There are a few events you'll find on every list of the world's worst industrial or environmental disasters.

And among these few is the 1976 dioxin poisoning thousands of people

when an Italian chemical plant in Seviso exploded.

Just how bad was it really? Are we giving it too much or too little attention?

Well that's coming up right now, un Skeptoid. I'm Brian Dunning from Skeptoid.

Reconsidering the Sevaso dioxin disaster.

Welcome to the show that separates fact from fiction, science from pseudoscience,

real history from fake history, and helps us all make better life decisions

by knowing what's real and what's not.

Today we're going to point the skeptical eye at a 1976 industrial disaster at a chemical plant in

Sevaso Italy long considered one of the worst in history.

Thousands of local residents were exposed to dioxin, widely believed to be one of the most toxic chemicals there is.

We're going to see how bad it really was, and whether those labels are really deserved.

Developing effective solutions depends on having an accurate understanding of a problem.

So if the way we regard Se-as-O today is inaccurate, then we're setting ourselves up to fail

when we respond to some future similar event.

So what is dioxin anyway?

Surprisingly, this is not a simple question.

There are hundreds of chemicals that are classified as dioxins,

falling into three groups,

PCDs, PCDFs, and PCBs.

All dioxins are persistent organic pollutants,

...