Particulate air pollution
Particulate pollution (also known as particulates or fine particles) is the name given to microscopically small quantities of solid or liquid that are carried by a gas or another liquid. For instance, the smokestack of a coal plant ejects coal smoke into the air. Water vapor droplets in the clouds can pick up these smoke particles and drop them later in the form of acid rain.
How is particulate air pollution measured?
Due to the different sizes, shapes and chemical compositions of these microscopic particulate air pollution agents, the task of measuring the potential damage that they can do is often an arduous undertaking. Most agencies involved in pollution research and prevention classify these particles by size: fine particles are less than 2.5 microns (10^-6 m) across and inhalable coarse particles are between 2.5 and 10 microns across. To put these measurements into perspective, a human hair is usually between 70 and 100 microns thick; a red blood cell is about 7 microns across.
What are some other sources of particulate air pollution?
According to a study carried out by the US Environmental Protection Agency (EPA), one of the leading sources of fine particulate air pollution is also the oldest: fires. During 2002, EPA estimates put the quantity of fine particulate air pollution originating from fires at well over one million tons. Since man first learned to create a spark and build fires for light, warmth, and comfort, he has also sent untold tons of untreated, unfiltered smoke into the air. While the concern over particulate air pollution may be a recent occurrence, the sources and the issue itself are both as old as civilization, whether the source is a small campfire or a raging forest blaze.
According to the same study, road dust generated over eight hundred thousand tons of fine particulate air pollution, followed by electricity generation at five hundred thousand. Surprisingly, fossil fuel use (coal, oil, kerosene, gasoline) and automobile usage combined for less than four hundred thousand tons, less than a third of the total for fires.
Of course, air pollution is not limited to outdoor sources. Indoor air pollution can also be a major source of particulate air pollution. Dust, sheet rock particles, cigarette smoke and dirty ventilation systems can create fine particles that can contribute to an increase in indoor particulate air pollution.
What are some effects of exposure to particulate air pollution?
The results of several studies produced by the United Nations World Health Organization (WHO) reveal “(l)ong-term exposure to current ambient (particulate air pollution levels) may lead to a marked reduction in life expectancy. The reduction in life expectancy is primarily due to increased cardio-pulmonary and lung cancer mortality.”
Exposure to fine particulate air pollution sources is considered especially hazardous. These fine particles can accumulate in the lungs and hamper breathing functions. The small sacs inside the lungs (called “alveoli”) that are responsible for the exchange of oxygen and carbon dioxide can become damaged from lengthy exposure to fine particles. Such exposures can result in chronic obstructive pulmonary disease (COPD) and other respiratory diseases. Fine particulate air pollution can also aggravate existing conditions such as asthma, bronchitis and heart disease.
Since most fine particles are smaller than red blood cells, fine particulate air pollution can also damage these healthy cells. These particles can attack normal red blood cells, which can lead to fatigue, high blood pressure and poor circulation. In more serious cases, long-term exposure can result in the formation of blood clots, which can form into the causes of strokes and deep vein thrombosis (DVT).
What can be done to prevent particulate air pollution and its effects?
Many agencies, both government-run and privately owned, are taking steps to curb the problem of particulate air pollution. The US EPA has imposed limits on the quantity of particulates that facilities can emit: 150 micrograms per cubic meter of air day for inhaled coarse materials and 35 micrograms per cubic meter of air per day for fine particulates.
Individuals can also contribute to both the reduction of particulates in the air and the effects that exposure to these agents can have on their health. Standard energy conservation and fire safety measures can help stem the rising tide of particulate air pollution. Also, people with respiratory problems such as asthma or COPD should not engage in strenuous outdoor activities on days where the local forecast details potential issues with air quality.