Monday, September 16, 2013

Air Pollution Warning to Pregnant Mothers

You may have limited control over your environment, but alarming connections between air pollution and fetus development suggest that pregnant mothers should do all they can to avoid airborne toxins.  Recent studies indicate that a pregnant mother's exposure to air pollution, polycyclic aromatic hydrocarbons (PAHs), and pesticides is associated with low birth weight.  

Mother and child looking at chimney stalks


This should be a significant concern to mothers, since infants with a low birth rate often experience considerably more health problems compared to infants of normal weight.  Statistically more likely health problems of a low-birth-rate infants include:
  • Post-birth problems, such as perinatal morbidity and infections
  • Delayed motor skills development
  • Learning disabilities
  • Social development problems
While you may be able to reduce the use of some pesticides around the home during pregnancy, there are often pollution sources outside your direct control, such as city traffic and community-wide pesticide applications used to control vermin in towns or cities.  The CDC sites the example of a 1997 pesticide application in a Manhattan borough of New York City that, in that one application, exceeded the total amount of all pesticides applied in any other single county in all of New York.  It is likely that pregnant mothers in that borough did not even know of this application, nor had any knowledge regarding the health risk that the pesticide presented to them, their children, and particularly to their fetuses.  More recent research confirmed that prenatal pesticide pollutant exposure  can have adverse effects on birth size and a child's neurodevelopment.


Why fetuses are more vulnerable to air pollution and pesticides


As the fetus grows, development of all the systems it will need to survive (including the circulatory, digestive, endocrine, immune, lymphatic, muscular, nervous, reproductive, respiratory, skeletal, and urinary systems) are in hyper development, going through more and faster changes than it will experience at any time in its life post-birth.  This period of rapid development means that any interference in the normal development process can have a much more profound effect on the unborn child.

For example, in early life, the nervous system is still developing, which makes it highly influenced by exposure to neurotoxic pesticides.  Likewise, certain metabolic and enzyme activities performed by the kidneys and liver are not yet "mature" or complete and are easily disrupted during fetal development.
A 2005 neurotoxicolgy study found that several other factors contribute to a fetus’ vulnerability to air pollution and toxins:

  • The fetus absorbs and retains toxic substances at a higher rate than post-birth.
  • The fetus has a reduced ability to detoxify chemicals and repair damage to DNA, compared to post-birth children.
  • The fetus also has a higher rate of cell proliferation occurring during any toxin exposure.

In a 2003 study of a group of minority women and their infants, scientists discovered that developing fetuses may be as much as 10 times more susceptible to DNA damage from before-birth exposure to airborne polyaromatic hydrocarbons than the mother is. 

Other studies have shown negative effects on an infant's growth from pre-birth exposure to certain pesticides. In one of these studies, involving pregnant women at prenatal clinics in January 1998, scientists followed them until 2004, capturing data showing that, when the EPA phased out residential use of the pesticide chloropyrifos in 2001, infants exposed prenatally to this pesticide before the phase-out had significantly reduced birth weight and shorter length. Similar studies showed that toxin-exposed infants were born with low activity levels of important enzymes that affect the infant's ability to metabolize and detoxify they were exposed to.  And a 2007 study showed that infants with prenatal pesticide exposure had smaller head circumferences (Berkowitz et all. 2004, Wolff et al. 2007).  Statistically, smaller head circumferences correlate with reduced intelligence and decreased cognitive function later in life.

Traffic pollution


What can pregnant mothers do to protect their unborn children?


Scientists admit that reliably measuring exposure to environmental pollutants is difficult, as exposure can vary widely within a community, even within a home depending on such things as the amount and type of chemical and individual users in daily patterns of life. For example, it is likely that a mother is exposed to more cleaning chemicals than the children in the home.  And from individual to individual, exposure duration or magnitude can vary widely.  But there are steps you can take to reduce the danger of exposure to pesticides and air pollutants during pregnancy that may result in a low birth weight for your child:

  • Quit smoking, and avoid being in the presence of other smokers while pregnant.
  • Avoid unnecessary exposure to indoor or outdoor air pollution.
  • Consider getting a portable indoor air purifier that you can take with you from room to room.
  • Drink purified water to ensure that your water is not contaminated with lead, which is considered by the CDC to be an environmental risk factor.
  • In many states, you can help reduce air pollution where you live by reporting smoking vehicles or other general air pollution complaints.  In California, for instance, you can File an Air Pollution Complaint online.
  • Consider putting a carbon monoxide detector in your home that will sound an alert when the levels are too high.
  • Switch from using chemical-based household cleaners to more natural cleaning methods, such as vinegar.

To become a more informed pregnant mother, and to get more information on what you can do to help avoid low birth weight problems, you can learn about toxic air pollutants from the EPA, or explore the CDC's National Environmental Public Health Tracking Network (Tracking Network) – a system of integrated health, exposure, and hazard information and data from a variety of national, state, and city sources.  

Ric Moxley
Contributing Writer


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