Miranda, J. The possible influence of volcanic emissions on atmospheric aerosols in the city of Colima, Mexico. Environmental Pollution, Moya, M. Characterization of size-differentiated inorganic composition of aerosols in Mexico City. Atmospheric Environment, 37 25 : Raga, G. Evidence for volcanic influence on Mexico City aerosols. Geophysical Research Letters, 26 8 : Rojas-Ramos, M. A seven months prospective study of the respiratory effects of exposure to ash from Popocatepetl volcano, Mexico.
Environmental Geochemistry and Health, Searl, A. Occupational and Environmental Medicine, 59 8 : Wakisaka, I.
Effects of volcanic activity on the mortality figures of respiratory disease. Japan Journal of Hygiene, 42 6 : WHO, Yano, E. Chronic pulmonary effects of volcanic ash: an epidemiological study. Archives of Environmental Health, 41 2 : Health effects of volcanic ash: a repeat study.
Archives of Environmental Health, 45 6 : Existing Guidelines Ambient and occupational guidelines exist for particulate matter. Since sulphate aerosol is consistently in the PM 2. The adverse impact of acid deposition downwind is also well recognised here Delmelle et al. Popocatepetl, Mexico: Particulate sulphate levels in Mexico City can be doubled by emissions from Popocatepetl Moya et al. PM 10 levels in the city already exceed the Mexican hour standard on most days of the year due to vehicular and fixed emission sources Moya et al.
Much of this was resuspended ash, meaning that personal exposure levels were considerably higher for certain activities, such as sweeping, when occupational exposures were frequently exceeded. The majority of the deposited tephra was PM10 and this was found to be responsible for increases in respiratory morbidity Bernstein et al. The groups most heavily exposed to resuspended ash following the eruption were emergency workers and police officers Baxter et al.
Pinatubo, Philippines: Ash is suspected to have been the cause of increased mortality due to respiratory infection in the area of Pinatubo in the months following its eruption Mason, References Allen, A.
For example, look at the two photos of Pittsburgh, Pennsylvania below. On the left, there are a lot of particles in the air, and on the right, there are a lot fewer particles. Can you see the difference? Figure 1. The effect of particulate matter on visibility in Pittsburgh, PA. On the left there are very high levels of particulate matter, which makes the sky look gray-ish and decreases the visibility.
On the right, the levels of particulate matter are much lower, which makes the sky look clearer. Figure 2. Metric Size and Scale. The objects in our world range greatly in size—this chart shows the sizes of common objects, shown in a logarithmic scale meaning that the scale is ordered by exponents of For example, 1 millimeter is 10 -3 meters, which is the same as of a meter.
In the top row, all of the objects are multiples of 7—the cell membrane is the smallest object, the Rubella virus is 10 times bigger, a red blood cell is times bigger, human hair is 10, times bigger, and an ant is 1,, times bigger. In the bottom row, most of the objects are multiples of 2. How many times bigger is a pinhead than PM 2. How much bigger is PM 2. Figure 3. Sources of Aerosol Particles in our Atmosphere. There are many sources of aerosol particles in our atmosphere—some are natural sources, such as mineral dust and sea spray.
Other sources such as urban smog and vehicle exhaust are caused by human activities. Figure 4. Sea Spray Aerosols. When waves break in the ocean, aerosol particles are formed. Image credit: Haim Weizman. Another natural source of particulate matter is sea spray from the ocean. Think about walking along the beach—does the crisp ocean breeze feel different from the wind when you are further inland? When you are near the ocean, you are probably feeling the sea spray—small droplets of water and other particles that are suspended in the air.
The ocean water contains salt and other organic compounds that are released by the algae, bacteria, and other life forms that live in the ocean. When waves break, droplets of sea water containing these salts and organic matter are entrained in the atmosphere.
The water in these small droplets can evaporate, which leaves a solid particle made up of the sea salt and organic compounds. Human sources of aerosol particles include smoke from fires, vehicle exhaust, and factories. When hydrocarbon fuels such as the gasoline in our cars are burned, what happens?
On a cold day, you may see smoke coming out of the exhaust pipe in your car, and maybe even some drops of water. When fuel is burned, it undergoes combustion. Combustion is a chemical reaction where the fuel reacts with oxygen O 2 in the air to break down into smaller compounds—the main products are carbon dioxide CO 2 and water H 2 O. A particulate which is more commonly referred to as particulate matter refers just to the suspended solid or liquid matter. Give four examples of particulate matter that arises from the following:.
Sulfates from oxidation of sulfur dioxide from volcanoes, sulfates from oxidation of biogenic reduced sulfur species primarily dimethylsulfide from phytoplankton , smoke from forest fires, organic compounds from oxidation of terpenes and related volatile organic compounds emitted from plants, sea-salt particles from sea-spray, dust from winds over arid regions.
Fly ash from burning coal, soot from diesel smoke, sulfates from burning coal or other sulfur containing fossil fuels, smoke from human set wildfires or fireplaces, carbonaceous aerosol from oxidation of anthropogenic volatile organic hydrocarbons. Describe Raleigh scattering by particulates. Raleigh scattering occurs when aerosol particles are considerably smaller than the wavelength of light. Raleigh scattering is most efficient for smaller wavelengths of light e.
The key difference between aerosol and particulate matter is that the term aerosol refers to a collection of suspended particles and the surrounding gases whereas the term particulate matter refers to the suspended solid or liquid matter in the air.
Both terms aerosol and particulate matter describe particles in the air. An aerosol is a collection of both particles and air while the particulate matter is only the particles suspended in the air. Overview and Key Difference 2. What is Aerosol 3. What is Particulate Matter 4. Aerosol is a suspension of solid particles or liquid droplets in air or another gas. Aerosols are either natural or man-made.
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