published Thursday, February 25th, 2010

Cleaveland: More on plastics warnings

In a little publicized update in January, the U.S. Food and Drug Administration (FDA) advised mothers to breastfeed their infants during their first year of life if possible.

The advisory reflected concern that bisphenol A (BPA), a chemical frequently found in many foods and infant products might cause hormonal abnormalities in children exposed to the substance at an early point of their development.

BPA is a component of many plastics used in water and soda containers, liners for canned goods including infant formula, vat-liners in wine production and dental sealants. Billions of pounds of BPA, which has been employed in producing plastics for decades, are manufactured worldwide each year. BPA is linked to plastic through a weak chemical bond that is easily broken by heat and exposure to ultraviolent radiation. BPA acts as a weak estrogen in animals and therein lies the concern.

The developing fetus is exposed to BPA through the blood of its mother. The newborn infant may be exposed through maternal milk, infant formula, and canned food. Though BPA is broken down within the human body, the chemical is often detected in human blood, urine, milk and cord blood.

Samples from many freshwater streams in the U.S. contain traces of BPA. BPA enters food when it is heated in plastic containers or cans lined with BPA. BPA enters water supplies when the chemical is leached from countless cans and plastic bottles discarded in landfills.

In April 2009, the Endocrine Society, a respected international group of research and clinical specialists in glandular disorders issued a statement of concern about BPA and other chemicals capable of disrupting normal hormonal action within human beings. Citing a large number of studies the Society described effects in experimental animals that occurred at BPA levels considered safe by the FDA.

In rat models, maternal exposure to BPA at varying doses, resulted in precancerous breast changes in one-third of female off-spring. No breast changes were seen in females with no prenatal exposure to BPA. Exposure to estrogens during a woman's life, from intrauterine life to senior years, increases the risk for developing breast cancer. Extensive animal studies indicate that BPA can act as an estrogen capable of causing malignant changes. The extent to which these animal studies can be extended to humans fuels much of the debate about the safety of BPA.

In studies using male rat models, early-life exposure to BPA increases the risk of subsequent development of prostate cancer. Malignant changes have also been detected in cell cultures of prostate tissue. These changes have been seen at BPA levels below the FDA threshold for toxicity.

Against a backdrop of extensive, new information, the FDA issued a soft, tentative advisory to reduce human exposure to BPA. Manufacturers will be encouraged to develop alternatives to BPA. Tighter monitoring of BPA use is proposed. The FDA supports recommendations that infants be nursed during their first year.

The Internet reflects the opposing passions regarding the safety of BPA. The Environmental Working Group calls for tight state controls on baby bottles and other BPA-containing products for children. Nature News and Environment California offer well-documented overviews of potential adverse effects of BPA. Industry sponsored sites such as Bisphenol-A.org promote the safety of BPA. The American Chemical Council in a January statement vouched for the safety of BPA.

For the perplexed parent and consumer, U.S. Department of Health and Human Services offers useful information at http://www.hhs.gov/safety/bpa/.

From my reading, especially of the lengthy Endocrine Society report (Endocrine Reviews, June 2009), I consider BPA a health risk to children from womb forward. My advice:

* Nurse newborns for their first year of life, if at all feasible.

* Buy only BPA-free baby bottles, cups, and children's products.

* Do not heat any food or infant formula in plastic-lined cans or plastic containers unless these are BPA-free.

* Purchase water and soda in glass or BPA-free containers.

* Discard old or scratched plastic containers and utensils.

* Press Congress and state legislators to investigate thoroughly the safety of BPA.

Contact Clif Cleaveland at cleaveland1000@comcast.net.

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