More importantly, it represents a dangerous health hazard. Over 4,000 different chemicals have been identified in ETS, and at least 43 of these chemicals cause cancer. Although ETS is dangerous to everyone, fetuses, infants and children are at most risk. This is because ETS can damage developing organs, such as the lungs and brain. Secondhand Smoke and its effect on the Fetus and Newborn Maternal, fetal, and placental blood flow change when pregnant women smoke, although the long-term health effects of these changes are not known.
Some studies suggest that smoking during pregnancy causes birth defects such as cleft lip or palate.
Smoking mothers produce less milk, and their babies have lower birth weight. Maternal smoking also is associated with neonatal death from Sudden Infant Death Syndrome, the major cause of death in infants between one month and one year of age. Secondhand Smoke and its effect on Children's Lungs and Respiratory Tracts Exposure to ETS decreases lung efficiency and impairs lung function in children of all ages. It increases both the frequency and severity of childhood asthma. Secondhand smoke can aggravate sinusitis, rhinitis, cystic fibrosis, and chronic respiratory problems such as cough and postnasal drip.