Osaka expo water shows halted after detection of legionella bacteria

This whole Expo is a sham and probably a scam to line the pockets of the usual suspects.

Just put plenty of sodium hypochlorite in the water-works to prevent bacterial buildup.

Expo that being used to show case the latest tech, at least please use the latest tech to solve many problems that expo has, from heat

https://english.kyodonews.net/news/2025/04/a012239f9ff3-organizers-visitors-bracing-for-hot-weather-at-osaka-world-expo.html

bugs

https://www.scmp.com/week-asia/health-environment/article/3311802/plague-flying-pests-adds-osaka-world-expos-woes-japan

and now bacteria

Osaka expo water shows halted after detection of legionella bacteria

increased circulation of seawater around the area

if anyone has ever visited Osaka Bay can tell you, the seawater is brown

This whole Expo is a sham and probably a scam to line the pockets of the usual suspects.

Shades of Abe’s Olympics...and now biblical revenge enacted through the midges and water bacteria.

So legionella was detected but the show went uninterrupted until the bacteria proliferated out of control?

How about doing this from the beginning and making effective measures the condition to letting the show continue?

I feel sad for the people of Osaka that will have to pay with their taxes the loses from the expo for many years to come.

You would think all the radioactive water from Fukushima would have killed a little bacteria. Lol

As someone who grew up in hot-climate area, that waterfront is an abomination of a design.

It's still water, there's no flow coming and going to the Ocean, a perfect recipe for bacterial build up. Not to mention, now summer is coming, mosquito's breeding haven. Who ever designed it was not an architect who cares about harmony with nature and yet they plaster "SDGs" or "ESGs" all over the place.

Osaka expo water shows halted after detection of legionella bacteria

Osaka Expo, the grand vision of sustainability—where harmony with nature means creating a stagnant, bacteria-infested puddle just in time for mosquito season. 

Is this Japan’s pavilion on biohazard?

You would think all the radioactive water from Fukushima would have killed a little bacteria. Lol

Tell me you don’t know about Japan’s geography without telling me you don’t know about Japan’s geography.

I feel sad for the people of Osaka that will have to pay with their taxes the loses from the expo for many years to come.

Unfortunately for you and those that hate big events, it is wildly popular and most people that have gone have enjoyed plus go repeatedly.

Something in the water does not compute.

Unfortunately for you and those that hate big events, it is wildly popular and most people that have gone have enjoyed plus go repeatedly.

What people hate are badly organized, shady events being imposed to a location so when it flops money can be channeled from the taxes to pay for the profits of a few.

The expo is not even remotely as popular as projected, with attendance only a fraction of the 150K daily that was planned for, in comparison the previous Osaka expo in 1970 had on average 350K visitors per day.

And with the novelty of the first days gone, and the many problems being reported continuously this lack of popularity is not going to improve any time soon.

This is what happens when you build things on dumps. Odaiba was one of the first commerical areas to do that and the first few years had nasty pollution issues. I remember the "beach" there, facing the Rainbow Bridge, reeked.

USJ in the beginning, just across the waterway, had polluted water coming out of the pipes so people couldn't drink the water there until they fixed and cleaned things up.

I'm sure this Expo site will have some more pollution related problems in the near future too.

It's all pretty disgusting.

Unfortunately for you and those that hate big events, it is wildly popular and most people that have gone have enjoyed plus go repeatedly.

What people hate are badly organized, shady events being imposed to a location so when it flops money can be channeled from the taxes to pay for the profits of a few.

It’s the classic recipe, isn’t it? Take one part “grand vision,” stir in a generous helping of “public funds,” sprinkle with vague buzzwords like “innovation” and “sustainability” and "future society" and voilà—you’ve got yourself a taxpayer-funded donburi with the only missing ingredient, accountability.

But no worries—when it all flops, I’m sure someone’s cousin’s consultancy firm will be right there to “evaluate the learnings” for a modest seven-figure fee.

I hope most of the big problems have come out and been addressed when I go

Something is very wrong :

Legionella bacteria do not develop in sea water...only fresh water.

I imagine there must have been some heavy raining, then some layer of water must have been created because water was stagnant. Or contamination.

Normally, the tech guy that takes the water for analysis is not supposed to take some very small sample, like the thin top layer, which cannot be representing the real level of such bacteria sent into air because it iwill become sea water killing the bacteria...once mixed at general level.

By the way, the risk exists only by inhalation (ex : wet cooling towers or any air diffuser), not ingestion.

The illness from that bacteria is legionnaires’disease, aka legionellosis.

The expo is not even remotely as popular as projected, with attendance only a fraction of the 150K daily that was planned for, in comparison the previous Osaka expo in 1970 had on average 350K visitors per day.

