Stories of people & places, festivities & traditions from my travels around the world

Okunoshima: Japan's secret poison gas island

by Lucy Hornberger

The ruins of a poison gas storehouse on Okunoshima

Visitors to Hiroshima Prefecture who have a more than passing interest in military matters and Japan's war time activities may wish to visit Okunoshima. Like Hiroshima's Peace Park, Okunoshima is now a facility for peace studies, but offers a counterpoint to Hiroshima's nuclear memorials. In another dark episode in the country's 20th century history, this tiny, rural island - now better known for its holiday village and abundant tame rabbits (link to follow) - was Japan's most important site for the production of poison gas. The number of victims of this horrible industry are unknown (how and where the gas was used is still shrouded in mystery, although the little evidence that exists points to China). In addition to the intentional victims of the gas, there was also widespread suffering among the hapless workers who were put to work manufacturing the gas.
Okunoshima is located in Japan's inland sea, the Setonaikai, between the main islands of Honshu and Shikoku. The island first came to the Japanese government's attention in the 1890s when it was heavily fortified against Chinese attacks (the Sino-Japanese war was raging) and developed into a stronghold bristling with 200 cannons. Worse was to come when in the 1929 it was selected to be the site of Japan's poison gas production programme, despite Japan both signing and ratifying the Hague Convention of 1899 which specifically forbids the use of poisons. Due to the need for secrecy the island then fell off the map - Japanese mapping of the period has blank space where the island is located. At the height of production the Okunoshima plant had more than 5000 workers and produced 1200 tons of poison gases per year.
A variety of gases were produced, including tear gas, sneezing gas and paralytic gas. The main production, however, was focused on the erosive poisons Yperite and Lewisite, both of which are blister agent Mustard Gases (vesicant gases) which cause agonising pain and life threatening injuries.
Production came to an end in 1945 when the American Occupation Force closed down the island's operations, disposed of the gas that remained on the site (allegedly, and alarmingly, by dropping the barrels into the Pacific Ocean!) and destroyed the facilities and incinerating the equipment using flame guns. It is said that the plant's employees, fearing repercussions and even execution at the hands of the Americans, burnt as many records as they could before the occupying force arrived. This has hampered researchers, and it was only in the 1980s that it became public knowledge that Japan both produced and used poison gas during the Second World War.
Okunoshima's factory complex was the size of a small town, but has completely disappeared, replaced by a large hotel, a rabbit-covered meadow and tennis courts. Plenty of traces of the gas manufacturing do survive however, ranging from the concrete pedestals on which the gas tanks were stored, the shell of the facility's diesel powered station and the concrete air raid shelters for the military chiefs (the rest of the workers were left to shelter as best they could in earth holes covered with branches).
The island's small Poison Gas Museum (which has adequate English information for non-Japanese-speaking visitors) is a memorial to the facility's employees, who worked punishingly long hours under a harsh military ethos that tolerated no discussion or complaint, and suffered unpleasant and in many cases deadly effects of the gasses that they produced. The rudimentary rubberised clothing and gas masks that were supposed to protect them from the gasses often failed, eye injuries were common and longer term effects included severe blistering, cancer and chronic respiratory and digestive issues. Former workers, some of whom are still alive, are now part of a government medical support programme, similar to the one provided for Hiroshima's hibakusha. The workers on Okunoshima were involved in production only. Poison gas 'training and testing' was carried out at another facility (the Narashino Military Academy near Tokyo) and one can only wonder what horrors occurred there.
A corner of the Okunoshima museum displays colourful strings of senbazuru (the thousand origami cranes that have become symbolic of Japan's wish for lasting peace) and fervent calls for an end to war, and especially an end to chemical weapons and poison gas. A sign states that poison gas is "a weapon of indiscriminate mass destruction that does not spare civilians. We hope that his abhorrent history will never be repeated."
Okunoshima is located in Hiroshima Prefecture and can be accessed by regular ferry from Tadanoumi Ferry Port, which is about 200 metres from Tadanoumi Station on the JR Kure Line, about 2 hours from Hiroshima City.
The Okunoshima Poison Gas Museum

A chilling archive photo of rubber-suited and masked workers by a poison gas tank.

Specialised ceramic vessels and piping used in the manufacture of poison gas on Okunoshima

These concrete pedestals once held poison gas tanks for storage.

The shell of the Okunoshima facility's power station.

A model of the main poison gas production area on Okunoshima.

Today a tourist hotel stands on the site of the Okunoshima poison gas plant.

Senbazuru strings of a thousand origami cranes, and anti-poison gas messages in the Okunoshima museum.

Article & photos posted April 9th, 2016

Text and photos copyright © 2016 Lucy Hornberger. All rights reserved. Unauthorized use prohibited.


Stefanie on April 18, 2016:
Thank you for this and the previous two posts. It's not something I had expected to come across on this site, to be honest, so thank you all the more for it. Growing up in East Germany, I was taught about Hiroshima and Nagasaki a lot - especially because the crime was committed by the Americans (they were, of course, the prime antagonist to the Communist block in those days). I remember being particularly touched by the story of the little girl who folded a thousand paper cranes before she died from the effects of the nuclear bomb (though have to admit I never actually checked whether this was a true story - but in the end, it does not really matter). Your posts together show both sides of the picture, at least in part - thank you.
There is little to add to the words of the remarkable lady you met who survived the bomb. I wished her message was more prominent in schools around the world today. And, deliberately or not, that post once again showed how "insignificant" things can have the most far reaching of consequences: a game of "stone, paper, scissors" deciding fate... In this way, absolutely apt for this blog: "Travels with Fortuna" indeed!

Fortuna replies:
Thank you Stefanie! The little girl who folded the 1000 paper cranes definitely did exist – her name was Sadako Sasaki. Full info here:
There is a rather lovely children’s monument in the Hiroshima Peace Park which features a statue of her. The monument is surrounded by huge numbers of strings of 100 cranes, brought from all over the world (recent ones were from Sweden and the Island of Reunion when we were there).

Stefanie on April 20, 2016:
Thanks Fortuna for the additional information and photos! I remember seeing a picture of this statue - but didn't know whether there was a true or "made up" story behind it. How nice to know.

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