Particulate Matter

Particulate Matter

Introduction

The term "particulate matter" includes a wide range of organic or inorganic substances when released into the air from natural and artificial sources. The combustion of fossil fuel-generated traffic (a major source of particulate pollution in cities) can produce various types of particles: large particles, the release of unburned materials (fly ash), fine particles, formed by the condensation of vaporized material during combustion, and secondary particles, through atmospheric reactions of removed contaminants and gases. In relation to its health effects are usually distinguished; PM10 (particles "thoracic" less than 10 microns that can penetrate to the lower respiratory tract), PM2.5 (particles "breathable" under 2.5µm, which can penetrate to the gas exchange areas of the lung), and ultrafine particles (smaller than 100 nm, which can pass through the bloodstream) ((Bruce, 2000).

Scientists today believe that the SPM is the problem more severe environmental pollution because of its harsh conditions the respiratory tract and lungs. PM10 are behind many respiratory diseases, cardiovascular disease, and lung cancers. On the other hand, studies on long-term effects have estimated that exposure to particulate matter can reduce life expectancy by several months to two years. According to a European Commission study, published in early 2005, the presence of these particles in the atmosphere causes 288,000 premature deaths each year. Another study by the World Health Organization (WHO) published in 2004 states that exposure to particulate matter causes premature death of 13,000 children aged between one and four years of age every year.

Dust is a natural component of air and consists of coarse dust and particulate matter. The latter consists of very small, invisible particles (particles). Particles smaller than 10 micrometers (microns) and thus ten times smaller than the thickness of a hair are referred to as respirable particulate matter (PM 10). Basically, the health hazard is greater, the smaller the particles. Particulate matter, which is smaller than 2.5 micrometers (PM 2.5), can reach up into the lungs.

Airborne particulate matter, as opposed to ozone or nitrogen oxides (NO, NO 2) discussed only in recent years as an air pollutant in public. Since 2001 in Austria valid extension of the Air Pollution Control Act (IG-L) provides stringent particulate limits before. The city of Vienna has already been successfully countermeasures to reduce the burden of the Vienna air from pollutants (Dockery, 1993).

Discussion

Atmospheric pollution describes harmful gases, solid particles, and liquid droplets that are present in the atmosphere in quantities above natural ambient levels. The main gases in the atmosphere are nitrogen (78.08%), oxygen (20.95%), and argon (0.93%). Carbon dioxide, a greenhouse gas, accounts for 0.038%. Given this composition, pollutants are present in very small proportions, usually measured as the mixing ratio of the number of molecules of the pollutant per total number of air molecules, such as parts per million (ppm) or parts per billion (ppb), or as a mass concentration per unit volume of air, such as micrograms per cubic meter (µg/m3). Each year, millions of tons of pollutants are emitted into the atmosphere, and the effects on ...