Toxic death theory 'carries little weight'

Confusion still shrouds mystery of dead tourists

* Published: 11/05/2011 at 12:00 AM
* Newspaper section: News

Thai experts are unconvinced by an independent investigation which suggested that a 23-year-old New Zealand tourist died from excessive exposure to a lethal toxin used to kill bedbugs at a Chiang Mai hotel.

A toxic substances expert from the Public Health Ministry and the Department of Agriculture said they did not think chlorpyrifos - which is used in insecticide sprays - was the cause of the death of Sarah Carter.

Although the experts confirmed Thailand has not banned the substance, approval is needed before it is imported or exported.

The Downtown Inn hotel in Chiang Mai, where four foreign tourists died mysteriously earlier this year.

Carter died on Feb 6, and her friends Emma Langlands and Amanda Eliason became gravely ill while they were on holiday in the Downtown Inn Hotel in Chiang Mai.

Five people died from unexplained causes in Chiang Mai over a 16-day period after New Year. Four stayed at the Downtown Inn Hotel.

The mystery over Carter's death resurfaced recently after an investigation commissioned by the New Zealand TV show 60 minutes found traces of the potentially lethal toxin in the Downtown Inn where the tourists stayed.

UN scientist Ron McDowall said there was a strong likelihood Carter died from excessive exposure to the substance.

The other four who died after staying at the hotel experienced identical symptoms to those suffered by Carter.

Chiang Mai Public Health Office deputy chief Surasing Visaruthrat told the Bangkok Post that although the authorities had not yet ruled out all possible causes of the deaths, the bedbug insecticide assumption "carries little weight".

Thorough checks conducted by the doctors when the three tourists were admitted to the hospital found no traces of insecticides, he said.

An autopsy performed by Maharaj Hospital also found no toxic substance residue. The doctors suspected Carter died from food poisoning, according to a Chiang Mai police report.

"We can't jump to a conclusion that toxin exposure was the cause of the death because the substance was allegedly found in the hotel room alone, not in the victim's body," Dr Surasing said.

Dr Surasing yesterday chaired a meeting of the investigation team. The meeting, attended by doctors and experts from various agencies, ended with no conclusion on the deaths.

Dr Surasing said the team would meet again after receiving test results of samples collected from the victims' bodies. The samples were sent for testing at laboratories in the United States and Japan.

Meanwhile, an official from the Department of Agriculture said Thailand did not ban chlorpyrifos, which is also used as an ingredient in insecticides for use on farms.

"It is hard to believe that a bedbug spray containing chlorpyrifos would be able to kill people unless a large amount of the chemical got into the body," said the official, who asked not to be named.

The official said chlorpyrifos is easily dissipated in the air, which means it causes no ill effects to the environment.

Industrial Work Department's hazardous substances control bureau director Mongkol Pruekwatana said chlorpyrifos is a hazardous substance Type 3 under the hazardous substance act, which requires approval for manufacturing, importing and exporting."The company that used the substance for pest control services might have imported it as powder, mixed it with water and used it to spray termites, resulting in leftover residue on beds," Mr Mongkol said.