Mortality related to cold and air pollution in London after allowance for effects of associated weather patterns.
We looked for atypical weather patterns that could confound, and explain large inconsistencies in, conventional estimates of mortality due to SO(2), CO, and smoke. Using Greater London data for 1976-1995 in the linear temperature/mortality range 0-15 degrees C we determined weather patterns associated with pollutants (all deseasonalized) by single regressions of daily temperature, wind, rain, humidity, and sunshine at successive days advance and delay. Polluted days were colder (P<0.01 for SO(2), CO, and smoke) and less windy and rainy than usual, and this cold weather was more prolonged than usual with 50% maximum temperature depression 5.9 days (95% interval 4.0-7.7) before high SO(2), compared to 2.0 (1.6-2.3) days before average cold days. We also used multiple regression of mortality at 50+ years of age on all these weather factors and pollutants at 0-, 1-, 2- to 4-, 5- to 13-, and 14- to 24-day delays to allow for the atypical weather patterns. This showed cold weather associated with 2.77 excess deaths per million during 24 days following a 1 degrees C fall for 1 day, but no net excess deaths with SO(2) (mean 28.0 ppb) or CO (1.26 ppm). It suggested (P>0.05) some increase with smoke, perhaps acting as surrogate for PM(10), for which data were too scanty to analyze.
Keatinge
W R
WR
Biomedical Sciences, St. Bartholomew's and the Royal London School of Medicine and Dentistry, Queen Mary and Westfield College, Mile End Road, London, E1 4NS, United Kingdom.
Donaldson
G C
GC
D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000397:Air Pollution / Q000009:adverse effects* / Q000032:analysis; D002248:Carbon Monoxide / Q000009:adverse effects / Q000032:analysis; D003081:Cold Climate / Q000009:adverse effects*; D006801:Humans; D008131:London; D008875:Middle Aged; D009026:Mortality / Q000639:trends*; D012044:Regression Analysis; D012906:Smoke / Q000009:adverse effects / Q000032:analysis; D013458:Sulfur Dioxide / Q000009:adverse effects / Q000032:analysis; D013696:Temperature; D013997:Time Factors; D014887:Weather
D012906:Smoke; D013458:Sulfur Dioxide; D002248:Carbon Monoxide