Clean air is essential to good health. Unfortunately foreign matter commonly called pollutants or contaminants are adding a whole host of ingredients, which alone and in concert, give rise to a variety of serious health risks.
Everyday we typically inhale the equivalent of two heaping tablespoons of airborne particles that our bodies must process and eliminate. The smallest of these particles can be inhaled and end up settling deep inside the lungs in areas where the body's natural mechanisms can't remove them and this in turn can cause the greatest harm.
Inhaling particles also appears to disrupt the body's ability to regulate the pumping of blood. As particulate counts rise on any given day, a critical indicator called heart rate variability can decrease and upset the hearts beat-to-beat variations. It has been estimated that annually in the United States approximately 64,000 people die prematurely from heart and lung disease due to particulate air pollution.
The issue of gases and air pollution is a wide-ranging and very complex subject. There are thousands of chemicals and chemical compounds that can contaminate the air we breathe. Examples of gasses we are most familiar with are ozone, carbon monoxide, benzene and radon.
When we take a breath contaminants enter the lungs where they are allowed to pass into the bloodstream. Once in the bloodstream they are disbursed throughout the entire body where they can bring about a reaction or negatively impact a persons health by damaging certain parts of the anatomy.
The effects of air pollution on human health can vary greatly and can give birth to a multitude of health problems. Every contaminant poses its own set of problems. A persons age, their relative state of well-being, as well as the type and the amount of exposure are all factors in a complex equation.
In the broadest terms the effects can range from itchy eyes and nose, headaches, raspy throat, fatigue, wheezing, long-term acute changes in lung function, respiratory illnesses, impairment of the immune system or a shortened life expectancy.
Numerous studies have demonstrated that the cleaner the air, the healthier it is for people to breathe.
Particulate Matter or PM is a term used to describe a collection of contaminants that pollute the air and pose a variety of significant risks to human health. The term particulate matter encompasses both solid particles and liquid droplets that are found floating in the air. They come in a expansive range of sizes and can come from natural sources but the greatest amount of matter is generated by man-made sources.
Some particles are large or dark enough to be seen as haze, soot or smoke. Others are so small they can only be seen by an electron microscope. They are distinguished by size and those posing the greatest threat are referred to as PM10 and PM2.5. The numbers, 10 and 2.5 refer to the particles size as measured in micrometers or microns.
Fine" particles are smaller than 2.5 microns in diameter and coarse particles are between 2.5 and 10 microns. Particulate matter comes from sources such as windblown dust, vehicles traveling on paved and unpaved roads, as well as crushing and grinding operations. Some particles are emitted directly from their sources, such as smokestacks and engines. In other cases, gases such as sulfur oxide (SO), sulfur dioxide (SO2), nitrogen oxide (NOx), and volatile organic compounds (VOC) interact with other compounds in the air to form fine particles. Their chemical and physical compositions vary depending on location, time of year, and weather conditions. For the most part, the fine particles (PM2.5) are produced by the combustion of fossil fuels such as oil, diesel fuel, gasoline, coal and wood. Buses, trucks, automobiles, airplanes, fireplaces, wood stoves, industrial processes such as metal smelting, steel production and coal powered generation are all significant sources of particulate matter.
Both fine and coarse particles can collect in the respiratory system. Adverse health effects have been linked to exposures to particulate matter over both short periods - a day or so - and longer periods - a year or more. Exposure to particulate matter results in people with existing heart or lung conditions being at an increased risk of admission to hospitals or emergency rooms or premature death. Seniors and children are also at the greatest risk.
Recent studies reveal that fine particles (PM2.5) can travel deeper into the lungs, past our primary respiratory defense mechanisms lodging in the alveoli the small air sacs in the farthest reaches of the lung.
A study by Joel Schwartz of the Harvard School of Public Health documented the fact that for every increase in the level of particle air pollution there is a measurable increase in chronic respiratory illness as well as an increase in mortality. A clear example of this is pneumonia related deaths. Pneumonia is a disease of the lower lung where fine particles not coarse particles - come to rest. During periods of increased particulate pollution pneumonia related deaths increase.
In recent years studies have also begun to reveal a relationship between heart attacks and periods of high particulate air pollution. PM2.5 causes inflammation and blood clotting. and may contribute to heart attacks by blocking flow of blood through the heart. More recent studies have begun to show that these particles may also create electrical reactions that affect the central nervous system, which in turn may also contribute to the problem.