title: Formation mechanisms of trichloromethyl-containing compounds in the terrestrial environment: a critical review.
abstract: Natural trichloromethyl compounds present in the terrestrial environment are important contributors to chlorine in the lower atmosphere and may be also a cause for concern when high concentrations are detected in soils and groundwater. During the last decade our knowledge of the mechanisms involved in the formation of these compounds has grown. This critical review summarizes our current understanding and uncertainties on the mechanisms leading to the formation of natural trichloromethyl compounds. The objective of the review is to gather information regarding the natural processes that lead to the formation of trichloromethyl compounds and then to compare these mechanisms with the much more comprehensive literature on the reactions occurring during chemical chlorination of organic material. It turns out that the reaction mechanisms during chemical chlorination are likely to be similar to those occurring naturally and that significant knowledge may therefore be transferred between the scientific disciplines of chemical chlorination and natural organohalogens. There is however still a need for additional research before we understand fully the mechanisms occurring during the formation of natural trichloromethyl compounds and open questions and future research needs are identified in the last part of the review.
authors: Tokyo Institute of Technology, Department of Environmental Chemistry and Engineering, Nagatsuta 4259, Midori-ku, Yokohama 226-8502, Kanagawa, Japan. Electronic address: breider.f.aa@m.titech.ac.jp.
authors: Florian
authors: F
authors: Breider
authors: Geological Survey of Denmark and Greenland, Department of Geochemistry, Øster Voldgade 10, DK-1350 Copenhagen, Denmark; Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen, DK-1350 Copenhagen, Denmark.
authors: Christian Nyrop
authors: CN
authors: Albers
mesh_terms: D054879:Halogenation; D006843:Hydrocarbons, Chlorinated / Q000737:chemistry*; D012989:Soil Pollutants / Q000737:chemistry*
chemical_list: D006843:Hydrocarbons, Chlorinated; D012989:Soil Pollutants
keywords: Chlorination; Chloroperoxidase; Halogenase; Trichloroacetic acid; Trichloromethane; Trichloromethyl compounds