How Secondhand Smoke Affects Children and Pregnant Women Early life secondhand smoke exposure assessed by hair nicotine biomarker may reduce children's neurodevelopment at 2 years of age ScienceDirect Does Vaping Cause Secondhand Smoke? Secondhand smoke and secondhand aerosol In the United States, about 8% of all women who are pregnant smoke cigarettes, and another roughly 4% report using electronic cigarettes or vapes. To learn more about the dangers of smoking