caa a22 4500 37886145X CHVBK 20180305123347.0 cr unu---uuuuu 161128e20030101xx s 000 0 eng 10.1351/pac200375112159 doi (NATIONALLICENCE)gruyter-10.1351/pac200375112159 Barton H. A. USEPA Office of Research and Development, National Health and Environmental, Research Laboratory, Experimental Toxicology Division, B143-01, Research Triangle Park, NC 27711, USA Endocrine active substances and dose response for individuals and populations [Elektronische Daten] [H. A. Barton] Dose-response characteristics for endocrine disruption have been major focuses in efforts to understand potential impacts on human and ecological health. Issues include assumptions of thresholds for developmental effects, effects at low doses with nonmonotonic (e.g., "U-shaped") behaviors, population vs. individual responses, and background exposures (e.g., dietary phytoestrogens). Dose-response analysis presents a challenge because it is multidisciplinary, involving biologists and mathematicians. Statistical analyses can be valuable for evaluating issues such as the reproducibility of data as illustrated for contradictory findings on low-dose effects. Mechanistically based modeling provides insights into how perturbations of biological systems by endocrine active substances can create different dose-response behaviors. These analyses have demonstrated that higher order behaviors resulting from the interaction of component parts may appear highly nonlinear, thresholded, low-dose linear, or nonmonotonic, or exhibit hysteresis. Some effects need to be evaluated as population impacts. For example, alterations in male:female ratio may be important at the population level even though not adverse for the individual. Descriptions of the contributions of background exposures to dose-response behaviors are essential. The challenge for improving dose-response analyses is to better understand how system characteristics create different dose-response behaviors. Such generalizations could then provide useful guidance for developing risk assessment approaches. © 2013 Walter de Gruyter GmbH, Berlin/Boston Pure and Applied Chemistry De Gruyter 75/11-12(2003-01-01), 2159-2166 0033-4545 75:11-12<2159 2003 75 pac https://doi.org/10.1351/pac200375112159 text/html Onlinezugriff via DOI 1 research article jats NATIONALLICENCE 856 40 https://doi.org/10.1351/pac200375112159 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Barton H. A. USEPA Office of Research and Development, National Health and Environmental, Research Laboratory, Experimental Toxicology Division, B143-01, Research Triangle Park, NC 27711, USA NATIONALLICENCE 773 0- Pure and Applied Chemistry De Gruyter 75/11-12(2003-01-01), 2159-2166 0033-4545 75:11-12<2159 2003 75 pac CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-gruyter