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Health effect of particles
Each time we breathe in around half a litre of air enters our lungs and brings oxygen to our body. But as the atmosphere also contains thousands of particles, these particles also enter our lungs. Depending on their size and composition, these particles may be bad for our health. Centuries before pollution began to pose a significant health hazard, men and women already had respiratory problems due to their activities.
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Historical signs
In 1555, the Danish bishop Olaus Magnus said that the farmers should thresh hay against the wind “because the dust is so fine that one can not notice its inhalation and accumulation in back of the throat”. So even in the Sixteenth Century, the effect of particles on human health had been recognised.
Over the coming centuries, especially during the Industrial Revolution, workers were exposed to dangerous levels of particulate matter. In the 1800's lung disease became a major problem for coal miners, particularly in Great Britain, where much of the world's coal was mined
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1. (on the left) Coal miners at the beginning of the 20th century in center of France. Source:www.icilacreuse.com.
2. (below) Cotton workers at Dean Mills near Manchester in 1851. Source: The Illustrated London News.
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In many countries people still work in poor conditions. Particle effects are still a problem, particularly for construction workers, bakers and farmers who are all exposed to high levels of dust.
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Links between particles and health
Scientific studies have shown that an increase in particulate air pollution leads to an increase in respiratory problems like asthma and bronchitis. Emergency admissions and hospitalisation for respiratory disorders increases as particle concentrations in the air increase. Long term exposure to high particle concentrations can lead to lung cancer.
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3. You can see here the aerosol concentration versus time of day. Red lines are measurements in a busy street in Paris and blue lines are measurements in an area inside Paris. Green lines show particle concentrations measured in a rural area. All measurements were performed on September 16, 2003. Look at how concentrations are greater when people go to work in the morning and come back home at the end of the afternoon. These high aerosol concentrations are from vehicle emissions. Click to enlarge! (30 K). Source: Airparif.
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Values in cities
As particles are dangerous for health, the European Community has set air quality standards. These state that particle levels should not exceed, on average, 44.8 µg m-3 over any one year. This means that if we weigh all the particles in one cubic meter of air, the mass of particles shouldn't be greater than this value. However, aerosol concentrations often exceed 100 µg m-3 in European cities during the day.
As a matter of fact, there is no known value below which particle concentration has no ill effect on health.
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The toxicity of particles depends mainly on their size and their chemical composition. The smaller a particle is, the deeper it can penetrate into the respiratory system. Have a look in the 'read more' section for more details on the respiratory system and the effects of particle size on health.
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About this page
author: Dr. Justine Gourdeau - LaMP, Clermont-Ferrand, France
scientific reviewer: Dr. Serge Despiau, LEPI, Toulon, France
last published: 2003-10-14
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