Air pollution is defined as the presence in the atmosphere of polluting elements that alter its composition and affect any component of the ecosystem. From an anthropocentric point of view, air pollution refers to pollutants that affect human health or well-being. Depending on their origin, pollutants are classified as anthropogenic, derived from human activity, or natural, resulting from natural processes, for example volcanic eruptions or suspended pollen. Depending on their physical state, they are gases such as sulfur oxides (SOx), nitrogen oxides (NOx), carbon monoxide (CO), hydrocarbons and ozone (O3) or particles such as dust and aerosols.
They are considered primary when they are present as they were emitted and secondary, when they are formed from the primary ones by a chemical reaction such as O3 and sulfuric and nitric acids. Depending on their size, the particles are deposited near or at some distance from the emission source. If they are very small, they can be suspended and transported great distances.
Within the suspended particles, those with a diameter less than or equal to 10 µm (PM10) are called "respirable" due to their ability to enter the respiratory tract. The smaller the particles, the greater their ability to penetrate the respiratory tree. Fine particles whose aerodynamic diameter is ≤ 2.5 µm easily reach the terminal bronchioles and alveoli, from where they can be engulfed by alveolar macrophages and cross the alveolar-capillary barrier to be transported to other organs by the bloodstream.
The particles may contain organic compounds such as polycyclic aromatic hydrocarbons and/or inorganics such as salts and metals. "Air quality standards" have been established, which is the level of air pollutants above which undesirable effects are expected to occur.
It is possible, with the help of mathematical models, to calculate the range of a toxic cloud coming from, for example, an industrial chimney. This type of study requires the participation of specialized professionals capable of determining the risk of both the probability of occurrence of the phenomenon and the severity of the disease that could occur in the recipient of this environmental toxin.
ANALYSIS METHODS
EPA (Environmental Protection Agency)
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