Transcript Asthma and our Environment

Asthma and our
Environment
Is there an environmental cause for
the increase in asthma cases in
children?
Annie Stephano
Asthma
Chronic inflammation of the bronchial airways
which causes the normal function of the airways to
become excessive and over-reactive, thus
producing increased mucus, mucosal swelling,
and muscle contraction.
American Lung Association
Symptoms
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Coughing
Wheezing
Chest tightness
Shortness of breath
Faster or noisy breathing
Low dissolved oxygen levels
Asthma is incurable, but the symptoms are
reversible and controllable.
Genetics of Asthma
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Susceptibility to develop asthma is genetic
Complex gene-environment interaction
Polygenic
Atopy- increased levels of immunoglobulin E after
exposure to common environmental allergens
• Person is 6 times more likely to develop asthma is a
parent has asthma
• 6 candidate asthma susceptibility genes:
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ADAM33
DPP10
PHF11
SETDB2
GPRA
SPINK5
TNF
Triggers
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Allergens
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Irritants
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Animal dander (skin, hair, feathers)
Dust mites
Cockroaches
Pollen
Mold
Cigarette smoke
Air pollution
Chemicals
Dust
Changes in weather (cold air)
Strong odors (i.e. from paint or cooking)
Scented products
Stress
Others
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Medicines (aspirin)
Sulfites in food or beverages
Gastroesophageal Reflux Disease (GERD)
Infections
Asthma
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Affects 17.3 million Americans (~ 6.4%)
6.5 million are under 18 years old
2.7 million are under 5 years of age
Most common chronic disease in children in the
U.S.
• Prevalence rates as high as 24% in some
urban areas
Asthma
• More common in boys than girls for children
under 18 years of age
• Prevalence rate has increased 70% from
1982 to 1994
• Number of children with asthma has doubled
since 1980
• Racial disparity with asthma
– White 8%
– Puerto Rican 19%
– Black 13%
• Death rate of asthma has fallen 1 million to
2.5 million deaths per year since 1999
Morbidity and Mortality Weekly Report
There is an environmental
cause for the increase in
childhood asthma cases.
Air pollution
• Studies conducted around the world have found a linear
relationship between pollution levels and asthma cases
– Mexico City, Czech Republic, Washington D.C.
• Air pollution has adverse effects on lung development
from 10 to 18 years of age, leading to underdeveloped
lungs
• Children have smaller airways and an increased need
for O2 relative to their body size (more pollutant inhaled
per pound of body weight)
Air pollution
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Ozone
Particulate matter (PM2.5, PM10)
CO
Diesel exhaust particles (DEPs)
VOCs
NO2
SO2
Climate Change
• Increasing atmospheric CO2
and global climate change has
begun to exhibit adverse
effects on plant growth and
maturation
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Faster plant growth
Earlier plant maturity
Longer growing seasons
Earlier pollen seasons and
increased season duration
– Increase in pollen quantity
There is NOT an
environmental cause for
the increase in childhood
asthma cases.
Allergens: Primary Cause of
Asthma
• More than 50% of current asthma
cases in U.S are due to allergies
– Cat allergies (30%)
– Fungus, Alternaria (20%)
– White Oak (20%)
– Other (30%)
Other factors
• Use of antibiotics,
anti-bacterials
prevents immune
essential
interactions
• Better diagnosis