Table 2.

Environmental chemicals detected in normal human parathyroids. Intact normal parathyroid glands (40 mg) dissected from donated post-mortem thyroids were prepared, analyzed, and quantified for environmental chemicals as described in Methods.

Chemical	Mean (ng/g)	SE (ng/g)	Detection Frequency
p,p′-DDE	4.858	2.095	4 out of 4
PCB-28	0.003	0.004	1 out of 4
PCB-74	0.016	0.013	3 out of 4
PCB-153	0.171	0.128	2 out of 4
hexachlorobenzene	0.086	0.064	4 out of 4
trans-nonachlor	0.471	0.380	4 out of 4
	Non-detectable in any normal tissue:
p,p′-DDT			0 out of 4
p,p′-DDD/o,p′-DDT			0 out of 4
o,p′-DDD			0 out of 4
PCB-49			0 out of 4
trans-chlordane			0 out of 4