OVERVIEW OF THE RADIOLOGICAL ACCIDENT IN GOIANIA

摘要

In September 1987 a very serious radiological accident occurred in Goiania, Goias State, Brazil, when a 50.9 TBq ~(137)Cs source was inadvertently removed from a therapy unit and dismantled by scrap dealers. The spread of contamination was through human contact and distribution of source fragments among friends. Screening for contamination of people established that 249 persons were contaminated, 21 presenting acute radiation syndrome or radiodermatitis and ten in serious condition. Four of these died. Following area radiation surveys, seven highly contaminated sites were identified and isolated. The total area of these sites was 5000 m~2, and they were distributed within an area of 2 km~2, in the central districts of Goiania. Following the detection of the accident, other mitigation measures took place immediately, such as medical care of patients, and monitoring of the potable water supply, the sewage and rainwater systems, and the money in circulation in Goiania. The accident had consequences, directly or indirectly, for all inhabitants of the city, and in some aspects for Goias State as a whole. The consequences were of a social, emotional, psychological and economic nature. A strong discrimination arose against the inhabitants of Goiania and against the products of all of Goias State, with deep social and economic impacts. The gross domestic product of Goias State fell by 15%. During the cleanup operations, seven houses had to be demolished and large amounts of soil had to be removed. The total volume of waste removed from contaminated sites was 3500 m~3; it was placed in 5700 packages. It was necessary to construct a disposal facility to store the waste. The Goiania accident demonstrated that each accident is unique, particularly in the case of a radioactive source. Nevertheless, lessons learned from the intervention in one accident could be useful on future occasions.