GI effects resulting from high levels of inhalation have been reported. Six days after the accident, the patient reported dizziness, nausea, and loss of appetite. On the ninth day after the accident, the clinical findings were loss of appetite, abdominal pain, diarrhea, tenesmus, and pus and blood in the stool. The clinical findings were undoubtedly due to the chemical effects of UF4. In corresponding animal studies, exposure to enriched uranium damaged elements of the GI tract.
Natural uranium is inhaled daily in very small amounts by all persons.
The source of this uranium is mostly resuspended soil particles of very small diameter. The reported concentration units are in micrograms or mBq, per unit wet weight, per unit dry weight, per cubic centimeter of wet bone, per unit ash weight, or per gram of calcium. In some cases it is not stated whether the bone marrow was removed. It is of value to convert across the various units to compare data, and data for different bone types. It is necessary to convert to activity per unit wet bone when estimating radiation doses to cells on bone surfaces, the targets for carcinogenesis.