Smoking (adults) remains legal in Canada and is not designated as a disability. There is proof that smoking can affect

[answerhappygod]

Smoking (adults) remains legal in Canada and is not designated
as a disability. There is proof that smoking can affect the
health of smokers and those in close contact with the smoker.
However, because smoking has been proven to be addictive, it
could be a matter of time when withdrawal symptoms are questioned
to be a disability due to adverse effects.
There are organizations that advertise to "non-smoking
applicants"; but this can be a slippery slope.