fis_ling_ozon

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ozon/ls/fisling 2007

1. What is Ozone (O3)?

Ozone (O3) is a gas that can form and react under theaction of light and that is present in two layers of the

atmosphere. High up in the atmosphere, ozone forms alayer that shields the Earth from ultraviolet rays.However, at ground level, ozone is considered a majorair pollutant.

Ground-level ozone the focus of this study is formedfrom other pollutants and can react with othersubstances, in both cases under the action of light.Concentrations are often low in busy urban centres andhigher in suburban and adjacent rural areas, particularly

on sunny days in summer. However, ozone can betransported through air over long distances and acrossborders. Ozone is known to cause adverse healtheffects, but more research is needed.
http://www.greenfacts.org/glossary/mno/ozone.htmhttp://www.greenfacts.org/glossary/mno/ozone.htmhttp://www.greenfacts.org/glossary/abc/atmosphere.htmhttp://www.greenfacts.org/glossary/abc/atmosphere.htmhttp://www.greenfacts.org/glossary/mno/ozone.htmhttp://www.greenfacts.org/glossary/mno/ozone.htm


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2. How does Ozone (O3) affect human health?

Short-term exposure to ozone peaks cantemporarily affect the lungs, the respiratory tract,and the eyes. It can also increase thesusceptibility to inhaledallergens. Long-termexposure to relatively low concentrations ofozone can reduce lung function.

2.1 Human population studies at ozone levelscurrently observed in Europe have reachedinconsistent conclusions regarding effects ofozone on the frequency ofasthma. They haveprovided little evidence of long-term effects on

lung cancer or mortality. However, resultssuggest that long-term ozone exposure mayaffect lung function growth in children.
http://www.greenfacts.org/glossary/mno/ozone.htmhttp://www.greenfacts.org/glossary/pqrs/respiratory-tract.htmhttp://www.greenfacts.org/glossary/pqrs/susceptibility.htmhttp://www.greenfacts.org/glossary/ghi/inhalation-inhale.htmhttp://www.greenfacts.org/glossary/abc/allergy.htmhttp://www.greenfacts.org/glossary/jkl/lung-function.htmhttp://www.greenfacts.org/glossary/mno/ozone.htmhttp://www.greenfacts.org/glossary/abc/asthma.htmhttp://www.greenfacts.org/glossary/jkl/lung-function.htmhttp://www.greenfacts.org/glossary/jkl/lung-function.htmhttp://www.greenfacts.org/glossary/abc/asthma.htmhttp://www.greenfacts.org/glossary/mno/ozone.htmhttp://www.greenfacts.org/glossary/jkl/lung-function.htmhttp://www.greenfacts.org/glossary/abc/allergy.htmhttp://www.greenfacts.org/glossary/ghi/inhalation-inhale.htmhttp://www.greenfacts.org/glossary/pqrs/susceptibility.htmhttp://www.greenfacts.org/glossary/pqrs/respiratory-tract.htmhttp://www.greenfacts.org/glossary/mno/ozone.htm


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2. How does Ozone (O3) affect human health?

2.2 Ozone appears to have effects on health independently ofother pollutants, particularly in the case of short-term exposure

to concentration peaks which occur especially in the summer.More...2.3 The presence of other air pollutants, especiallyparticulate matter, can enhance or otherwise influence theeffects ofozone, and vice versa.

2.4 Individuals in a population respond differently to ozoneexposure, depending on how old they are, if they are asthmatic,how much air they breathe in, and for how long they have beenexposed to ozone. The reasons for this difference inresponsiveness remain largely unexplained but appear to bepartly linked to genetic differences. More...2.5 No exposurethreshold has been identified below which nobodys health isaffected by ozone exposure. This is because differentindividuals respond very differently to ozone exposure. A

