Table 1.

Results of multilevel linear regression models of log concentrations of key PCB, BFR, and OPE chemicals (as determined by principal component analysis) in silicone wristbands worn by office workers in the USA, UK, China, and India.

Variable	Polychlorinated Biphenyls				Brominated Flame Retardants
	PCB-11		PCB-101		BDE-47		BDE-209		BEHTBP
	% Change	p	% Change	p	% Change	p	% Change	p	% Change	p
Country (Ref: United States)
United Kingdom	170%	0.15	Excluded		−98.2% ***	<0.0001	273% **	0.0023	−26.70%	0.31
China	942% **	0.0022	Excluded		Excluded		72.60%	0.22	−88.3% ***	<0.0001
India	1730% ***	<0.0001	Excluded		Excluded		227% **	0.0063	−74.6% ***	0.00012
Year of Building Construction	−0.35%	0.68	−2.02% *	0.029	−0.13%	0.84	−0.14%	0.77	−0.55%	0.15
Carpeting in Workstation	–		–		129%	0.3	−22.90%	0.4	−23.50%	0.24
Foam Chair at Workstation	–		–		−22.90%	0.59	15.30%	0.5	23.30%	0.36
Average # Times Hands Washed	1.59%	0.87	−54.1% *	0.034	−10.60%	0.44	0.51%	0.93	−2.53%	0.74
Wore Wristband Under Sleeve	23.80%	0.38	105%.	0.09	−22.10%	0.47	−33.7% **	0.0085	7.67%	0.69
Variable	Organophosphate Esters								OPEs: TBPPs		OPEs: ITPs
	EHDPP		TiBP		TnBP		TpCP		4tBPDPP		2IPPDPP
	% Change	p	% Change	p	% Change	p	% Change	p	% Change	p	% Change	p
Country (Ref: United States)
United Kingdom	206% *	0.019	113% **	0.0081	−49.4%.	0.092	−41.90%	0.75	−76.9% *	0.045	93.10%	0.38
China	15.70%	0.77	−41.2%.	0.069	−73.8% **	0.0047	−98.8% *	0.023	−96.4% ***	0.00026	−61.60%	0.25
India	62.60%	0.3	−47.7% *	0.024	−67.7% **	0.0079	−57.10%	0.62	−91.2% **	0.0018	−89.3% **	0.0058
Year of Building Construction	−0.64%	0.27	−0.02%	0.96	0.01%	0.99	−1.17%	0.57	−0.50%	0.57	−0.03%	0.98
Carpeting in Workstation	16.70%	0.66	23.90%	0.29	39.30%	0.26	−6.70%	0.96	328% **	0.0079	571% **	0.002
Foam Chair at Workstation	−22.90%	0.3	7.62%	0.68	29.10%	0.15	267%.	0.088	25%	0.46	0.50%	0.99
Average # Times Hands Washed	−1.16%	0.87	−1.76%	0.75	−4.60%	0.34	−17.10%	0.39	3.80%	0.66	−13.10%	0.25
Wore Wristband Under Sleeve	−17.70%	0.29	7.51%	0.61	12.90%	0.33	105%	0.2	−4.38%	0.84	−3.78%	0.9

OPEs = organophosphate esters; ITPs = isopropylated triaryl phosphates; TBPPs = tertbutylated triaryl phosphates. Excluded = fewer than 5% of samples in the country had detectable levels so were excluded from model.

Note: Model outcomes were log-transformed before analysis, so model estimates were transformed to percent differences.