OVER EXPOSURE TO THE SUN

Sunlight is good for humans to a certain extent only. If people are exposed to sunlight above a certain limit, it can cause damage to skin and hair. Life threatening diseases like cancer can also be caused besides short term effects like dehydration and rashes.
The sunlight consists of different types of rays. Ultraviolet rays are the most harmful. The ozone layer helps to filter the harmful rays. But the depletion in the ozone layer has increased the risk of skin cancer and other harmful effects of sunrays.
The ultraviolet rays consist of three types: ultraviolet A, ultraviolet B and ultraviolet C. The ultraviolet A helps fair skinned people to get a healthy tan. Ultraviolet B radiation may cause sun burns, rashes, dehydration and severe damage to skin, hair, eye and immune system. Ultraviolet C is very harmful to humans and all life forms on the Earth. It is not being filtered properly due to ozone layer depletion. Skin cancer is on the increase.
Some exposure to sunlight has health benefits, such as through stimulating the production of Vitamin D by the body (this aids the absorption of calcium and phosphorus, which are essential for healthy bones). Vitamin D is available through nutritional sources, but this does not always provide enough. There is also evidence that exposure to sunlight improves mental wellbeing and may be linked to a reduction in the risk of developing multiple sclerosis.
Risks of exposure to too much ultraviolet radiation
Sun burns are caused due to over exposure. Blood vessels in the skin expand causing inflammation, pain and redness. Moles are more susceptible to harmful effects of the sun. If there are any moles present in the body, they should be regularly checked or examined for any signs of itching or color change.
The sun rays darken the human skin but lighten the hair. The ultraviolet rays of the sun help to break down the keratin and melanin. The hair becomes lighter and drier. The effect of lightening of the hair due to over exposure to sun is called sun bleaching. The hair may lose moisture and lose its natural softness. The exposed head can absorb the sun’s rays directly and also cause giddiness. Hats or scarves can prevent harmful effects to an extent. However it is not advisable to be exposed to the sun rays for a long period.
There are a number of negative side effects that can result from spending too much time in the sun. These include:

• Deterioration of the skin, including premature ageing and loss of elasticity.
• Rashes, itchiness and dryness.
• Damage to the eyes.
• Sunburn.
• Skin cancer.

People whose pattern of sun exposure has been intermittent are at an increased risk of developing melanoma or basal cell carcinoma. Those who have more continuous exposure (such as outdoor workers) are at an increased risk of developing squamous cell carcinoma. Evidence also shows that overexposure to sunlight in childhood and adolescence is an important risk factor in developing skin cancer.

According to the World Health Organisation, skin cancer kills over 60 000 people a year.
Of the 60 000 deaths, 48 000 are caused by malignant melanomas and 12,000 by other
skin cancers. Skin cancer is caused by sun exposure in more than 90 per cent of cases.
How to protect yourself
Sun Block: Even if you don’t burn, aim for the highest possible UV protection. It is the UVA rays (that don’t cause burning) that you are trying to block out. Ideally you should aim for an SPF of 30 or more to offer protection.
• Apply sun block to all areas, even those covered in loose clothing. UVA rays can penetrate water, clothing and glass to affect the skin.
• Towel drying, sweating and swimming all reduce effectiveness of sun block.
• Use sun block as part of your daily skin care regimen. Choose a face cream that includes a high SPF to protect your skin all year around.
Sun exposure: While sun block may protect you to some degree from UVA and UVB rays, it will not entirely protect you from skin cancer.
Skin cancer is not only associated with the time spent in the sun, but also with the intensity of the UV rays at the time of exposure.
• Avoid the sun during the peak hours of exposure from 12am to 3pm.
• Wear thick cotton clothing to block out UVA rays.
• Wear a wide-brim hat or stay in the shade of an umbrella when in the sun.
If you do have risk factors for skin cancer (like fair skin or a family history of skin cancer), then consider going for a yearly check-up with a dermatologist. They will note the size, shape and distribution of any skin markings and follow their progress.