Additionally to what the others already said:
LD50 and “bad for your health” are quite separate things.
Vitamin D for example has an LD50 of ~30mg per kg. So according to your logic, it’s way unhealthier than aspartame (factor ~100). Though in reality you would die without vitamin D intake.
I personally don’t understand why the loudness and dust pollution (which often also seems to be a bigger issue with bikes compared to cars as well) is much more regulated with bikes and cars, since a lot more people are suffering because of it compared to the “fun” for a few (assholes…).
One way or the other, the future is likely electronic, and I hope that this will happen sooner than later… As when using electronic bikes these issues compared to cars turn around:
Also issues like short battery life (or sluggish bike when using a big battery) will likely be solved incrementally in the future. In the meantime please (targeted to politicians) just regulate them slowly towards electronic bikes (e.g. allow only very silent new bikes, which is basically a death sentence to combustion, when very silent).