Impact Of Selected Post-Mining And Metallurgical Dumps On Air Pollution On Sites In The Czech Republic And Poland

Abstract The paper studies the possible influence of selected post-mining and air pollution on metallurgicaldumps at czech republic and polish sites on air pollution load in the region. The content of PAHs and heavy metals were determined in dust samples taken from surface dumps SZOTKÓWKA I “of KWK” JAS-MOS and ČSM. The obtained data were used for modeling pollution load around hald using models SYMOS’97. On the basis of the models was assessed the effect of hunger on both air pollution situation around in terms of PAHs, heavy metals and PM10.


INTRODUCTION
The aim of the work consisted in quantifying the size of emissions of heavy metals and polycyclic aromatic hydrocarbons (PAHs) as well as their impact on air quality in the Ostrava-Karvina region as a result of mining and metallurgical activities (dumps). The material stored on the heaps undergo very often chemical and mechanical changes, some of them are even initiated by burning practices (e.g. Heřmanice heap). Emitted and deposited dust particles get into the atmosphere via winds, traffic and transportation as well as by mining the heap waste. These activities may contribute to the deterioration of air quality in the neighbouring areas (airborne dust, carcinogens) and has not been explored yet. The current issue of air quality in the region was the subject of the project "Air Quality Information System in the Polish-Czech border area in the Moravian and Silesian Region" (Air Silesia) [1], but the question of dust resuspension from waste piles was not solved.
By this time, the exploration works in the area of dumping sites associated with air pollution have primarily been focused on the issue of suspended particles, in particular as part of the EIA (Environmental Impact Assessment) projects addressing the use of materials stored in the dumps for construction purposes. These works were carried out on a small number of sites; however, they were not comprehensive studies, so it is impossible to derive the overall impact of dumps on air quality.
The emissions of gaseous substances from thermally active dumps represent the second area linked to air quality, on which the surveys have been focused so far. However, the results obtained are burdened with unacceptably high uncertainties that preclude their use for draft regulations concerning further exploitation of dumps.
The lack of information on the contents of heavy metals and polycyclic aromatic hydrocarbons in the emissions into the atmosphere is the main drawback of recent ratings. Considering the smaller (zero) explorability, this project focused on air pollution impacts of dumps associated with the emissions of heavy metals and polycyclic aromatic hydrocarbons.
Although the content of the mineral phases is considered relatively harmless to the environment [2], determining precisely the mineral phases using X-ray diffraction was an integral part of the research [3]. All analyses were, however, focused on PM 10 , which was at the center of greatest interest [4][5][6].
Own research was performed within the project CZ. 3

SITE SELECTION
For the entire project, 10 sites on the Czech side and 10 sites on the Polish side of the border were selected. The pilot study was then conducted on one site in the Czech Republic and one in Poland, specifically on the dumps of the ČSM Mine ( Fig. 1) and "Szotkówka I" of KWK "Jas-Mos" (Fig. 3).

ČSM MINE DUMP
The ČSM Mine dump where the mine material, namely the washery dirt of the dense liquid "washing plant" is stored is administered by the company OKD, a.s. For the study, samples were collected from 18 sampling points (Fig. 2).

METHODOLOGY
Chemical analyses of both inorganic and organic fractions as well as mineralogical description of the dump surface layer were conducted on both dumps. The subsequent evaluation of the data aimed at determining the size and composition of potential emissions of unhealthy particles and the circumstances of their occurrence. By modelling techniques, it was then possible to determine the impact of the investigated dumps on air quality. This is important for decision about further use of the areas for land reclamation, mining or other purposes.
Both partners, the VŠB-TUO and GIG Katowice dispose of investigator teams, having many years of experience, and well-equipped modern laboratories [7].

Sampling methodology
The applied sampling methodology was based on the US EPA AP-42 standard detailed in Appendix C.1 [8].
One representative sample (RS) was obtained from 6 sub-samples (primary), each collected from the area of 1 m 2 at a maximum depth of 2.5 cm. Next, the RS was adjusted by the following successive steps:  From the RS collected from 1 point (12-25 kg), a laboratory sample weighing about 5 kg was prepared in the laboratory.  From the laboratory sample, first the fraction PM 200 , then the fraction PM 40 was obtained by sieving.  By using a centrifuge, the PM 10 fraction from the PM 40 fraction was obtained, and the PM 10 fraction was further used for the determination of heavy metals and PAHs.

