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Thyroid Disorder Toxin Found in River

Posted July. 29, 2006 03:00,   


The government is taking emergency measures after perchlorate, known to cause thyroid disorders, was detected in a great quantity in the Nakdong River water system, an important source of drinking water for Yeongnam residents.

The Ministry of Environment revealed on July 28 that 2,225ppb of perchlorate was detected in a water quality investigation on the major water intake station in Nakdong River and the regions around, surpassing the standard of US Environmental Protection Agency (EPA) (24.5ppb) by up to 90 times.

The concentration of perchlorate did not surpass the standard amount in the water of the water intake station and water purification plant used as drinking water, but it greatly surpassed the standard amount in the sewage disposal plant close to the water intake station.

Ministry of Environment carried out water-quality investigations three times this month on July 7, 12 and 26 on the major water intake stations and sewage disposal plants in Nakdong River and the number of residents who use the water in the water intake stations included in the investigations is 3,270,000 in Daegu, Busan, Gyeongbuk, and a part of Gyeongnam.

The water in which the concentration of perchlorate was detected surpassed the US EPA standard by 90 times was revealed to be water flowing into the Gumi Sewage Disposal Plant discharged from Gumi Industrial Complex 3.

The concentrations of perchlorate detected in Gumi Sewage Disposal Plant were 1,892ppb (influent) and 800.3ppb (discharged water), surpassing the U.S. EPA standard by as high as 77 times.

On July 26 at the same spot the concentration turned out to be 1,522.4ppb (influent) and 1,224.3ppb (discharged water), and on July 12, 889.1ppb (influent) and 740ppb each.

Meanwhile, the concentrations of perchlorate detected under Owegwan Bridge, Owegwan Water Intake Station, under Seongju Bridge and in the Hyeonpung water system were under the U.S. EPA standard.

At the water intake stations and sewage disposal plants in Maegok, Gangjeong, Maeri, Mulgeum, Chilseo and Changam, either perchlorate was not detected or the concentration was 19.1ppb at minimum, staying under the standard.

The Ministry of Environment stated that it is carrying out a close investigation on whether the perchlorate is produced as a by-product in the purifying processes, as the investigations showed that the concentration of perchlorate was higher in the water that underwent purification processes than in the water flowing into the purification plant.

The government advised company A that had been discharging large amounts of perchlorate through detergents to reduce the use and discharge of perchlorate.

Company A is known to have lowered the concentrations of perchlorate in the sewage from 16,060ppb to 70ppb from July 17 by running the biochemistry disposal facility.

Meanwhile voices are being raised that the government did not disclose instantly when it confirmed the detection of hazardous substances early this month.

It was revealed that the Busan City, University of Pusan, and the civil organizations had confirmed the concentration of perchlorate to be 82.1ppb at Owegwan Water Intake Station, 34.1ppb at Goryeong Water Intake Station, and 1828ppb in water discharged from Gumi Sewage Disposal Plant in the investigation they carried out late last month and requested the government to take appropriate measures.

The Ministry of Environment stated that it plans to expand the investigation on perchlorate all over the nation and devise standards on the amount of emission permitted and the quality of water.

Eun-Woo Lee libra@donga.com