Another tourist has died due to suspected methanol poisoning in Laos, the fourth person to pass away in what some believe might be a mass poisoning incident.
Bianca Jones, 19, from Australia, was confirmed to have died on Thursday by her family, hours after U.S. officials announced the death of an American man, and days after Danish authorities confirmed the deaths of two young Danish women, aged 19 and 20 —all in Laos.
Jones's friend Holly Bowles is currently in hospital on life support. It is unclear how many other tourists became ill in the same incident, but their number includes people from New Zealand, the Netherlands and the U.K.
It is believed that these people might have consumed drinks laced with methanol while travelling across Southeast Asia.
What is methanol?
Methanol is a type of alcohol, similar to ethanol—the alcohol used in alcoholic drinks—but it has two carbon atoms, rather than just one.
It is colorless and flammable like ethanol, and used in antifreeze, windshield washer fluid, perfumes and fuel.
Sometimes, methanol is added to cheap or counterfeit alcoholic drinks to boost their alcohol content, but this can be very dangerous.
Dr. Wayne Carter, Associate Professor at the University of Nottingham, said in a statement that methanol can be masked by mixing it with ethanol.
"It can go undetected until the toxic effects are felt—highlighting the potential for toxicity with fatal consequences," said Carter. "For some people, even low levels of methanol ingestion—as little as 15ml of a 40 percent solution—can cause death."
Why is methanol toxic?
Like ethanol, methanol reacts with oxygen in the body. In the case of ethanol, this process makes acetaldehyde—a toxic chemical—and then acetate, or acetic acid, the acid found in vinegar.
However, methanol becomes formaldehyde—a cancer-causing chemical used in industrial glues and embalming corpses—and formate, or formic acid, which is a strong and toxic acid.
Dr. Christopher Morris, senior lecturer at Newcastle University, said in a statement: "Formate, which is the main toxin produced, acts in a similar way to cyanide and stops energy production in cells, and the brain seems very vulnerable to this. This leads to certain parts of the brain being damaged."
"The eyes are also directly affected, and this can cause blindness, which is found in many people exposed to high levels of methanol."
He explained that formic acid could raise acidity levels in the body, leading to tissue and organ damage, and potentially organ failure and death in severe cases.
What is methanol poisoning?
Professor Sir Colin Berry, Emeritus Professor of Pathology at Queen Mary University of London, explained in a statement that the symptoms of methanol intoxication are initially similar to feeling drunk.
However, after a while, patients may develop a headache, nausea, vomiting, abdominal pain and visual problems, ranging from blurred vision to hallucinations or total loss of vision.
"In later stages, generally developing between 18 and 48 hours after methanol ingestion, drowsiness may progress to coma," said Berry, adding that seizures may occur too.
Professor Alastair Hay, Emeritus Professor of Environmental Toxicology at the University of Leeds, said in a statement that methanol poisoning is sometimes treated with dialysis to remove methanol from the blood—often while giving the person ethanol to keep them mildly drunk.
"The principle behind administering ethanol is quite simple; it delays methanol metabolism," said Hay, explaining that "both alcohols are broken down by the same liver enzyme," but that the enzyme prefers ethanol.
Therefore, keeping the patient drunk serves to slow down the metabolism of methanol into its dangerous byproducts.
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