τεμιΰεψιθο ξεχφσ - ξρψθο ΰε μΰ ?
φιθεθ δδεγςδ αϊβεαδτεμιΰεψιθο ξεχφσ -Polyurethane
αϊεψ δϊημδ μΰ ξετις αξΰβψ δπϊεπιν δςεμξι ςμ ηεξψιν ξρψθπιν.
http://toxnet.nlm.nih.gov/cgi-bin/si...CPDB.htm#jumpp
ξφγ ωπι , λο ξετις ατιψρεξιν ςμ ωϊμιν μηζδ ωςωειιν ξδηεξψ δζδ , ωξρψθπιν αδημθ ...
http://www.preventcancer.com/press/p...s/may12_95.htm
εβν δηεξψι τιψεχ ωμε ξρψθπιν ...
αχιφεψ λγΰι μδξπς ξωιξεω !!!
ΰε μδωϊξω αξχεν ωΰιο ριλει ωϊδιδ ΰιϊε αξβς ΰε ςν δηεξψιν ωξϊτψχιν ξξπε.
ΰξιψ.
Carcinogenicity of Polyurethane Foam
In a series of publications from 1960 to 1964, Dr. Wilhelm Hueper (Chief of the Environmental Cancer Section at the National Cancer Institute) reported on the induction of carcinomas and/or sarcomas following intraperitoneal or subcutaneous injection of PUF in rats.4,5,6,7 Apart from the induction of carcinomas, the possibility that the sarcomas could have been "solid state tumors" was definitively excluded. Furthermore, Hueper demonstrated the rapid in vivo degradation of PUF.
On the basis of these findings, Hueper warned:
- "Since polyurethane plastics have been used in cosmetic and orthopedic surgery during recent years, these observations are of distinct significance and practical importance, (and) should caution against the indiscriminate use of polyurethane plastics in medical practice."4
- "against indiscriminate parenteral use of polyurethane plastics in medical practice."5
- "It is premature to conclude from the present absence of carcinogenic (human) responses that the innocuousness of these materials is established. (as) any cancerous reaction might require an induction period of some 30 years or more."7
On the basis of Hueper's studies, a senior FDA staff scientist concluded in 1991 that "PU[polyurethane] is acting as a straight-forward chemical carcinogen-- and is not an appropriate material for use in breast implants."8
The carcinogenicity of PUF was subsequently confirmed by the induction of fibrosarcomas and carcinomas in rats following intraperitoneal and intrapulmonary administration, respectively.9,10 The authors excluded the possibility that the sarcomas were "solid state tumors, "and emphasized that their findings were "consistent with a mechanism of biological degradation."10
Carcinogenicity of Contaminants and Degradation Products of Polyurethane Foam
2,4 - Diaminotoluene (TDA) and 2,4 - toluene diisocyanate (TDI) have been demonstrated to be carcinogenic contaminants and degradation products of PUF in both in vitro and in vivo studies.11,12,13,14,15,15 Additionally, TDA has been identified in both the urine and breast milk of women with silicone gel breast implants.17,18,19 It was accordingly concluded in 1994 that "TDA release from PU foam covers of -- breast implants will undoubtedly produce delayed adverse health effects."16
The carcinogenicity of TDI in mice and rats was first reported in 1983.20 Of particular interest was the induction of a statistically significant incidence of mammary fibroadenomas, besides malignant tumors in other sites in rats. On the basis of these data the International Agency for Research on Cancer (IARC) determined that there was "sufficient evidence" of TDI's carcinogenicity in mice and rats, including the induction of mammary tumors in female rats.21 These conclusions were subsequently reiterated by the National Toxicological Program.22 TDI is currently regulated by: the Environmental Protection Agency (EPA), under the Clean Air Act (CAA), Comprehensive Environmental, Response, Compensation and Liability Act (CERCLA), Resource Conservation and Recovery Act (RCRA), and Superfund Amendments and Reauthorization Act (SARA); the Occupational Safety and Health Administration (OSHA) under the Hazard Communication Standard and as a Chemical Hazard in laboratories; and by the FDA as an indirect food additive.
There is substantial evidence on the carcinogenicity of TDA dating back to 1955. when it was found that subcutaneous injection induced local sarcomas in rats.23 Invasive and metastatic liver cancer was subse-quently induced in rats fed with TDA.24 It is worthy of note that on the basis of these data, the cosmetic industry voluntarily eliminated the use of TDA in hair dyes in 1971. A statistically significant incidence of benign and malignant mammary tumors was induced in rats fed with TDA;25 these tumors developed after only one month feeding. A statistically significant incidence of liver cancer and vascular tumors was induced in mice, and benign and malignant breast tumors, besides tumors in other sites, were induced in rats following feeding of TDA.26 On the basis of these data, IARC concluded that there was "sufficient evidence " of the carcinogenicity of TDA in mice and rats.27 These conclusions were reiterated by the National Toxicology Program, which further warned that "the presence of TDA, even as a trace contaminant, may be a cause of cancer."28
TDA is currently regulated by EPA as a priority hazardous substance under SARA; OSHA under the Hazard Communication Standard as a Chemical Hazard in laboratories; and by the FDA which requires warning labels on coal tar hair dyes containing TDA under the Federal Food Drug, and Cosmetic Act.
An unpublished Congressionally-mandated NCI report emphasized that concerns on "a carcinogenic hazard were recently heightened by reports that the polyurethane foam coating that envelopes the silica gel -- may dissolve and produce the chemical 2,4 diaminotoluene (TDA) -- linked to increased rates of breast and hepatocellular carcinomas in rats and mice and possibly also sarcomas and lymphomas in mice."29
ωξψε ςμ χωψ