Lead exposure is a problem. There is no safe level of lead. Flint raised an alarm. Flint received attention. Give credit to the activists and the mayor. Activists in other cities can use Flint as inspiration. Flint is lucky that you had no power to effect their lives.

The ridiculous argument that the children of Flint are being stigmatized is just that, ridiculous. The children of Flint were told that their lives didn't matter by the state government via an overseer, the state health department, and the Governor. They already know that every life isn't scared.

Regarding the FDA Anderson-cigarettes

The story starts in September 2008, during the administration of President George W. Bush. The FDA detained early batches of e-cigarettes on the grounds that they appeared to be unapproved medical devices designed to deliver the drug nicotine.

The manufacturers quickly took the agency to court, arguing that their products were neither devices nor drugs. Instead, they claimed that e-cigarettes were most akin to traditional cigarettes, which the Supreme Court had recently said the FDA could not regulate without new legislation from Congress. The companies sought an injunction against the FDA on the grounds that the agency was causing them immediate and irreversible economic harm.

The FDA’s response was, in essence, that e-cigarettes barely resemble cigarettes and look a lot more like nicotine inhalers, which are regulated devices that contain drugs. As the case was pending, FDA released early data revealing the presence of harmful chemicals in e-cigarettes. The agency also held a press conference and warned the public of the risks of addiction and lung injury.

I remember this moment well because at the time I served as principal deputy commissioner of the FDA. “We’re concerned about them because of what we know is in them and what we don’t know about how they affect the human body,” I told The New York Times.

The FDA’s efforts didn’t help. District Court Judge Richard Leon issued a restraining order against the FDA to prevent “irreparable” harm to the e-cigarette industry. Criticizing the agency for “its tenacious drive to maximize its regulatory power,” Leon wrote, “I am not convinced that the threat to the public interest in general or to third parties in particular is as great as FDA suggests.”

https://www.statnews.com/2019/11/21/e-cigarettes-fda-hands-tied/

The FDA repeatedly appealed the decision

The CDC is tasked with finding the cause of the outbreak, and it did. It had issued a warning in August

https://www.statnews.com/2019/11/08/vaping-illnesses-vitamin-e-acetate/

Just like the Flint lead poisoning, some labeled the CDC as being alarmist.

After analyzing fluid from the lungs of patients in the recent vaping-disease epidemic, the Centers for Disease Control reported last week that every victim had traces of an additive used in marijuana vaping but never used in nicotine vaping. That should not come as a surprise, because there was never any evidence or suggestion that nicotine e-cigarettes such as Juul makes had caused any harm to their users. But the CDC had pretended otherwise in August, warning people not to use any kind of e-cigarette.

The CDC’s warning, amplified by alarmist media coverage, confused the public about the risk of vaping THC—the active chemical in marijuana—while discouraging smokers from switching to a safer source of nicotine. A national survey in September found that 58 percent of American adults mistakenly believed that the new epidemic was related to e-cigarettes like Juul, and that only 22 percent believed e-cigarettes were healthier than tobacco cigarettes. In reality, researchers have so far failed to find any long-term harm from nicotine vaping, and British public-health authorities have declared e-cigarettes at least 95 percent safer than tobacco cigarettes.

The CDC’s scare, coupled with a subsequent announcement that the Food and Drug Administration planned to ban the flavors used by more than 80 percent of adult vapers, amounted to welcome news for the declining tobacco industry. Cigarette sales had been plummeting (along with smoking rates among adults and young people) since Juul’s rise to popularity three years ago. But after the CDC’s and FDA’s actions, the Wall Street Journal reported, tobacco-industry analysts said that they expected cigarette sales to improve and were already seeing signs of that trend.

https://www.city-journal.org/cdc-trump-vaping

misc. data I have collected related to the vaping jihad and its narratives

 [...] The Surgeon General of the United States indicates that nicotine does not cause cancer.[29] [....]

[29] National Center for Chronic Disease Prevention Health Promotion (US) Office on Smoking Health (2014). The Health Consequences of Smoking—50 Years of Progress: A Report of the Surgeon General, Chapter 5 - Nicotine. Surgeon General of the United States. pp. 107–138. PMID 24455788.

~ Wikipedia

Here's the evidence that the FDA knew exactly what was causing the vaping-related illnesses by Sept. 5 and informed state officials at that time. As you say, the CDC pretended for months that the FDA didn't really know what it was doing and was jumping to conclusions, allowing for alarmist speculation and propaganda to develop and inspire proposed vaping bans allover the place before they finally announced: oh, by the way, the FDA was correct, but we thought a period of fear and paranoia inspiring all kinds of nanny state suggestions would be a good thing (themselves whispered to follow this program by a variety of lobbyists of the Puritan jihadi type? The mystery for me: how come such jihadis haven't given equal time to smoking marijuana and injesting THC?)

Here from April, considerable evidence that vaping nicotine does not lead to cigarette smoking among children and adolescents. Oh did I mention I tend, from experience, to trust UK sources for epidemiological studes over most of our U.S. sources?

I am reminded of how nearly every kid's tonsils were yanked out in the 1950's based on sure medical conventional wisdom. Now we know that tonsils are an important part of the immune system. Kids who had their tonsils out were famously alllowed to eat ice cream. This made kids open to the procedure. Ah but dairy....And how we drove to the Wisconsin state line in the 60's to buy authentic color margarine (which was not allowed to be sold because the dairy farmers wanted butter to be your only yellow choice in Wisconsin.) We did this to save my father from having a heart attack, which butter supposedly caused. Turns out the dairy farmers were the ones concerned for his health? P.S. Guess what, the latest: pediatricians agree children under 5 should have only breast milk and/or whole cow's milk and water, ruling out other drinks; other liquids may harm their development. Those fruit juices GenX and millennials raised on? Toxic, I guess. And adults should reconsider full fat dairy, too. 

Edit to add pre-emptive, don't bother I'll do it myself: Ok, boomer.