Browsing by Author "Stanley, Fintan"

Now showing 1 - 1 of 1
  • Thumbnail Image
    ItemOpen Access
    An Analysis of Human Exposure to Alpha Particle Radiation
    (2018-12-17) Stanley, Fintan; Goodarzi, Aaron A.; Lees-Miller, Susan P.; Cobb, Jennifer A.
    High linear energy transfer (LET) ionizing radiation (IR) is the predominant source of IR humans are exposed to. Radon gas, which emits a high energy alpha-particle, represents the greatest single lifetime source, but also remains comparatively understudied versus low LET IR sources such as x-rays. The inhalation radon (222Rn) gas from indoor air exposes lung tissue to alpha particle radiation, damaging DNA and increasing the lifetime risk of lung cancer. Buildings can concentrate radioactive radon (222Rn) gas to harmful levels. To enable cancer prevention, I examined how Canadian Prairie radon exposure is modified by environmental design and human behavior and evaluated different radon test modalities. I also developed a high-throughput, benchtop alpha-particle irradiation system to facilitate future research into the biological consequences of high LET radiation exposure. Initially, I examined 90+ day radon test results from 2,382 residential homes from an area encompassing 82.5% of the Southern Alberta population. Remediated homes were retested to determine efficacy of radon reduction techniques in this region. Subsequently, 11,726 Alberta and Saskatchewan homes were radon tested, coupled to geographic, design and behavior metrics. Canadian Prairie homes contained 140 Bq/m3 average radon (min <15 Bq/m3; max 7,199 Bq/m3) and 17.8% were ≥ 200 Bq/m3. Geostatistical analysis indicates significant variation between regions. More recently constructed homes contain higher radon versus older. Finally, I also designed and validated a benchtop, 96 well plate-based 241Am irradiation system to expose cultured eukaryotic cells to alpha particles in a controlled environment. My validation of this novel setup includes quantification of nuclear alpha particle-induced DNA damage signalling (γH2AX) using a purpose-designed 3D analysis method, physical readouts of alpha particle-induced DNA damage by alkaline comet assay, and an investigation of cellular viability after alpha particle exposure. This method brings significant advances over existing techniques in its ease of setup and use, affordability, accessibility and flexibility and should enable future alpha particle radiation biology. Collectively, my work demonstrates that radon is a genuine public health concern in the Canadian Prairies, legitimatizes efforts to understand the consequences of radon exposure to the public, and suggest that radon testing and mitigation is likely to be an impactful cancer prevention strategy.