to be life threatening contaminants. The biosorption of mercury and lead by marine actinomycetes isolated from marine sediment collected from the Bay of Bengal coast of Puducherry, India, was evaluated. The maximum tolerance concentration （MTC） of Streptomyces sp. was determined by a well diffusion method and a broth dilution method. The effects of the initial metal ion concentration, the pH and the biomass dosage on the biosorption of mercury and lead ions were investigated. The MTC of the isolate to metals was 200 mg. L 1 for mercury and 1800 mg. L-1 for lead. At neutral pH, the isolate had a maximum biosorption of metal ions of 200 mg.L 1 and 150 mg.L~ for mercury and lead respectively. Fourier transform infrared （FTIR） absorption spectra showed the chemical interactions between the functional groups in the biomass such as hydroxyl （- OH）, amine （-NH2）, earboxyl （- COOH） and the metal ions. The isolate was further characterized by molecular taxonomy and identified as a member of the genus Streptomyces. Based on the phenotypic and phylogenetic analysis, the strain was classified as a new species of the genus Streptomyces and designated as Streptomyces VITSVK9 sp. （HM137310）. A blast search of the 16S rDNA sequence of the strain showed the most similarity （95%） with Streptomyces sp. A515 Ydz-FQ （EU384279）. Based on the results, it can be concluded that this marine Streptomyces could be used as a biosorbent for the removal of heavy metal ions from aqueous environments.