Table 7.

Calculated Dose Conversion Coefficients (D_T per K_a)^a for 11 organs at three potentials (kV peak) in four time periods (see Table 1 for defining parameters) without protective lead aprons and for two thicknesses of lead aprons.

Organ or tissue	kV peak	No Apron				0.25 mm Pb Apron				0.5 mm Pb Apron
		<1949	1949-1954	1955-1968	>1968	<1949	1949-1954	1955-1968	>1968	<1949	1949-1954	1955-1968	>1968
RBMb	70	0.062	0.109	0.145	0.165	0.418	0.421	0.435	0.450	0.503	0.505	0.514	0.526
	80	0.085	0.141	0.184	0.208	0.498	0.502	0.516	0.530	0.585	0.586	0.596	0.606
	90	0.110	0.174	0.222	0.247	0.550	0.554	0.565	0.574	0.630	0.631	0.638	0.644
Skin (front only)	70	1.06	1.29	1.40	1.45	1.90	1.91	1.92	1.94	2.00	2.00	2.01	2.02
	80	1.13	1.36	1.47	1.52	1.99	1.99	2.01	2.02	2.08	2.08	2.09	2.10
	90	1.19	1.42	1.53	1.58	2.04	2.04	2.05	2.06	2.12	2.12	2.12	2.13
Thyroid	70	0.562	0.860	1.01	1.08	1.66	1.67	1.68	1.70	1.77	1.77	1.78	1.79
	80	0.645	0.947	1.10	1.17	1.75	1.75	1.77	1.78	1.84	1.84	1.85	1.86
	90	0.728	1.03	1.18	1.25	1.79	1.80	1.81	1.82	1.87	1.87	1.88	1.88
Breast	70	0.614	0.891	1.02	1.07	1.51	1.52	1.53	1.54	1.59	1.59	1.60	1.60
	80	0.686	0.959	1.09	1.14	1.57	1.57	1.58	1.59	1.63	1.63	1.64	1.64
	90	0.756	1.02	1.15	1.20	1.60	1.60	1.61	1.61	1.65	1.65	1.65	1.65
Ovary	70	0.123	0.227	0.308	0.352	0.850	0.856	0.876	0.896	0.976	0.978	0.990	1.01
	80	0.168	0.290	0.382	0.431	0.957	0.962	0.981	0.999	1.07	1.08	1.09	1.10
	90	0.216	0.351	0.450	0.499	1.02	1.03	1.04	1.05	1.12	1.13	1.13	1.14
Lens of eye	70	0.935	1.13	1.20	1.23	-	-	-	-	-	-	-	-
	80	0.979	1.17	1.23	1.26	-	-	-	-	-	-	-	-
	90	1.02	1.20	1.26	1.29	-	-	-	-	-	-	-	-
Lung	70	0.192	0.338	0.439	0.490	1.02	1.03	1.04	1.06	1.14	1.14	1.15	1.16
	80	0.246	0.407	0.517	0.572	1.11	1.12	1.13	1.15	1.21	1.21	1.22	1.23
	90	0.302	0.473	0.587	0.641	1.17	1.17	1.18	1.19	1.25	1.25	1.26	1.26
Brain	70	0.074	0.137	0.185	0.212	-	-	-	-	-	-	-	-
	80	0.102	0.176	0.232	0.262	-	-	-	-	-	-	-	-
	90	0.132	0.214	0.275	0.306	-	-	-	-	-	-	-	-
Colon	70	0.176	0.319	0.419	0.470	1.04	1.05	1.07	1.10	1.19	1.19	1.20	1.22
	80	0.232	0.392	0.503	0.560	1.16	1.17	1.19	1.21	1.29	1.29	1.30	1.31
	90	0.291	0.464	0.580	0.637	1.23	1.23	1.25	1.26	1.34	1.34	1.35	1.35
Testes	70	0.694	1.016	1.167	1.232	1.76	1.76	1.78	1.79	1.85	1.85	1.86	1.87
	80	0.778	1.097	1.248	1.313	1.83	1.83	1.84	1.85	1.90	1.90	1.91	1.91
	90	0.860	1.171	1.318	1.380	1.86	1.87	1.87	1.88	1.92	1.92	1.93	1.93
Heart	70	0.214	0.378	0.493	0.552	1.31	1.32	1.32	1.33	1.44	1.44	1.44	1.44
	80	0.276	0.459	0.585	0.648	1.39	1.39	1.40	1.40	1.48	1.48	1.48	1.48
	90	0.341	0.536	0.668	0.731	1.42	1.43	1.43	1.43	1.48	1.48	1.48	1.48

^aK_a refers to air kerma directly above personnel monitoring device in the absence of a protective apron, but underneath the apron when the protective device is worn. K_a under a protective apron is estimated from K_a outside the apron and the TF (eq. 5 and Table 6).

^bNominal values for a phantom of BMI equal to 23.6 kg m⁻² based directly on mono-energetic dose coefficients from ICRP (1977) and air kerma weighting methods as described in the text.