Mad as a Hatter

次のイディオムの知識はありましたが、水俣病とmad hatter's diseaseを結びつけることはできていませんでした。

（ウィズダム）

(as) màd as a hátter

まるで気が違って; かんかんになって(!帽子職人は水銀中毒になり神経が侵されるという考えから).

（英和大辞典）

Mád Hátter

━ n. ［the ～］ マッドハッター《Lewis Carroll の Alice’s Adventures in Wonderland に登場する頭のおかしい帽子屋》.

このあたりを結びつけて説明していくのは定番中の定番のようで次のような記事がありました。

Mad as a Hatter: Global efforts to reduce mercury emissions

Feb. 18, 2013, 2:41 PM By Sudipta Chakraborty

Did you ever wonder what made the Mad Hatter from Alice in Wonderland so mad? The phrase “mad as a hatter” actually comes from Mad Hatter disease, better known as mercury poisoning. In the 19th century, fur treated with mercury was used to make felt hats. Hatters were confined in small spaces and breathed toxic mercury fumes, resulting in “mad” or irrational behavior.

Today mercury is used in manufacturing processes, as a vaccine preservative, in dental amalgam fillings, certain medications and cosmetics, and in fluorescent light bulbs. But the most common cause of mercury toxicity in humans results from eating fish and shellfish that have been contaminated by industrial runoff.

Last month representatives of more than 140 countries agreed to the terms of a treaty called the Minamata Convention that would ban the use of mercury in switches, certain fluorescent lamps, cosmetics, most batteries and certain medical thermometers and blood pressure devices by 2020. The treaty is scheduled to be finalized this fall in Minamata, Japan, where industrial waste poisoned an entire village 50 years ago.

カナダでも先住民の地域で水銀被害が起こっているそうで、水俣病も引き合いに出しながら同じような説明がなされています。

VEZINA: The public health disaster of mercury poisoning at Grassy Narrows

Jul 23, 2021  •  July 23, 2021  •  3 minute read  •  Join the conversation

It has been known for a long time that methylmercury is extremely toxic.

Indeed, the saying “mad as a hatter” and the Mad Hatter character in Lewis Carroll’s Alice’s Adventures in Wonderland, originally came from the effects of mercury poisoning on workers in the hat-making industry, because of the process to convert fur into felt going back to the 18th century.

Exposure to large amounts of methylmercury can result in a wide range of mental and physical health problems which, as late as 1975, the medical community in Canada did not know how to identify reliably.

That’s one of the major reasons the Ontario health ministry at the time sent medical experts to Japan to study and better understand the effects of mercury poisoning, known as Minamata disease.

The disease derives its name from Minamata Bay in Japan, where in the late 1950s the local population was exposed to mercury poisoning from the wastewater of a local chemical plant, which entered the human food chain because of people consuming fish.

連想を生み出し、イメージを膨らませることができるようになるには雑学的な浅く広くのアプローチが必要ですね。10年ほど前にジョニーデップはMad hatterを演じていました。