Health consequences after Chernobyl disaster are less than feared
http://www.100md.com
《英国医生杂志》
More than 4000 people could eventually die of radiation exposure from the disaster at the Chernobyl nuclear power station in 1986, but the long term health effects have been less than originally feared.
A report published this week by an international team of scientists, Chernobyl抯 Legacy: Health, Environmental, and Socioeconomic Impacts, found that fewer than 50 deaths so far could be directly attributed to radiation from the disaster. Nearly all of these were in rescue workers, who were exposed to high levels of radiation. The report predicts a further 3940 deaths from radiation induced cancer and leukaemia in the 200 000 emergency workers who were in the area in 1986-7, 116 000 evacuees, and 270 000 residents of the most contaminated areas, based on estimates of the radiation doses that they received. This is far lower than earlier speculations that radiation exposure might result in tens of thousands of deaths.
Figures analysed in the report show that about 4000 cases of thyroid cancer, mainly in people who were children and adolescents at the time of the disaster, have resulted from contamination. At least nine children have died of thyroid cancer, but the survival rate of people developing this type of cancer has been almost 99%, based on statistics from Belarus.
The report found no evidence or likelihood of decreased fertility among the affected population and no increase in congenital malformations that can be attributed to radiation exposure. The authors attributed this to the fact that most emergency workers and people living in contaminated areas received relatively low whole body radiation doses, comparable to natural background levels. Also, because the doses were so low, there was no evidence of any effect on the number of stillbirths, adverse pregnancy outcomes, delivery complications, or the overall health of children. A modest but steady increase in reported congenital malformations was seen in both contaminated and uncontaminated areas of Belarus, but this was thought to be due to improved reporting, not radiation.
Burton Bennett chairs the Chernobyl Forum, the group that produced the report, comprising representatives from United Nations?agencies (including the International Atomic Energy Agency and the World Health Organization) and the governments of Belarus, Russia, and Ukraine. He said, "This was a very serious accident with major health consequences, especially for thousands of workers exposed in the early days who received very high radiation doses, and for the thousands more stricken with thyroid cancer. By and large, however, we have not found profound negative health impacts to the rest of the population in surrounding areas, nor have we found widespread contamination that would continue to pose a substantial threat to human health, with a few exceptional, restricted areas."
The report considered that the mental health impact of Chernobyl was the largest public health problem. People living in affected areas tended to have negative self assessments of their health, believed they had shortened life expectancy, and tended to lack initiative and depend on help from the state. Persistent myths and misperceptions about the threat of radiation have resulted in "paralysing fatalism" among residents, the report warned, noting that, "Poverty, lifestyle diseases now rampant in the former Soviet Union, and mental health problems pose a far greater threat to local communities than does radiation exposure."
Members of the Chernobyl Forum are meeting this week to consider the report findings and recommendations, which include focusing assistance efforts on highly contaminated areas and redesigning government programmes to help those genuinely in need. The report also recommended continued close monitoring of workers who have recovered from acute radiation syndrome and other highly exposed emergency personnel and focussed screening of children exposed to radioiodine for thyroid cancer and highly exposed clean-up workers for non-thyroid cancers. In addition, it called for long term monitoring of caesium and strontium radionuclides to assess human exposure and food contamination and to analyse the impacts of radiation reduction measures. The expert panel also said that better information should be given to the public about all aspects of the disaster, including the persistence of radioactive contamination in certain food products and about food preparation methods that reduce radionuclide intake.(Susan Mayor)
A report published this week by an international team of scientists, Chernobyl抯 Legacy: Health, Environmental, and Socioeconomic Impacts, found that fewer than 50 deaths so far could be directly attributed to radiation from the disaster. Nearly all of these were in rescue workers, who were exposed to high levels of radiation. The report predicts a further 3940 deaths from radiation induced cancer and leukaemia in the 200 000 emergency workers who were in the area in 1986-7, 116 000 evacuees, and 270 000 residents of the most contaminated areas, based on estimates of the radiation doses that they received. This is far lower than earlier speculations that radiation exposure might result in tens of thousands of deaths.
Figures analysed in the report show that about 4000 cases of thyroid cancer, mainly in people who were children and adolescents at the time of the disaster, have resulted from contamination. At least nine children have died of thyroid cancer, but the survival rate of people developing this type of cancer has been almost 99%, based on statistics from Belarus.
The report found no evidence or likelihood of decreased fertility among the affected population and no increase in congenital malformations that can be attributed to radiation exposure. The authors attributed this to the fact that most emergency workers and people living in contaminated areas received relatively low whole body radiation doses, comparable to natural background levels. Also, because the doses were so low, there was no evidence of any effect on the number of stillbirths, adverse pregnancy outcomes, delivery complications, or the overall health of children. A modest but steady increase in reported congenital malformations was seen in both contaminated and uncontaminated areas of Belarus, but this was thought to be due to improved reporting, not radiation.
Burton Bennett chairs the Chernobyl Forum, the group that produced the report, comprising representatives from United Nations?agencies (including the International Atomic Energy Agency and the World Health Organization) and the governments of Belarus, Russia, and Ukraine. He said, "This was a very serious accident with major health consequences, especially for thousands of workers exposed in the early days who received very high radiation doses, and for the thousands more stricken with thyroid cancer. By and large, however, we have not found profound negative health impacts to the rest of the population in surrounding areas, nor have we found widespread contamination that would continue to pose a substantial threat to human health, with a few exceptional, restricted areas."
The report considered that the mental health impact of Chernobyl was the largest public health problem. People living in affected areas tended to have negative self assessments of their health, believed they had shortened life expectancy, and tended to lack initiative and depend on help from the state. Persistent myths and misperceptions about the threat of radiation have resulted in "paralysing fatalism" among residents, the report warned, noting that, "Poverty, lifestyle diseases now rampant in the former Soviet Union, and mental health problems pose a far greater threat to local communities than does radiation exposure."
Members of the Chernobyl Forum are meeting this week to consider the report findings and recommendations, which include focusing assistance efforts on highly contaminated areas and redesigning government programmes to help those genuinely in need. The report also recommended continued close monitoring of workers who have recovered from acute radiation syndrome and other highly exposed emergency personnel and focussed screening of children exposed to radioiodine for thyroid cancer and highly exposed clean-up workers for non-thyroid cancers. In addition, it called for long term monitoring of caesium and strontium radionuclides to assess human exposure and food contamination and to analyse the impacts of radiation reduction measures. The expert panel also said that better information should be given to the public about all aspects of the disaster, including the persistence of radioactive contamination in certain food products and about food preparation methods that reduce radionuclide intake.(Susan Mayor)