RESEARCH ON RADON (222Rn) CONTENT IN DRINKING-WATER SAMPLES COLLECTED FROM SIBIU COUNTY

The isotope radon (222Rn), an inert water-soluble gas that may contaminate water, represents a potential risk for human health, including cancer. The present study reports the evaluation of the 222Rn concentration in drinking-water samples collected in 2020 from 10 sources located in Sibiu County, as measured using the pulse ionization chamber. Values of 222Rn varied from 0.0549 to 37.4770 Bq/l, with an average of 4.586 Bq/l. These values were below the maximum level of 100 Bq/l recommended by WHO and EU Directive/Euratom. With the exception of the sample from groundwater, the others showed 222Rn values below the maximum level of 11.1 Bq/l, as recommended by US EPA. In the case of impermeable soils, this radionuclide floats inside the cracks until it reaches the atmospheric air, so it is harmful to human health both in water and in the air. Evaluation of radon in water, in particular from groundwater sources becomes essential for the management of remedial solutions.

Assessment of health risks from environmental factors. 16 Years of collaboration between the United States Environmental Protection Agency (US EPA), hygiene and environmental organizations in the Russian Federation: results and reflections

Environmental health risk assessment has a long history in both the United States and Russia. Risk assessment methods have arisen and developed to protect against the dangers of the forced use of tens of thousands of chemicals in the modern world. Because chemicals play such an important role, it is impossible to ban their use altogether, and the task of their safe use becomes more and more critical. With the solution of this problem, the creation of modern environmental legislation began, based on an assessment of the hazard or potential hazard associated with the impact of these substances on humans. Risk assessment has become the scientific basis for calculating exposure limits for many chemicals that pollute the environment. Since compliance with environmental legislation is costly to industry, methods have been developed. They are being improved on to quantify the burden of proof and the appropriateness of environmental quality regulation. Environmental Health Risk Assessment was first developed by the United States Environmental Protection Agency (US EPA). Russia has accumulated a great deal of practical experience in assessing environmental risks and developing appropriate methodological recommendations. Thus, the basis was created for long-term cooperation between the two countries. This article summarizes the history of such collaboration, including a joint project to disseminate practical risk assessment in Ukraine.

Vinyl Acetate Emission Rates and Explosions in Tank Farms in Dilovasi and Yumurtalik, Turkey: A Case Study

The emission estimations for vinyl acetate from storage tanks located in Dilovasi and Yumurtalik, Turkey, were completed by using the US EPA standard regulatory storage tanks emission model (TANKS 4.9b). Total annual emission was determined to be 7,603.15 kg/year for Yumurtalik and 6,057.06 kg/year for Dilovasi. In addition, ALOHA software was used in order to define emergency responses required in the case of vinyl acetate leakage based on different scenarios. According to ALOHA program modelling results, the threat regions occurred were 113 and 236 m for the red threat region, 299 and 663 m for the orange threat region, and 790 m and 2.0 km for the yellow threat region for vinyl acetate toxic vapour in Dilovasi and Yumurtalik, respectively. The threat regions determined were 10 and 15 m for the red threat region, 9.14 m for orange threat region, and 20 and 49 m for the yellow threat region for modelling of flammable area for the vapour cloud of vinyl acetate in Dilovasi and Yumurtalik, respectively. The amount of thermal radiation was determined to be 10 kW/m2 at a distance of 9.96 m from the tanks in both Dilovasi and Yumurtalik during a jet fire.

Lifetime Carcinogenic Risk Proportions from Inhalation Exposures in Industrial and Non-Industrial Regions

The aim of this work was to estimate the share of selected significant risk factors for respiratory cancer in the overall incidence of this disease and their comparison in two environmentally different burdened regions. A combination of a longitudinal cross-sectional population study with a US EPA health risk assessment methodology was used. The result of this procedure is the expression of lifelong carcinogenic risks and their contribution in the overall incidence of the disease. Compared to exposures to benzo[a]pyrene in the air and fibrogenic dust in the working air, several orders of magnitude higher share of the total incidence of respiratory cancer was found in radon exposures, for women 60% in the industrial area, respectively 100% in the non-industrial area, for men 24%, respectively 15%. The share of risks in workers exposed to fibrogenic dust was found to be 0.35% in the industrial area. For benzo[a]pyrene, the share of risks was below 1% and the share of other risk factors was in the monitored areas was up to 85%. The most significant share in the development of respiratory cancer in both monitored areas is represented by radon for women and other risk factors for men.

Study on the Removal Efficiency of Heavy Metals in Flue Gas of Small Sintering Machines

Heavy metal pollutants such as Hg, Pb, Cr, and Cd contained in flue gas from the sintering equipment bring about environmental hazards. In this paper, 4 small sintering machines with different control technologies were selected, and the US EPA 29 method was used to analyze the emission concentration of heavy metals from the sintering machines, and the removal efficiency of the different flue gas control technologies on the of heavy metal pollutants was analyzed. The results show that the dry flue gas desulfurization combining baghouse dedusting method has high removal efficiency of heavy metals in flue gas, with mercury removal efficiency of 60.06%, Pb removal efficiency of 92.92%, Cd removal efficiency of 92.20%, Cr removal efficiency of 55.14%. The removal efficiency of heavy metals is obviously higher than that of conventional electrostatic precipitation combining wet desulfurization. This is mainly ascribed to those heavy metals are mainly concentrated in the fine particulate matters of the fly ash. Dust removal technology can effectively coordinate the control of Hg, Cr, Pb and Cd in the flue gas. The semi-dry desulphurization and baghouse dedusting technology can promote the enrichment of Hg and Cr in fly ash. The results of this study can provide theoretical guidance for the control of Hg, Cr, Pb, Cd and other heavy metal pollutants control in sintering equipment, and for flue gas ultra-low emission transformation.