COPD and asthma are chronic lung diseases that result in impaired air flow in the lungs, often causing coughing, wheezing, and shortness of breath. In uncontrolled COPD and asthma, people may experience a rapid worsening of symptoms, which may include fever, difficulty breathing, and chest pain. These exacerbations are the most serious expression of asthma and COPD and are usually caused by lung infections or air allergens. However, the biological basis for susceptibility to airway infection and inflammation is not well understood. Increased oxidative stress within the airways has been linked to several airway diseases. This increase in oxidative stress may reduce production of key fatty acid anti-inflammatory mediators. In turn, this may disrupt the airway's natural immune response mechanisms, making the airways more vulnerable to infection or inflammation during COPD and asthma exacerbations. This ancillary study will determine whether susceptibility to persistent airway infection in asthma and COPD stems from increased oxidative stress that impairs the natural formation of protective fatty acid mediators.