Children living with 1 or more smoking parents are at increased risk for involuntary smoke exposure, which can cause many negative health outcomes (1). Children living with smokers are also more likely to smoke, even after accounting for other sociodemographic factors (2,3). A smoke-free environment can not only protect children from exposure to involuntary smoke, but also convey an antitobacco social norm that prevents and reduces smoking behavior in the future (4–7). The home, the car, and children’s outdoor play areas are 3 primary sources of involuntary smoke exposure for children (8).

Half of US households with underage children and at least 1 smoking parent did not have a voluntary smoke-free home rule by 2007, versus more than 90% of households with children but no smoking parents (9). However, it is unclear what the prevalence has become in recent years. Furthermore, research has examined voluntary smoke-free rules in cars (10–12) and has found overwhelming support among the US general population for voluntary smoke-free car policies when children are present (13). Yet, support for voluntary car rules has not been examined among households with children and at least 1 smoking parent, a vulnerable subset of households. Even less is known about attitudes toward smoking restrictions in outdoor children’s play areas like playgrounds and sport fields.

The 2010–2011 Tobacco Use Supplement to the Current Population Survey (TUS-CPS) collected information on respondents’ reports of voluntary smoke-free home rules and attitudes related to smoking restrictions in cars and outdoor children’s play areas. Attitudes are theoretical determinants and good predictors of behaviors (14) and also reflect levels of support for future legislation to expand public smoke-free laws. Using data from this survey, we aimed to update the prevalence of voluntary smoke-free home rules and examine the distribution of parental attitudes related to voluntary smoke-free rules in cars and outdoor children’s play areas among US households with underage children and 1 or more smoking parents during 2010–2011. We also investigated parental and household factors associated with these outcomes.

The overall response rate for the 2010–2011 TUS-CPS was 74% (ie, 74% of eligible individuals responded to the supplement). The rate for self-respondents was 56% (ie, 56% of eligible individuals answered the supplement themselves). Our study sample included parents from 8,083 households, of which 37.8% were single-parent households and 62.2% 2-parent households (Table 1).

Overall, 60.1% (95% confidence interval [CI], 58.8%–61.3%) of households with children and 1 or more smoking parent established a voluntary smoke-free home rule inside the home. Most (84.6%; 95% CI, 83.8%–85.4%) parents from these households thought that smoking should never be allowed inside cars when children are present, including 72.2% of those who did not have a voluntary smoke-free rule in their homes (Figure). Fewer parents (71.5%; 95% CI, 70.5%–72.5%) were supportive of smoke-free rules in outdoor children’s play areas, which included 61.3% of those not from a smoke-free household.

On the household level, children whose parents were single fathers or mothers, had not completed high school education, were non-Hispanic African American, or were aged 40 years or older were less likely to be protected by a voluntary smoke-free home rule than were their counterparts (P < .05) (Table 2). Households with an annual income less than $25,000 and with a child aged 6 years or older were also less likely to institute a voluntary smoke-free home rule (P < .05).

A positive attitude toward a voluntary smoke-free car rule when children are present was more likely to be reported by individuals from 2-parent households, who had a college education, who were non-Hispanic African American or Hispanic, with an annual household income of $50,000 or more, and who had infants living in the home (P < .05) (Table 3). Similar predictors were observed for a supportive attitude toward smoke-free outdoor children’s play areas. Compared with non-Hispanic white parents, non-Hispanic African American and Hispanic parents were more likely to express that smoking should be banned in outdoor children’s play areas (P < .05). The attitude was also more likely to be reported by people from 2-parent households than by those from single-parent households and by those who had a college degree than by those who did not (P < .05). In additional analyses, we found that support for smoke-free rules was stronger from nonsmoker households with children; 96.3% of parents from these households advocated voluntary smoke-free rules in cars, and 87.4% of parents from these households advocated voluntary smoke-free rules in outdoor areas (data not shown).

We found that more than one-third of US households with children and 1 or more smoking parents had not voluntarily adopted smoke-free home rules by 2010–2011. Children living in these homes are likely to be exposed to involuntary smoke. The existence of a voluntary smoke-free home rule was associated with parental education, parental race/ethnicity, parental age, household income, age of the youngest child, and household structure. The results are in agreement with those of other studies that found persistent disparities by these parental and household factors (9,17–20), and indicate that disparities in home rules have not improved by 2010–2011. Healthy People 2020 calls for increasing the overall proportion of voluntary smoke-free homes by approximately 10% (from 79.1% to 87.0%) and eliminating health disparities (21). Therefore, continued work is warranted to encourage the adoption of voluntary smoke-free home rules and reduce disparities in involuntary smoke exposure and tobacco-use–related diseases among smoker households with children.

Most parents agreed that smoking should not be allowed in cars when children are present. Strong support for voluntary smoke-free rules in cars may reflect the perception that the space in a car is more confined than a home and suggests that parents are more concerned about involuntary smoke exposure for children in a car. Parents may perceive that it is safe to smoke in certain areas of the home (eg, different rooms, balconies) or at certain times, as long as children are not present. In comparison, a car offers less ambiguity about likely exposure of children riding with smoking adults. In addition, time spent in a car is usually short and requires less effort from parents to refrain from smoking. More than two-thirds of parents thought smoking should be disallowed in outdoor play areas, which was not as strong a preference as that for car rules. However, a preference for voluntary smoke-free rules in outdoor areas could indicate more antitobacco attitudes, considering that the concentration of involuntary smoke in an outdoor environment may be lower than that of indoor settings (22). These results suggest widespread support among parents for comprehensive legislation banning smoking in areas where children are likely to be present. The support in states with strong antitobacco programs, such as California, Florida, and Massachusetts, is generally higher than the national benchmark (Appendix).

