Secondhand smoke is especially harmful for kids.
Introduction
Surgeon General Report

Secondhand smoke is dangerous for children at all levels, causing:
Sudden Infant Death Syndrome
acute middle ear infections
tonsillectomy
meningococcal infections
cancers and leukemias in childhood
slower growth
adverse neurobehavioural effects
upper respiratory tract infections
Unfavorable cholesterol levels
initiation of atherosclerosis (heart disease)
