Regional background monitoring of persistent organic pollutants (POPs) has been carried out at the Košetice Observatory since 1988 within the national research and monitoring projects (Project TOCOEN, Project Ambient Air – Carcinogenesis – Carcinology, Project BETWEEN) and within the 6th stage of the EMEP programme devoted to POPs monitoring.

Regional POPs monitoring at the Košetice Observatory serves as a basis for evaluation of these pollutants contamination levels and data on POPs monitoring are used within the EMEP activities for the validation of global and regional models for transport and development of these substances. POPs are determined in samples of ambient air (weekly samplings), wet deposition (each precipitation episode) and in surface water, sediments, soils, moss and needles (once a year at 8 further localities in the area of the Košetice Observatory). This globally unique programme is carried out in the given extent only at the Košetice Observatory at present as a part of EMEP programmes aimed at air pollution monitoring, depositions and the so called integrated monitoring. In all mentioned samples polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and selected chlorinated pesticides (OCPs) are detected. Sampling and detection procedures are based on the methods recommended by EMEP.

The 2000 results have been summarised in Tables 2-80 and 2-81 listing the observed concentrations of PAHs and OCPs, and namely in gaseous phase, SPM and their sum representing concentrations in ambient air (their annual arithmetic and geometric means, median and the minimum/maximum values calculated).

Figs. 2-78, 2-79, 2-80, 2-81, 2-82, 2-83, 2-84, 2-85, and 2-86 depict the long-term profiles of concentrations of the monitored pollutants for the period 1996–2000 and their seasonal variations. Typical seasonal trends remained unchanged, in case of PAHs with the maximum in the winter period (heating season) and in case of PCBs and OCPs with the maximum values observed, on the contrary, in the summer (warmer) period when there is more intensive evaporation from terrestrial and aquatic systems where they are deposited in the winter period. Both the graphs and average values show evident decline in regional background concentrations of the monitored substances. Levels of OCPs continue to correspond to the European background. Predominance of degradation metabolites (DDE, DDD) continues to be observed with DDT, i.e. old loads.

Fig. 2-78 shows the overview of month averages of sum of PAHs concentrations for the period 1996–2000, Fig. 2-79 the overview of seasonal variation of month averages of PAHs concentrations. Similarly, for the same period (1996–2000) the overviews of month averages of sum of PCBs, HCHs and HCB concentrations are presented as well as overviews of seasonal variations of month averages for PCBs, HCHs, DDTs and HCB.

Similar trends in seasonal variations and the decline of the level of the monitored pollutants for the period of 1997–1999 can be observed also in the samples of wet atmospheric deposition (Figs. 2-87, 2-88, 2-89, 2-90, 2-91, 2-92, and 2-93). Fig. 2-87 shows the overview of concentrations of individual monitored PAHs during all precipitation episodes for the period 1997–1999, Fig. 2-88 shows the seasonal variation of the sums of PAHs.

The same overviews of the observed concentrations of individual pollutants, the overview of month averages and seasonal variations are presented also for PCBs (Figs. 2-89 and 2-90). Further the observed concentrations of HCHs (Fig. 2-91), DDTs (Fig. 2-92) and HCB (Fig. 2-93) are presented.

Besides the results of PAHs measurements obtained at Košetice station within the cooperation between CHMI and RECETOX MU Brno the ISKO database has stored data from Public Health Service stations since 1997. In 2000 data from 8 stations were included (Prague 10-Šrobárova, Plzeň-Roudná, Ústí n. L.-Moskevská, Hradec Králové-Sukovy sady, Žďár nad Sázavou, Brno-Húskova, Karviná-OHS and Ostrava-Přívoz). Since 1999 data from the Polish stations PIOS Cziernawa and Jeleniov have been also included. The courses of daily average concentrations of benzo[a]pyrene, benzo[a]anthracene and sum of PAHs for 2000 at the above Public Health Service stations and Košetice station are shown in Fig. 2-94. The figure illustrates the fact that Ostrava Region is due to the pattern of air pollution sources (mainly coke production) the most afflicted area in terms of the above pollutants. The 2000 annual average concentration of benzo[a]pyrene at Karviná station amounted to 4 ng.m^-3. The proposed annual limit value (IH_r) for benzo[a]pyren (1 ng.m^-3) [13] was exceeded several times and apparently also in long terms at this station. In 2000 it was exceeded at all Public Health Service stations, with the exception of Brno-Húskova station (Tab. 2-79). The 1 ng.m^-3 benzo[a]pyrene concentration represents the lifetime risk of lung cancer in 8.7 of 100,000 cases [12].

Tab. 2-79 Annual average benzo[a]pyrene and sum PAHs concentrations in 2000

Tab. 2-80 Observed concentration of polycyclic hydrocarbons (PAHs), Košetice observatory 2000 (gas phase, aerosol, gas phase + aerosol – minimum, maximum, arithmetic and geometric mean, median)

Tab. 2-81 Observed concentration organochloride pollutants (OCPs), Košetice observatory 2000 (gas phase, aerosol, gas phase + aerosol – minimum, maximum, arithmetic and geometric mean, median)