Results of research on the hazard posed by polycyclic aromatic hydrocarbons contained in the dusts emitted from motor vehicle braking systems have been presented. The polycyclic aromatic hydrocarbons (PAHs) constitute a group of chemical compounds that pose a serious danger to the human health, chiefly because of their carcinogenic properties. Investigations into the issue of environmental pollution with polycyclic aromatic hydrocarbons generated by motor vehicle traffic were carried out in connection with the work being done at PIMOT on systems to reduce dust emission from motor vehicle braking systems. The investigations included determination of PAH contents of the dust emitted from vehicle braking systems as well as the PAH concentrations in the indoor air in a room with the stand for testing dust emissions from braking systems and in the duct to carry away gases from that room. Moreover, the PAH contents of soil were measured in the context of location of the soil sampling points in relation to traffic routes. The PAH contents were measured in Warsaw and in Zabrze. The investigation results confirmed that PAHs considered as being most harmful to the human health due to their carcinogenic properties were actually present in the dusts emitted from braking systems. The PAH contents of soil were found to be very sensitive to the location of the soil sampling points in relation to traffic routes and this is a confirmation of the thesis that motor traffic is an important source of environmental pollution with polycyclic aromatic hydrocarbons.
The content of polycyclic aromatic hydrocarbons (PAHs) in water and sediments of the Blachownia reservoir (South Poland) was investigated. Spatial variability of PAH concentrations in the longitudinal profi le of the tank was determined. PAHs in samples were determined by gas chromatography coupled with mass spectrometric detection (GC-MS QP-2010 Plus Shimadzu) using an internal standard. Concentrations ranged from 0.103 μg/L to 2.667 μg/L (Σ16 PAHs) in water samples and from 2.329 mg/kg d.w. to 9.078 mg/kg d.w. (Σ16 PAHs) in sediment samples. A pollution balance was calculated and it was estimated that the infl ow load was 17.70 kg PAHs during the year and the outfl ow load was 9.30 kg PAHs per year. Accumulation of about 50% of the annual PAH loads (8.90 kg) is a threat to the ecological condition of the ecosystem. It was calculated that the PAH loads in bottom sediment were about 80 kg, which limits their economic use. Improvement of the ecological status of this type of reservoir can be achieved by removing the sediment. Analysis of the diagnostic ratios obtained for selected PAHs showed that the potential sources of PAH emissions in small agricultural – forest catchments can be combustion of a coal, wood, plant material (low emission, forest fi res, burning grass, etc.). Transportation is also signifi cant.
The impacts of long-term polycyclic aromatic hydrocarbons (PAHs) and heavy metal pollution on soil microbial communities functioning were studied in soils taken from an old coke plant. The concentrations of PAHs in the tested soils ranged from 171 to 2137 mg kg-1. From the group of tested heavy metals, concentrations of lead were found to be the highest, ranging from 57 to 3478 mg kg-1, while zinc concentrations varied from 247 to 704 mg kg-1 and nickel from 10 to 666 mg kg-1. High dehydrogenase, acid and alkaline phosphatase activities were observed in the most contaminated soil. This may indicate bacterial adaptation to long-term heavy metal and hydrocarbon contamination. However, the Community Level Physiological Profiles (CLPPs) analysis showed that the microbial functional diversity was reduced and influenced to a higher extent by some metals (Pb, Ni), moisture and conductivity than by PAHs.