There is a small group of workers who had higher doses, perhaps as high as 100 rem. However, individual doses for the workers who developed brain cancer were not provided. While chemical exposure may contribute to the risk of cancer, the only common factor among the workers was exposure to radiation. In summary, some researchers have linked certain nervous system health effects to radiation exposure. Health effects linked to high-dose exposure include cancerous and benign brain tumors in people exposed, and small brain size and mental retardation in children of women who were exposed during pregnancy.
Health effects linked to low-dose exposure include brain cancer among nuclear industry workers.
Hanford's Releases and the Nervous System U nfortunately, most of what is known about radiation's effects on the nervous system cannot be directly compared with the Hanford situation. Current knowledge comes from studies of people exposed to high organ doses or high whole-body doses of radiation received over minutes, hours, or days. In contrast, Hanford's releases resulted in some high radiation doses to the thyroid, some low doses to other organs, and low whole-body doses. These doses occurred over weeks, months, or years. While most studies of radiation's effect on the nervous system involve external exposure, most of the dose from Hanford's releases came from internal radiation exposure.