Dee ihe ndị ọzọ dị na paragraf a - Nsogbu ihi ụra na nsogbu ihi ụra zuru ebe nile, ha pụkwara ịkpata nnukwu nsogbu nye ndị ọ na-emetụta nakwa nsogbu akụ̀ na ụba na nsogbu ndị ọzọ na-akpata n'etiti ọha mmadụ. US National Transportation Safety Board, dị ka Dr. Charles Czeisler, onye so na Institute of Medicine na Director nke Harvard University Medical School Division of Sleep Medicine na Brigham na Women's Hospital si kwuo, chọpụtara na isi ihe kpatara (31%) nke ihe ọghọm ụgbọ ala dị arọ na-egbu onye ọkwọ ụgbọala bụ ike ọgwụgwụ metụtara (ọ bụ ezie na ọ na-adịkarịghị ejikọta ya na nsogbu ụra, dị ka ụra apnea), na ọgwụ ọjọọ na mmanya na-aba n'anya dị ka ọnụọgụ abụọ (29%). Ihi ụra nke ọma so n'ihe ndị na-akpata nnukwu ihe ọghọm, dị ka mmanụ a wụfuru n'ụgbọ mmiri Exxon Valdez
, ihe ọghọm nuklia na Chernobyl na Three Mile Island na mgbawa nke ụgbọ elu mbara igwe "Challenger".