EN
Pentachlorophenol (PCP) is known to be a very effective biocide, used very widely a few years ago. Eventually its use was stopped in many countries when it was shown that PCP is highly toxic, especially to water organisms, and to some land animals and plants. However, PCP is still present in the environment, mostly as a metabolic product of some pesticides. Roots of shallot (Allium ascalonicum auct.) were exposed to different concentrations of PCP: 0.001, 0.01, 0.1 and 1 mg/dm3 for 24 h. The tested solutions were adjusted to pH 3.0, 6.0 or 8.0. Root tip cells were analyzed either after 24 h of treatment or after treatment and 48 h recovery in water. Genotoxic effects of PCP in root tip cells were noted, the extent of which depended on the PCP concentration and pH. Chromosome and mitotic aberrations were found, including the significant occurrence of micronuclei, chromosome bridges and multipolar cells.