That is a very good question and not easy to answer. This will depend on the individual, the risk they are taking and the benefit that they will receive from it. As pointed out in the Radiation and Us page, we receive approximately 360 mrem of radiation every year. The legal limit imposed by the federal government in this country for an occupationally exposed worker is 5,000 mrem per year. If we look first at doses received in a short amount of time, (acute doses), the first biological effect begins to be able to be detected by laboratory analysis at 10,000 to 25,000 mrem. Actual immediate life threatening doses are limited to levels of 100,000 mrem and above. The life shortening doses may be lower than that, and are approximated by taking the data at higher doses where the effects are apparent and extrapolating the risk down to lower doses. Being conservative, the regulators use a model of a straight line from high doses down through the zero dose/zero risk point, so that any dose presents some small risk. Also you need to know that doses received over a longer period of time allows for repair of cells by the body, and presents less of a risk. See the Radiation and Risk page for more information. So to answer the question, the doses receive by the workers in nuclear power, an extra 100 to 5,000 mrem per year (average about 500 mrem), are seen by most scientific organizations as presenting a low risk compared to normal occupational hazards encountered during a working lifetime. Children, fetuses and embryos are more sensitive and have a longer expression time than adults, and so have smaller allowable doses. It is really a personal choice how much is too much. In some situations, such as to save someone's life, I personally would accept around 100 rem, but in the normal course of my work, I would rather keep my dose to less than 5 rem per year.
Too much radiation from the sun can permanently damage your skin and could cause skin cancer.
any amount, about how much you can withstand
If the radiation technician was not careful and used too much radiation it could happen but radiation machines are designed not to release too much radioactivity. Trust me no medical professional would want to use a lot of radiation because he would harm the patient and himself.
Too much ultra violet radiation. It does so by using the radiation to create more ozone and warming the upper atmosphere.
The ozone protects us from much UV radiation. It is present as ozone layer.
he glows. And then dies.
Their size. The smaller something is, the less ultraviolet radiation it can receive.
Yes, nuclear radiation can affect the lungs. The radiation can be cancerous and dangerous, so try not to breathe too much of it.
It has ozone
he will burn from the inside out
She was exposed to too much radiation so she blew up.