threshold has been determined for lung damage andinflammation, but studies on this topic have generally nottested especially sensitive subjects.
http://www.greenfacts.org/glossary/mno/ozone.htmhttp://www.greenfacts.org/air-pollution/ozone-o3/level-2/02-health-effects.htm#1.%20What%20is%20Ozone%20(O3)?http://www.greenfacts.org/glossary/pqrs/particulate-matter.htmhttp://www.greenfacts.org/glossary/mno/ozone.htmhttp://www.greenfacts.org/glossary/mno/ozone.htmhttp://www.greenfacts.org/glossary/abc/asthma.htmhttp://www.greenfacts.org/glossary/ghi/gene.htmhttp://www.greenfacts.org/air-pollution/ozone-o3/level-2/02-health-effects.htm#2.%20How%20does%20Ozone%20(O3)%20affect%20human%20health?%20http://www.greenfacts.org/glossary/tuv/threshold-health-science.htmhttp://www.greenfacts.org/glossary/mno/ozone.htmhttp://www.greenfacts.org/glossary/ghi/inflammation.htmhttp://www.greenfacts.org/glossary/ghi/inflammation.htmhttp://www.greenfacts.org/glossary/mno/ozone.htmhttp://www.greenfacts.org/glossary/tuv/threshold-health-science.htmhttp://www.greenfacts.org/air-pollution/ozone-o3/level-2/02-health-effects.htm#2.%20How%20does%20Ozone%20(O3)%20affect%20human%20health?%20http://www.greenfacts.org/glossary/ghi/gene.htmhttp://www.greenfacts.org/glossary/abc/asthma.htmhttp://www.greenfacts.org/glossary/mno/ozone.htmhttp://www.greenfacts.org/glossary/mno/ozone.htmhttp://www.greenfacts.org/glossary/pqrs/particulate-matter.htmhttp://www.greenfacts.org/air-pollution/ozone-o3/level-2/02-health-effects.htm#1.%20What%20is%20Ozone%20(O3)?http://www.greenfacts.org/glossary/mno/ozone.htm


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3. How are we exposed to Ozone (O3)?

3.1 Ozone (O3) is formed when other pollutants reactunder the action of light. It is mainly formed outdoors.

3.2 Outdoorozone levels vary across city areas andtimes of the day, with peaks in the afternoon. Ozoneconcentrations indoors are generally 50% lower thanthose outdoors. Indoor sources of ozone includephotocopiers and electrostatic air cleaners.

3.3 Unlike levels of other air pollutants, ozone levels tendto be lower in urban polluted areas. This is becauseozone disappears when it reacts with other pollutants,such as nitric oxide (NO). At places and times whenpeak levels occur, short-term exposure can temporarily

affect the lungs, the respiratory tract and the eyes, andincrease susceptibility to inhaledallergens. Since dayswith mildly elevated ozone levels are much morefrequent than days with high peaks, their overall impacton public health may be expected to be greater.
http://www.greenfacts.org/glossary/mno/ozone.htmhttp://www.greenfacts.org/glossary/mno/ozone.htmhttp://www.greenfacts.org/glossary/mno/ozone.htmhttp://www.greenfacts.org/glossary/def/electrostatic-air-cleaner.htmhttp://www.greenfacts.org/glossary/mno/ozone.htmhttp://www.greenfacts.org/glossary/mno/nitrogen-oxides-NOx-nitric-oxide-NO-nitrogen-dioxide-NO2.htmhttp://www.greenfacts.org/glossary/mno/nitrogen-oxides-NOx-nitric-oxide-NO-nitrogen-dioxide-NO2.htmhttp://www.greenfacts.org/glossary/pqrs/respiratory-tract.htmhttp://www.greenfacts.org/glossary/pqrs/susceptibility.htmhttp://www.greenfacts.org/glossary/ghi/inhalation-inhale.htmhttp://www.greenfacts.org/glossary/abc/allergy.htmhttp://www.greenfacts.org/glossary/abc/allergy.htmhttp://www.greenfacts.org/glossary/ghi/inhalation-inhale.htmhttp://www.greenfacts.org/glossary/pqrs/susceptibility.htmhttp://www.greenfacts.org/glossary/pqrs/respiratory-tract.htmhttp://www.greenfacts.org/glossary/mno/nitrogen-oxides-NOx-nitric-oxide-NO-nitrogen-dioxide-NO2.htmhttp://www.greenfacts.org/glossary/mno/nitrogen-oxides-NOx-nitric-oxide-NO-nitrogen-dioxide-NO2.htmhttp://www.greenfacts.org/glossary/mno/ozone.htmhttp://www.greenfacts.org/glossary/def/electrostatic-air-cleaner.htmhttp://www.greenfacts.org/glossary/mno/ozone.htmhttp://www.greenfacts.org/glossary/mno/ozone.htmhttp://www.greenfacts.org/glossary/mno/ozone.htm


