Profound DNA methylomic differences between single- and multi-fraction alpha irradiations of lung fibroblasts.

Background: Alpha (α)-radiation is a ubiquitous environmental agent with epigenotoxic effects. Human exposure to α-radiation at potentially harmful levels can occur repetitively over the long term via inhalation of naturally occurring radon gas that accumulates in enclosed spaces, or as a result of a single exposure from a nuclear accident. Alterations in epigenetic DNA methylation (DNAm) have been implicated in normal aging and cancer pathogenesis.

Consequences of changing Canadian activity patterns since the COVID-19 pandemic include increased residential radon gas exposure for younger people.

The COVID-19 pandemic has produced widespread behaviour changes that shifted how people split their time between different environments, altering health risks. Here, we report an update of North American activity patterns before and after pandemic onset, and implications to radioactive radon gas exposure, a leading cause of lung cancer. We surveyed 4009 Canadian households home to people of varied age, gender, employment, community, and income.

Chromatin and the Cellular Response to Particle Radiation-Induced Oxidative and Clustered DNA Damage.

Exposure to environmental ionizing radiation is prevalent, with greatest lifetime doses typically from high Linear Energy Transfer (high-LET) alpha particles the radioactive decay of radon gas in indoor air. Particle radiation is highly genotoxic, inducing DNA damage including oxidative base lesions and DNA double strand breaks. Due to the ionization density of high-LET radiation, the consequent damage is highly clustered wherein ≥2 distinct DNA lesions occur within 1-2 helical turns of one another.

A high-throughput alpha particle irradiation system for monitoring DNA damage repair, genome instability and screening in human cell and yeast model systems.

Ionizing radiation (IR) is environmentally prevalent and, depending on dose and linear energy transfer (LET), can elicit serious health effects by damaging DNA. Relative to low LET photon radiation (X-rays, gamma rays), higher LET particle radiation produces more disease causing, complex DNA damage that is substantially more challenging to resolve quickly or accurately. Despite the majority of human lifetime IR exposure involving long-term, repetitive, low doses of high LET alpha particles (e.