Also, let's just pretend that rather than being recycled, that the electrolytes are drained and then the batteries are incinerated without pollution controls and their contents spread to the far corners of the world, so everyone is exposed to them in low levels. Of course, that's not what actually happens, but let's adopt the anti-EV crusader attitude for a moment. What would be the consequence? Unlike gasoline vapours (a known carcinogen), the inorganic chemicals that make up the cathodes and anodes in lithium-ion batteries all appear - at low levels - likely to be more
beneficial to human health than harmful.
* Nickel: While some people have allergies to (bulk) nickel, and significant workplace exposure to nickel compounds can be carcinogenic or to aid in infection, in low levels it appears to
act as a probiotic (because human intestinal bacteria require it) and likely essential human nutrient. Humans are furthermore already exposed to significant amounts of dietary nickel from stainless steel cookware - far more than humans would conceivably ever be exposed to from the mythical "incinerated batteries"
* Cobalt: Pasturelands are frequently
deficient in cobalt. Cobalt is required for bacteria to produce B12, which is a cobalt compound.
* Lithium: Lithium occurs naturally in groundwater, generally at 0 to 170ppm. Increasingly research is indicating that
low levels of lithium in water are associated with a wide range of mental disorders, including depression, suicide, and violent behavior. Which can make sense, as lithium in high doses is used to
treat those conditions.
There's increasing argument that water for human consumption should contain a minimum level of lithium.
(Some batteries also have silica in the anodes, but burned silica is just... silica clay. Graphite or amorphous carbon is also used in anodes, and some aluminum in the cathodes, but again, nothing particular special about them)
So while it's certainly possible to have too much nickel, cobalt and lithium and have negative effects from that, in general most places could use more of them, not less.
(It is, of course, a moot point because li-ion battery packs aren't actually incinerated).