Can you see ozone

Section Navigation. Facebook Twitter LinkedIn Syndicate. Ozone and Your Health. Minus Related Pages. Links with this icon indicate that you are leaving the CDC website. The area of the ozone hole is determined from a map of total column ozone. It is calculated from the area on the Earth that is enclosed by a line with a constant value of Dobson Units.

The value of Dobson Units is chosen since total ozone values of less than Dobson Units were not found in the historic observations over Antarctica prior to Also, from direct measurements over Antarctica, a column ozone level of less than Dobson Units is a result of the ozone loss from chlorine and bromine compounds.

The graphs above show the progress of the ozone hole for The gray shading indicates the highest and lowest values measured since The red numbers are the maximum or minimum values. The stratospheric temperature and the amount of sunlight reaching the south polar region control the depth and size of the Antarctic ozone hole. The data for the ozone hole area , the minimum ozone , and the minimum stratospheric temperature are available.

Ozone is a gas composed of three atoms of oxygen. Ozone occurs both in the Earth's upper atmosphere and at ground level. Ozone can be good or bad, depending on where it is found. Called stratospheric ozone, good ozone occurs naturally in the upper atmosphere, where it forms a protective layer that shields us from the sun's harmful ultraviolet rays. This beneficial ozone has been partially destroyed by manmade chemicals, causing what is sometimes called a "hole in the ozone.

Learn more about stratospheric, or "good" ozone. Tropospheric, or ground level ozone, is not emitted directly into the air, but is created by chemical reactions between oxides of nitrogen NOx and volatile organic compounds VOC.

This happens when pollutants emitted by cars, power plants, industrial boilers, refineries, chemical plants, and other sources chemically react in the presence of sunlight. Ozone is most likely to reach unhealthy levels on hot sunny days in urban environments, but can still reach high levels during colder months. Ozone can also be transported long distances by wind, so even rural areas can experience high ozone levels.

In a scientific paper, researchers provided further evidence in a nationwide study that older adults faced a higher risk of premature death even when levels of ozone pollution remained well below the current national standard.

Data updated as of January 31, Environmental Protection Agency. EPA, , Section 8. Who is more vulnerable to die from ozone air pollution? Air Pollution and Mortality in the Medicare Population. N Engl J Med.

Relationship between visits to emergency departments for asthma and ozone exposure in greater Seattle, Washington. Ann Allergy Asthma Immunol. Short-term associations between ambient air pollutants and pediatric asthma emergency department visits. Environ Res. Chronic exposure to ambient ozone and asthma hospital admissions among children. Environ Health Perspect. Jerrett M, Burnett RT, et al. Long-term ozone exposure and mortality. Ozone, oxidant defense genes, and risk of asthma during adolescence.

Birth outcomes and prenatal exposure to ozone, carbon monoxide, and particulate matter: Results from the Children's Health Study. Ambient air pollution exposure and full-term birth weight in California. Environ Health. This November your donation goes even further to improve lung health and defeat lung cancer.

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