Table 2. Geometric means (GMs) and geometric mean ratios (GMRs) and 95% confidence intervals (CIs) of urine dimethylarsinate (DMA) and total arsenic recalibrated to reflect non-dietary and non-smoking sources of arsenic among Mexican-Americans using public water (N=1569).

Recalibrated urine DMA and total arsenic were obtained from residuals regressing each log-transformed arsenic variable (DMA and total arsenic) on smoking status (never/ever/current), natural log-transformed arsenobetaine, and natural log-transformed intake of rice, cereals, juices, wine, chicken, and turkey in g/kg bodyweight/day (See Methods). Geometric means were further adjusted for age, education, and body mass index. P for trend was estimated by entering each NHANES 2-year cycle in the model as an ordinal variable.

		Dimethylarsinate (DMA)		Total arsenic
	N	Geometric Mean	Geometric Mean Ratio	Geometric Mean	Geometric Mean Ratio
2003/2004	257	4.06 (3.93, 4.19)	1 (reference)	6.05 (5.86, 6.24)	1 (reference)
2005/2006	300	3.37 (3.27, 3.49)	0.83 (0.70, 0.98)	5.23 (5.07, 5.40)	0.87 (0.75, 1.00)
2007/2008	263	3.67 (3.55, 3.79)	0.90 (0.75, 1.09)	5.79 (5.61, 5.98)	0.96 (0.82, 1.12)
2009/2010	327	3.23 (3.12, 3.33)	0.79 (0.66, 0.95)	5.39 (5.22, 5.57)	0.89 (0.78, 1.01)
2011/2012	160	2.69 (2.60, 2.78)	0.66 (0.54, 0.81)	3.54 (3.43, 3.65)	0.59 (0.52, 0.66)
2013/2014	262	2.58 (2.50, 2.67)	0.64 (0.54, 0.75)	3.18 (3.08, 3.28)	0.53 (0.46, 0.60)
P for trend			P<0.01		P<0.01