The effects of radiation on our health

our body is made of billions of cells which are arranged to form organs approximately one and a half meters of DNA are stored in each cell DNA is a giant molecule formed by two complimentary strands which are wound into a double helix the hereditary message is chemically coded along the DNA molecules there are four different elements which make up the code and which are referred to as bases their sequence determines our genetic heritage these bases combine to form an amino acid proteins are all amino acid chains the DNA sequences contain genetic information which are referred to as genes and which carry the manufacturing drawing for all the proteins of a cell DNA undergoes permanent attacks and there are numerous aggressive agents the following could be mentioned solvents and pesticides combustion smoke viral aggressions ultraviolet radiation and ionizing radiation all molecules can be affected by radiation but it is when DNA is impacted that there are the greatest consequences for cellular operations the action of ionizing radiation on DNA may be direct as well as indirect via the water contained inside the cells water consists of free radicals these free radicals which are chemically very reactive damage the DNA molecules located nearby DNA damage induced by radiation varies according to the nature of the radiation and the level of exposure luckily the cell has been provided with extremely efficient repair systems so there is a repair system which starts operating when DNA is damaged most cases the repair works but sometimes errors in the genetic code persist these are referred to as mutations the future of a badly repaired cell is uncertain it can be identified and eliminated by the immune system or survived without any consequences for the body however both cases can affect our health when cells die in great numbers or when they are transformed into cancerous cells if the radiation dose is high a significant number of cells will be damaged and will die this will involve effects which are referred to as deterministic effects high doses generate systemic effects on the people who've been exposed their severity depends on the dose and exposure on the size of the body area which has been exposed and on the type of organs which have been affected the occurrence of cancerous cells is the other serious consequence however as opposed to deterministic effects this effect does not systematically affect each person who has been exposed the development of a cancer cannot be predicted at the scale of an individual only the risk of occurrence in an individual can be estimated such effects are referred to as stochastic effects several groups of studies have shown that there is an increased risk of cancer in populations exposed to high doses and that in some cases it may take several decades before the cancer appears the following are four cases in the 1930s female workers in the clockmaking industry use radium based paint to paint the hands of the clocks and the numbers on the alarm clock dials in the 1950s before the mines were ventilated uranium miners used to inhale air which was highly contaminated with radon there after the levels of exposure dropped systematically the bombs of Hiroshima and Nagasaki in August 1945 caused the immediate death of 200,000 people the 300,000 survivors were irradiated with various doses which were all delivered at a high rate for more than 30 years the survival rate for cancer patients has steadily increased as progress has been made in the medical fields but secondary cancer caused by treatment is still a risk despite efforts to target only cancerous cells during radiation treatment the Rays still touch the healthy surrounding tissue and may have carcinogenic effects these last three groups of studies have made it possible to quantify the relationship between radiation doses and cancer frequency but it is difficult to assess the validity of this cause-and-effect relationship when the results are extrapolate it for current doses which are much lower in order to determine if these extrapolation czar accurate studies are also conducted on low doses and dose rates as there is no scientific evidence a careful attitude involves considering that effects exist at low doses as regards radiation protection actions are conducted on the basis of this principle of precaution you

Channel: Institut de Radioprotection et de Sûreté Nucléaire - IRSN

Views: 279,833

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Keywords: dna, Health, radioactivity, ionising radiation

Id: tq6FDyFeCN0

Length: 7min 15sec (435 seconds)

Published: Thu Jun 06 2013