COLD RELATED MORTALITIES AND PROTECTION AGAINST COLD IN YAKUTSK, EASTERN SIBERIA - OBSERVATION AND INTERVIEW STUDY

Objective To assess how effectively measures adopted in extreme cold i n Yakutsk control winter mortality. Design interviews to assess outdoo r clothing and measure indoor temperatures; regressions of these and o f delayed cause-specific mortalities on temperature.Setting Yakutsk, e ast Siberia, Russia Subjects: AU people aged 50-59 and 65-74 years liv ing within 400 km of Yakutsk during 1989-95 and sample of 1002 men and women who agreed to be interviewed.Main outcome measures Daily mortal ity from all causes and from ischaemic heart, cerebrovascular, and res piratory disease. Results Mean temperature for October-March 1989-95 w as - 26.6 degrees C. At 10.2 degrees C people wore 3.30 (95% confidenc e interval 3.08 to 3.53) layers ofclothing outdoors, increasing to 4.3 9 (4.13 to 4.66; P < 0.0001) layers at - 20 degrees C. Thick coats, of ten of fur, replaced anoraks as temperature fell to - 48.2 degrees C, 82% of people went out each day when temperatures were 10.2 degrees C to - 20 degrees C, but below - 20 degrees C the proportion fell steadi ly to 44% (35% to 53%) at -48.2 degrees C (P < 0.001), and overall shi vering outdoors did not increase. Living room temperature was 17.9 (17 .2 to 18.5)degrees C at 10.2 degrees C outdoors, 19.6 (18.8 to 20.4)de grees C at - 20 degrees C, and 19.1 (18.6 to 19.6)degrees C at -48.2 d egrees C. Mortality from all causes and from ischaemic heart and respi ratory disease was unaffected by the fall in temperature. Mortality fr om respiratory disease (daily deaths per million) rose from 4.7 (4.3 t o 5.1) to 5.1 (4.4 to 5.7) (P = 0.03), but this was offset by a fall i n deaths from injury Conclusions People in Yakutsk wore very warm clot hing, and in extremely cold weather stayed indoors in warm housing pre venting the increases in mortality seen in winter in milder regions of the world. Only respiratory mortality rose, perhaps because of breath ing cold air.