Tritium levels in Chinese cabbage and radish plants acutely exposed to HTO vapor at different growth stages.
To simulate an acute exposure of Chinese cabbage and radish plants to airborne HTO, the potted plants were exposed to HTO vapor under semi-outdoor conditions for 1h at different times from the early to late growth stages. The plants were grown outdoors and the plant tritium was measured at the end of an exposure (h(0)) and at harvest. The leaf tissue free water tritium (TFWT) concentrations at h(0) were considerably lower than estimated equilibrium concentrations. In the leaves of Chinese cabbage, the exposure at the earlier growth stage generally ended with a higher TFWT concentration. Such a tendency was not apparent either in the leaves or roots of radish. On the other hand, the earlier stage exposure gave rise to lower TFWT concentrations at the harvest of both crops. For the OBT (organically bound tritium), however, the same occurred only in the Chinese cabbage leaves. During the period between the exposure and harvest, the TFWT concentrations reduced by factors of up to 1.1 x 10(6) for the Chinese cabbage leaves and 1.3 x 10(4) for the radish roots. Based on the activity ratios of OBT to TFWT at harvest, it is estimated that OBT mostly contributes much more to the ingestion dose than TFWT does.
Choi
Yong Ho
YH
Nuclear Environment Research Division, Korea Atomic Energy Research Institute, Yuseong, Daejeon 305-600, Republic of Korea. yhchoi@kaeri.re.kr
Lim
Kwang Muk
KM
Lee
Won Yun
WY
Park
Hyo Guk
HG
Choi
Geun Sik
GS
Keum
Dong Kwon
DK
Lee
Hansoo
H
Kim
Sang Bog
SB
Lee
Chang Woo
CW
D000393:Air Pollutants / Q000032:analysis*; D001937:Brassica / Q000254:growth & development / Q000378:metabolism*; D031224:Raphanus / Q000254:growth & development / Q000378:metabolism*; D012588:Scintillation Counting; D014316:Tritium / Q000032:analysis* / Q000493:pharmacokinetics*; D014835:Volatilization
D000393:Air Pollutants; D014316:Tritium