The safety of various chemical raw materials used for the production of certain polymer materials for plastic end-products is repeatedly being called into question. Environmental medicine experts are concerned about the raw material bisphenol A, which is used in polycarbonate production. Bisphenol A is suspected of developing an estrogen-like effect, which can have negative consequences in the prenatal phase. These hormones affect the development of important organs.

Plasticizers (phthalates), too, have repeatedly been in the firing line, and have in the past caused a considerable amount of debate, not just in connection with plasticized PVC for toys. Evidently as a consequence of this, BASF recently announced that it would withdraw completely from DEHP production in Europe (see PIE 14, 2005).

Although in many cases unsubstantiated and misleading reports have been published about such substances, there are some reports that need to be taken seriously. An investigation recently performed by US endocrinolo-gists, for example, gives some reason for concern because – as reported in the “Deutsches Ärzteblatt” – it found that administering bisphenol A to male mice triggered increased growth of the prostate gland. In the “US Pro-ceedings of the National Academy of Sciences”, the research team headed by Frederick vom Saal from the University of Missouri in Columbia expressed the fear that these changes could, in the long term, cause tumours.

Now, a team headed by Ana Soto from Tufts University in Boston has found that prenatal exposure to bisphenol A in female mice triggers changes in the structure of the mammary gland, which can have consequences at a later date. It found a fourfold increase in the formation of the mammary ducts. Since these structures are frequently a starting point for breast cancer in humans, the authors consider the findings to be alarming, particularly as they occurred at a bisphenol A concentration of just 25 nanograms per kilogram bodyweight, which is less than 1% of the current US threshold.

Like the animal experiments relating to prostate development, these find-ings do not prove that this PC raw material has carcinogenic potential, “but they did direct the attention of the research team to the plastic ar-ticles that are nowadays found all over the place and were until now re-garded as safe,” commented the German medical journal in an endeavour to allay any major concerns.

Phthalates, too, have recently come under fire again. One of the reasons is a new report published by a US research group headed by Shanna Swan from the University of Rochester in the US state of New York dealing with a study of the effects of prenatal phthalate exposure on male infants, in which the concentration of the plasticizer in the mother´s blood was re-lated to the result of a genital examination of her children. The result according to various German sources was that “Higher concentrations of four phthalate metabolites (MEP, MBP, MbzP and MiBP) correlated with subtle de-velopment anomalies like reduced anogenital distance or a growth defect of the scrotum or penis”. According to the US research team, the probability of later infertility is also enhanced by the plasticizers.

Although studies that classify plasticizers as harmless in PVC toys are appearing all the time, the EU Commission recently brought the public debate to an end by finally banning the use of various phthalates for babies´ toys (see PIE 15, 2005).

• e-Service:Study “Decrease in anogenital distance among male infants with prenatal phthalate exposure“ as PDF document (357 KB)Study “Use of di(2-ethylhexyl)phthalate containing medical products and urinary levels of mono (2-ethylhexyl) Phthalate in neonatal intensive care unit infants“ as PDF document (380 KB)