EFFECTS ON MARINE ORGANISMS FROM POLYCYCLIC AROMATIC-HYDROCARBONS (PAH) AND OTHER CONSTITUENTS OF WASTE-WATER FROM ALUMINUM SMELTERS WITH EXAMPLES FROM NORWAY

A brief review is presented of the effects from the main stress factor s in Norwegian aluminium smelter effluents: PAH, fluoride and depresse d pH from the combination of Soderberg technology with treatment of ga ses in seawater scrubbers. The main focus is on PAH. It is shown that toxic effects from fluoride or depressed pH are usually not to be expe cted outside the primary dilution zone. Generally, ecological effects in the recipients are restricted to 1-2 km from the waste outfalls. Th e apparent discrepancy between toxicity thresholds of PAH from the lit erature and the merely moderate adverse effects in Norwegian recipient s is considered to be due to (i) the inadequate relevancy of tests wit h dissolved PAH for effluents dominated by PAH in the particulate stat e and (ii) less availability of soot associated with oil derived PAH i n sediments, and the probable role of dissolved organic matter in maki ng pore water PAH less available than unassociated PAH in solution.