Ozone and Health Risks
Good Ozone. Stratospheric ozone is good ozone in that it protects life on Earth from harmful biologically damaging ultra-violet (UVB) solar radiation. Increase levels of UVB radiation resulting from ozone loss may be linked to coronal eye damage, skin cancer, cell damage in all forms of life, alteration of plant physiology, and weakening of the immune system.
The United Nations Report http://sedac.ciesin.org/ozone/UNEP/UNEP94toc.html
is a comprehensive assessment of the environmental effects of ozone depletion. Especially Chapter 2
"EFFECTS OF INCREASED SOLAR ULTRAVIOLET RADIATION ON HUMAN HEALTH" http://sedac.ciesin.org/ozone/UNEP/chap2.html or Here if you have no internet connection
and Chapter 3
"EFFECTS OF INCREASED SOLAR ULTRAVIOLET RADIATION ON TERRESTRIAL PLANTS" http://sedac.ciesin.org/ozone/UNEP/chap3.html
The executive summary of this report is concise with lots of information
http://sedac.ciesin.columbia.edu/ozone/UNEP/execsum.html or Here if you have no internet connection. The 2000 update to this summary is located at http://www.gcrio.org/ozone/unep2000summary.html
Another good web site is:
http://www.gcrio.org/CONSEQUENCES/summer95/impacts.html
Bad Ozone Ozone in the lower troposphere especially in urban areas is bad ozone. In urban environments sunlight can combine with fossil fuel combustion byproducts (oxides of nitrogen and some hydrocarbons) to create ozone. Ozone is a major component of this photochemical smog and can irritate eyes, throats, lungs, and damage vegetation. Ozone concentrations during ozone alert days can be dangerous to those with chronic lung disease.
Tropospheric Ozone (Bad Ozone)
See Interactive air quality guide from USA Today http://www.usatoday.com/news/nation/2001/08/20/smog-usat.htm
When ozone builds up--generally as a result of our use of fossil fuels--it reacts very strongly with animal and plant tissues, and even damages tough materials such as rubber, plastics and outdoor paints. You've probably seen hydrogen peroxide fizz--and perhaps felt it burn your gums or skin tissues, or "smart." Like ozone, hydrogen peroxide is closely related to a very stable molecule: water, or H2O. With an added oxygen atom, it changes to H2O2, becoming very reactive. The fizz and burn of hydrogen peroxide on a scratch or wound illustrate how, at high concentrations, ozone's own strong reactivity can irritate and damage the sensitive tissues of your eyes, lungs, nose, sinuses and throat, causing burning eyes, shortness of breath, chest tightness, wheezing, coughing and nausea. The sustained, higher levels of ozone that cause these effects usually begin with human activity. |
figure from USA today
http://www.usatoday.com/news/nation/2001/08/20/smog-usat.htm Thus, ozone can produce the following health effects: |
HOW OZONE DISTURBS YOUR BODY -- Inhaled ozone travels down the windpipe and enters the lungs through the large bronchial tubes, which branch into smaller airways, or bronchioles. At the end of the bronchioles are tiny air sacs called alveoli, which fill up and expand like little balloons to put oxygen into the bloodstream. Ozone primarily injures these key oxygen exchangers, the alveoli, along with the bronchioles. Animals also suffer from ozone. Studies demonstrate how ozone exposure injures their lung cells and causes unusual changes in lung tissue. Other studies have shown that ozone can make people more susceptible to bacterial pneumonia, a potential killer. People with existing lung diseases--asthma, bronchitis, or emphysema--are particularly vulnerable to the respiratory effects of ozone. There are also particularly sensitive individuals. |
Ground-level ozone can harm plants, trees, and crops by preventing the plant from being able to use the sun's energy. Ozone does this by reacting with the molecular links between the carbon atoms (called the carbon-carbon bonds) in the plant's photosynthetic machinery. |
References. http://www.so.wustl.edu/science_outreach/curriculum/ozone/info/troposphere/health.html
http://www.ucar.edu/learn/1_7_1.htm
Ozone alerts and chronic lung disease
Health Risks of Stratospheric Ozone (Good Ozone) depletion
Many written statements below are from:
The United Nations Environmental Program UNEP (1994 Exec Summary)
http://sedac.ciesin.columbia.edu/ozone/UNEP/execsum.html
Other URL references are also given such as:
"Solar ultraviolet radiation effects on biological systems"B L Diffey
http://www.ciesin.org/docs/001-503/001-503.html
http://www.doc.mmu.ac.uk/aric/eae/Ozone_Depletion/ozone_depletion.html
(excerpt from UNEP 1994 Exec Summary)
UV radiation has been shown in experimental systems to damage the cornea and lens of the eye. Chronic exposure to UV-B (resulting in a high, cumulative, lifetime dose) is one of several factors clearly associated with the risk of cataract of the cortical and posterior subcapsular forms. The 1989 Report noted that a 1% increase in stratospheric ozone depletion has been predicted to be associated with a 0.6 to 0.8% increase in cataract; this estimate, although crude, has not been improved upon in the intervening years.
