Bisphenol A is released from used polycarbonate animal cages into water at room temperature.

Bisphenol A (BPA) is a monomer with estrogenic activity that is used in the production of food packaging, dental sealants, polycarbonate plastic, and many other products. The monomer has previously been reported to hydrolyze and leach from these products under high heat and alkaline conditions, and the amount of leaching increases as a function of use. We examined whether new and used polycarbonate animal cages passively release bioactive levels of BPA into water at room temperature and neutral pH. Purified water was incubated at room temperature in new polycarbonate and polysulfone cages and used (discolored) polycarbonate cages, as well as control (glass and used polypropylene) containers. The resulting water samples were characterized with gas chromatography/mass spectrometry (GC/MS) and tested for estrogenic activity using an MCF-7 human breast cancer cell proliferation assay. Significant estrogenic activity, identifiable as BPA by GC/MS (up to 310 micro g/L), was released from used polycarbonate animal cages. Detectable levels of BPA were released from new polycarbonate cages (up to 0.3 micro g/L) as well as new polysulfone cages (1.5 micro g/L), whereas no BPA was detected in water incubated in glass and used polypropylene cages. Finally, BPA exposure as a result of being housed in used polycarbonate cages produced a 16% increase in uterine weight in prepubertal female mice relative to females housed in used polypropylene cages, although the difference was not statistically significant. Our findings suggest that laboratory animals maintained in polycarbonate and polysulfone cages are exposed to BPA via leaching, with exposure reaching the highest levels in old cages.

[1]  F. Dessì-Fulgheri,et al.  Perinatal Exposure to the Estrogenic Pollutant Bisphenol A Affects Behavior in Male and Female Rats , 1999, Pharmacology Biochemistry and Behavior.

[2]  F. Olea-Serrano,et al.  Estrogenicity of resin-based composites and sealants used in dentistry. , 1996, Environmental health perspectives.

[3]  M. Gage,et al.  Reduced sperm counts in guppies (Poecilia reticulata) following exposure to low levels of tributyltin and bisphenol A , 2000, Proceedings of the Royal Society of London. Series B: Biological Sciences.

[4]  C. Gupta.  Reproductive Malformation of The Male Offspring Following Maternal Exposure To Estrogenic Chemicals (44516) , 2000, Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine.

[5]  Baby alert. New findings about plastics: parents may want to replace some baby bottles and teethers. , 1999, Consumer reports.

[6]  Ho Chul Lee,et al.  Fast Screening Method for Bisphenol A in Environmental Water and in Food by Solid-Phase Microextraction (SPME)(PROCEEDINGS OF 24TH SYMPOSIUM ON TOXICOLOGY AND ENVIRONMENTAL HEALTH) , 1999 .

[7]  R. Bigsby,et al.  The xenoestrogen bisphenol A induces growth, differentiation, and c-fos gene expression in the female reproductive tract. , 1998, Endocrinology.

[8]  J. He,et al.  PHYSICAL ASPECTS OF THE THERMAL AND HYDROLYTIC AGEING OF POLYESTER, POLYSULPHONE AND POLYCARBONATE FILMS , 1994 .

[9]  D. Feldman,et al.  Bisphenol-A: an estrogenic substance is released from polycarbonate flasks during autoclaving. , 1993, Endocrinology.

[10]  C. Sonnenschein,et al.  In Utero Exposure to Bisphenol A Alters the Development and Tissue Organization of the Mouse Mammary Gland1 , 2001, Biology of reproduction.

[11]  H. Makino,et al.  Determination of Bisphenol A in Effluents of Hemodialyzers , 2001, Nephron.

[12]  T. Croley,et al.  Estrogenic potency of chemicals detected in sewage treatment plant effluents as determined by in vivo assays with Japanese medaka (Oryzias latipes) , 2001, Environmental toxicology and chemistry.

[13]  Arnold Factor,et al.  Mechanisms of Thermal and Photodegradations of Bisphenol A Polycarbonate , 1996 .

[14]  Norman C. Billingham,et al.  Polymer Durability: Degradation, Stabilization, and Lifetime Prediction , 1996 .

[15]  G. Rottinghaus,et al.  pH-dependent cytotoxicity of contaminants of phenol red for MCF-7 breast cancer cells. , 1991, Endocrinology.

[16]  Development of an ER action indicator mouse for the study of estrogens, selective ER modulators (SERMs), and Xenobiotics. , 2001, Endocrinology.

[17]  C. Tohyama,et al.  Bisphenol‐A Affects Spermatogenesis in the Adult Rat Even at a Low Dose , 2001 .

