Influence of waste dump remediation on the levels of mercury in the air.

Mercury concentrations in air were measured at three measuring sites in the vicinity of a waste dump Jakusevec in Zagreb, Croatia over a 4-year period, from the beginning to the end of remediation. Measurements at the beginning of the remediation show that the concentrations of mercury at all three measuring sites were relatively high. Annual mercury mass concentrations in 2001 were between 17 and 445 ng m(-3). Annual mercury averages in 2004 ranged from 8 to 10 ng m(-3). Mercury variations were analysed with regard to the meteorological conditions. The results of this investigation show that in regard to mercury, the remediation was successful.

Zinc levels in suspended particulate matter in Zagreb air.

Monitoring of zinc in total suspended particulate matter (TSPM) started in Zagreb, Croatia in 1972 at two measuring sites, located in the city centre and in the northern part of the city. Monitoring of zinc concentrations in PM10 started in the northern part of the city in 2003. The obtained data show a decreasing trend of zinc in TSPM. Over the past 3 years, the measurement of zinc in PM10 particles has been performed, and the obtained data, in comparison to zinc in TSPM, have shown that 82%-93% of zinc was in the small PM10 particles.

Heavy metals and acidic components in total deposited matter in Sibenik and National Park Kornati, Croatia.

This article presents the results of 6 years (1999-2004) of monitoring acidic components (fluoride, chloride, nitrate, sulfate) and heavy metals (lead, cadmium, thallium) in total deposited matter (TDM) in the town of Sibenik and the National Park Kornati, Croatia, in order to determine their levels, spatial and temporal variations, and possible emission source. Bulk deposition samples were collected using the Bergerhoff samplers. TDM matter was determined gravimetrically. Acidic anions were analyzed using ion chromatography. Metallic components were determined by atomic absorption spectrometry. Results show that the levels of measured pollutants were relatively low compared to those reported in other investigations. Statistical analysis indicates that the measured pollutants originate from several sources such as resuspended soil, industry, road dust, traffic, and secondary aerosols as the most important. The levels of TDM show a slightly increasing trend at all sampling sites. A significant increasing trend in the levels of nitrate and sulfate in TDM could be the consequence of increasing traffic activity and urbanization. The significant increasing trend in the ratio between nitrate and sulfate in TDM indicates that the nitrate and sulfate relative contribution to acidification is increasing. The level of heavy metals in TDM was in order of lead > thallium > cadmium at all sampling sites with slightly decreasing trend.

PAH mass concentrations measured in PM10 particle fraction.

This paper presents daily, monthly and yearly variations of PAH mass concentrations measured in PM(10) particle fraction, collected at one measuring site in Zagreb air between 2001 and 2004, and seasonal differences in PAH mass concentrations in PM(10) samples collected from 21 March 2003 to 20 March 2004. Twenty-four hour samples were taken in the northern residential part of Zagreb using a low-volume (50 m(3)) sampler and glass or quartz filters. The analysis was performed using a high-performance liquid chromatograph (HPLC) and fluorescence detector with changeable excitation and emission wavelength. The annual average mass concentrations over the four-year measuring period for BaP ranged from 1.17 ng/m(3) in 2004 to 1.87 ng/m(3) in 2003 and were below the limit value (2 ng/m(3)) set by the Ordinance on Recommended and Limit Air Quality Values in Croatia. The highest concentrations of all PAHs measured in PM(10) samples collected from 21 March 2003 to 20 March 2004 were found in the winter and the lowest in the summer. Winter average of BaP was 2.94 ng/m(3) and summer average 0.12 ng/m(3). Autumn average was 2.76 ng/m(3) and was very similar to winter concentrations. Spring average of 0.58 ng/m(3) was higher than the summer average (0.12 ng/m(3)). Mass concentrations of all measured PAHs were much higher in the autumn than in the spring. Although annual averages for BaP did not exceed the limit value, autumn and winter BaP mass concentrations did, which calls for measures for reducing PAH emissions in the autumn and winter.

Carcinogenic activity of polycyclic aromatic hydrocarbons bounded on particle fraction.

Polycyclic aromatic hydrocarbons (PAHs) originate from a variety of natural and industrial processes. In this paper, concentrations of nine PAHs in PM10 particle fraction were measured concurrently at four different sites (rural, urban residential, urban traffic, and residential-industrial) in continental Croatia. Measurements at all of the four sites showed much higher average concentrations for all of the PAHs in the winter period. The highest winter average values were measured at the industrial site and the lowest at the rural and the urban residential site. In the summer, the highest average values were also measured in the industrial area, except for benzo(ghi)perylene and indeno(1,2,3-cd)pyrene, which showed the highest average values in the rural area. Factor analysis has been applied to PAH concentrations to identify their potential sources. Extracted factors have been interpreted on basis of previous studies and weather conditions. The diagnostic ratios calculated in this study indicated mixed sources at all of the sites. The contribution of gasoline and diesel from traffic was significant at all of the sites except for the urban industrial. In the winter, potential PAH sources also arose from wood combustion. The industrial site differed from the other sites with the highest influence of diesel sources and refinery during the summer months. The contribution of BaP in total carcinogenic activity exceeded 50 % in both seasons at all of the measured sites, which suggests that BaP could be suitable as a marker of the carcinogenic potential of a PAH mixture.

PAH levels and profiles in the suspended particulate matter in Zagreb through four seasons.

This paper presents the analysis of polycyclic aromatic hydrocarbons (PAHs) measured in all four seasons in suspended particulate matter (SPM) collected with a high-volume sampler on one measuring site in the northern part of Zagreb. About 30 samples of SPM were analysed for each season, including workdays and weekends and there were no differences amongst them. The concentrations of all PAHs were highest in winter and lowest in summer. The spring PAH concentrations were lower than the autumn ones, as the spring had more sunny and warm days. The profiles of PAH/BaP at the measurement sites showed that the main source of PAHs in spring and summer was traffic while a substantial amount of autumn and winter PAHs, besides traffic, came from heating.