Spatial distribution of PAHs in the UK atmosphere using pine needles

A study of the spatial distribution and mixture of polycyclic aromatic hydrocarbons (PAHs) in pine needles sampled across the U.K. in the summer of 1994 is presented. PAHs reach pine needles via atmospheric transport and deposition processes. Phenanthrene was distributed irregularly across the U.K., while the other PAHs generally decreased on a northward gradient from the southern England to northern Scotland by a factor of similar to 7. A relationship was found between the mean PAH concentrations of each area sampled and the population density. Fingerprint technique enabled differences in the PAH composition among the different areas to be highlighted. A southern, central, and northern fingerprint were determined over a more general uniform contamination pattern. Calculated air concentrations, through bioconcentration factors (BCF) based on octanol-air partition coefficients (K-oa), were compared with measured data from the literature. The underestimation of the calculated values were related to the K-oa of each compound, indicating that for log K-oa values > 8-9, K-oa-based BCFs do not correctly predict mean air concentrations.