Scientific rambling
Japan's discharge of nuclear wastewater from the Fukushima nuclear disaster into the ocean continues to raise concerns about the health effects of radiation. Ionizing radiation, classified as a Group I carcinogen, has long been linked to various cancers and genetic diseases, as evidenced by the suffering experienced by survivors and descendants of the atomic bomb** and Chernobyl.
Even, people will ask, is there any radiation from mobile phones? Does the microwave oven have radiation? Is there any radiation from the signal tower on the roof? Is there any radiation from the security checkpoints in the subway station? In fact, everything has radiation, and we are exposed to low levels of radiation at any time and in any place, and when we talk about the harm of radiation, we can't talk about the dose of radiation – we are hooligans to talk about the harm of radiation regardless of the dose.
For the dose of radiation, there is a unit called millisievert (MSV), if the radiation dose is less than 100 millisieverts, generally will not cause obvious harm to the human body, if the human body is exposed to more than 100 500 millisieverts for a long time, the number of white blood cells in the blood is reduced, if the dose is larger, it may lead to cancer and genetic diseases. The radiation dose of a cell phone or microwave oven is about 0000014 millisieverts, according to the standard of 100 millisieverts, will hardly cause harm to the human body.
However, these standards apply to the human body as a whole, and for a long time, scientists did not fully understand the effects of ionizing radiation on individual cells.
Radiation, whether in the form of energetic particles or electromagnetic waves, often destroys our cellular DNA, leading to cancer and genetic diseases. A recent study**, published in Cell Genomics, titled "Quantitative and Qualitative Mutant Effects of Ionizing Radiation on Normal Cells," revealed the effects of radiation on individual cells.
Using meticulous analysis techniques, the research team comprehensively analyzed the whole genome sequence of cells before and after irradiation, and pinpointed the radiation-induced DNA mutations. Experiments involving cells from different organs in humans and mice exposed to different doses of radiation revealed mutational patterns associated with exposure levels.
Notably, the results of the study showed that radiation exposure to 1 gray (GY) resulted in an average of 14 gene mutations in cells after each exposure. Unlike other carcinogens, radiation-induced mutations mainly include short base deletions and a range of structural variants, including inversions, translocations, and various complex genome rearrangements.
Gray is a unit of absorbed dose, used to quantify the degree of harm to the human body from radiation, 1 gray radiation per hour, equivalent to exposure to this radiation, every kilogram of human tissue absorbed 1 joule of energy per hour. However, there are many types of radiation, and the harm of 1 joule ray is much higher than that of 1 joule X-ray, so people have defined equivalent dose units such as sieverts or millisieverts to quantify the harm of radiation to the human body.
For an individual as small as a cell, the absorbed dose of 1 gray is almost equivalent to the equivalent dose of 1 sievert.
Interestingly, experiments with low radiation dose rates on cells over a period of 100 days showed that the amount of mutation at the same total radiation dose reflected the amount of mutation at high dose exposure. To put it simply, for a single cell, a low radiation dose for a long time produces a higher mutation rate than a short period of high radiation dose.
"With this study, we have clearly elucidated the effects of radiation on cells at the molecular level, and now we have a better understanding of how radiation changes the DNA of our cells," said researchers from Seoul National University School of Medicine in South Korea. ”
Based on this research, researchers will continue to study the effects of very low and very high doses of radiation on the human body, which may lead to the development of safe and effective radiotherapy** technologies. ”
Professor Kim from the Seoul National University School of Medicine said, "With this research, we believe that we now have a tool to accurately understand the effects of radiation on human DNA, and we hope that using the research methods used in this study, many follow-up studies will emerge." ”