Attitudes are likely to overestimate actual parental behaviors regarding rules restricting smoking voluntarily in cars and outdoor children’s play areas. For example, Cheng et al found that at the national level the rates of voluntary smoke-free rules in home and cars among US households with smokers were similar (20). However, in our study, the rate of support for voluntary car rules was substantially higher than the rate of existence of voluntary home rules. According to the theory of planned behavior — which posits that personal attitudes toward behavior, subjective norms (social pressure), and perceived behavioral control together shape the behavioral intentions and behaviors of an individual (14) — the gap between attitudes and behaviors may be explained by lack of perceived control over the behavior and subjective norms. For example, compared with parents in 2-parent households, single parents may be limited in their ability to step away from children to smoke outside the home. Likewise, smoking parents may be more likely to be surrounded by others who smoke and this, in turn, may dissuade them from implementing voluntary smoke-free rules in their homes and cars. The high rates of positive attitudes, however, suggest that smoking parents are aware of the harm of smoking around children and possess high level of readiness to implement voluntary smoke-free rules in cars and outdoor play areas.

Our findings have implications for public health efforts, including policies aiming to help parents overcome barriers and translate their antitobacco beliefs and attitudes into actions. Health promotion programs should emphasize the threat of involuntary smoke exposure to children and promote the voluntary adoption of smoke-free rules in homes and private cars. Efforts to encourage (eg, through campaigns directed to resident associations and landlords) or even mandate smoking bans in outdoor areas in housing complexes should be implemented. A “complete” voluntary smoke-free car rule when children are present should also be recommended or even required by law, as some states and municipalities have already done. Because residual tobacco smoke contamination that remains after the cigarette is extinguished (known as thirdhand smoke) can continue to harm the health of children (23,24), public education about thirdhand smoke and its detrimental health effects should be increased to promote adoption of voluntary smoking bans, even when children are not present.

The widespread endorsement of negative attitudes about smoking in cars and outdoor areas in smoker households is notable, considering smokers traditionally hold less negative views about tobacco and are less likely to have a home nonsmoking rule (9). Our additional analyses showed that support for nonsmoking rules is even greater among nonsmoker households with children. Combined, these results suggest that most parents in households with underage children, regardless of smoking status, would be supportive of legislation to ban smoking in these areas. Most provinces of Canada and all states of Australia have now prohibited smoking in motor vehicles with a minor present (25). In the United States, 7 states (Arkansas, California, Louisiana, Maine, Oregon, Utah, and Vermont) implemented statewide policies to ban smoking in cars when children are present, although the cutoff age for child passengers varies by state (26). In addition, certain cities or counties in Hawaii, Indiana, New Jersey, and New York also have similar bans. We recommend that all states pass laws to ban smoking in vehicles when there are underage children present. Likewise, policy makers should also consider extending smoke-free policies to outdoor children’s play areas. Across the country, California has led the way and mandated smoke-free playground spaces designated for children (27). Its experience should inform similar efforts in other states.

Attitudes toward voluntary smoke-free rules in car and outdoor play areas were predicted by parental and household factors similar to voluntary home rules. We found that, compared with non-Hispanic white parents, African American parents were less likely to voluntarily adopt a smoke-free home rule, but they were more likely to report a positive attitude toward voluntary smoke-free rules in cars and outdoor play areas. There is no reason to believe that potential information bias is systematically different between the report of attitudes and behaviors. Therefore, such findings are suggestive that African American smoking parents may encounter special difficulties in setting up voluntary smoke-free rules in the home. For example, they may have less access to other adults who can watch their children when they step out to smoke. The findings may also reflect that African American families are more likely to live in unsafe neighborhoods that make it challenging to smoke outside the home (28). These results underscore the need to conduct additional research to identify barriers to voluntary adoption of smoking bans among these populations and interventions to support their implementing smoke-free rules in homes, cars, and outdoor play areas.

This study has limitations. First, parental practice and attitudes related to voluntary smoke-free rules are based on self-reported data. As smoking continues to decline in perceived normalcy, these findings may be biased due to social desirability. Second, positive attitudes toward voluntary smoke-free rules in cars and outdoor children’s play areas do not necessarily equal support for legislation in corresponding places. For example, some individuals may think that it is their decision to implement a smoke-free rule in their cars and the government should not interfere and dictate this behavior. Therefore, future surveys should ask respondents about their own behaviors in these places and about their support for legislation applying to these 2 settings. Third, the response rate for self-reported data was moderate and may have caused selection bias. However, the rate is within range (40%–60%) recommended for surveys of high importance about decisions on key policies or resources allocation (29).

We found that children living in more than one-third of households with 1 or more smoking parents were not protected by voluntary smoke-free home rules by 2010–2011. The findings call for tobacco control and prevention efforts to continue to promote voluntary smoke-free home rules among households with both smoking parents and underage children, especially among households with single parents, parents of lower socioeconomic status, and parents without infants. We also found that parents from smoker households are generally supportive of voluntary smoke-free rules in cars when children are present and in outdoor children’s play areas, providing evidence and encouragement to policy makers to take action to ban smoking in these locations.