Contribution of a nuclear fuel chemical separations facility to the plutonium content of a tobacco crop.

Tobacco, an important crop in the southeastern United States, can potentially contribute via the inhalation pathway to the dose-to-man from radionuclides. To evaluate this potential dose-to-man from the interception and retention of Pu aerosols, a tobacco crop was grown near a chemical separations facility at the Savannah River Plant (SRP) which releases Pu to the atmosphere. Average leaf 238Pu and 239, 240Pu concentrations were 9.8 and 5.1 fCi /g X dry wt, respectively. These concentrations indicate that 2.5% of the deposition occurring during the tobacco growth period was on merchantable leaves. Leaf Pu concentrations were slightly greater than Pu concentration of stem tissue. Tobacco grown near the facility had 10 times higher Pu concentrations than that grown off the SRP. Pu concentrations of tobacco were similar to other broadleaf crops. Dose commitment would be 1000 times greater for tobacco usage than wheat or soybean consumption when these crops were all grown under identical Pu deposition situations.