Are trace amounts of toxins ok for you ? Why do doctors say a little is ok ?

The average doctor is very supportive of trace amounts of toxins being injected into you and even very young children.
The average doctor (mine included) will deride you for suggesting you may want to avoid these toxins.

I don't think that "trace amounts" are ok at all.
While we in our daily lives strive to avoid toxins, why should our doctors continue to say a little is still ok ?

While we try to rempove BPA from our diet, reduce our exposure to plastics around our food, eating organic foods, banning chemical crop sprays - why are our doctors still condoning their support of pure injections of chemicals ?

Would an organic food consumer condone the injections a doctor will prescribe ?