Air Pollution Ozone
1. What is Ozone (O3)
The source document for this Digest states:
Ozone is the most important
photochemical oxidant in
the troposphere. It is
photochemical reactions in
the presence of precursor
pollutants such as
volatile organic compounds.
In the vicinity of strong
emission sources, where there is an abundance of
is “scavenged” and as a result its
concentrations are often low
in busy urban centres and higher in suburban and adjacent rural
areas. On the other hand,
is also subject to long-range atmospheric transport and is
therefore considered as a trans-boundary problem.
As a result of its
displays strong seasonal and diurnal patterns, with higher
concentrations in summer and
in the afternoon. The correlation of
with other pollutants varies by season and location.
There is evidence from controlled human and animal
exposure studies of the
adverse health effects.
Epidemiological studies have also addressed the effects of short
and long-term exposures to
and provided important results. However, the health effects of
have been less studied than those of
PM and thus more research
is needed, especially addressing the spatial and seasonal
patterns and misclassification of individual exposure in
association with health outcomes.
Source & ©: WHO Regional Office for Europe
"Health Aspects of Air Pollution" (2003), Chapter 6 Ozone (O3), Section 6.1 Introduction
The same information on