Prior to the first nuclear explosion at Alamogordo, New Mexico on July 16, 1945, the dietary intake of radiocesium was ZERO

Naturally Occurring Radionuclides:
Isotope Name	Half-life	Principle Decay Mode	Maximum Energy	Product of:
Radium-226	1599.0 y	alpha	4.78450 Mev	Natural Source 238U decay scheme
Radon-222	3.82351 d	alpha	5.48966 Mev	Same
Polonium-210	138.3763 d	alpha	5.30451 Mev	daughter 210Bi in radium decay scheme
Artificially Produced Radionuclides which also exist Naturally*:
Tritium	12.346 y	beta	0.018610 Mev	6Li
Carbon-14	5730 y	beta	0.155 Mev	14N
Krypton-85	10.701 y	beta	0.672 Mev	84Kr
Artificial Radionuclides Produced by the Fission Process:
Strontium-89	50.55 d	beta	1.488 Mev	88Sr
Strontium-90	28.82 y	beta	0.546 Mev	fission
Iodine-129	157 x 107 y	beta	0.150 Mev	fission
Iodine-131	8.040 d	beta	0.6065 Mev	fission
Cesium-134	2.062 y	beta	1.454 Mev	133Cs
Cesium-137	30.174 y	beta	0.51163 Mev	fission
Transuranic Nuclides Produced by the Fission Process:
Neptunium-237	2.14 x 106 y	alpha	4.2 Mev	241Am
Plutonium-238	87.71 y	alpha	5.49921 Mev	238Np
Plutonium-239	2.4131 X 104 y	alpha	5.1554 Mev	235mU
Plutonium-241	14.355 y	alpha	5.17 Mev	Multiple n-capture from 238U, 239Pu
Americium-241	432.0 y	alpha	5.48574 Mev	241Pu
Curium-242	162.76 d	alpha	6.1129 Mev	same as 241Pu
Curium-244	18.099 y	alpha	5.80496 Mev	same as 241Pu
Other Important Fission Products Include:
Molybdemum-99	67 hr	beta	1.23 Mev
Technetium-99	2.12 x 105 y	beta	0.292 Mev
Ruthenium-103	39.8 d	beta	0.70 Mev
Ruthenium-106	1 y	beta	0.039 Mev
Silver-110m	252 d	gamma	0.74 Mev
Tellurium-132	78 hr.	beta	0.22 Mev
Barium-140	12.8 d	beta	1.02 Mev
Cerium-144	290 d	beta	0.31 Mev
Europium-154	8.2 y	beta	0.70 Mev
Important Activation Products Include:
Nickel-63	100 y	beta	0.067 Mev
Nickel-59	76,000 y	electron capture	1.06 Mev
Cobalt-58	0.194 y	e.c. and gamma	0.474 Mev
Cobalt-60	5.2719 y	beta	0.31788 Mev
Iron-55	2.68 y	e.c.
Manganese-54	0.855 y	gamma	0.835 Mev
Niobium-95	35 d	beta	0.160 Mev
Zirconium-95	0.175 y	gamma	0.396 Mev