Workplace Secondhand Smoke Exposure During Pregnancy: Who is protected?

There is no safe level of exposure to secondhand smoke, and avoiding this preventable health hazard is particularly important for the health of pregnant women and their unborn babies. Secondhand smoke exposure is associated with chronic diseases such as lung cancer, coronary heart disease, and stroke and with adverse reproductive effects, including low birth weight, when mothers are exposed during pregnancy. However, some women cannot avoid secondhand smoke during pregnancy because many workplaces still allow smoking. Although a lot of progress has been made in making U.S. workplaces smoke-free, only 26 U.S. states and the District of Columbia have laws requiring all private workplaces, restaurants, and bars to be smoke-free. In the other 24 states, pregnant women may be unable to avoid secondhand smoke if smoking is allowed in their workplace.

NIOSH researchers wanted to know how big the problem might be, how many women of reproductive age are exposed, and what types of workers are the most likely to be exposed to secondhand smoke at work. To answer these questions, we used data from the 2010 National Health Interview Survey (NHIS), a survey of the health of the American people that includes questions about work. We looked at the demographic and workplace characteristics of women of reproductive age to see which nonsmoking women were most likely to be exposed to secondhand smoke at work.

We estimated that about 1 in 10 nonsmoking, working women of reproductive age in the United States are exposed to secondhand smoke at work. Women working in the accommodations and food services industry (women working in hotels, restaurants, or bars) were more than twice as likely as women employed in other industries to be exposed to secondhand smoke at work. Many states’ smoke-free laws don’t cover hotels, restaurants, bars, or patios, leaving these women unprotected.

We also found that black women were twice as likely to be exposed to secondhand smoke at work during pregnancy as white women. Women with fewer years of formal education (who did not graduate from college or high school) were more likely to be exposed compared with women with more years of education. Also, women with low and moderate incomes were more likely than women with higher incomes (those making over $45,000) to work in places where they were exposed to secondhand smoke.

When we looked at jobs where women reported potentially dangerous work conditions (chemical exposures; breathing vapors, dust, gas, or fume; being harassed, bullied, or threatened at work), women with these potentially unsafe jobs were twice as likely to be exposed to secondhand smoke as women with jobs not associated with such hazards. In addition, women who were the most worried about losing their jobs were more than three times as likely to be exposed to secondhand smoke as women who felt they had job security.

The characteristics of women who are most likely to be exposed to secondhand smoke at work (i.e. less education, lower income, exposure to chemicals) are the same characteristics that put a woman at the highest risk for pregnancy complications like premature birth and low birth weight. In this way, workplace exposure to secondhand smoke might increase the risk of pregnancy complications for working women who are already vulnerable.

It’s clear that not all pregnant women and their babies are equally likely to be protected from exposure to secondhand smoke at work. Women who are most likely to report smoke-free workplaces are white, more educated, have high incomes, and have safe, stable jobs. Unfortunately, while all workers deserve a safe and healthy workplace, this is not equally likely to be the case for everyone.

What can we do?

NIOSH recommends that all workplaces be smoke-free. Smoke-free workplaces aren’t just good for pregnant workers and their babies, but for the health of every worker. Until every state has a comprehensive smoke-free law, employers can take the initiative to create their own smoke-free workplace policies to protect their most important assets — their workers.

More information on how to create a smoke-free workplace can be found on CDC’s tobacco website.

NIOSH recommendations for smoke-free workplaces can be found on the NIOSH website.

Candice Y. Johnson, Ph.D.

Dr. Johnson is a reproductive epidemiologist in the NIOSH Division of Surveillance, Hazard Evaluations, and Field Studies.