Particulate matter is the name given to very small solid particles and liquid droplets
that are, in fact, so tiny that they are invisible to the human eye and readily float
in the air for a long time. The only time you can see them is when they gather in
large numbers and appear as smoke or haze. Of great concern are the so-called 'fine'
particles that are less than 2.5 microns in diameter (1 micron equals 0.001mm). The
composition of particulate matter is generally diverse and depends largely on the
source: combustion appliances, tobacco smoke, car exhaust etc.
Particulate matter, and certain chemicals that can attach to the particles, can penetrate
deep into the sensitive regions of our airways and may not be removed by the self-cleaning
process of the lungs. The particles irritate or damage the delicate tissues of the
lung and cause persistent coughs and wheezing. Continuous exposure may result in
the onset or exacerbation of serious respiratory and cardiovascular disorders and
premature death. Worldwide studies, using different techniques and conducted under
a variety of circumstances gave undeniable proof of the negative health effects of
particulate matter. The World Health Organization estimates that almost half a million
excess deaths occur globally every year. In Sydney, an estimated 400 people die prematurely
every year as a direct result of particulate matter. These figures, however, aren't
based on indoor pollution alone, they include the exposure to outdoor particles as
well.
Scientists agree that there is no safe limit for particulate matter levels. Long-term
exposure to even low concentrations can be harmful. Unfortunately the risk factors
are a repetition of earlier paragraphs: children, the elderly and people with lung
and cardiovascular illnesses are at greatest risk. Studies of children, living in
areas with air pollution, clearly associate fine particles with coughing, wheezing
and bronchitis.
Particle pollution - especially fine particles - contains microscopic solids or liquid
droplets that are so small that they can get deep into the lungs and cause serious
health problems. Numerous scientific studies have linked particle pollution exposure
to a variety of problems, including:
- increased respiratory symptoms, such as irritation of the airways, coughing, or difficulty
breathing, for example;
- decreased lung function;
- aggravated asthma;
- development of chronic bronchitis;
- irregular heartbeat;
- nonfatal heart attacks; and
- premature death in people with heart or lung disease.
Source: US EPA
