Dr. Nguyen Trung Nguyen, director of the poison control center of Bach Mai Hospital in Hanoi, said Thursday that the hospital has admitted six patients severely affected with tin poisoning, including the deceased. In all cases, blood tin concentrations were 10 times higher than the permitted threshold, marking the first instances of acute tin poisoning reported in Vietnam.

The deceased and five other colleagues were working at the recycled plastic fertilizer division of a curtain manufacturing company in Thanh Mien District, Hai Duong Province in northern Vietnam.

Before they started working for the company, all six were in good health. But, very soon, from four days to a month, the workers had common symptoms: psychosis, especially memory loss, confusion, agitation and abnormal behavior.

The dead man, whose name has not been revealed, was hospitalized on July 9 with all the above-mentioned symptoms. He fell into a coma soon after and died. Specific details of the death, including when it happened, were not revealed.

A magnetic resonance imaging (MRI) scan showed the deceased’s brain had suffered from diffuse white matter injury, metabolic acidosis and severe hypokalemia (abnormally low potassium content in the blood). Initially, his family suspected he was suffering from mental problems as his father just died and he’d had some problems with a personal relationship.

His relatives told doctors that some of his colleagues had also experienced similar symptoms, whereupon doctors advised the workers brought to the hospital for urgent examination.

A 42-year-old worker was later hospitalized in an abnormal mental state, showing symptoms of dementia, driving and wandering aimlessly around the village. Test results revealed serious blood disorders.

Nguyen said that doctors at the hospital researched medical information, consulted experts and international colleagues as they tried to diagnose the problem. On being advised to check tin concentration in the blood, tests were done by the Institute of Chemistry under the Vietnam Academy of Science and Technology.

Results showed that concentration of tin in his blood was more than 200 micrograms/liter, more than 40 times the permitted threshold.

The patient was put on a regimen of dialysis and tin detoxification. After a week of intensive treatment, his condition improved and memory gradually returned.

Blood samples of the 35-year-old deceased patient showed tin concentration 50 times higher than the safe level.

Among the six cases, some did not show typical symptoms, but tests showed severe hypokalemia, metabolic acidosis or brain damage, and the concentration of tin in the blood significantly high.

Doctor Nguyen said the patients were poisoned with organic tin compound. Tin exists as metallic atom, including inorganic tin compounds, and organic tin compounds. Metallic tin and inorganic tin are essentially non-toxic.

Organic tin compounds are highly toxic and easily absorbed via the skin, respiratory and gastrointestinal systems. They are used as a plastic and heat stabilizer.

There is no specific treatment regimen for tin poisoning, a new occupational health problem in Vietnam. Only a few cases have been recorded in the world and the risk of tin poisoning comes from plastic recycling and mining operations.

The Bach Mai Hospital has reported the cases to the Ministry of Health and relevant agencies for follow up action to find out the source of poisoning and take measures to prevent its recurrence.

The poison control center has called on people who work in conditions with high risks of tin poisoning to get their health examined urgently.

The Hai Duong General Hospital and the province’s Center for Disease Control has announced that among 15 people who have had their health checked, eight have showed symptoms of tinnitus and hearing loss, and six have hypokalemia. They have been asked to be hospitalized for further evaluation and treatment, but no one has done so to date, worrying health professionals about the risk of tin poisoning.