On Friday afternoon, 12 pupils poisoned by an unidentified gas
leak in southwest China were still in hospital, and 185 others had
returned home, as experts continued to try to pin down the cause of
the incident.
Of the 12 students, three are being treated for upper
respiratory tract infection but the others?could leave the
hospital soon, said Shi Jun, head of Xingjing County People's
Hospital in Ya'an City of Sichuan Province.
The 197 pupils from Xinmiao Township Primary School were taken
to hospital after a smell of bad eggs and something burning
assailed them at about 9:00?AM Thursday. Many soon suffered
headaches, vomiting and chest pains.
The smell was similar to a mixture of carbon monoxide and
sulfureted hydrogen, two exhaust gases which might have been
discharged from two nearby factories.
The factories -- an electrolytic zinc plant and a lead and zinc
washery -- are located only a few hundred meters from the
school.
But experts found the factories had not discharged untreated
pollutants into the air or water, and speculated that the students
might have been poisoned by a mixture of gases.
They said that exhaust gases from the factories might have mixed
with gases from sanitary sewage, forming an inversion layer in the
atmosphere which helped the mixture to spread.
Most of the students are eight to 10 years old. Six teachers and
a cook who were also at the school were not affected, according to
Yue Minggui, a teacher of the school.
(Xinhua News Agency June 23, 2007)