Following recent eruption of Mt Ontake and the sad news of over 30 people found in 'cardiac arrest', why would the eruption cause it?

My initial thought would be that the cause of death would normally be suffocation or burns from the hot ash. Is it to do with elements/compounds present in volcanic ash?

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    $\begingroup$ That article doesn't give reasons, but shock or fear-induced excitement might trigger a heart attack in someone who was already prone to it. Likewise, dust, ash and toxic fumes in the air might cause breathing difficulties that could also lead to cardiac arrest. $\endgroup$
    – naught101
    Commented Sep 29, 2014 at 0:42
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    $\begingroup$ Notice the terminology. They are "in cardiac arrest". They didn't "die from cardiac arrest". If I recall correctly, this is just the Japanese way of saying that someone is dead until an examination by an offical police doctor. After all, all dead people are "in cardiac arrest" by definition. $\endgroup$
    – Gimelist
    Commented Sep 29, 2014 at 6:42

1 Answer 1


Michael's comment is correct, in Japan, according to the article Japan volcanic eruption: Mt Ontake rescuers find more than 30 people in 'cardiac arrest' (Radio Australia), state

Police said the 31 people were found in "cardiopulmonary" arrest on Sunday but declined to confirm their deaths pending a formal examination, as per Japanese custom.

and more directly, from More than 30 feared dead on Japan's Mount Ontake after volcano erupts (Washington Post)

using the terms for heart and lung failure that Japanese authorities employ to describe bodies. People cannot be declared dead in Japan until doctors have examined them.

It is very likely, given how close they were to the eruptive crater and the sudden inhalation of hot volcanic ash, gases and other materials, the victims went into cardiopulmonary arrest due to their lungs being overwhelmed by the sudden quantity. Additionally, burns, fear, debris could have likely caused shock causing cardiac arrest.

Several case studies from other volcanoes are presented in the article The respiratory health hazards of volcanic ash: a review for volcanic risk mitigation (Horwell and Baxter, 2005).

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    $\begingroup$ Thanks, I had in mind it might be to do with Japanese law. I came across the term ' in unresponsive state' being used in another article, so after seeing 'cardiac arrest', I thought the cause of death was already established. Also, thanks for the link to Horwell and Baxter article. Very interesting $\endgroup$
    – Jerry
    Commented Sep 29, 2014 at 12:05
  • $\begingroup$ it is like this in many countries,the thing here is that death is a medical diagnosis that can only be given by a medical doctor. $\endgroup$ Commented Sep 25, 2020 at 12:06

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