Ọkụ ekwentị a esighị ike ka "ionising radiation" a - nke bụ 'X ray', "ultraviolet" na "gamma radiation", nke nwere ike ịmerụ anyị ahụ na mkpụrụndụ site n'ịgbanwe DNA anyị - mana amatabeghị mkpamkpa ọ na-akpa n'ahụ mmadụ. 
Oku ekwenti a esighi ike ka "ionising radiation" a - nke bu 'X ray', "ultraviolet" na "gamma radiation", nke nwere ike imeru anyi ahu na mkpurundu site n'igbanwe DNA anyi - mana amatabeghi mkpamkpa o na-akpa n'ahu mmadu. 