Table 3.

Results of linear regression models of percentage differences in hormonal activities ($\mathrm{\mu }\mathrm{g}\text{-eq}/\mathrm{g}$ or $\text{ng-eq}/\mathrm{g}$) for an interquartile range (IQR) increase in summed concentrations $(\text{ng}/\mathrm{g})$ of three chemical classes in 46 dust samples: per- and polyfluoroalkyl substances (PFAS), organophosphate esters (OPEs), and polybrominated diphenyl ethers (PBDEs).

	Thyroid hormone receptor $\mathrm{\beta }$ antagonism ($\mathrm{\mu }\mathrm{g}\text{-eq}/\mathrm{g}$)				$\text{PPAR}\mathrm{\gamma }$ antagonism ($\mathrm{\mu }\mathrm{g}\text{-eq}/\mathrm{g}$)				Androgen receptor antagonism ($\mathrm{\mu }\mathrm{g}\text{-eq}/\mathrm{g}$)				Estrogen receptor $\mathrm{\alpha }$ agonism ($\text{ng-eq}/\mathrm{g}$)				Thyroid hormone transport interference ($\mathrm{\mu }\mathrm{g}\text{-eq}/\mathrm{g}$)
Covariate	$\mathrm{\Delta }\text{IQR}$ (%)	$p$	IQR	$n$	$\mathrm{\Delta }\text{IQR}$ (%)	$p$	IQR	$n$	$\mathrm{\Delta }\text{IQR}$ (%)	$p$	IQR	$n$	$\mathrm{\Delta }\text{IQR}$ (%)	$p$	IQR	$n$	$\mathrm{\Delta }\text{IQR}$ (%)	$p$	IQR	$n$
Model 1: unweighted effects of chemicals	($R^2=0.22$)				($R^2=0.17$)				($R^2=0.11$)				($R^2=0.0014$)				($R^2=0.14$)
$\sum$ PFAS	7.00**	0.01	267	15	1.06	0.6	267	15	5.58*	0.04	267	15	$–0.674$	0.8	267	15	1.86	0.6	267	15
$\sum$ OPEs	25.7*	0.02	29,000	8	25.2**	0.005	29,000	8	8.83	0.4	29,000	8	0.193	1	29,000	8	38.5*	0.01	29,000	8
$\sum$ PBDEs	$–3.93$	0.4	1,020	19	$–1.28$	0.7	1,020	19	$–3.8$	0.4	1,020	19	$–0.313$	1	1,020	19	$–4.22$	0.5	1,020	19
Model 2: potency-weighted effects of PFAS	($R^2=0.22$)				($R^2=0.013$)				($R^2=0.083$)				($R^2=0.039$)				($R^2=0.0014$)
Potency-weighted $\sum$ PFAS	27.5*	0.01	116	4	$–1.21$	0.7	57	4	No RPFsa	—	0	0	$–5.05$	0.2	13.2	1	0.755	0.8	44.1	13
$\sum$ PFAS of unknown potency	0.7	0.9	14.7	7	3.37	0.5	14.7	7	0.856	0.9	36.2	8	$–2.63$	0.7	14.7	7	Few detectsc	—	—	2
$\sum$ PFAS designated inactiveb	$–12.0$	0.2	218	4	0.182	1	172	4	5.11	0.3	261	7	1.88	0.8	261	7	NA	—	0	0
Model 3: potency-weighted effects of OPEs	($R^2=0.18$)				($R^2=0.18$)				($R^2=0.086$)				($R^2=0.016$)				($R^2=0.12$)
Potency-weighted $\sum$ OPEs	26.8#	0.08	81,500	7	$–2.22$	0.5	2,450	4	$–14.1$	0.3	5,500	6	$–4.14$	0.5	3,190	4	No RPFsa	—	0	0
$\sum$ OPEs of unknown potency	10.9*	0.02	189	6	1.97	0.6	189	6	12.7#	0.06	243	7	$–0.543$	0.9	189	6	34.4*	0.02	29,000	19
$\sum$ OPEs designated inactiveb	2.54	0.2	5,450	6	24.6**	0.004	28,600	9	7.2	0.5	28,600	6	1.59	0.9	28,400	9	NA	—	0	0
Model 4: potency-weighted effects of PBDEs	($R^2=0.18$)				($R^2=0.024$)				($R^2=0.022$)				($R^2=0.071$)				($R^2=0.00012$)
Potency-weighted $\sum$ PBDEs	20.2*	0.02	316	2	No RPFsa	—	0	0	$–2.78$	0.6	301	3	7.71#	0.08	173	1	No RPFsa	—	0	0
$\sum$ PBDEs of unknown potency	$–4.55$	0.3	963	5	0.210	1	963	5	4.41	0.5	66.2	4	$–1.59$	0.7	963	5	$–0.423$	0.9	1,020	8
$\sum$ PBDEs designated inactiveb	$–3.05$	0.8	14.5	1	4.82	0.3	160	3	$–2.16$	0.6	909	1	Collineard	—	94.1	2	NA	—	0	0

Note: Assay activities were log-transformed in the models, but the estimates are transformed and presented as the percentage difference in activity for an IQR increase in the chemical covariate. —, not available; IQR, interquartile range; $n$, number of chemicals contributing to the sum for that covariate; NA, not applicable; $\text{PPAR}\mathrm{\gamma }$, peroxisome proliferator-activated receptor lowercase gamma 2; RPF, relative potency factor; $\mathrm{\Delta }\text{IQR}$, change in interquartile range. ^#, $p<0.10$; *, $p<0.05$; **, $p<0.01$.

^aNone had RPFs available, so this covariate could not be included in the model.

^bDesignated as inactive in Tox21 assays of the chemicals (for antagonism/agonism) or in the exact luciferase assays by the laboratory (for transport interference).

^cThe few PFAS in this unknown assay classification were too infrequently detected and, thus, were excluded from the model.

^dThis covariate was very collinear (Spearman $r=0.9$), so it was excluded from the model.