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Photochemical air quality models have become widely utilized tools for assessing the effectiveness of control strategies adopted by regulatory agencies. These models are large-scale air quality models that simulate the changes of pollutant concentrations in the atmosphere by characterizing the chemical and physical processes in the atmosphere.
Air pollution can cause diseases, allergies, and even death; it can also cause harm to animals and crops and damage the natural environment (for example, climate change, ozone depletion or habitat degradation) or built environment (for example, acid rain). [3] Air pollution can occur naturally or be caused by human activities. [4]
A great many computer programs for calculating the dispersion of air pollutant emissions were developed during that period of time and they were called "air dispersion models". The basis for most of those models was the Complete Equation For Gaussian Dispersion Modeling Of Continuous, Buoyant Air Pollution Plumes shown below: [4] [5]
There are five types of air pollution dispersion models, as well as some hybrids of the five types: [1] Box model – The box model is the simplest of the model types. [2] It assumes the airshed (i.e., a given volume of atmospheric air in a geographical region) is in the shape of a box.
Air pollution measurement is the process of collecting and measuring the components of air pollution, notably gases and particulates. The earliest devices used to measure pollution include rain gauges (in studies of acid rain ), Ringelmann charts for measuring smoke , and simple soot and dust collectors known as deposit gauges . [ 1 ]
Looking down from the Hollywood Hills, with Griffith Observatory on the hill in the foreground, air pollution is visible in downtown Los Angeles on a late afternoon.. Air pollution is the introduction of chemicals, particulate matter, or biological materials into the atmosphere that cause harm or discomfort to humans or other living organisms, or damage ecosystems.
For example, such a regulation might limit the concentration of NOx to 55 ppmv in a dry combustion exhaust gas corrected to 3 volume percent O 2. As another example, a regulation might limit the concentration of particulate matter to 0.1 grain per standard cubic foot (i.e., scf) of dry exhaust gas corrected to 12 volume percent CO 2.
Air pollution can affect nearly every organ and system of the body, negatively affecting nature and humans alike. Air pollution is a particularly big problem in emerging and developing countries, where global environmental standards often cannot be met. The data in this list refers only to outdoor air quality and not indoor air quality, which ...