EDIT: based on another commenter, OP's claim isn't even factual.

And it took the US until 1996 (after fall of USSR)? Not to mention that it was capitalism (General Motors) that spread the hoax about leaded gasoline being safe, under the guise of scientific research in 1921.

This is not the gotcha you think it is.

Did chatgpt not include this or...?

https://bpb-us-w2.wpmucdn.com/sites.gatech.edu/dist/a/1473/files/2020/09/sovenv.pdf

Nevertheless, the Soviet Union took effective action to protect the population from lead exposure; it banned lead-based (white lead) paint and it banned the sale of leaded gasoline in some cities and regions. While leaded gasoline was introduced in the 1920s in the United States, it was not until the 1940s that leaded gasoline was introduced in the Soviet Union (5). In the 1950s, the Soviet Un- ion became the first country to restrict the sale of leaded gaso- line; in 1956, its sale was banned in Moscow, Leningrad, Kiev, Baku, Odessa, and tourist areas in the Caucasus and Crimea, as well as in at least one of the “closed cities” of the nuclear weap- ons complex (6, 7). The motivation for the bans on leaded gaso- line is not entirely clear, but factors may have included Soviet research on the effects of low-level lead exposure (8), or sup- port from Stalin himself (5). In any event, the bans on leaded gasoline in some areas prevented what could have been signifi- cant population lead exposure. In the United States and other OECD countries, leaded gasoline has been identified as one of the largest sources of lead exposure (9, 10). Lead-based paint is another potentially significant source of population lead exposure.

Bonus: a great example of capital at work,

Along with a number of other coun- tries, in the 1920s the Soviet Union adopted the White Lead Convention, banning the manufacture and sale of lead-based (white lead) paint (11). In the United States, however, the National Paint, Oil and Varnish Association successfully opposed the ban, and lead-based paint was not banned in the United States until 1971 (12).

Two generations of Americans.

The first commenter is talking a hypothetical scenario of socialism being bad, so the second commenter (the one you responded to) responded with actual example of that same hypothetical scenario happening, but except by a capitalist power (the US). I don't think your response makes sense at all here.

They are not joking. You can see them continuing here: https://lemm.ee/comment/3563759

And this isn't whataboutism (not that it matters). The first commenter ridiculed socialism by using a hypothetical scenario. The second commenter showed with evidence this hypothetical scenario is actually real under capitalism.

My point is that capital has successfully fought to put lead into American's blood and lungs for over 100 years.

What textbook?