. Author manuscript; available in PMC: 2014 May 1.

Published in final edited form as: Environ Res. 2013 Mar 7;123:10.1016/j.envres.2013.01.005. doi: 10.1016/j.envres.2013.01.005

Table 1. Mean and median levels of urinary perchlorate and other factors: comparison of the National Health and Nutrition Examination Surveys 2001-2 and 2007-8^a.

	Perchlorate (µg/L)		Iodine (µg/L)		Thiocyanate (µg/L)		Totalthyroxine (µg/dl)		Thyroidstimulatinghormone (IU/L)

	2001	2007	2001	2007	2001	2007	2001	2007	2001	2007
N	2276	6044	2274	5921	2273	6044	2276	6044	2273	6044
Mean	5.34	5.98	425	447	2405	2525	8.16	7.82	2.04	2.03
Median	3.85	3.90	170	160	1400	1220	8.00	7.60	1.38	1.57
Standard deviation	7.07	9.15	4131	10169	2862	3660	1.92	1.66	8.83	2.74
10^th Percentile	1.20	1.14	50	53	360	303	6.00	6.00	0.63	0.69
90^th Percentile	10.0	12.0	488	453	6000	6530	10.50	9.80	2.94	3.47

Includes all subjects with a urinary perchlorate and serum thyroxine measurement.

Table 1. Mean and median levels of urinary perchlorate and other factors: comparison of the National Health and Nutrition Examination Surveys 2001-2 and 2007-8a.