By Kim Rahn
Villagers in a residential area of northern Seoul fear possible radioactive exposure after the detection of higher-than-normal levels of radiation in several spots.
With the asphalt suspected of containing radioactive materials, environmental groups are calling for the government to thoroughly investigate the situation and take protective measures for residents.
But the authorities say the radiation level is not serious enough to harm humans.
On Thursday, members of the Korea Federation for Environmental Movements and Child Save, an online community to protect children from radioactivity, conducted an investigation at several locations in Wolgye-dong in Nowon.
The investigation came two days after a member of Child Save detected by chance a high level of radiation at one spot with a portable detector Tuesday.
In the inspection, up to 3 micro-Siverts of radiation per hour were detected on the asphalt road in front of a high school.
“If converting this into a yearly-exposure level, it is equivalent to 26 milli-Siverts (mSv) per year, 26 times the annual radiation dose limit of 1 mSv,” a member of the federation said.
Such high levels of radiation were detected mainly on roads which were asphalted more than five years ago, while newly-paved roads showed permissible levels.
After the Child Save member first detected the situation and reported it to the authorities, the Korea Institute of Nuclear Safety (KINS) investigated the spot Wednesday and said the radiation level was 1.4 mSv per hour, about 10 times Seoul’s average radiation level in the air. It added the radioactive material there was cesium 137.
“Even if a person were to stand on the spot for an hour every day for a year, he or she would receive about 50 percent of the annual radiation dose limit. The detected amount is not that harmful to people’s health,” a KINS official said.
But the environmental groups’ own investigation on the same day showed the level was not 1.4 but 2.5 mSv.
Group members said the difference was because the KINS measured the level in the air, 1 meter above the ground, while they measured the level on the surface of the asphalt.
“The KINS said staying on the contaminated spot for an hour is not dangerous, but residents or street vendors stay there for hours every day. They could be exposed to 12 mSv of radiation, 12-fold the annual dose,” the member said.
“The radioactive asphalt was laid at least five years ago, so local citizens may have been exposed to radioactivity for a long time. The government should check their health and investigate possible similar cases in other parts of Seoul,” the group said.
Nowon District Office started removing the asphalt from the locations in question and is repaving them.
It said it has asked Seoul City to investigate other areas in the capital.
The KINS will announce the result of its investigation as early as next week.