2. What is the Research Question? Teacher - Cindy Johnson School - Palacios High School Mentor – Dr. John Ford Department of Nuclear Engineering (Radiation Biologist) Partner in Research – Bret Breitenkamp

3. HOW DO LOW DOSES OF BACKGROUND OR EXOTIC PARTICLE RADIATION AFFECT THE RISK OF CANCER OR TISSUE INJURY IN HUMANS The Answer:

4. INTRODUCTION AND BACKGROUND Type of Engineering in lab - Nuclear Field of Application - Biology, Physics, Medicine Background Information on Research  Uses thyroid, trachea, and other cells from rats  Exposes them to low levels of radiation  Such as x-rays, alpha sources or beams, proton beams, ion beams, and gamma sources  Uses different exposure methods such as single cell suspensions, monolayer cultures, or whole excised trachea

5. Background continued  CR-39 (plastic polymer) is placed along side, front or back of the tissue  Expose tissue to radiation  Cut, examine, and evaluate the tissue  Transplant cells back into rat and evaluate at different time periods  Develop, examine, photograph, score, and measure the CR-39 slide for radiation hits

6. The ASSAY  Assay - the data measured in the research  Number of tumors in transplant  Colonies that survived in culture  Changes in proteins or cells that could lead to cancer (preneoplastic transformation)  Number of Gap junction communications

7. Research Results Some of transplanted tissue formed tumors after irradiation Preneoplastic transformation is cell density dependent Neutrons can cause tumors in transplants Alpha particles are not effective at inducing preneoplastic transformations Bystander effects were observed between cells irradiated and those that were not

8. Comparison of Normal and Transplant Follicles

9. Transplant Tumor

10. Relevance of the Research Little is known about the effects of low level radiation on humans Exposure to low levels of radiation occurs daily in medicine and space Observed effects in rat cells could be beneficial to cancer research and medicine in humans Use to determine the amount of low dose radiation human tissue could be exposed to without damage.

11. Relevance continued Determine if the guidelines for low dose radiation need to be lowered for human safety Establish the importance of control guidelines for disposal of low dose radiation and equipment containing low dose radioactive material Develop materials to protect astronauts from space radiation

12. Dr. John Ford’s Background BS and MS in Nuclear Engineering from Mississippi State University Ph.D in Biomedical Sciences from University of Tennessee at Knoxville 1987-1993 Research at Oak Ridge National Lab 1994-1998 Research at MRC-Radiation and Genome Stability Unit in the United Kingdom 1998-present Texas A and M

13. Overview of My Research Activities Activity 1-Develop and analyze irradiated CR-39 slides Activity 2- Determine more information about the radiation environment of the polymer that contained irradiated tissue Activity 3- My class project or projects: –Determine which polymer would make the best low level radiation detector –Determine which polymer would be best at stopping alpha particles

14. Research Protocol Source of radiation is counted using a Gieger-Mueller tube CR-39 polymer is cut into microscopic slide size with a scalpel and labeled. CR-39 is exposed to the source by placing the source face down onto the slide. (different sources could be used) After the determined time period, the source is removed by inverting the slide.

15. Developing CR-39 After exposure the slides are placed in 6.5N NaOH and incubated for 4 hours at 65-70 degrees Celsius. The NaOH is changed at 2 hrs. The slides are then washed for several minutes under running water Slides are air dried and 3-10 fields of view at 450x are photographed for scoring and 1-2 at 750x are obtained for measurement.

16. Heavy ion streak in plastic

17. Alpha particle penetrations

18. Data Information Data Generated: –Count holes in several fields of view in a microscope –Estimated the number of holes on the slide in mm squared –Do this for each type of polymer used Data Interpreted: –Compare and graph the data collected from the different types of polymers –Determine which polymer is the best at detecting radiation and blocking alpha particles –Determine which polymer would be the most cost effective to use

19. Importance of Research Best polymer to use in radiation detectors Best low cost polymer that blocks radiation Use to determine radiation found in homes or space Increase understanding of low dose radiation and its effects for my students

20. Summary Dr. Ford is working on how low dose radiation affects cells. This can be used to determine how much low dose radiation is acceptable for the human cell The data could also be used to determine controls for low dose radioactive waste and disposal of that waste I can adapt this research to use in my Chemistry class by evaluating the effects of radiation on different polymers

21. Chemistry Class Lesson Introduce Nuclear Chemistry as part of the unit on Atoms Students experiment to determine the sensitivity of polymers to alpha radiation Students experiment to determine which polymer would shield alpha particles the best Students use a Gieger counter to determine environmental materials that contain radiation and determine the amount of radiation given off Students determine their annual exposure to background and low dose radiation

22. Acknowledgements Dr. John Ford for research, pictures and help Texas A&M University for opportunity National Science Foundation for financial support and opportunity South Texas Nuclear Power Plant