That's a bit hyperbolic. The fact of the matter is, there has been an irresponsible lack of studies conducted on the long-term effects of tear gas exposure:
https://med.umn.edu/news/u-m-study-shows-little-research-available-long-term-effects-tear-gas-use
However, the CDC does warn that it could potentially cause issues long-term:
https://www.cdc.gov/chemical-emergencies/chemical-fact-sheets/riot-control-agents.html
The bottom line: Governments should be strictly regulating the use of these agents until further research is conducted. The fact that people with asthma can fucking die from the exposure should be justification enough, let alone other potential long-term side effects.