Although the use of DDT was stopped in Czechoslovakia in 1974, it can still be found in some agricultural localities in South Moravia. In neighbouring Austria, where this insecticide was never much used, its levels in the atmosphere are minimal. This finding has been verified by Recetox (the Research Centre for Toxic Compounds in the Environment), which together with colleagues in Austria monitored for four years the concentration of nine types of air pollutants in five regions of both countries.
“The Monairnet project established a monitoring network in twenty localities. Between September 2011 and August 2012 we collected more than 570 samples, and we are now performing detailed analysis on them," says project manager Pavel Čupr. The incidence of so-called 'persistent organic pollutants' was measured by scientists at locations in Lower Austria, Upper Austria, South Moravia, South Bohemia and the Highlands region of Bohemia and Moravia.
“We are concerned with harmful substances that can carry over long distances, can accumulate in tissues of living organisms, are highly toxic and persist in the environment for a long time," explains Čupr.
DDT, for instance, is still in the soil; it is released into the atmosphere when the soil is tilled and at higher temperatures. In Austria specialists have measured higher concentrations of pentachlorobenzene, which results from technological processes in iron and steel works and incineration plants, and is released from landfill sites. It has been recorded in industrial localities, such as Linz.
“This substance has also been recorded at the Sonnblick mountain station, which proves that it can carry over long distances," says Čupr, before adding that the main routes by which substances travel to the Alps are still the subject of analysis.
In the course of their research Recetox scientists used two new sampling devices, which provided them with useful samples. The atmospheric deposition sampler can isolate and sample harmful substances in precipitation or in dust particles, while the new combination sampler can sample up to six particulate fractions at the same time as it samples gas fraction.
The results of the measurements may also be applied in specific instances, such as the drawing up of municipal zoning plans.
“The data may be useful to local administrators as they make decisions on how localities should be used," adds Čupr. “In so doing they take air quality into account."