Radioactive rebar linked to cancer
Medical experts fear for the health of former residents of radiation contaminated buildings who may no longer be checking up on their health
By Chiu Yu-Tzu / STAFF REPORTER
A five-year study of the incidence of disease among residents of radiation-contaminated buildings was recently completed, showing that the possibility of chromosome aberration -- damage to DNA -- was proportional to long-term exposure to low-dose radiation.
\nFrom November 1995 to June 2000, a research team at National Yang Ming University (陽明大學) kept track of more than 4,100 sample people who once lived in buildings that had been constructed in Taipei City between 1982 and 1983 using radioactive steel reinforcing bars.
\nA high incidence of diverse cancers was discovered among samples taken from the group.
\nThe researchers said that cancer could be induced by various factors, including personal lifestyle and environmental and occupational conditions. Exposure to radiation exceeding safety limits is also a factor that deserves close attention, they said.
\n"We found that DNA damage and chromosome aberration was closely related to samples' long-term exposure to low-dose radiation," Chang Wu-shou (張武修), leader of the research team, told the Taipei Times.
\nThe 4,100 sample patients, who have been receiving treatment at Taipei Municipal Jen-ai Hospital, are among some 7,800 residents recorded by the Taipei City Government as victims of radiation contamination.
\nEighty-nine of the 4,100 samples were diagnosed with cancer, including cervical cancer, breast cancer, liver cancer, leukemia and thyroid cancer. Researchers said that high incidence of the disease might be attributed to chronic low-dose radiation exposure.
\nOver the course of the research period, 39 of the 89 cancer sufferers died.
\nResearchers said that the situation did not mean that the mortality from cancer in the group was higher than that in other population groups because there was no direct link between cancer and the patients' exposure to low-dose radiation.
\nResearchers, however, concluded that excessive radiation did have a negative impact on humans.
\n"For example, we discovered that the height of children who had been exposed to radiation [exceeding the safety limits] was generally below average," said Chang, an environmental health sciences professor. He also said that the incidence of cataracts (白內障) among children who lived in radiation-contaminated buildings was higher than the national level.
\n"We also concluded that radiation causes damage to white blood cells, weakening people's immune systems," Chang said.
\nChang's study, supported by the National Health Research Institute (國家衛生研究院), might raise public awareness of safety issues regarding radiation. The research, however, has not been welcomed by the Atomic Energy Council (AEC, 原能會), the government's nuclear watchdog responsible for everything from radioactive medical waste to nuclear waste, because the history behind the research was the last thing officials of the council wanted to be reminded of.
\nOfficials from the council contacted Chang several times, asserting that his research on low-level radiation would not result in any new scientific discoveries. They told him that a low dose of radiation has been demonstrated to be beneficial to humans.
\nChang, however, said the council should be ashamed of itself for discouraging him from conducting his research because Taiwan was the only country which could provide such samples for medical research.
\n"Contaminated buildings in other countries would be dismantled immediately after radiation pollution was confirmed," Chang told the Taipei Times.
\nIn the early 1980s, rebar contaminated with Colbalt-60 was used in the construction of more than 100 buildings in several counties in Taiwan. The situation was not publicly known until a 1992. One day that summer a Taiwan Power Company (Taipower, 台電) worker took a Geiger counter, an instrument to measure the intensity of radiation, back to his home and discovered levels of background radiation that greatly exceeded safety limits.
\nHigh amounts of radiation had actually been detected years earlier. In 1985 a dentist had an x-ray machine set up in his apartment in Minsheng Villas (民生別墅) in Taipei and dangerous amounts of radiation had been detected. The dentist was banned from operating the machine. However, AEC officials did not mention to residents that high levels of radioactivity came from the walls of the building rather than the x-ray machine.
\nThe truth was exposed later. Because of a dispute over promotions at the council, high-ranking officials revealed in 1992 that AEC officials had been involved in a cover-up of the radiation-contaminated buildings.
