Workers engaged in manufacture and use of dynamite experience acute toxic reactions with headache during work, weakness at the end of the working day, tachycardia and hypotension. Sudden death has been reported in dynamite workers after 2-4 days freedom of exposure, possibly due to rebound vasoconstriction resulting in acute hypertension or myocardial ischemia. In the present study 12 volunteers were examined before and during GTN exposure. Most of them experienced headache during work, and a slight but significant rise in heart rate and a fall in systolic blood pressure was found. In serial blood samples from cubital vein very high concentrations of GTN were detected. These high values can be explained by local absorption through the skin of the hand and the lower arm, and do not reflect the mixed venous plasma concentrations. Great interindividual variations were found in GTN plasma concentrations during work, probably indicating different working habits.
Pregnancy outcome was studied in a county in Norway 3 years prior to and 3 years subsequent to the Chernobyl nuclear plant accident on 26th April 1986. More detailed analyses have been performed for the 12 months prior to and subsequent to the accident. A significant increase in the spontaneous abortion rate the first year after the accident was followed by a slight decrease during the second and third years, but figures were still higher than the period prior to the accident. The rate of legal abortions was unchanged. During the entire observation period the number of births increased continuously, with the exception of a decrease in the last 2 months of 1986 and the first month of 1987. A higher incidence of spontaneous abortions was found for pregnancies conceived during the first 3 months after the accident. This increase in the spontaneous abortion rate is noteworthy, and more especially its long-term persistence, which cannot be the result of external radiation. The internal radiation from food polluted by radioactive fallout is a possible explanation. Changes in nutrition in order to avoid polluted food may also be of importance.
The outcome of pregnancies in six countries in Norway has been studied during 12 months prior and subsequent to the Chernobyl accident. The accident took place in a period with an annual increase of births of approximately 3%. However, the year after the accident a decrease of 0.7% was observed with particularly low numbers during February--April 1987. Concomitantly, the miscarriage fraction of all pregnancies increased by 16.3% and particularly during November 1986--January 1987. The same pattern was found when observations from Haukeland Hospital were analyzed separately. When the time of conception was taken into consideration we found that conceptions during the period May--July 1986 ended more often as miscarriages. We have no explanation of the observations. The external radiation exposure seems too small to have produced these effects. The internal radiation from food may have played a role. People may also have changed their food intake, using less vegetables, due to fear of these being polluted by radioactive fallout.
A few previous studies have revealed an increased risk for sudden infant death syndrome (SIDS) during weekends and holidays suggesting environmental factors as potential trigger mechanisms for death. In the present study, the weekend/holiday effect has been assessed on the basis of 1480 SIDS cases in 19 Norwegian counties during a 19-year period (1967-85). The phenomenon has been confirmed for 17 of the 19 counties. Special attention has been attached to differences in the geographical and seasonal distribution of the phenomenon. Deaths of other causes in infancy did not display such a dependency on the day of the week.