Organochlorinated pesticides were widely applied in Armenia until the 1980s, like in all former Soviet Union republics. Subsequently, the problem of areas contaminated by organochlorinated pesticides emerged. Environmental, waste and food samples at one pesticide burial site (Nubarashen) and three former pesticide storage sites (Jrarat, Echmiadzin and Masis) were taken and analysed on the content of organochlorinated pesticides, polychlorinated dibenzo-p-dioxins and furans and dioxin-like polychlorinated biphenyls. Gradient sampling and diffusivity-based calculations provided information on the contamination release from the hot spots on a local scale. A risk analysis based on samples of locally produced food items characterised the impact of storage sites on the health of nearby residents. All four sites were found to be seriously contaminated. High pesticide levels and soil and air contamination gradients of several orders of magnitude were confirmed outside the fence of the Nubarashen burial site, confirming pesticide release. A storage in Jrarat, which was completely demolished in 1996 and contained numerous damaged bags with pure pesticides until 2011, was found to have polluted surrounding soils by wind dispersion of pesticide powders and air by significant evaporation of lindane and β-endosulfan during this period. Dichlorodiphenyltrichloroethane-contaminated eggs, sampled from hens roaming freely in the immediate surroundings of the Echmiadzin storage site, revealed a significant health risk for egg consumers above 1E-5. Although small in size and previously almost unknown to the public, storage sites like Echmiadzin, Masis and Jrarat were found to stock considerable amounts of obsolete pesticides and have a significant negative influence on the environment and human health. Multi-stakeholder cooperation proved to be successful in identifying such sites suspected to be significant sources of persistent organic pollutants.
The use of galvanized scrap as a charge material for electric steel-smelting production leads to the formation of metallurgical dust suitable for the extraction of non-ferrous metals. The issues related to the behavior of chlorine and its compounds in zinc and lead containing EAF-dust is not sufficiently studied. Current research exhibits the danger of chlorine and its compounds in charge and, consequently, in emissions of EAF. Chlorine and its compounds are considered to be the main components associated with the formation of highly toxic organic substances – dioxins and furans (D&F). D&F enter the environment not only in gaseous form, but also in the form of compounds adsorbed on the surface of dust particles. According to various data, D&F concentration is 5-500 ng / kg of dust and depends on the technological parameters of melting. Analysis of the formation processes of D&F in EAF and their behavior in the captured dust is given. It was found that at the studied chlorine content of 1.3% in EAF-dust from the charge materials, 99.9% of chlorine form relatively safe compounds, mainly chlorides, and a small amount goes to the formation of D&F. The amount of D&F adsorbed on the surface of captured dust particles was 474 ng / kg of dust. As strong toxicants, D&F increase the hazard category of dust from the 4th to the 3rd and above that must be considered at dust usage. In addition, the transport of D&F in the environment is due to solid particles that absorb poisons on their surface. Therefore, EAF dust, with D&F adsorbed on its surface, can provoke their entry into organisms. The ways of reducing D&F emission in the production of EAF-steel and the resource-saving and environmentally safe technologies of dust processing are considered. In particular, the possibility of using lime milk for the off-gases irrigation in the EAF gas flue was analyzed and it was shown that it allows to reduce the D&F content to acceptable limits. The efficiency of the proposed activities was evaluated.
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