AIR POLLUTION & ASTHMAP R E P A R E D B Y : J O R D A N T Y S O N

ASTHMA: WHAT IS IT?

A chronic respiratory disorder

Sensitive and inflamed airways Airways overreact to certain air pollutants Bronchial tube tightens less airflow to lungs Increased mucous production narrows airways Shortness of breath, chest tightness, coughing, wheezing

COMPARE AND CONTRAST

SIMPLE STATISTICS ON ASTHMA

Affects ~ 3 million people in USA ; increasing

Prevalence in urban areas > rural areas

Due to combination of genetic predisposition factors + environmental exposure to airway irritants

Air pollution: sulfur oxides, nitric oxides, ozone, particulate matter

NITRIC OXIDE

Atmospheric pollutant Cigarette smoke Vehicles

Dual effects in asthma pathology Quantity Type of enzyme Location of release

DUAL EFFECTS OF NO IN ASTHMA PATHOLOGY

OZONE

In the troposphere, sunlight reacts with:

• Ozone precursors (ie. NOx, such as NO2)

• Volatile organic compounds(VOC)s

Increased ozone production

NO2 + Sun UV NO + O O2 + O O3

PARTICULATE MATTER

Sources Industrial processes, wood combustion & fossil fuels, construction, wild fires, windblown dust, etc.

• Sulfur and nitrogen oxide

are contributors

Composition bioaerosol

components, metals,

organic molecules,

and elemental carbon

PARTICULATE MATTERIncreased PM increased emergency room visits and medication use by

asthmatics

Promotes sensitization leading to: Allergic inflammation & airway hyper-responsiveness

Samples with transition metals are the most capable of exacerbating asthma

Promotes ROS formation epithelial injury airflow limitations/asthma symptoms

Increased peroxidation products in lungs, blood, and urine of asthmatic subjects

SUMMARYPeople with asthma have very sensitive and inflamed airways, which tend to

overreact by constricting and/or overproduce mucous when certain substances in the air are inhaled

Symptoms: shortness of breath, chest tightness, coughing, and wheezing

Many asthma medications are iNOS inhibitors

Ozone production is elevated by the presence of ozone precursors and volatile organic compounds (VOCs)

Particulate matter (PM) sources anthropogenic (burning fossil fuels & wood) and natural (windblown dust and wild fires)

PM samples with high concentrations of transition metals are the most capable of exacerbating existing asthma and sensitization.

Transition metals lead to generation of ROS, which promote allergic reactions, inflammation, and tissue damage leading to an amplification of symptoms