Johnson, PD; Goldberg, SJ; Mays, MZ; Dawson, BV
Because the study "Threshold of Trichloroethylene Contamination in Maternal Drinking Waters Affecting Fetal Heart Development in the Rat" (Johnson et al. 2003) was a long-term and continuous study, the authors compiled the data from controls of several treatment groups. The control "sets" were statistically analyzed comparing the data to each other before being combined. The authors opine that the control values were statistically consistent across and throughout all the treatment groups. Using the control data in a cumulative manner increased the generalizability of the data, which purports to demonstrate the background rate and variability around rate estimates. The larger sample size somewhat increased statistical power without the inappropriate use of further valuable animal resources.
Table 1.
Table 1 presents the date ranges of experimental treatment and the coinciding control treatments. Each treatment exposure had a corresponding control group. Also, because of the more detailed information on competing financial interests now included in EHP's Instructions to Authors, the authors now report that S.J. Goldberg served as an expert witness for a plaintiff in a judicial hearing in 1997. As previously stated in a prior letter to the editor (Johnson et al. 2004), at all times throughout this research, the authors were free to design, conduct, interpret, and publish the research without compromise by any controlling sponsor as a condition of review or publication.
References
Johnson PD, Dawson BV, Goldberg SJ. 1998a. Cardiac teratogenicity of trichloroethylene metabolites. J Am Coll Cardiol 32(2):540-545.
Johnson PD, Dawson BV, Goldberg SJ. 1998b. A review: trichloroethylene metabolites: potential cardiac teratogens. Environ Health Perspect 106(suppl 4):995-999.
Johnson PD, Dawson BV, Goldberg SJ, Mays MZ. 2004. Trichloroethylene: Johnson et al.'s Response [Letter]. Environ Health Perspect 112:A608-A609.
Johnson PD, Goldberg SJ, Mays MZ, Dawson BV. Threshold of trichloroethylene contamination in maternal drinking waters affecting fetal heart development in the rat. 2003. Environ Health Perspect 111:289-292.
