241 Am and 244 Cm were analysed from peat samples collected in Finland immediately after the Chernobyl accident. The separation method included co-precipitation, anion exchange and extraction chromatography. Activities of 241 Am and 244 Cm were measured by alpha spectrometry. The activity of Chernobyl-derived 241 Am varied between 0.0115 and 9.32 Bq/m 2 and that of 244 Cm from < 0.002 to 1.97 Bq/m 2 (reference date 1.5.1986). The origin of 241 Am in Finland is predominantly from atmospheric nuclear tests. However, the geographical distribution of Chernobylamericium is uneven and depending on a location even 100% of 241 Am in peat originated from the Chernobyl accident. The deposition pattern of Chernobyl-derived 241 Am and 244 Cm resembles that of other refractory nuclides, such as 95 Zr, 141 Ce and 239,240 Pu.

Addition of propranolol to a suspension of human red cells was found to cause outflow of K+ ions and, to a lesser degree, inflow of Na+ ions, until a new stationary state was reached in which their cell/medium concentration ratios did not deviate much from unity. The cell volume decreased. Lactic acid production increased slightly. Against the outflow of bulk K+ ions, tracer K+ and Rb+ ions accumulated very rapidly in the cells and then began to flow out. The ratio of inward to outward rate constant of K+ tracer immediately decreased, while that of Na+ tracer increased, transiently exceeding the medium/cell concentration ratio of Br‐ tracer, in which no abrupt change occurred. In the propranolol‐induced stationary state the cationic tracer rate constants were higher than in the untreated cell, but not so high as just after addition of propranolol. Their order was K.+ > Rb+ > Cs+ > Li+ > Na+. It is suggested that an accelerated “carrier”‐mediated exchange diffusion of cations across the cell membrane, driven by the flow of bulk ions down their gradients, would explain the rapid tracer ion movements.

An estimation of the intakes of 30 food additives in Finland was conducted combining analytical data, food balance sheets, import and export statistics. The results indicated that most calculated average food additive intakes were well below the ADI values and internationally at an acceptable level. The intakes of nitrates, nitrites, saccharin and cyclamates were above or close to the respective ADI values. More studies are planned on these substances in order to establish possible special risk groups.

Comparison of heavy metal intakes between Finland, West Germany and Japan suggests that the average oral exposure to lead and cadmium in Finland is 30-40% of that in the other two countries. Environmental contamination is the obvious cause of high heavy metal content of vegetables and liver in West Germany and Japan and this explains a part of the difference observed in the intake rates. For example cabbage and lettuce in West Germany contain on average over 10 times more lead than the corresponding Finnish products. On the other hand a part of the difference is explained by food consumption habits. For example there is a high consumption of fish and seaweed in Japan, and beer in West Germany, and these products also significantly contribute to intake of heavy metals. Since international comparisons of intakes of food contaminants are at present inaccurate and difficult to conduct, a co-ordinated international study should be implemented. The analytical work should be centralized or alternatively an intercalibration of participating laboratories could precede the actual study. The sampling should cover polluted areas in proportion to their yield of crops.