**4. Conclusion**

**District Samples number Samples number**

24 Organic Pollutants - Monitoring, Risk and Treatment

**Table 15.** The load of soils by DDT and its metabolites in the North Bohemian region

number of DDE exceeding of preventive limit (from 14 to 24).

**Table 16.** The load of soils by DDT and its metabolites in the North Moravian region

**District Samples number Samples number**

**increased DDT/DDE/DDD**

Decin 27 0/0/0 0/0/0 0.001/0.001/0.001 Usti/Labem 33 1/0/0 3.03/0/0 1.13/0.001/0.001 Teplice 47 4/4/3 8.5/8.5/6.4 1.21/0.15/0.26 Most 39 6/1/0 15.4/2.6/0 0.06/0.03/0.01 Chomutov 33 1/0/0 3.03/0/0 0.04/0.001/0.001 Together 179 12/5/3 6.7/2.8/1.7 1.21/0.15/0.26

DDT and its congeners have been still registered in agricultural soil of the Czech Republic in spite of DDT use finished in 1974 [22]. DDT decomposition is generally reflected by slowly increased contents of DDE in soils. This trend is more visible in the North Moravian region where the ratio of DDT/DDE/DDD has value 3.5/4/1 while in the North Bohemian region has value 4/1.7/1 (indicating relatively more recent load). We have the hypothesis about non legal use of high doses of DDT in the North Bohemian forests (the Ore Mountains) during the bark beetle calamity in the eighties of 20th century (unsworn information). The level of soil load by DDT and its metabolites is comparable in both regions. Only the Decin district in the North Bohemian region, where no exceeding was observed, differs from the other dis‐ tricts. This fact shows no gap with our hypothesis because the Ore Mountains range does not reach the Decin district area. The general trends of DDTs concentration are complicated in the soils of the Czech Republic because a strong oscillation of DDTs values was observed [23]. Nevertheless the data of Czech National Stocktaking show the decreasing number of DDT exceeding of preventive limit during 2000 – 2002 years (from 60 to 18) and increasing

Only the maximal values of DDTs in the soils of both regions exceed preventive limits and

**increased DDT/DDE/DDD**

Ostrava 40 3/3/0 7.5/7.5/0 0.35/0.18/0.005 Karvina 33 2/4/1 6.01/12.1/3.03 0.069/0.032/0.049 Frydek-Mistek 33 2/1/1 6.01/3.03/3.03 0.057/0.033/0.022 Together 106 7/8/2 6.6/7.55/1.89 0.35/0.18/0.049

**Samples increased % DDT/DDE/DDD**

**Maximum value (mg/kg) DDT/DDE/DDD**

the maximum 1.21 mg/kg reaches 30.25% of proposed indication limit value.

**Samples increased % DDT/DDE/DDD**

**Maximum value (mg/kg) DDT/DDE/DDD**

The data of soil load by observed POPs groups in two environmentally affected areas indi‐ cate generally higher load of the North Moravian region in comparison with the North Bo‐ hemian region. This result is especially supported by the comparison of soil load by polycyclic aromatic hydrocarbons. The load relate to spatial coincidence of various pollution sources connected with high concentration of metallurgy and with high urbanization rate in the Ostrava agglomeration. The load of soil by polyaromatic hydrocarbons has diffuse char‐ acter and exceeding of proposed preventive limit value (based on PAHs background values in Czech soils) was detected on most observed localities. The exceeding of proposed indica‐ tion limit value for PAHs in soil (derived from human health risks) was detected in the North Moravian region as well. Markedly increased soil load was also monitored in the case of PCBs in the North Moravian region where the effect of increased urban environment plays important role. Nevertheless, the intensity of the load by PCBs is lower and only pre‐ ventive limit values were exceeded. The different trends were proved for two POPs groups – monoaromatic hydrocarbons and DDTs and its metabolite. While soil load by DDTs is comparable in both regions (with some qualitative differences) the load of agricultural soils by MAHs is markedly higher in the North Bohemian region and especially in the Most dis‐ trict. This is the consequence of petrochemical industry situated close to the Most town. The recent development in both regions may be evaluated as better in the North Bohemian re‐ gion where the investment into technologies in coal-fired power stations decreased the load of environment by contaminants. The adverse emission situation in the North Moravian re‐ gion with increased concentration of metallurgy is still remaining.
