Environmental noise exposure.

Use of permanent hair dyes and the risk of breast cancer. A prospective study of permanent hair dye use and hematopoietic cancer. dye use and breast cancer: a case-control study among screening participants. Mortality of workers exposed to toluene diisocyanate in the polyurethane foam industry. Response In his comments on our paper, Kulig states that "the estimated dose of polyurethane was too high." The polyurethane foam mass (4.87 g) used in this study corresponds to the mass of foam covering two implants of 500 g each. The 2.7 g referred by Kulig corresponds to the mass of foam covering two implants of 250 g each. Another criticism was that "polyurethane oligomers were incorrectly assumed to be 2,4-toluenediamine (2,4-TDA)". We did not assume that all the degradation products were oligomers. We also did not use an implant study to calibrate the model. The text and data in Figure 2 of our paper was clearly identified as an intravenous (iv) bolus of 0.52 mg/kg of 2,4-TDA. Obviously, this would result in serum concentrations above the detection limits, so that the model could be calibrated. We never claimed that the data in our Figure 2 was from an implant or that the implant degradation product, 2,4-TDA, could be detected in serum. This iv bolus data of pure 2,4-TDA was used initially to calibrate the PBPK model. Subsequently, the PBPK model was used to simulate routes of administration in the rat and in rat (0.021 g) and human (4.872 g) implants in our Table 2. Table 3 in our paper shows a list of metabolism and excretion parameters, and not plasma or urinary levels of 2,4-TDA as indicated in Kulig's comments. In Figure 3, we plotted 2,4-TDA serum concentrations of the simulated low-dose rat iv bolus, feeding, and implant cases, and not, urinary 14C 2,4-TDA as Kulig claimed in his comments. The 14C data were used only to validate the excretion of 2,4-TDA in rats. We did not use an inappropriate scaling factor. Metabolism has been clearly shown to scale with the 0.7 power of the body weight (1). Thus, the scaling factor is (58/0.25)0.7 = (232)07 = 45. This has nothing to do with the use of an inhalation route. This factor applies to the forward rate constant for metabolism in the liver. Kulig stated that "previous risk assessments , polyurethane studies in animals and humans, and relevant epidemiology were not considered in …