1. Why the hole in the atmospheric ozone layer above us?

2. What has been done about this?3. Why should I worry ourselves about

the Ozone Layer Depletion?

Dramatic loss of ozone in the lower stratosphere over Antarctica was first noticed in the 1970s by a research group

from the British Antarctic Survey (BAS) who were monitoring the atmosphere above Antarctica

News media confuses it with the problem of global warming

ozone contributes to the greenhouse effect

over Antarctica (and the Arctic), stratospheric ozone depleted over past 15 years at certain times of the year

hole presently size Antarctica, 10km altitude - lower stratosphere

Mr. OZONE: Will I be able to continue enjoying this life without problems?

Chlorofluorocarbons are created and used in refrigerators and air conditioners. These chlorofluorocarbons are not harmful to humans and have been a benefit to us. Once released into the atmosphere, chlorofluorocarbons are bombarded and destroyed by ultraviolet rays. In the process chlorine is released to destroy the ozone molecules

The time of year - more UV is received in the late spring and early summer and much less is received in the late fall and early winter.

Life style – determines a person’s risk to UV exposure. Skiing, sunbathing, or swimming can lead to extremely high exposures. Use of tanning parlors also increase risk.

Damage to plant cell DNA molecules - makes plants more susceptible to pathogens and pests

Reductions in photosynthetic capacity in the plant - results in slower growth and smaller leaves

Causes mutations in mammalian cells and destroys membranes

Ozone depletion causes increases in UV rays’s effects on aquatic ecosystems by:

1. decreasing the diversity of aquatic

organisms – reduces food stock and also destroys several fish and amphibians.

Suppress immune system Accelerate aging of skin due high exposure Cause an outbreak of rash in fair skinned

people due to photo allergy – can be severe

Skin cancer

Premature aging (photoaging) of the skin (different from normal chronological aging)

Cataracts and eye disorders (corneal sunburn and blindness)

Immune system damage

Protect the skin against the solar radiation using skin creams with SPF The greater the numerical value of the SPF the

greater the protection Use lip balm with SPF Cover up

Sunglasses with 100% UV block Wrap around sunglasses Eye protection for children Hats

The Ozone is Earth’s only defense against harmful UVR Studies indicate ozone thinning throughout the globe due to 2

mechanisms: Meteorological Chemical

Research indicates microorganisms, are extremely sensitive to increasing UV-B levels

There is a lot of uncertainty and debate among researchers as to the degree in which land plants are affected by UV-B

In the last decade, there has been an increase in skin cancer and cataracts all related to increase UV-B exposure

What are the 2 mechanisms responsible for ozone depletion? Explain each mechanism.

Explain 4 effects of ozone depletion.

What efforts have been implemented to counter the effects of ozone depletion?

How to protect ourselves from UVR ?