I was recently at the ABC Kids Expo show, and all around me were products being touted at BPA-free or bisphenol A free. As I was there selling Zigo’s, I knew nothing about this, but after my wife returned home from Whole Foods this week with six pricey BPA-free water bottles, I decided to investigate.

Bisphenol A (BPA) is a building block of many polymers used in a diverse array of products, notably including plastics used in drinking bottles and food containers, as well as a broad range of household products. From various exposures, including diet, inhalation of dust, and transdermally, BPA is detectable in 90% of the US population. Although concerns regarding the potential toxicity of BPA have been circulating for more than 70 years, a recent study (I. A. Lang et al. Association of Urinary Bisphenol A Concentration With Medical Disorders and Laboratory Abnormalities in Adults. J. Am. Med. Assoc. 300, 1303–1310; 2008) has significantly raised the alarm. Utilizing recently made available large-scale epidemiological data on urinary BPA levels¹, Lang et al. demonstrated in a cross-sectional population study including 1,455 adults aged 18 through 74 years that higher urinary BPA levels are associated with cardiovascular disease, diabetes and elevated liver enzymes, but not with other common diseases studied. Prior studies of BPA have focused on estrogenic activity, liver damage, disrupted pancreatic beta-cell function, thyroid dysfunction, and risk of obesity, all primarily in animal studies. But animals are not people and species-specific differences have been blamed for the previously observed BPA effects.

This large scale cross-sectional study is powerful but not the final word. A cross-sectional study of this nature is a snapshot that associates urinary BPA levels at a given moment with a chronic disease or another assay. BPA is excreted quite rapidly in the urine and this study does not actually indicate anything about the effects of long-term exposure to the chemical. A longitudinal study is required in which individuals are followed for many years and the association of BPA levels and the development of chronic disease charted over time. Another limitation of the study is that BPA urinary levels were statistically analyzed in regard to eight major diagnostic groupings and eight blood-based assays. Multiple regression analysis of this nature is notoriously susceptible to the detection of false positive results due to the large number of variables analyzed.

Nevertheless, this study, on the heels of numerous well-conducted animal studies that demonstrate metabolic and estrogenic effects of BPA at doses below the current acceptable daily intake dose (ADI) of 50 µg/kg per day, is likely to spur action. Canadian regulatory agencies have already declared BPA a “toxic chemical”. It is likely that the U.S. will not be far behind. Despite the FDA’s August draft report stating that “food contact” products containing BPA are safe, pressure is no doubt mounting, as well it should. The burden should be on industry to prove safety, not on the public to prove hazard.

As for me, I’m keeping my BPA-free bottles. But the true load of BPA in the environment is from myriad sources and is essentially unavoidable. Regulators should act and they should act now.

Tip: Avoid Type 7 and Type 3 (PVC) plastics with food or beverages as they can leach BPA, especially at elevated temperatures.

¹ US National Health and Nutrition Examination Survey (NHANES) 2003-2004

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