THE SOUTH KARELIA AIR-POLLUTION STUDY - RELATIONSHIP OF OUTDOOR AND INDOOR CONCENTRATIONS OF MALODOROUS SULFUR-COMPOUNDS RELEASED BY PULP-MILLS

We studied the indoor penetration of ambient air malodorous sulfur com pounds released by pulp mills. The indoor and outdoor concentrations w ere simultaneously measured with automatic SO2 analyzers. The filterin g effect of three different materials connected to a gaseous filter un it was tested during six study periods. The tested materials were Sorb ixofil(R) based on gypsum impregnated by KMnO4, Purafil(R) based on Al O3, both absorbing sulfur compounds by oxidation, and carbonized tissu e. The periods lasted from 14 to 88 days. The results indicated that m alodorous sulfur air pollutants penetrated indoors effectively, but af ter some delay because the dilution was slow. In a comparison of diffe rent filter materials, Purafil(R) was the most effective, producing lo w indoor concentrations. The study concludes that people living near p ulp mills are exposed to substantial amounts of malodorous air polluta nts, both indoors and outdoors. This exposure can be reduced by using gaseous sulfur sensitive filter materials connected to a controlled ve ntilation system.