Sidestream smoke that enters the air directly from a burning cigarette, cigar, or pipe
a.is less of an environmental and health concern than mainstream smoke.
b.has more carbon monoxide, ammonia, and benzene than mainstream smoke.
c.is not classified as a form of indoor air pollution.
d.has not been shown to be injurious to non-smokers.
b.has more carbon monoxide, ammonia, and benzene than mainstream smoke.