The environmental significance of polycyclic aromatic hydrocarbons (PAHs) generated by the production of aluminum and manganese alloys is an important issue in numerous Norwegian fjords. The fate of these compounds have been elucidated by analyzing surface and subsurface sediment samples collected over a 15-year period from seven smelter-affected fjords applying principal component analysis (PCA). Consistent patterns within and between fjords and between production types suggested causal relationships and formed the basis for formulating hypotheses regarding the fate of the compounds. The PCA was able to dif ferentiate between various combustion origins at receptor locations, so far hidden in the traditional treatment of the data restricted to individual fjords. This differentiation reflected industrial processes and most probably cleaning arrange ments at the different plants. The source-specific signals were discernible over considerable distances and down to concentrations 3-4 times background levels. Compound-specific transformation reactions occurring during transport and incorporation into the sediments contributed little to the total variance and did not suppress the source-specific signals. This may imply a rather low availability to the bottom fauna and raise questions as to the potential harm inflicted by smelter-generated PAHs.