Cyto- and genotoxic effects of usnic-acid (+)- and (–)-enantiomers have been studied in human peripheral-blood lymphocytes. It has been shown that usnic-acid enantiomers in concentrations of 0.04–0.30 mM have pronounced cytotoxic action. Usnic-acid enantiomers in concentrations of 0.04–0.30 mM have exhibited a genotoxic effect; moreover, the genotoxicity of usnic-acid (–)-enantiomer in concentrations of 0.15 and 0.30 mM was twice as high as that of (+)-enantiomer. The effect of usnic-acid (+)- and (–)-stereoisomers has been accompanied by the formation of atypical DNA comets. Furthermore, (–)-usnic acid has induced 2.5–3.5 times more atypical comets than its (+)-stereoisomer.

It has been shown that the growth of technogenic dust pollution is accompanied by the accumulation of heavy metals in soil and plant phytomass, compared to the control, and that the morphometric and...