The phrase "air pollution les" is not correct in written English.
It appears to be a truncated or incomplete phrase, and without additional context, it cannot be used meaningfully.
Example: "The recent studies on air pollution les have raised concerns about environmental health."
Alternatives: "air pollution levels" or "air pollution issues".
For acute mortality the LE loss per air pollution death can be obtained by dividing the LE loss of Eq.14 by ΔNdeaths, the number of acute deaths that are attributable to a pollution peak.
By formulating the analysis of air pollution mortality in terms of LE (life expectancy) rather than mortality risk, one obtains a unified framework for time series studies, intervention studies and cohort studies.
The APHEA studies have taken place in two stages, and the latest (APHEA2) comprised eight European cities in the investigation of associations of air pollution on daily cardiovascular admissions (Le Tertre et al. 2002).
Cohort studies [ 12- 14] measure a long term relative risk from which one can calculate [ 15- 18] the ultimate LE gain that can be achieved by a permanent reduction of air pollution; it is equal to the LE change at the end of a sufficiently long intervention study.
This also prevents the determination of the LE loss per air pollution death.
Since the usual calculation of LE loss due to air pollution is based on cohort studies such as the one of Pope et al. [ 2], we should comment on the relation with the method developed in the present report.
Eq.10 for the population-average LE change attributable to air pollution follows logically but it yields only a lower bound which increases with the length of the observation window, i.e. the number of lags included in the TS.
In view of the available information, it is plausible to assume that the LE change due to air pollution is proportional to the time integral of past concentrations weighted by exponential decay factors.
But because of the overlap of direct and displaced deaths the individual LE loss due to an air pollution death cannot be determined.
If all air pollution deaths occurred immediately after exposure, the corresponding LE loss could be determined by the observing the decrease in death rates after the initial peak due to a pollution peak.
