Environmental Engineering Reference
In-Depth Information
parents and children were measured, and significant and strong effects of air
pollution, by district, were found on prevalence rates of cough, phlegm, persistent
cough and phlegm, and wheeze for both the mothers and the fathers. In addition,
the odds ratios increased as ambient total suspended particle concentration increased
across the three urban districts (16). There was also a positive and significant
association between total suspended particle levels and the adjusted odds ratios for
cough, phlegm, hospitalization for diseases, and pneumonia in children. Further-
more, parental smoking status was associated with cough and phlegm, and use of
coal in the home was associated only with cough prevalence (17). A study from
Beijing found significant associations between SO
4
2
−
concentration and total
mortality and mortality due to cardiovascular disease, malignant tumour and lung
cancer (r > 0.50 in all cases) (18). The correlations were found not only between
the current SO
4
2
−
concentration and these mortalities, but also for SO
4
2
−
levels
measured up to 12 years prior to death, suggesting long-term effects of air
pollution. No significant associations were observed for mortality from respiratory
diseases and cerebrovascular diseases (r = 0.30-0.50). This study indicates that the
concentration of SO
4
2
−
in air is a useful air pollution indicator in areas where coal
is used as the main source of energy. Areas with high levels of SO
4
2
−
experienced
higher mortality owing to a variety of chronic diseases.
The HEI PAPA project has now produced its first published papers (19-22). In
the cities of Hong Kong, Wuhan, Shanghai (all China) and Bangkok, Thailand,
PM10, SO
2
, NO
2
and Ozone were all found to be associated with day-to-day
variations in mortality, with effect estimates being equal to or larger than those
reported from North America and Europe (22). In most analyses, there was little
indication of a threshold concentration below which no effects on mortality were
seen. Effects were larger in economically more deprived cities (Wuhan and Bangkok)
which was attributed to populations being less able to protect themselves from
high exposures. In Wuhan, there was also a clear interaction between pollution
and temperature, pollution effects being higher on high temperature days (19).
Within the Hong Kong population, effects were also shown to be larger for
populations living in economically more deprived areas (21).
3. Concluding Remarks
Air pollution has negative effects on the health of populations worldwide. New
studies from Asia suggest that short-term variations in PM and several gaseous
pollutants are associated with short-term variations in mortality, with effect
estimates being as high as or higher than those reported from North America or
Europe. Studies on effects of long-term exposure to air pollution are still scarce in
Asia, and conducting such studies is a priority and a challenge for the near future.
A large fraction of the world population lives in China, India and other rapidly
developing economies in Asia with associated large increases in energy production
and consumption. Air pollution emissions are high, producing widespread
