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 • 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 • 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: • ADAM33 • DPP10 • PHF11 • SETDB2 • GPRA • SPINK5 • TNF
Triggers • Allergens • Animal dander (skin, hair, feathers) • Dust mites • Cockroaches • Pollen • Mold • Irritants • Cigarette smoke • Air pollution • Chemicals • Dust • Changes in weather (cold air) • Strong odors (i.e. from paint or cooking) • Scented products • Stress • Others • Medicines (aspirin) • Sulfites in food or beverages • Gastroesophageal Reflux Disease (GERD) • Infections
Asthma • 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
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 • 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 • 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