Question

What are two effects on human health that scientists believe will result from ozone depletion?

Short answer

Ozone depletion increases skin cancer risk and causes eye cataracts.

Step-by-step solution

Understanding Ozone Layer Depletion

The ozone layer is a layer in the Earth's stratosphere that contains a high concentration of ozone (O3). It absorbs most of the Sun's ultraviolet radiation. Ozone depletion refers to the thinning or reduction of this layer, primarily due to human-made chemicals like chlorofluorocarbons (CFCs).

Identifying Effect on Skin Health

With the depletion of the ozone layer, more ultraviolet (UV) rays from the sun reach Earth's surface. One significant effect of increased UV radiation exposure is a higher risk of skin cancers, such as melanoma and non-melanoma skin cancers, as the UV rays damage skin cells' DNA.

Identifying Effect on Eye Health

Another effect of increased UV radiation due to ozone depletion is on eye health. Long-term exposure to these rays can lead to cataracts, a condition where the lens of the eye becomes cloudy, leading to vision impairment or blindness.

Key concepts

Ultraviolet Radiation

Ultraviolet (UV) radiation is a type of energy emitted by the sun. Normally, the ozone layer acts like Earth's sunscreen, blocking a significant portion of this radiation from reaching our planet's surface.
However, with ozone depletion, more ultraviolet rays penetrate through the atmosphere. These rays are invisible and cannot be felt, but they have powerful effects.

• Types of UV Rays: UV radiation is divided into three categories - UVA, UVB, and UVC. Each of these has different levels of energy and effects on the skin and environment.
• Impact of UV Exposure: Increase in UV radiation due to ozone depletion results in more exposure to these harmful rays, elevating health risks.

Understanding the nature and effects of UV radiation is fundamental to recognizing the importance of efforts to protect the ozone layer.

Skin Cancer

Skin cancer is one of the most common consequences of prolonged exposure to UV radiation. Without the protective shield of the ozone layer, the skin receives higher doses of harmful UV rays.
This can lead to various forms of skin cancer, such as melanoma and non-melanoma skin cancer.

• Melanoma: A severe form of skin cancer that begins in cells known as melanocytes. It's less common but more dangerous if not diagnosed early.
• Non-Melanoma Skin Cancers: These include basal cell carcinoma and squamous cell carcinoma, which are more common and generally less aggressive.
• DNA Damage: UV rays can directly cause damage to the DNA in skin cells, leading to mutations that may turn cancerous.

Protecting skin from UV exposure by using sunscreen or wearing protective clothing is crucial in reducing these risks.

Cataracts

Cataracts are a major eye health concern related to increased UV radiation exposure. A cataract forms when the proteins in the eye's lens begin to deteriorate and clump together, causing a cloudy area.

• Vision Impairment: This cloudiness can block or distort vision, making everyday tasks difficult or impossible.
• Risk Factors: UV radiation is a major factor that can speed up the formation of cataracts, especially with prolonged exposure without protection.
• Prevention Measures: Wearing sunglasses that block UV rays can help protect your eyes and reduce the risk of cataracts.

Recognizing the link between UV exposure and eye damage highlights the need for protective measures and policies to reduce UV radiation on Earth due to ozone layer depletion.

Chlorofluorocarbons

Chlorofluorocarbons (CFCs) are a group of human-made chemical compounds once widely used in various industries, particularly as refrigerants and aerosol propellants.
They are infamous for their role in ozone depletion.

• Ozone Depleting Potential: Once released into the atmosphere, CFCs can linger for years, slowly rising to the stratosphere where they are broken down by UV radiation, releasing chlorine atoms that destroy ozone molecules.
• Environmental Impact: Every chlorine atom from CFCs can destroy thousands of ozone molecules, significantly thinning the ozone layer.
• Regulatory Efforts: The Montreal Protocol is a key international treaty aimed at phasing out the production and use of ozone-depleting substances like CFCs.

Understanding CFCs' impact emphasizes the importance of continued regulatory measures to protect and restore the ozone layer.