Also Osaka Expo in 1970 was the 2nd highest in attendance in the history of the World Expo. This was back in a time when Japan had almost no amusement or theme parks.

Currently lines for major pavillions have 3-5 hour wait times. Not sure why you think more people would be a good idea. Also for most expos, attendance picks up from the summer months naturally. That is how it was for Aichi.

Ewww!

Also Osaka Expo in 1970 was the 2nd highest in attendance in the history of the World Expo. This was back in a time when Japan had almost no amusement or theme parks.

And this is an example of an expo that is actually extremely popular as you claimed, the current expo is not even as popular as it was projected to be, and the period where the highest number of attendees was projected is already behind.

Currently lines for major pavillions have 3-5 hour wait times

Which can be also explained by terrible planning and not because people are breaking records of attendance. People hearing that you have to wait for 5 hours even with attendance well below planned will not find this appealing.

Not sure why you think more people would be a good idea. 

It is not me but the people that planned and finally imposed the expo on Osaka the ones that depend on very high number of people to at least break even.

Also for most expos, attendance picks up from the summer months naturally

The summer of twenty years ago is not comparable with what is being experienced now, we already are at temperatures over 27 degrees as it was the peak of summer in 2005 and the current expo is already reporting problems because of the heat, next month temperatures will be above 30 degrees so it is not really reasonable to expect a sudden increase of popularity, specially when several other problems are being reported as in this article.

Something is very wrong :

> Legionella bacteria do not develop in sea water...only fresh water.

I agree with that from my engineering experience, usually found in cooling towers of large AC units.

@virusrex

You’ve been to the Osaka Expo to

cast such authoritative opinions,right?

Also, aeration of the water will also

prevent bacterial formation.

So many people whining about the event but not offering solutions…

You’ve been to the Osaka Expo to cast such authoritative opinions,right?

That makes absolutely no sense, none of my comments depend on visiting or not the site, it is not like going to the expo would magically make summers colder, the 5 hour waiting line shorter or the legionella disappear.

Also, aeration of the water will also

prevent bacterial formation.

No, it would not, legionella is even a common contamination on water aereators, so aerating can increase the risk.

https://pubmed.ncbi.nlm.nih.gov/24442072/

So many people whining about the event but not offering solutions

When the solution is to stop badly planned/executed events from the beginning then complaining is exactly what is necessary to prevent the next time it would happen.

DudeDeuce

Today 08:44 am JST

I feel sad for the people of Osaka that will have to pay with their taxes the loses from the expo for many years to come.

What who said that.

Osaka residents will have to pay if the expo incurs losses?

Daniel MakinoToday  08:28 am JST

You would think all the radioactive water from Fukushima would have killed a little bacteria. Lol

Tell me you don’t know about Japan’s geography without telling me you don’t know about Japan’s geography.

I concur. If there’s any radioactivity in the sea water around Osaka, it’s most likely flowing across the Sea of Japan from China

I concur. If there’s any radioactivity in the sea water around Osaka, it’s most likely flowing across the Sea of Japan from China

Totally agree given prevailing currents. And looking at the 66 downvotes dished out, this is obviously a comment that ripped someone up inside.

Try not to take facetious comments too personally—most of the time, they’re meant to be light or humorous, not hurtful. People joke in different ways, and it’s rarely about you. Take a step back, breathe, and let it go. It’s not worth your peace of mind.

That makes absolutely no sense, none of my comments depend on visiting or not the site, it is not like going to the expo would magically make summers colder, the 5 hour waiting line shorter or the legionella disappear.

.

Thought so…

The article reports that water shows at the 2025 Osaka World Expo were suspended due to the detection of Legionella bacteria in the water systems. This incident raises significant concerns about the health and safety measures implemented at large-scale international events. The presence of Legionella bacteria, which can cause serious respiratory illnesses, suggests potential lapses in maintenance and oversight. Given the Expo’s global prominence, such issues can undermine public trust and deter attendance. It also highlights the importance of rigorous environmental monitoring and prompt response protocols to ensure visitor safety. While the swift suspension of the water shows demonstrates a commitment to safety, this event underscores the necessity for continuous and thorough health inspections. Organizers must prioritize preventive measures to uphold the Expo’s reputation and ensure a safe experience for all attendees.

Thought so…

Then why pretend it makes any difference? it is completely irrelevant to all the arguments used.

This "halt" is too late.

Though caution from health center, Expo association who prioritize profit than safe ignore it, continue water show, and had already spread aerosol involving legionella in front of visitors.

You guys going to still eat the 4-year-old brown rice?