Source:
Scotsman/UK
June 22, 2004]
GLOBAL warming could lead to more people in
Britain suffering the misery of asthma,
new research suggests today.
A major study of almost 670,000 children has found
a clear link between indoor humidity and asthma rates in Western Europe.
Every 10 per cent increase in indoor humidity was
associated with a 2.7% increase in the prevalence of asthma symptoms,
the researchers found.
House dust mites, which trigger asthma attacks,
thrive in moist air, and humidity encourages mould which can irritate
the airways.
The study also found that places where average
outdoor humidity dropped below 50 per cent for at least one month a year
had lower rates of asthma. Warmer
temperatures caused by climate change are expected to drive up humidity
levels, especially in cities.
Experts believe summers in the city will get
stickier because of the "urban heat island" effect caused by asphalt and
concrete trapping heat at night.
The impact of climate change was acknowledged by
the authors of the asthma study, led by
Dr Stephen Weiland from the University of Ulm in Germany.
Writing in the journal Occupational and
Environmental Medicine, they said the evidence showed that climate can
affect rates of asthma and
eczema in children. The researchers
added: "This may also have implications for the assessment of potential
health effects due to climate change."
The scientists found that temperature, altitude,
humidity and latitude all influenced the prevalence of
asthma and eczema.
Information was collected between 1992 and 1996 from children aged six
to seven, and 12 to 13, from more than 50 countries.
The research formed part of a major worldwide
investigation, called the International Study of Asthma and Allergies in
Childhood (ISAAC).
When the data was analyzed, it showed the strong
link between indoor humidity and asthma
rates for both age groups. The trend emerged in Western Europe, where
the study focused on 57 centers in 12 countries.
Increasing latitude was associated with higher
rates of eczema, and higher outdoor
temperatures with lower rates.
An association has been seen before between
thunderstorms and higher numbers of hospital admissions due to
asthma, but little is known about the
effect of long-term climatic conditions on the disease.
Londoners can expect many more sweaty nights in
years to come, as a result of rising levels of greenhouse gas in the
atmosphere, New Scientist magazine reported last week.
In the past 30 years, there have been only 20
nights when the minimum temperature in London failed to fall below 20°
C. Doubling carbon-dioxide levels could quadruple that figure, but
adding the urban heat island effect could see it soar by a factor of six
- an extra three nights a year at least.
Richard Betts, from the Met Office’s Hadley Centre
for Climate Prediction in Exeter, said: "This could have quite
significant effects on human health."
Last year’s heat wave in Europe is estimated to
have caused at least 20,000 deaths.
Children who live in households where gas is
frequently used to cook meals are more likely to suffer from respiratory
illnesses than other youngsters, research claimed today.
A study of more than 400 children under the age of
six found that 26 per cent had one or more respiratory conditions, such
as allergic rhinitis, asthma or
bronchitis.
The researchers suggested that frequent use of gas
cooking produced higher levels of nitrous oxide and other fumes that
could build up in poorly ventilated kitchens.
The study, published in Archives of Disease in
Childhood, focused on 426 children living in two housing estates in Hong
Kong, one in an area of high environmental pollution.
The research found little link between passive
smoking in the home and respiratory illnesses. This might be explained
by parents avoiding smoking in the presence of their children.