The 289 area code was created as an area code overlay for the Mississauga (Streetsville) area. Unlike the previous solutions, this process did not require the place to be geographically separated by different area codes.
Ionizing radiation is a term used for radiation whose quanta have energy to directly or indirectly ionize (one or more electrons are released from the atom of the given substance) molecules or atoms while passing through matter, hence the name ionizing radiation.
The effects of one type of radiation can be reproduced by any other type. A given total dose will cause more damage if received in a shorter time period. A fatal dose (600 R) causes a temperature rise of only 0.001 C, and ionization of 1 atom in 100 million.