Shortly after the discovery of X-rays and radioactivity in the late 19th century, it was realized that radiation could have harmful effects on humans. Partly due to ignorance and partly due to accidental circumstances, a series of injuries have been reported among radiologists and others exposed to excessive radiation, ranging from minor skin lesions to bone cancer and delayed leukemia.

It was not until the early 1920s, however, organized efforts were made to recommend and enforce safety measures for X-ray and radium manipulation.  You can also look for the services of medical imaging through various online sources.

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Nuclear Radiation Exposure:

The extent of injury in a particular body tissue produced by ionization radiation depends on the energy deposited by the radiation in that tissue. It also depends on how short a distance this energy is deposited. Thus an alpha particle with the same energy level as gamma-ray can cause much greater damage to tissue. All ionizing radiations have qualitatively similar biological effects and can be broadly classified as Internal and External radiation exposures.

It is worthwhile to note that exposure due to external radiation (e.g. Gamma rays) can be decreased by increasing the distance from the source or by means of suitable shielding. Internal exposure, due to ingestion or inhalation can be reduced by enhancing the biological elimination process thereby reducing the biological half-life.

within acceptable limits, nuclear radiation does not pose risk to the human.  However, any violation of the various exposure limits set by the International Radiological Protection Commission for public workers and professionals can adversely affect skin burns, cancer, or even sudden death.