The environmental behaviour of polychlorinated phenols and its relevance to cork forest ecosystems: a review

Abstract

Pentachlorophenol (PCP) has been used as a herbicide, biocide and preservative worldwide since the 1930s and as a result, extensive and prolonged contamination exists. The environmental impact increases when its many degradation products are taken into consideration. A number of chloroanisols and their related chlorophenols have been found in cork slabs collected from Portuguese oak tree forests before stopper manufacturing, and contamination by PCP and polychlorinated anisole (PCA) has been detected in Canadian forests. It is suggested that the use of polychlorinated phenols, in particular PCP, is thought to be a cause of the cork taint problem in wine, a major socio-economic impact not only for industry but on sensitive and highly biodiverse ecosystems. It also highlights particular issues relating to the regional regulation of potentially toxic chemicals and global economics world wide. To fully understand the impact of contamination sources, the mechanisms responsible for the fate and transport of PCP and its degradation products and assessment of their environmental behaviour is required. This review looks at the current state of knowledge of soil sorption, fate and bioavailability and identifies the challenges of degradation product identification and the contradictory evidence from field and laboratory observations. The need for a systematic evaluation of PCP contamination in relation to cork forest ecosystems and transfer of PCP between trophic levels is emphasised by discrepancies in bioaccumulation and toxicity. This is essential to enable long term management of not only transboundary contaminants, but also the sustainable management of socially and economically important forest ecosystems.

Transport and dynamics of toxic pollutants in the natural environment and their effect on human health: research gaps and challenge

“…Many studies have shown that, for some compound classes, the degradation products of primary pollutants can be more significant in terms of toxicity (e.g. McLellan et al 2007) and, coupled with compound specific differences in environmental partitioning, can adjust the chemical exposure profile (e.g. Edgar et al 2003Edgar et al , 2006, compromising accepted chemical behavioural models.…”

Headspace single drop and hollow fiber liquid phase microextractions for HPLC determination of phenols

“…They also have substantial applications in agriculture as herbicides, insecticides and fungicides. Due to their moderate bioaccumulation and high toxicity, they can cause serious health hazards, which depend on the degree of chlorination and the position of the chlorine atoms [1,2], and most of them are determined as priority contaminant by the US Environmental Protection Agency [3]. Therefore, developing reliable, sensitive and simple methods is of great interest for the determination of phenols in environmental, food, and biological samples.…”

Characterization of a novel 2,4,6-trichlorophenol-inducible gene encoding chlorophenol O-methyltransferase from Trichoderma longibrachiatum responsible for the formation of chloroanisoles and detoxification of chlorophenols

“…Chloroanisoles, specially 2,4,6-trichloroanisole (2,4,6-TCA) and pentachloroanisole (PCA) are significant environmental pollutants frequently detected in many ecosystems such as different types of soils (Palm et al, 1991;D'Angelo and Reddy, 2000), river and marine sediments (Barakat et al, 2002), lake and river waters (Nystrom et al, 1992;Jiang et al, 2000), marine troposphere (Führer and Ballschmiter, 1998), and vegetable materials like the bark of the cork-oak in Mediterranean forests (McLellan et al, 2007). Chloroanisoles arise as a consequence of a detoxification reaction of highly toxic chlorophenolic pesticides, which consists in the Omethylation of their reactive hydroxyl group (Cserjesi and Johnson, 1972;Gee and Peel, 1974).…”