Methods of analysis 2.1. Determination of heavy metals
The content of metals (As, Cd, Cr, Cu, Ni, Pb, V, Zn) in the PM10 particulate matter was determined by ICP-OES, after total digestion with aqua regia.

Mineralogical analysis
The mineralogical analysis on both sites was performed on the X-ray diffractometer from Bruker.

Modelling
The aim of mathematical modelling consisted in evaluating the impact of emissions of heavy metals and polycyclic aromatic hydrocarbons generated by the dumps on air quality. The methodology provided in US EPA AP-42 Section 11.9 Western Surface Coal Mining [9] was used for calculating the average annual emissions of suspended particles used as input into the modelling. The average annual mass flow of PM = 850 kg/ha/year.
Taking into consideration that the emission (resuspension) occurs as from a certain wind speed, the emission distribution of suspended particles during the year was calculated based on the methodology provided in US EPA AP 42 Section 13.2.5 Industrial Wind Erosion [10].
The approach for considering frost days was taken from the methodology provided in the CHMI VaV/740/2/02 project, DP 2: 2 Considering the Particles Resuspension from the Earth's Surface [11].
The actual model calculation of the emission spread for both sites was made using the SYMOS'97 software. The software evaluates air pollution contribution to the average annual concentrations under the mass flow, wind direction, air stability and frequency, and that for the wind class 11 and 20 m/s. The total air pollution contribution to the average annual concentrations was then evaluated as the sum of contributions under the two wind speeds. Then the calculation of the highest 24-hour PM 10 values was performed.
The climate data (wind roses) required for modelling using SYMOS'97 were delivered by the Czech Hydrometeorological Institute (hereinafter referred to as ČHMI) in Ostrava-Poruba.

RESULTS
For both sites, the total air pollution contribution to the average annual concentrations of suspended particulate matter PM 10 (µg/m 3 ) was calculated.
With regard to the maximum potential negative impacts of dust emissions from the dump, the total air pollution contribution to the average annual concentrations of benzo(a)pyrene (representative of PAHs) was modelled. The benzo(a)pyrene was chosen with respect to the verified concentration in the heap surface layer and its potential effects on the health of the surrounding population. At the same time, it is a pollutant with a defined air pollution limit. In the case of heavy metals, arsenic (As) was selected due to toxicity and the concentration on the dump surface. Referring to laboratory certified concentrations on the surface of the dumps, other representatives of these groups of pollutants have significantly less potential effects on health and air pollution situation.

SUMMARY AND CONCLUSIONS
Main conclusions from modelling of PM 10 With regard to the overall air pollution concentration and considering the fact that the highest impact occurs during the period of low total air pollution concentrations (windy weather with good dispersion conditions), the impact of both studied dumps on the average annual concentrations of suspended particulate matter PM 10 and PM 2,5 may be considered as relatively insignificant and local (demonstrably the first hundred meters). However, the impact on the maximum daily values of suspended particulate matter PM 10 is locally significant (potential to exceed the set limits).

Main conclusions from modelling -metals, B[a]P
The impact of both studied dumps on the annual average concentrations of arsenic and benzo(a)pyrene is irrelevant. The influence of main sources of the pollutants in the region (individual heating of family houses, transport, industry sources) is an order of magnitude greater.
Maxima of average annual air pollution contributions reach within an order of magnitude hundredths (arsenic) to ten-thousandth (benzo(a)pyrene) of the pollution limits.
Compared to the Szotkówka I dump, the ČSM dump produces significantly higher emissions, and thus even air pollution contributions of benzo(a)pyrene are apparent. However, the caused air pollution level is generally very low in an absolute value even for this dump.
The difference in the pollution contribution of arsenic at individual sites corresponds approximately to the difference of the air pollution contribution of suspended particulate matter PM 10 (in the case of the ČSM site,