“The most basic link we have in common is that we all live on this small planet. We all breathe the same air, we all value our children’s future, and we are all mortal” (John Fitzgerald Kennedy).
How does pollution affect respiratory health?
Outdoor air contains a range of naturally occurring pollutants, including soil, dust, pollens and fungi. In addition, human activity generates complex mixtures of pollutants. Sources of air pollution are either stationary or mobile. Stationary sources are usually energy or manufacturing companies and are responsible for emissions of sulfur dioxide (SO2), as well as considerable amounts of nitrogen oxide (NOx) and other particulate matter. In contrast to pollution from stationary sources, airborne smog derives from emissions from automotive or mobile sources. Ozone (O3) is a product of complex photochemical reactions involving nitrogen oxide and volatile organic compounds (VOCs) emitted from automobile exhaust. Nitric acid (HNO3) is a more important contributor to atmospheric acidity than sulfuric acid (H2SO4) and is formed in the atmosphere from the reaction of nitrogen oxide (NOx) with the hydroxyl radical (OH-). Emissions from motor vehicles are also responsible for much of the carbon monoxide (CO) and particulate pollutants.
Ambient air pollutants are monitored at central stations, but the regional average measured at such stations may not adequately characterize personal exposures.
There is also a misconception that indoor air is uniformly cleaner than outdoor air, but NO2 concentrations, for example, can be quite a bit higher in indoor air as a result of gas stoves.
The site of deposition of pollutants in inhaled air, whether gases or aerosols, is largely determined by their solubility in water. Therefore, water-soluble gases induce toxic effects in the proximal airways and only damage the distal airways when inhaled in large concentrations. In contrast, gases that have relatively low water solubility, such as NO2 and O3 (ozone), can predominantly damage the distal lung. The less soluble the gas, the greater the potential to cause damage at the level of the terminal respiratory unit.
Most inhaled particles with an aerodynamic mean mass diameter of more than 10 microns are deposited in the nasopharynx and do not penetrate below the larynx. Particles of 2.5 to 6 microns are deposited primarily in the conduction airways below the larynx, and particles between 0.5 and 2.5 microns are deposited in the distal airways and alveoli.
Ozone (O3) is an environmental pollutant, almost always together with other pollutants such as dioxide (NO2), can irritate and inflame the bronchi and thus can contribute to aggravate asthma patients. Sulfur dioxide (SO2) can also cause bronchitis and bronchoconstriction.
Ambient particulate matter, a complex mixture of different sizes, can affect respiratory and cardiovascular health by increasing morbidity and mortality.
Interpretation of the action of these particles is complicated by the difficulty of separating the various ambient particles and the possible synergistic interactions of other ambient air components. Exposure to carbon monoxide (CO) levels in ambient air can exacerbate ischemic heart disease, and increase cardiorespiratory morbidity and cardiac mortality.
Who is most susceptible to these effects?
People with chronic lung disease, such as asthma and chronic obstructive pulmonary disease (COPD), and heart disease are most susceptible to the effects of air pollution.
How can these types of diseases be prevented and how should care be provided in these cases?
Actually, environmental pollution is more of an aggravating factor than a cause of respiratory diseases. Only continuous and prolonged exposure could cause them, such as exposure to fumes from indoor cooking stoves.
The only way to prevent the aggravation of the above chronic lung diseases is to reduce environmental pollution. The care of patients with exacerbations of chronic respiratory diseases is the same as when exacerbations are due to other causes.