Role of Chloroacetic Acids in the Environment: Trichloroacetic Acid in the System Picea Abies/Soil

Chloride was previously considered to be a chemically inert substance in the environment, and chlorinated organic compounds were considered to be only of anthropogenic origin. The role of chlorine in the environment is, however, much more active and complex than previously thought. Our recent studies of chloroacetic acids (CAA) in environmental processes confirmed that such compounds may affect coniferous trees and play an important role as intermediates in the decomposition of soil organic matter. Using 14C-labelled tri- (TCA) and dichloroacetic acid (DCA) it was found that CAA are quickly microbially degraded to carbon dioxide and chloride while chlorination of soil organic matter was confirmed using chlorine 36. An important factor is the action of microorganisms, mainly of fungi. Microorganisms or enzymes of chloroperoxidase type are able to convert chloride to chlorine radical, which then chlorinates soil organic matter. The aim of the project is to elucidate formation and degradation processes of CAA and chloroform in the forest ecosystem - an important sink of carbon - and evaluate their role and importance in the geographic situation of the Czech Republic, also in relation to global changes. TCA, DCA and chloroform are followed by radioindicator methods in the study. A practical result will be the knowledge of influence of road salting on the natural formation of chloroform and other chlorinated compounds of toxicological and ecotoxicological interest, i.e. substances penetrating into ground waters and influencing thus their quality.

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CONTACT PERSON:

Ing. Miroslav Matucha, CSc.
e-mail: matucha@biomed.cas.cz
URL: www.ueb.cas.cz
Ústav experimentální botaniky AV ČR
(Isotope Laboratory)