December 18, 2008

Pregnancy Don'ts: Drinking, Smoking . . . and Breathing?

From a developmental standpoint, the 280 or so days between conception and birth are among the most important in a person’s entire life. During this period, pregnant women are cautioned to avoid a wide variety of exposures that can inhibit fetal organ development and growth. However, a recent report highlights the risk posed by one type of exposure against which women can’t realistically protect themselves—pollution in the air they breathe.

The list of pregnancy “don’ts” is lengthy, and with good cause. Certain types of exposures have long been definitively linked to particular outcomes in fetal health and development. Pregnant women are advised against consuming alcohol, because drinking can cause fetal alcohol syndrome. And they’re warned away from eating too much fish – at least of the variety that is likely to contain mercury, because fetal exposure to mercury can lead to damage to the nervous system, including brain damage, learning disabilities and hearing loss – and in severe cases, even death. (To learn about FDA’s recent backpedaling on the issue of how much fish is safe for pregnant women, click here.)

Smoking, another clear pregnancy “don’t,” nearly doubles a mother’s risk of delivering a low birth weight baby and also increases the risk of preterm delivery. Babies born under these conditions are more likely to experience health problems as newborns and to face an increased risk of chronic lifelong disabilities such as cerebral palsy.

As it turns out, breathing polluted air is associated with some of the same health outcomes as smoking. In a recent report, Professors Beate Ritz, M.D., Ph.D., and Michelle Wilhelm, Ph.D., researchers at UCLA, point out that while the study of air pollution’s impact on reproductive outcomes is still a developing area of science, “more evidence is emerging that air pollution exposures in pregnancy and early childhood put children at higher risk of adverse health outcomes.”

The report reviewed epidemiologic literature, including a study conducted by the authors. In it, they examined births from 1990-2003 to women residing in California’s South Coast Air Basin. They “consistently found that mothers exposed to high levels of [carbon monoxide] and particles during pregnancy are at higher risk of adverse birth outcomes, including preterm delivery, low birth weight, and congenital heart defects.” Specifically, women living in more polluted areas experienced a 10- to 30-percent increase in risk for preterm birth and low birth weight, and between 5- and 20-percent increase in risk for infant mortality. More recently, preterm birth and low birth weight have also been linked to ozone and nitrogen dioxide exposures. Vehicle exhaust is a major source of all these pollutants.

Worse yet, there are environmental justice concerns associated with these increased risks. For socioeconomically disadvantaged persons, the stress of air pollutants is often layered on top of factors such as exposure to more toxins at work and/or in their neighborhoods, and lack of adequate access to health care. In one of their studies, Ritz and Wilhelm found that when meteorological conditions caused vehicle-emitted pollutant levels to peak, vehicle-related air pollution disproportionately affected women in low-income and disadvantaged neighborhoods. Under such conditions, African American and Hispanic women experienced the highest risks of preterm birth, along with younger (teenage) and older (over 35) mothers. The authors write, “[i]n a region where a large proportion of the most polluted neighborhoods are those that are home to the poorest women and children with the least resources, these women and their offspring are clearly the groups that carry the greatest burden of our collective air pollution problem.”

Carbon monoxide, particulates, ozone and nitrogen dioxide are all “criteria pollutants,” regulated under the federal Clean Air Act. Failure of urban areas throughout the country (including California’s South Coast Air Basin) to attain federal air quality standards is part of the problem. (To read more about repeated failures to attain the federal ozone standard, see CPR’s 2006 report, here.)

Ritz and Wilhelm identify another important problem, concluding that “air pollution impacts on pregnant women and infants are not taken into consideration in setting environmental standards on a state or federal level.” When EPA reviews air standards, Wilhelm explained, “the studies reporting links between air pollution and pregnancy outcomes were reviewed only very briefly and not quantitatively.”

So what can be done to protect pregnant women, developing fetuses and young children (particularly those with socioeconomic disadvantages) from the risks associated with air pollution—risks that science has only recently focused on? As it turns out, Congress anticipated that scientific understanding of the health risks posed by air pollution would continue to grow and evolve, and wrote the Clean Air Act to require EPA to revise, “from time to time,” air quality criteria for listed pollutants, and to require that EPA adjust the criteria for air pollutants so that they “accurately reflect the latest scientific knowledge useful in indicating the kind and extent of all identifiable effects on public health or welfare which may be expected from the presence of such pollutant[s] in the ambient air.”

So statutory authority for EPA to do something about the problem is already in place. Toward that end, the Obama Administration can take two important and immediate steps to make sure that theory becomes reality. CPR’s recent report, Protecting Public Health and the Environment by the Stroke of a Presidential Pen: Seven Executive Orders for the President’s First 100 Days recommends that President Obama amend (or replace) two Executive Orders originally issued by President Clinton, both with the aim of providing more effective protection to vulnerable members of our communities.

The report calls on President Obama to amend Executive Order 13045, entitled “Protection of Children from Environmental Health Risks and Safety Risks” to mandate that federal agencies establish an affirmative agenda for protecting children from a variety of pollutants, including fine particulate matter and ozone, two of the air pollutants implicated in the UCLA study. CPR’s proposed changes would also require the reform of risk assessment policy so that children are accounted for as a vulnerable group. (For more information on CPR’s proposed “Healthy Kids” Executive Order, see CPR President Rena Steinzor’s blog entry here.)

Additionally, the report urges President Obama to amend or replace Executive Order 12898 on Environmental Justice so that, among other things, it imposes on federal agencies a substantive obligation to take affirmative steps to ameliorate environmental injustice, and to hold those agencies accountable for carrying out their environmental justice obligations. (For more information on CPR’s proposed changes to the Executive Order on Environmental Justice, see CPR Director Rob Verchick’s blog entry here.)

These two actions would go a long way toward ensuring that breathing the air doesn’t become another pregnancy “don’t,” with the result that pregnant women (and young children) are warned to stay inside to avoid breathing outdoor air. While it may (or at least ought to) sound like an unrealistic prospect, sadly that’s exactly the advice air quality advisories currently provide to sensitive populations on “Code Red” ozone days. 


Margaret Clune Giblin, Policy Analyst, Center for Progressive Reform. Bio.

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