Healthy Milk, Healthy Baby
Chemical Pollution and Mother's Milk
Chemicals in Mother's Milk
Ask new mothers to describe the experience of nursing their babies, and you'll hear a wide range of stories -- from frustration at problems with getting their babies to cooperate to a description of nursing as the most nurturing and loving experience a woman can have.
What very few of them have reason to suspect is that in addition to all the positives about breastfeeding, scientists are now becoming aware of a small but troubling negative: small doses of chemical pollution are invading mothers' milk. How? Put simply, some forms of pollution persist in the environment. They work their way into water and air, then end up in plants and animals, and from there work their way up the food chain to humans. By unhappy coincidence of chemistry, rather than being flushed out of our bodies, they attach themselves to fatty tissues in humans and accumulate. Those fatty tissues are a source of nutrients for mother's milk, so as a mother's body calls on its reserves of fat for lactation, the pollutants go along for the ride, invading mother's milk, and in turn, the baby.
Not all pollutants behave this way, but one important class of chemicals does -- the persistent organochlorines. Many of these chemicals are known as persistent organic pollutants (POPs) because they persist for years in the environment and in the human body.
First things, first. It's not time to panic, and not time to stop nursing. In almost all cases, the health benefits of nursing far outweigh the potential problems from POPs. But it is time to learn more about the problem, and ultimately to take social and political action to protect our children's children from facing a more difficult choice when it's their time to care for a newborn.
We've already made important progress toward that end. On May 22, 2001, the United States joined many other nations in agreeing to ban the production or use within their borders of many of the most troubling chemicals. Over the last three decades, bans on these chemicals imposed by individual nations have been very effective at reducing the threat these chemicals pose, so scientists fully expect that the new treaty, called the Stockholm Convention, will usher many of these chemicals into virtual nonexistence. In addition, the terms of the treaty establish a process to add to its list of banned chemicals.
Unfortunately, although the Stockholm Convention has now been ratified by more than 50 countries and gone into effect, the United States has yet to ratify. In fact, the treaty is tied up in the U.S. Senate, and the ratifying legislation proposed by the Bush Administration would gut many of the major parts of the treaty as they concern the United States. In addition, the proposed legislation would provide a back door to weaken important environmental laws. In short, action to reduce levels of some of these dangerous chemicals has been effective in the past and the Stockholm Convention creates a method to restrict or ban these POPs, but the United States needs to participate in this worldwide effort.
The simple and natural truth is that women and their children have a fundamental right to clean breast milk. The presence of chemical industry wastes in "nature's first food" is a trespass on the most private parts of our lives. Considering all factors, breastfeeding is still recommended, but concerns that chemical pollutants detract from the many benefits of breastfeeding are real. That women are faced with doubts about their breast milk is an outrage that must be corrected by stopping the exposures at their source, not by stopping breastfeeding.
The Legacy of Toxic Pollution
The modern world is saturated with chemical pollution. Past and current uses of manmade chemicals and mined metals have led to the widespread contamination of air, water and soil. Because some chemicals are able to ride air currents or attach themselves to sediment particles in ocean currents, people in one country may be exposed to chemicals produced or used thousands of miles away. In addition, many of the products and activities that are part of everyday life put us in contact with environmental hazards. Driving cars, using plastics, using chemical products at work and for hobbies and emissions from incinerators and industrial facilities all can result in exposures to potentially hazardous chemicals.
Chemical pollutants in the environment can also enter people's bodies. In fact, in many ways, we have become reservoirs for these substances. The chemicals invade various parts of the body, including the liver, the brain, blood and breast milk. Some of the chemicals are short-lived, leaving the body quickly; others can stay for years.
Exposure to the Fetus and Infant
Although chemical pollutants affect all of us, the very young are the most vulnerable.
Pound for pound, children eat more, drink more and breathe more than adults. For example, a bottle-fed infant consumes relatively huge amounts of water each day -- when corrected for body weight, it's as if an adult were to drink seven liters of water or 35 cans of soda each day. So if chemical contaminants are in that water, the infant's exposure to them is disproportionately high. The consumption of breast milk is similarly large, making contaminants in breast milk and infant formula a particular concern to public health advocates. Among the chemicals that can invade breast milk, and that are the subject of these pages, are a number of members of the organochlorine class, including: chlordane; DDT; dieldrin, aldrin and endrin; hexachlorobenzene; hexachlorocyclohexane (lindane) heptachlor; mirex; toxaphene; dioxins and furans; PBDEs; and PCBs. Several substances that are not persistent organochlorines but that nevertheless threaten the purity of breast milk are covered on these pages as well, including: nitro musks and musk xylenes; lead, mercury, cadmium and other metals; and solvents.
Infants' brains and other organs are also undergoing rapid development, and it is critically important that their developing bodies receive the correct signals. Exposure to hazardous substances during critical periods of infant development can disrupt these signals of normal development and lead to health problems later in life.
Related Information on the Web
- The Transfer of Drugs and Other Chemicals Into Human Milk, a policy statement by the American Academy of Pediatrics, provides information and lists of drugs and chemicals that have been reported in breast milk.
- The Pesticide Action Network (PAN) Pesticide Database website provides current toxicity and regulatory information for pesticides. The PAN Pesticide Database brings together a diverse array of information on pesticides from many different sources.
- Our Stolen Future provides the latest news in science and policy related to endocrine-disrupting chemicals, persistent bioaccumulative toxicants, and other environmental contaminants. The site tells the story of how endocrine disruption was discovered, what it means, how it works and how families can protect themselves and their communities, all in clear, simple language intended for a general audience.
last revised 3.25.05