Secondhand Smoke and Electronic Cigarette Aerosol Resources US EPA Avoiding Tobacco Smoke and E Cigarette Aerosol Is a Key Part of Asthma Management Asthma and Allergy Foundation of America Secondhand e cigarette aerosols expose kids to less nicotine than cigarettes, study finds, but can still be risky CNN Do electronic cigarettes create thirdhand chemical residue? Thirdhand Smoke Resource Center