Assessing Environmental Threats to Pregnancy:
A Toxics & Environmental Hazards Program Update

By Noah Chalfin

For many women entering pregnancy, their initial excitement is often confronted by the secondary anxiety raised by wanting to "do it right." Most moms-to-be know not to use drugs, drink alcohol or smoke cigarettes while they're pregnant. Others may have heard about the dangers of mercury, so have cut down on eating fish. Concerns regarding drinking coffee, using pesticides in the home or garden, and risks from drinking tap water are appreciated in varying degrees. But which of these concerns are justified; which are simply myths; and most importantly, what should pregnant women do to protect the welfare of their developing child?

It used to be that the fetal environment was assumed to be a protected, safe-haven, free of risks. Today, most families living in the industrialized world know that the opposite is true. It is now widely known that the amniotic sac is not a fail-safe barrier protecting the child from the external hazards of our environment. While the doses that do in fact reach a fetus may be minute compared to those to which a mother may be exposed, the fragility of developing organs and nervous system networks have been shown to exhibit sensitivities far greater than those of adults. It may even be true that exposing a fetus to some environmental hazards during pregnancy can contribute to learning disabilities manifested only after puberty.

During the last nine months, we at CETOS have been assessing the current state of knowledge related to environmental hazards affecting pregnancy. While the information is extensive, it is widely scattered between governmental agencies, scientific research groups, public interest organizations, and corporate-initiated studies. At this point, there exists no complete public source from which to derive the appropriate information necessary for informed decision-making. Perhaps the most comprehensive evaluation of reproductive and developmental hazards is being conducted by the Office of Environmental Health Hazard Assessment (OEHHA), a branch of the California Environmental Protection Agency (CalEPA). OEHHA is designated as the authority responsible for enforcing the Safe Drinking Water and Toxic Enforcement Act of 1986 (also known as Proposition 65). Under Prop. 65, a database of reproductive and developmental hazards has been created. Currently, OEHHA has identified about 250 chemicals that are "known to the State to cause reproductive or developmental toxicity." However, of this number, only three substances have established regulatory standards. Additionally, very little is being done by this office to distribute any materials to the public in the form of alerts or guidance. To date, these resources are generally in the form of fish consumption advisories.

But where are these 250 substances found; how might a mother be exposed; how much is too much? These are the questions that remain unanswered. While the full extent of knowledge about the effects of environmental hazards on pregnancy may never be known, we believe it is crucial that the public be made aware of the currently understood risks. To do this, we have been developing a methodology to identify those hazards that pose the greatest threat to pregnancy, so that they can be addressed in an appropriate order of priority. This work has been made possible by a grant from the March of Dimes. We intend to expand this initial stage of research into an educational campaign that will offer the public a comprehensive, yet understandable evaluation of the most critical environmental threats to pregnancy.

From our preliminary research, it appears that certain metals such as lead, mercury, cadmium and arsenic; certain pesticide formulations, such as those containing organophosphates or organochlorines; and certain organic solvents may pose the most pervasive risks to pregnancy. Other hazards likely to contribute a risk to some extent include: polychlorinated biphenyls (PCB's), some pathogens, electro-magnetic fields (EMF's), and certain estrogenic substances.

Many threats to pregnancy are ubiquitous to the environments in which we all operate. Some amount of these substances is in the air, water and soil that we encounter daily. Some can be found in every fresh vegetable or fruit we eat, regardless of whether it was grown organically. And others can be found in many of the dietary supplements and medicines we use to treat other health or medical issues. Recent studies are showing that lead in car batteries and galvanized pipes, mercury in some Chinese herbal products, and arsenic and cadmium in certain garden soil amendments may all pose some threat to reproductive health.

So far, a pretty grim picture has been painted of the situation. However, it should be remembered that the vast majority of pregnancies will be successful, yielding a healthy child free of developmental problems. Perhaps the greatest contributing factor to reproductive disruption is from genetic heritage or other uncontrollable natural factors. Nevertheless, it appears that rates of certain reproductive disorders are increasing. For this, a widely held hypothesis is that elevated levels and wider distributions of environmental agents is a leading contributory factor.

Despite this hypothesis, it should be noted that while certain environmental factors may potentially affect pregnancy, maternal stress is a well-recognized source of risk in itself. Ironically, over-anxiety and fear about protecting a developing fetus may pose a greater threat to pregnancy than all other factors combined. Therefore, it is well worth understanding the credibility of the reported threats, before haphazardly altering ones habits, diet or usual approach to pregnancy. However, with this said, there are certain reasonable steps that a mother-to-be may want to take, to reduce the risks as much as possible.

A first step might be to cut-down on how often certain fish species are eaten. Species higher on aquatic food chains generally pose the greatest threats (i.e. shark, swordfish, tile fish and king mackerel). Other simple steps include thoroughly washing fresh vegetables and fruits before eating, drinking bottled water or using a water filter before drinking tap water, and avoiding exposure to toxic wood preservatives, solvents, paints, and pest control products.

We are working to resolve some of the inherent dilemmas to understanding environmentally occurring reproductive and developmental hazards: where they can be found; how much exposure may pose a threat to pregnancy; during what stages of pregnancy should they be avoided; how families can protect themselves; and where the best sources of information can be found to address common concerns. Our goal is to help bridge the gap between what is known in the scientific community and what is available to the public. It should be every family's right to know how to reduce the impact of environmental hazards on developing children, especially before they are even born.

The Toxics & Environmental Hazards Program staff will continue to bring you information about our activities in this area. Keep an eye out for more articles in subsequent Stopwatch's and for more frequent additions to our website (www.cetos.org). Please feel free to contact us with personal inquiries or for updates on our progress.