April 08, 2011 13:10
Concerns have risen over tap water being contaminated by radiation after rainfall on Jeju Island on Wednesday and nationwide showers on Thursday. But experts say there is nothing to worry about.
Drinking two liters of tap water and even rainwater from Jeju every day for two years would be equivalent to 1.4 times the radiation exposure from routine x-rays, while minute traces of radiation in tap water would be filtered out during the process of purification.
The Ministry of Environment said Thursday that levels of radioactive cesium-137 and iodine-131 would have no effect on tap water even if they seep into rivers or reservoirs.
Cesium, which has a half-life of 30 years and is considered the most hazardous of the radioactive contaminants, is composed of particles and can be filtered through water purification processes. In the case of iodine, which exists in gaseous form, only up to 20 percent can be filtered out through conventional methods, but the filtration rate can be boosted to between 60 to 70 percent by adding activated carbon to the processes, the ministry said.
But Cho Byung-ok at the ministry, said, "Iodine has a relatively short half-life of about eight days and is highly volatile, so there is a very slim chance of it being detected in the water supply. Although it's not filtered out completely during the purification process, iodine is easily released from the body through urine so there is no need to worry."
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