\nAfter a reporter from the Liberty Times discovered that radiation levels at the villa exceeded safety limits by hundreds of times, a comprehensive check was carried out on thousands of buildings constructed between 1982 and 1984 in Taipei City. More than 100 buildings, including office buildings, schools and kindergartens in the city were confirmed to be contaminated by radiation.
\nAt the time, thousands of residents, young and old, were identified as having been exposed to more than 1 milli-Sievert per year (mSv/y), a safety limit set by the International Radiation Protection Association (IRPA), for up to 12 years. Following the investigation in Taipei, buildings with radioactive reinforced steel bars were discovered elsewhere in the country, including Taipei, Changhua, and Taoyuan counties and also Keelung City.
\nHsu Ssu-ming (許思明), secretary-general of the Radiation Safety and Protection Association Taiwan (RSPAT), told the Taipei Times that the radiation-contaminated reinforced steel bars discovered to date only account for a small portion of the radioactive bars.
\nHsu said that an ironworks produced 20,000 tonnes of contaminated rebar but so far the government has discovered only 7,000 tonnes of the product.
\nThe 7,000 tonnes of contaminated rebar was used in more than 2,000 homes and 30 schools, affecting more than 10,000 residents.
\nHsu said that potential dangers from undiscovered radiation contamination continue to threaten the public because the ironworks lost all records of the steel bars.
\n"Where are undiscovered radiation-contaminated buildings? They could be all over the island," Hsu said.
\n"We strongly encourage victims to have free medical examinations to take care of their health," Hsu said.
\nHe pointed out that many victims relocated from the radiation-contaminated buildings ignore the potential threats to their health after they have moved away.
\nA teenage boy, who relocated to Kaohsiung County after going to a primary school contaminated by radiation in Taipei for two years, ignored the notification from the Taipei City Government and missed chances to receive treatment. He later discovered he had leukemia. By the time the Tzu Chi Foundation (慈濟) found enough suitable bone marrow for him from 140,000 donors, it was too late for him to have an operation. The boy died of the cancer last December.
\nThe boy, however, was not one of the subjects in Chang's research.
\n"The government has lost contact with too many victims and are therefore no longer getting any help," Hsu told the Taipei Times.
\nA group of residents led by Minsheng Villas residents established the Radiation Victims' Association Taiwan to fight for compensation from the government and to raise public awareness that being exposed to radiation was dangerous.
\nMany of the victims had spent their life savings on the apartments they saw as their dream homes, but which later became the source of their nightmares.
\nIn 1993, three officials were censured for neglect of duty after having learned in 1985 that Minsheng Villas was seriously contaminated by radiation. In 1994, the Taipei District Court accepted lawsuits for state compensation from 65 residents of Minsheng Villas.
\nBut it was not until 1997 that the court made a judgment in favor of 57 of the residents and told the government to compensate them for physical, property, and psychological losses resulting from the intentional negligence of government officials who had concealed information.
\nThat was the only successful case for victims who asked for state compensation.
\nThe AEC's role
\nFewer than 20 of the almost 200 buildings discovered to be contaminated by radiation were properly dealt with. Some residents continued to live in the radiation-contaminated buildings because the selling price offered by the AEC was far less than what the homeowners had originally paid.
\nThe AEC also carries out studies relating to radiation-contaminated buildings. Researchers from the medical school of National Taiwan University confirmed only that the rate of death of thyroid-related diseases among the victims was higher than that of other population groups.
\nAnother research paper by the AEC published in the British medical journal the Lancet in February last year shows that the incidence of chromosomes being affected in people who lived in radiation-contaminated buildings was substantially higher than that of control groups.
A teenage sufferer of skin cancer caused by exposure to radiation.
FILE PHOTO: RADIATION SAFETY AND PROTECTION ASSOCIATION TAIWAN
Staff of the Atomic Energy Council take away radiation-contaminated steel bars found in the Taipei's Shihlin district. Recently concluded research on residents of buildings found to have been built using radioactive steel suggests close links between long-term exposure to low-dose radiation and DNA damage.
PHOTO: LIN WEN-HUANG, TAIPEI TIMES
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