Other info at:
http://www.doc.mmu.ac.uk/aric/eae/Ozone_Depletion/Older/Eye_Disorders.html
This quote is from the Center for Disease Control CDC.
Approximately three fourths of all skin cancer-associated deaths are caused by melanoma. During 1973-1991, the incidence of melanoma increased approximately 4% each year (1). In addition, the incidence of melanoma is increasing faster than that of any other cancer (2). To characterize the distribution of deaths from melanoma in the United States, CDC analyzed national mortality data for 1973 through 1992. This report summarizes the results of that analysis. .....
.....In 1992, the rate of deaths from melanoma was 5.9 times higher for whites than for all other races (2.5 and 0.4 per 100,000 population, respectively), and 2.1 times higher for males than females (3.1 and 1.5, respectively).
http://www.cdc.gov/mmwr/preview/mmwrhtml/00036996.htm
This quote is from the UNEP Exec summary cited above
In susceptible (light-skinned) populations, UV-B radiation is the key risk factor for development of non-melanoma skin cancer (NMSC). Using information derived from animal experiments and human epidemiology, it is estimated that a sustained 1% decrease in stratospheric ozone will result in an increase in NMSC incidence of approximately 2%. The relationship between UV-B exposure and melanoma skin cancer is less well understood and appears to differ fundamentally from that of NMSC. Epidemiologic data indicate that the risk of melanoma increases with sunlight exposure, especially during childhood. There is, however, uncertainty about the relative importance of UV-B radiation, which directly determines the magnitude of the increase in melanoma that would result from ozone depletion.
Other Reference
http://www.doc.mmu.ac.uk/aric/eae/Ozone_Depletion/Older/Skin_Cancer.html
http://www.ciesin.org/docs/001-503/001-503.html
This quote is from the UNEP Exec summary cited above
Some components of the immune system are present in the skin, which makes the immune system accessible to UV radiation. Experiments in animals show that UV exposure decreases the immune response to skin cancers, infectious agents, and other antigens and can lead to unresponsiveness upon repeated challenges. Studies in human subjects also indicate that exposure to UV-B radiation can suppress the induction of some immune responses. The importance of these immune effects for infectious diseases in humans is unknown. However, in areas of the world where infectious diseases already pose a significant challenge to human health and in persons with impaired immune function, the added insult of UV-B induced immune suppression could be significant.
"EFFECTS OF INCREASED SOLAR ULTRAVIOLET RADIATION ON TERRESTRIAL PLANTS" http://sedac.ciesin.org/ozone/UNEP/chap3.html
This quote is from the UNEP Exec summary cited above
Physiological and developmental processes of plants are affected by UV-B radiation, even by the amount of UV-B in present-day sunlight. Plants also have several mechanisms to ameliorate or repair these effects and may acclimate to a certain extent to increased levels of UV-B. Nevertheless, plant growth can be directly affected by UV-B radiation.
References
Health risks of Stratospheric (Good) ozone depletion
Socioeconomic Data and Applications Center's http://sedac.ciesin.org/ozone/
UV radiation (UVA, UVB, UVC) http://sedac.ciesin.org/ozone/docs/UNEP98/UNEP98p6.html
http://sedac.ciesin.org/ozone/UNEP/UNEP94toc.html
http://www.gcrio.org/CONSEQUENCES/summer95/impacts.html
Bad Ozone
http://www.nmenv.state.nm.us/aqb/projects/Exposure-to-Ozone-and-Health-11-06-02.pdf
http://www.niehs.nih.gov/oc/factsheets/ozone/home.htm (several figures and text from above were extracted from this site)
http://www.usatoday.com/news/nation/2001/08/20/smog-usat.htm Great Interactive air quality tour.