Increased cancer incidence in north Sweden-an early promoting effect caused by the chernobyl accident.
2003 (English)In: Epidemiology, ISSN 1044-3983, Vol. 14, no 5 Suppl., S94-S94 p.Article in journal, Meeting abstract (Other academic) Published
Introduction: In Sweden the ground gamma radiation, due to uranium containing granite, contribute to the population's total radiation dose. After the Chemobyl nuclear power plant accident in 1986 as much as five percent of the released caesium-137 was deposited in Sweden, especially in the Northern part of the country. Our hypothesis was that this radiation caused increased cancer incidence, after adjustment by ground gamma radiation exposure.
Methods: The study base included the population of eight counties with the highest fallout after the Chernobyl accident, but also with unaffected areas in these counties serving as the reference. Each person 0-60 years of age living in the same parish at 31 December 1985 and 31 December 1987 were included in a cohort. With the coordinate of each person's dwelling from the National Land Survey of Sweden a total of 1 137 106 individuals could be given 1) ground gamma radiation exposure from the digital map of the Swedish Geological Agency and 2) caesium-137 exposure from a similar map created by Swedish Radiation Protection Institute. Accuracy of the dwelling coordinate was 100 metres and for the radiation exposures 200 metres as done by aeroplane measurements. Three time periods were analysed 1988-1991, 1992-1995 and 1988-1999.
Results: Population density, lung cancer incidence 1988-1999 and total cancer incidence 1986-1987 was risk factors for total cancer outcome in 1988-1999. Age adjusted ERR per 100 nGy/h for ground gamma radiation and total cancer incidence did not show any significant dose response measured, either in each three years time intervals or in the total period of 1988-1999. For caesium the ERR per 100 nGy/h (adjusted by population density, lung cancer incidence, total cancer incidence 1986-1987 and ground gamma radiation) was significant in 1988-1991 followed by a decline in risk 1992-1995 and then a slight but not complete return in risk. The ERR of 0.042 (95% CL 0.001;0.084) per 100 nGy/h for caesium exposure 1988-1999 is therefore dependent on the first three years increase, and to less extent by the following six years.
Conclusion: We have found an early effect of the Chernobyl fallout in Northern Sweden. However, even in the ERR of 0.101 per 100 nGy/h is relatively low in 1988-1991, it is stable in a stepwise regression, and therefore indicating a true effect. An interpretation of our results could be that the sudden exposure of ionizing radiation from Chernobyl might have acted as a late stage general promotor for cancer. Such an early effect can hitherto been overlooked in previous studies.
Place, publisher, year, edition, pages
Lippincott Williams & Wilkins, 2003. Vol. 14, no 5 Suppl., S94-S94 p.
Environmental Health and Occupational Health
IdentifiersURN: urn:nbn:se:liu:diva-26643DOI: 10.1097/00001648-200309001-00222ISI: 000185488600223Local ID: 11208OAI: oai:DiVA.org:liu-26643DiVA: diva2:247192
15th Conference of the International-Society-for-Environment-Epidemiology, Perth Australia, September 23-26 2003