So far! no-one has ever died from loaded halloween candy. (The few incidents have all been inside jobs, like a parent poisoning their own kid).
The fentanyl candy scare came from brightly colored Oxy tabs that looked like packed-powder candy such as Sweetarts. It was a non-issue, but made for a scare piece to frighten conservative people who believe in teen rainbow parties.
It's the same scare that's been around since he olden days. Seriously. They used to blast this in the news in the 90's before we went out Trick or Treating.
The original is a boomer humour comic complaining about PM10 pollution from cars and all the allergies it gives kids. The message of the comic is that we should invest in public transit and walkability to reduce car pollution.