TABLE 2.

Descriptive Statistics of Erythrocyte Metal Levels (ng/g) for ALS Cases and Controls

	Controls, n = 319					ALS Cases, n = 107
Metal	AM	GM	GSD	Min–Max	<LOD, n	AM	GM	GSD	Min–Max	<LOD, n
Arsenic	4.74	2.83	2.83	0.27–83.5	0	5.22	2.68	3.20	0.25–43.3	0
Cadmium	0.90	0.70	2.11	0.002–4.94	1	0.98	0.78	1.89	0.22–8.43	0
Copper	592	587	1.14	402–1,042	0	585	580	1.15	381–828	0
Lead	84.4	72.7	1.68	17.4–688	0	87.4	78.1	1.63	22.1–240	0
Manganese	14.5	13.9	1.35	5.33–31.1	0	14.5	13.7	1.39	7.45–34.8	0
Mercury	5.44	2.75	4.29	0.004–55.8	8	5.03	2.82	3.57	0.004–30.1	1
Selenium	123	117.7	1.31	56.4–670	0	118	115	1.25	62.0–230	0
Zinc	9,090	8,941	1.20	5,024–18,411	0	8,817	8,697	1.18	5,136–12,577	0

ALS = amyotrophic lateral sclerosis; AM = arithmetic mean; GM = geometric mean; GSD = geometric standard deviation; LOD = limit of detection.