The pine needle as a monitor of atmospheric pollution

THE concentrations of toxic chemicals in the atmosphere and their deposition and long-range transport are becoming one of the more prominent issues in environmental chemistry. In 1986, a report 1 was published documenting the levels of DDT (p,p′-dichlorodiphenyl-trichloroethane) and other organochlorine contaminants in the muscle tissue of pike and herring from areas in and around Sweden. There has previously been a downward trend in residue levels but in parts of Sweden and the south Baltic during 1983-84, the ratio of p,p′-DDT to its metabolites significantly increased, indicative of freshly released DDT from a source south of Sweden. (DDT has been restricted or banned in most of Europe since the 1970s.) It was established 2 that an increased forest spraying program using DDT was implemented in 1984 in the southern part of East Germany. DDT can be transported over very long distances 3 and in light of the above there is a need for an extensive field programme to monitor such pollution and locate its source. Here we test the hypothesis that the pine needle is a suitable monitoring matrix and delineate the extent of the DDT contamination of 1983–84. We conclude that the pine needle is a suitable monitor of atmospheric pollution and that because of the widespread distribution of the pine, it may provide time-series data for much of the Northern Hemisphere from which trends in atmospheric pollution may be discerned.