Environmental Engineering Reference
In-Depth Information
air pollution levels are often still higher than in developed countries. The remainder
of this paper will focus on such studies, notably on studies conducted in Asia.
2.1. Health effects of indoor exposure to biomass and coal smoke
It has long been known that indoor exposure to biomass fuel combustion products
may be very high in developing countries. Recent reviews include (7). Early
reviews (8) drew attention to the fact that, at that time, more than half of the world
population was probably exposed to high levels of indoor pollution from biomass
burning, with severe consequences. The WHO Global Burden of Disease project
recently estimated that in the developing world, 1,619,000 young children die
every year from acute respiratory infections worsened by indoor biomass smoke
exposure (9). A review focused on acute respiratory infections in children
documents the high burden of illness and death from this disease alone in relation
to indoor biomass combustion product exposure in developing countries (10).
Measurements using state of the art technology have confirmed that indoor PM
levels can be extremely high in households using biomass for heating and cooking
fuel. Levels of many hundreds of μg/m
3
have been observed regularly, and such levels
are much higher than outdoor PM levels even in highly polluted megacities (11).
Quite recently, it has been shown that rural women living in south China have
higher indoor PM exposures than urban women, and have more chronic
obstructive pulmonary disease (COPD) as a consequence (12).
2.2. Health effects of urban and industrial pollution in Asia
We now come to studies which are more generally about health effects of urban
and industrial air pollution on urban populations. As mentioned, the Health Effects
Institute Public Health and Air Pollution in Asia program reviewed a large number
of pertinent studies from Asia. Most of these were conducted in China, India,
South Korea and Japan. Generally, studies from Asia have documented similar
adverse health effects of air pollution as studies conducted in Europe and North
America, despite large differences in pollution levels and demography. Some
recent examples will be discussed below.
Several early time series studies covering the 1989-1990 period in Beijing
documented increases in daily mortality and hospital admissions with increasing
SO
2
and PM levels (measured as TSP) which ranged up to 400 and 900 μg/m
3
,
respectively (13). A much more recent study from Shanghai, covering the March
2004-December 2005 period, found evidence of a relationship between daily
fluctuations in PM2.5 and all-cause, cardiovascular and respiratory mortality (14).
PM2.5 levels were 56 μg/m
3
on average, and ranged from 8 to 235 μg/m
3
. The
authors also investigated the effect of coarse particles with a size range between
2.5 and 10 μm and could not demonstrate any effect (14). This observation is in
line with a recent review on the topic of coarse PM effects (15). In China, a
respiratory health study was conducted in the three cities of Lanzhou, Wuhan and
Guangzhou with different air pollution levels. Respiratory health parameters of