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4. Should current O3 guidelines be reconsidered?

4.1 Though the effects ofozone (O3) reductions on

public health have seldom been evaluated independentlyfrom other air pollutants, it was noted that O3 reductionsmay have some beneficial effects on lung function andasthma.

4.2 It is recommended that a guideline for short-term

exposure to ozone be set based on an 8-hour averagingtime. Because of insufficient information, no long-termguideline has been recommended yet.

4.3 Current WHO Air quality guidelines describe therelationships between exposure to ozone (O3) and

various health effects, and they propose a guidelinevalue for short-term (8-hour) exposure only. Newscientific evidence justifies reconsidering theseguidelines.
http://www.greenfacts.org/glossary/mno/ozone.htmhttp://www.greenfacts.org/glossary/mno/ozone.htmhttp://www.greenfacts.org/glossary/jkl/lung-function.htmhttp://www.greenfacts.org/glossary/abc/asthma.htmhttp://www.greenfacts.org/glossary/mno/ozone.htmhttp://www.greenfacts.org/air-pollution/toolboxes/who-air-quality-guidelines-europe.htmhttp://www.greenfacts.org/glossary/mno/ozone.htmhttp://www.greenfacts.org/glossary/mno/ozone.htmhttp://www.greenfacts.org/air-pollution/toolboxes/who-air-quality-guidelines-europe.htmhttp://www.greenfacts.org/glossary/mno/ozone.htmhttp://www.greenfacts.org/glossary/abc/asthma.htmhttp://www.greenfacts.org/glossary/jkl/lung-function.htmhttp://www.greenfacts.org/glossary/mno/ozone.htmhttp://www.greenfacts.org/glossary/mno/ozone.htm


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5. Conclusions on Ozone (O3)

Ozone (O3), a gas formed from other pollutants

under the action of light, is usually present in lowconcentrations in busy urban centres and in higherconcentrations in suburban and adjacent ruralareas, particularly on sunny days in summer.Exposure to it mainly affects the lungs, but it canalso affect the eyes and increase susceptibility toinhaledallergens. Individuals in a populationrespond differently to ozone exposure, whichappears to be partly due to genetic differences. The

current WHO Air quality guidelines whichrecommend a maximum value for short-termexposure should be reconsidered.
http://www.greenfacts.org/glossary/mno/ozone.htmhttp://www.greenfacts.org/glossary/mno/ozone.htmhttp://www.greenfacts.org/glossary/pqrs/susceptibility.htmhttp://www.greenfacts.org/glossary/ghi/inhalation-inhale.htmhttp://www.greenfacts.org/glossary/abc/allergy.htmhttp://www.greenfacts.org/glossary/ghi/gene.htmhttp://www.greenfacts.org/air-pollution/toolboxes/who-air-quality-guidelines-europe.htmhttp://www.greenfacts.org/air-pollution/toolboxes/who-air-quality-guidelines-europe.htmhttp://www.greenfacts.org/glossary/ghi/gene.htmhttp://www.greenfacts.org/glossary/abc/allergy.htmhttp://www.greenfacts.org/glossary/ghi/inhalation-inhale.htmhttp://www.greenfacts.org/glossary/pqrs/susceptibility.htmhttp://www.greenfacts.org/glossary/mno/ozone.htmhttp://www.greenfacts.org/glossary/mno/ozone.htm

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