Table 4 also shows the results for these same models
when the data are limited to 1992 and 1993. This may
represent the “cleanest” data set because the estimated
PM10 data are more complete than the measured PM10
data, and the mortality data do not include the anomalies
that appeared in 1994 and 1995. The PM10 coefficients
for the three-day lag and the five-day moving average
for all four mortality end points are comparable or
somewhat stronger than those obtained with the full four
years of data using either measured or estimated PM10.
This is strong support for the conclusion that the problems
with the daily mortality data in 1994 and 1995 did
not result in a false finding of a statistically significant
PM10 effect on mortality.