[18]  R. Einspanier,et al.  Amphibians as a model to study endocrine disruptors: II. Estrogenic activity of environmental chemicals in vitro and in vivo. , 1999, The Science of the total environment.

[19]  L. R. Harris,et al.  Normal reproductive organ development in CF-1 mice following prenatal exposure to bisphenol A. , 1999, Toxicological sciences : an official journal of the Society of Toxicology.

[20]  K A Thayer,et al.  Relative binding affinity-serum modified access (RBA-SMA) assay predicts the relative in vivo bioactivity of the xenoestrogens bisphenol A and octylphenol. , 1997, Environmental health perspectives.

[21]  Hajime Watanabe,et al.  Low dose effect of in utero exposure to bisphenol A and diethylstilbestrol on female mouse reproduction. , 2002, Reproductive toxicology.

[22]  C. Sonnenschein,et al.  The mouse uterotrophic assay: a reevaluation of its validity in assessing the estrogenicity of bisphenol A. , 2000, Environmental health perspectives.

[23]  N. Olea,et al.  Xenoestrogens released from lacquer coatings in food cans. , 1995, Environmental health perspectives.

[24]  I. Chahoud,et al.  In utero exposure to low doses of bisphenol A lead to long-term deleterious effects in the vagina. , 2002, Neoplasia.

[25]  Kristina A. Thayer,et al.  Environmental toxins: Exposure to bisphenol A advances puberty , 1999, Nature.

[26]  I. Chahoud,et al.  Parent bisphenol A accumulation in the human maternal-fetal-placental unit. , 2002, Environmental health perspectives.

[27]  Bernd Markert,et al.  Effects of Endocrine Disruptors on Prosobranch Snails (Mollusca: Gastropoda) in the Laboratory. Part I: Bisphenol A and Octylphenol as Xeno-Estrogens , 2000, Ecotoxicology.

[28]  J. Holme,et al.  Estrogen-like properties of brominated analogs of bisphenol A in the MCF-7 human breast cancer cell line , 2004, Cell Biology and Toxicology.

[29]  J. Cowie,et al.  Polymers: Chemistry and Physics of Modern Materials , 1973 .

[30]  M D Shelby,et al.  Assessing environmental chemicals for estrogenicity using a combination of in vitro and in vivo assays. , 1996, Environmental Health Perspectives.

[31]  J. Vandenbergh.  Coordination of social signals and ovarian function during sexual development. , 1989, Journal of animal science.

[32]  J. King,et al.  Perinatal exposure to low doses of bisphenol A affects body weight, patterns of estrous cyclicity, and plasma LH levels. , 2001, Environmental health perspectives.

[33]  P. Cooke,et al.  A Physiologically Based Approach To the Study of Bisphenol a and Other Estrogenic Chemicals On the Size of Reproductive Organs, Daily Sperm Production, and Behavior , 1998, Toxicology and industrial health.

[34]  J Ashby,et al.  Lack of effects for low dose levels of bisphenol A and diethylstilbestrol on the prostate gland of CF1 mice exposed in utero. , 1999, Regulatory toxicology and pharmacology : RTP.

[35]  D. Janszen,et al.  Effect of different sampling designs on outcome of endocrine disruptor studies. , 2000, Reproductive toxicology.

[36]  K. Paigen,et al.  A simple, rapid, and sensitive DNA assay procedure. , 1980, Analytical biochemistry.

[37]  J. Sumpter,et al.  Reproductive effects of long-term exposure to Bisphenol A in the fathead minnow (Pimephales promelas). , 2001, Environmental science & technology.

[38]  S. Parmigiani,et al.  Exposure to a low dose of bisphenol A during fetal life or in adulthood alters maternal behavior in mice. , 2002, Environmental health perspectives.

[39]  W. Kloas.  Amphibians as a model for the study of endocrine disruptors. , 2002, International review of cytology.

[40]  S. Kashiwada,et al.  Estrogenic influences of estradiol-17 beta, p-nonylphenol and bis-phenol-A on Japanese medaka (Oryzias latipes) at detected environmental concentrations. , 2001, Water science and technology : a journal of the International Association on Water Pollution Research.

[41]  W. Welshons,et al.  Low-dose bioactivity of xenoestrogens in animals: fetal exposure to low doses of methoxychlor and other xenoestrogens increases adult prostate size in mice , 1999, Toxicology and industrial health.

[42]  N. Olea,et al.  The E-screen assay: a comparison of different MCF7 cell stocks. , 1995, Environmental health perspectives.

[43]  S. Kenig,et al.  Life expectation of polycarbonate , 1985 .