Prime Minister Prayut Chan-o-cha has ordered the national police chief to urgently investigate how a power plant in Prachin Buri province lost a 25-kilogramme tube containing radioactive caesium-137 after local children reportedly developed symptoms related to respiratory diseases.
Government spokesman Anucha Burapachaisri on Friday appeared at a press briefing marking the first official statement from the government over the inspection of the missing tube from a National Power Plant 5A Company facility in the 304 Industrial Park in tambon Tha Tum of Si Maha Phot district.
Mr Anucha said Gen Prayut had urged the national police chief, Pol Gen Damrongsak Kittiprapas, to investigate how it disappeared and to hold local workers accountable.
Gen Prayut stressed the investigation should guarantee people's safety and pay attention to such environmental threats, said Mr Anucha.
As people expressed concern over the risk of radioactive contamination, Prachin Buri governor Narong Nakhonchinda said the tests showed radiation levels in the soil, water and air were safe.
Mr Narong said health examinations of local people near the steel plant did not reveal any contamination. He also gave assurances that local produce was still safe for consumption.
"Prachin Buri provincial officials have conducted tests to measure radiation levels and ensure food safety. Results indicated that agricultural products are free of radioactive substances," he said.
Prof Dr Sirirurg Songsivilai, permanent secretary at the Ministry of Higher Education, Science, Research, and Innovation, said health checks on 71 workers at a steel factory 10km from the power plant where traces of caesium-137 contamination had been found showed they posed no risk despite having come in direct contact with the tube.
Officials also tested oxygen there and found radiation levels were in a normal range.
Nonetheless, Gen Prayut ordered nine more checkpoints to be installed in Prachin Buri.
Kabinburi Hospital on Friday was informed by Ban Kok Kraton School that about 40 students had developed symptoms such as coughing, pink eye, sore throats and fever. Many were unable to attend classes. The school is 3km from the steel plant.
The hospital said many of the students had sore throats for days. Medical staff prescribed them medicine.
The cylinder went missing on Feb 23 but a complaint was not lodged until March 10. After days of frantic searching, authorities found radiated red dust believed to be from the remains of the tube at the plant.