Asthma is a chronic (i.e., long-term) inflammatory disease of the lungs. People with asthma have airways that are sensitive and react to what are known as asthma triggers, which are objects, acts, or events that cause the airways to become inflamed (UDOH, 2014b). Examples of triggers are tobacco smoke, dust, pets, and air pollution. These triggers cause wheezing, breathlessness, chest tightness, and coughing, usually at night or early in the morning (CDC, 2014).
Understanding asthma involves some knowledge of how the airways work. Airways are tubes that carry air into and out of the lungs. During an asthma episode, or attack, they are swollen and very sensitive. The muscles around the airways tighten, narrowing the passages and restricting the flow of air to the lungs. Cells in the airways may also produce large amounts of mucus, further shrinking the airways (Figure 1). This causes wheezing, breathlessness, chest tightness, and coughing (NHLBI, 2012a).
Figure 1: Normal airways and during an asthma attack
Asthma is one of the most common diseases in children. In the U.S., more than 25 million people are known to have asthma, 7 million of whom are children (NHLBI, 2012a). Asthma can be controlled by knowing the warning signs of an attack, staying away from triggers that can cause an attack, and following advice from your physician. When asthma is controlled, an individual (CDC, 2014):
- Won’t have symptoms such as wheezing or coughing
- Will sleep better
- Won’t miss work or school
- Can take part in physical activities
- Won’t have to go to the hospital.
To learn more about asthma in Utah, visit the Utah Department of Health Asthma Program.
Asthma and Air Pollution
Outdoor air pollution can be a trigger for an asthma attack. Air pollution can come from factories, cars, and other sources (CDC, 2014). High levels of air pollution directly affect individuals with asthma, COPD, and other lung and heart conditions. Both particulate matter and ozone can cause damage to lung tissue and aggravate the symptoms of existing respiratory diseases like asthma (UDOH, 2014b). Keeping track of the air quality through use of the air quality index will help individuals with respiratory diseases plan or modify their activities and exertion levels accordingly.
Chronic Obstructive Pulmonary Disease | Top
Chronic obstructive pulmonary disease, or COPD, refers to a group of lung diseases that cause airflow blockage and difficulty breathing. COPD includes two main conditions: emphysema and chronic bronchitis (CDC, 2013c). Most people who have COPD have both emphysema and chronic bronchitis. COPD can cause coughing that produces large quantities of mucus, wheezing, shortness of breath, and tightness of the chest, among other symptoms (NHLBI, 2013b). To understand COPD, it helps to understand how the lungs work. When you breathe, oxygen enters the bloodstream through small air sacs (called alveoli) at the end of the airways in the lungs. At the same time, waste gasses like carbon dioxide leaves the blood and is exhaled. Normally, the air sacs are elastic (or stretchy), and inflate and deflate like balloons during breathing. In COPD, less air flows through the airways due to one or more of the following (Figure 2) (NHLBI, 2013b):
- The airways and air sacs lose some of their elasticity.
- The walls between many of the air sacs are destroyed.
- The walls of the airways become thick and inflamed.
- The airways make more mucus than usual, which can clog them.
Figure 2: Normal lungs and lungs with COPD
In emphysema, the walls between many of the air sacs are damaged, causing them to lose shape and become floppy. The walls of the air sacs can also be destroyed, leading to fewer, larger sacs that reduces the amount of air that is exchanged (NHLBI, 2013b).
In chronic bronchitis, the lining of the airways is constantly inflamed and irritated, causing it to thicken. Large quantities of thick mucus also form in the airways, making it hard to breathe (NHLBI, 2013b).
COPD develops slowly and is a progressive disease, meaning that the symptoms typically worsen over time. COPD has no cure, and can limit the ability to perform routine activities. In severe cases, COPD may prevent even basic activities like walking and cooking. Most often diagnosed in middle-aged and older adults, COPD is a major cause of disability and the third leading cause of death in the U.S (NHLBI, 2013b). Fifteen million Americans report that they have been diagnosed with COPD, and the true number with COPD may be even higher (CDC, 2013c).
COPD and Air Pollution
While smoking is the primary cause of COPD, air pollution can play a substantial role in both causing the disease and in worsening the symptoms (EPA, 2013l). Air pollutants, such as particulate matter and ozone, irritate the lungs, and people with respiratory diseases like COPD are particularly sensitive to air pollution. It is important for people with COPD to monitor air quality in their area and modify their activities and level of exertion as needed (EPA, 2013l).
Respiratory Disease Trends in Utah | Top
The International Classification of Diseases (ICD), maintained by the World Health Organization, is the international standard diagnostic tool for epidemiology, health management, and clinical purposes and provides a system of diagnostic codes for classifying diseases. For diagnostic and analytical purposes, asthma, COPD, and a disease called hypersensitivity pneumonitis are combined into a category called Chronic Obstructive Pulmonary Disease and Allied Conditions. Hypersensitivity pneumonitis is an inflammation of the air sacs in the lungs caused by an allergic reaction to certain inhaled dusts that contains fungal spores (ALA, 2014).
Utah has experienced a slow but steady increase in the rate of emergency department (a.k.a. emergency room) visits due to COPD, asthma, and hypersensitivity pneumonitis over the past decade. Figure 3 shows the monthly age-adjusted rate of emergency department visits due to these respiratory diseases in Utah from 2000 to 2011. The rate ranges between 3 and 14 people per 100,000 Utahns. In other words, in a Utah population of 100,000 people, between 3 and 14 of those people will be admitted to an emergency department for asthma, COPD, or hypersensitivity pneumonitis during a given month. Emergency department rates for these respiratory diseases show clear seasonal variation, and are highest during the winter months of December, January, and February.
The rate of hospital admissions due to asthma, COPD, or hypersensitivity pneumonitis has remained fairly steady over the past decade. Figure 4 presents the monthly age-adjusted rate of people admitted to the hospital because of these respiratory diseases in Utah from 2000 to 2011. These rates range from a low of about 4 people per 100,000 per month in 2007 to a high of 15 per 100,000 per month in 2004. This rate displays the same seasonal variation as the rate of emergency department visits and peaks during winter months, mainly December and January.
The rate of death due to asthma, COPD, or hypersensitivity pneumonitis in Utah has also remained steady in recent years. Figure 5 shows the monthly age-adjusted rate of death due to these respiratory diseases for in Utah from 2000 to 2011. Though the death rate ranges from 1 to 4 per 100,000 per month, overall it shows little of the seasonal variation apparent in the rates of emergency department and hospital visits.
Data and Indicators | Top
The Utah Environmental Public Health Tracking Program (EPHT) has created a number of indicators exploring data on asthma in Utah. An indicator is a fact or trend that indicates the level or condition of something. Well known indicators include gross national product, unemployment rates, and presidential approval ratings. In a public health context, indicators show trends like cancer rates, drinking water contamination levels, and blood lead levels in children. Visit the EPHT frequently asked questions page for more information.
- Asthma Prevalence in Children
- Asthma Prevalence in Adults
- Asthma-Related Emergency Department Visits
- Asthma-Related Hospitalizations