Health Effects, Environmental Sources and Measures to Reduce Exposure - Essay Example

Several research studies indicate that exposure of the world's population to UVR (Ultraviolet Radiation) has been increasing over the last few decades. As part of an education program by the Public Health Department, this fact sheet is being made available to help protect the public from the adverse effects of ultraviolet radiation.

Health Effects of Exposure

All three types of UVR have biological effects on humans, plants, marine ecosystems, biogeochemical cycles, and materials.

• UVA (least energetic) can penetrate deep into the skin. It can cause immediate tanning, premature skin aging and lead to certain types of skin cancers developing.
• UVB (more energetic) can penetrate further and can cause sunburns, delayed tanning, and most forms of skin cancers.
• UVC (most energetic) is very dangerous for all life forms, even if the exposure is short.

The main concern, however, is increased exposure to UVB by humans. The possible health effects that may arise from exposure to UVB radiation include non-melanoma skin cancer and cataracts (EPA, 2011). In other words, it can cause damage especially to the skin, eyes, and also to our body's immune system (HC, 2008).

Symptoms of over-exposure on the skin: A visible sign of over-exposure is tanning of the skin and sunburn. This occurs due to an increase in melanocyte number and activity. The skin becomes red, swollen, and painful.

Effects on the skin from prolonged exposure: Premature aging, such as hardening, wrinkling, blotchiness, elasticity loss, dark patches, damaged DNA, and skin cancer.

Symptoms of over-exposure in the eyes: Temporary painful injuries, inflammation

Effects on the eyes from prolonged exposure: Cataracts, pterygium growth, macular degeneration, eyelid cancer

Immune system effects: Suppression of resistance to bacterial agents, enhanced risk of infection, meningitis, smallpox lesions, reactive herpes simplex virus

However, some UVR is essential for us too. For example, it produces vitamin D3 in the body, which helps to absorb calcium and phosphorus, and plays a role in the formation of blood cells, and in controlled amounts, it can be used to treat some skin conditions such as eczema and psoriasis (HC, 2008).

Environmental Sources of Exposure

Increased exposure to UV radiation is made possible due to the weakening and depletion of parts of the ozone layer. The ozone layer is able to filter the most dangerous form of UVR known as UVC, about 95% of UVB, and only about 5% of UVA. With a weakened ozone layer, however, more than the normal 5% of UVB is able to pass through from the Sun to reach the earth's surface.

The extent of exposure is dependent on geographical factors such as latitude, time of day, time of year (season), altitude, cloud cover, etc. (BOM, 2012). It is also affected by the amount of air pollution, which if high, actually helps to block UVR. Due to the reflective properties of UVR, high levels of exposure also exist in snowy, sandy, and watery places, and along concrete footpaths. And, due to its scattering properties, exposure is also possible despite being in the shade (skincancer.org, 2012). Artificial sources of UVR include lasers, certain types of lighting, and tanning equipment.

How to Reduce Exposure

Exposure to UVR can be minimized by controlling the time spent outdoors when the Sun is blazing during the midday period, especially in summer and if living close to the equator. Protection should also be sought from these artificial sources (FDA, 2012):

• Certain types of lasers
• Certain types of fluorescent, incandescent, and halogen lighting, and mercury vapor lighting
• Tanning booths

Products that can help to reduce exposure include a wide-brim hat, sunglasses that are rated to provide 100% UV protection, broad-spectrum sunscreen, and sun-protective clothing.