Table 2

Mercury concentrations in urine, hair, and nails

	n	Mean	SD	Median	Minimum	Maximum
Urinary mercury (nmol Hg/mmol creatinine):
Dentists	162	2.58	2.76	1.70	0.02	20.90
Controls	163	0.67	0.68	0.50	<0.01	4.20
Head hair (mass Hg/g):
Dentists	161	1.00	0.77	0.80	0.10	5.67
Controls	161	0.57	0.48	0.47	0.04	3.86
Public hair (mass Hg/g):
Dentists	167	0.88	1.00	0.69	0.09	11.71
Controls	168	0.46	0.36	0.37	0.03	2.54
Finger nail (mass Hg/g):
Dentists	164	5.25	20.60	1.05	0.12	239.60
Controls	155	0.32	0.30	0.23	0.02	2.49
Toe nail (mass Hg/g):
Dentists	163	0.71	1.38	0.38	0.20	14.74
Controls	155	0.24	0.19	0.18	0.02	1.22