Infants in Health Care Facilities Are Exposed to Thirdhand Smoke
Researchers have observed biomarkers confirming thirdhand smoke exposure in the urine of infants in the NICU. Found in incubators and cribs, particulates are likely being deposited in the NICU from visitors who have thirdhand smoke on their clothing, skin, and hair .
Animal Studies Link Thirdhand Smoke Exposure to Common Human Disease
Mice exposed to thirdhand smoke under conditions meant to simulate levels similar to human exposure are pre-diabetic, are at higher risk of developing metabolic syndrome, have inflammatory markers in the lungs that increase the risk for asthma, show slow wound healing, develop nonalcoholic fatty liver disease, and become behaviorally hyperactive . Another recent study published in 2017 showed that mice exposed to thirdhand smoke after birth weighed less than mice not exposed to thirdhand smoke. Additionally, mice exposed to thirdhand smoke early in life showed changes in white blood cell counts that persisted into adulthood [9,33].
In summary, recent research makes a compelling case for invoking the precautionary principle to ensure that children avoid exposures to thirdhand smoke in their homes, cars, and healthcare settings. Studies reveal that:
- children live in homes where thirdhand smoke is present and this exposure is detectable in their bodies 
- concentrations of thirdhand smoke exposure observed in children are disproportionately higher than adults 
- chemicals present in thirdhand smoke cause damage to DNA 
- thirdhand smoke contains carcinogens that put exposed children at increased risk of cancer 
- thirdhand smoke is being detected within medical settings  and in the bodies of medically-vulnerable children , and
- animal studies have linked exposure to thirdhand smoke to a number of adverse health conditions commonly seen in today’s pediatric population such as metabolic syndrome, prediabetes, asthma, hyperactivity  and low birth weight .
Using the Thirdhand Smoke Concept in Clinical Practice
The clinical setting is an ideal place to address thirdhand smoke with families as a component of a comprehensive tobacco control strategy.
The Cessation Imperative—A Novel Motivational Message Prompted by Thirdhand Smoke
While there are potentially many ways to address thirdhand smoke exposure with families, the CEASE program has been used in the primary care setting to train child health care clinicians and office staff to address second- and thirdhand smoke. The training also educates clinicians on providing cessation counseling and resources to families with the goal of helping all family members become tobacco free, as well as to helping families keep completely smoke-free homes and cars [35,36]. The concept of thirdhand smoke creates what we have coined the cessation imperative . The cessation imperative is based on the notion that the only way to protect non-smoking family and household members from thirdhand smoke is for all household smokers to quit smoking completely. Smoking, even when not in the presence of children, can expose others to toxic contaminates that settle on the surfaces of the home, the car as well as to the skin, hair, and clothing of family members who smoke. A discussion with parents about eliminating only secondhand smoke exposure for children does not adequately address how continued smoking, even when children are not present, can be harmful. The thirdhand smoke concept can be presented early, making it an efficient way to advocate for completely smoke-free families.
Thirdhand Smoke Counseling Helps Clinicians Achieve Key Tobacco Control Goals
The American Academy of Pediatrics (AAP) and the American Academy of Family Physicians (AAFP) recommend that health care providers deliver advice to parents regarding establishing smoke-free homes and cars and provide information about how their smoking adversely affects their children’s health [37,38]. It is AAP and AAFP policy that health care providers provide tobacco dependence treatment and referral to cessation services to help adult family members quit smoking [38,39]. Successfully integrating counseling around the topic of thirdhand smoke into existing smoking cessation service delivery is possible. The CEASE research and implementation team developed and disseminated educational content to clinicians about thirdhand smoke through AAP courses delivered online  as well as made presentations to clinicians at AAP-sponsored training sessions. Thirdhand smoke messaging has been included in the CEASE practice trainings so that participating clinicians in pediatric offices are equipped to engage parents on this topic. Further information about these educational resources and opportunities can be obtained from the AAP Julius B. Richmond Center of Excellence website  and from the Massachusetts General Hospital CEASE program’s website .
Counseling parents about thirdhand smoke can help assist parents with their smoking in the critical context of their child’s care. Most parents see their child’s health care clinician more often than their own . Increasing the number of pediatric clinical encounters where parental smoking is addressed while also increasing the effectiveness of these clinical encounters by increasing parents’ motivation to protect their children from tobacco smoke exposure are important goals. The topic of thirdhand smoke is a novel concept that clinicians can use to engage with parents around their smoking in a new way. Recent research conducted by the CEASE team suggests that counseling parents in the pediatric setting about thirdhand smoke can be useful in helping achieve tobacco control goals with families. Parent’s belief about thirdhand smoke is associated with the likelihood the parent will take concrete steps to protect their child. Parents who believe thirdhand smoke is harmful are more likely to protect their children from exposure by adopting strictly enforced smoke-free home and car rules . Parents who changed their thirdhand smoke beliefs over the course of a year to believing that thirdhand smoke is harmful were more likely to try to quit smoking .
Child health care clinicians are effective at influencing parents’ beliefs about the potential harm thirdhand smoke poses to their children. Parents who received advice from pediatricians to quit smoking or to adopt smoke-free home or policies were more likely to believe that thirdhand smoke was harmful to the health of children . Fathers (as compared with mothers) and parents who smoked more cigarettes each day were less likely to accept that thirdhand smoke is harmful to children . Conversely, delivering effective educational messages and counseling around the topic of thirdhand smoke to parents may help promote smoke-free rules and acceptance of cessation assistance.