UVA, SPF, Pollen count! What does it all mean?
Summer officially starts on the 21st June, so you're going to be hearing a lot about protecting yourself from the sun and how to control your allergies but what do all the abbreviations mean? Fear not Health Matters are here to help you understand just what it is you need to know.
Ultraviolet
The sun emits ultraviolet radiation in the UVA, UVB and UVC bands, but because these rays have to pass through the atmosphere's ozone layer, 98.7% of the ultraviolet radiation that reaches the Earth's surface is UVA. Lost already? Do not worry... UV is sort for Ultraviolet and the 3rd letter is the letter for that specific wave A being long wave, B being medium wave and C being short wave. UV rays can burn the eyes, hair and skin if these parts of the body are not properly protected. Most people are aware of the affect of UV through the painful condition of sunburn, but UV rays have many more other effect, both beneficial and damaging, on human health.
Beneficial effects
Vitamin D
The Earth's atmosphere blocks UV radiation from getting to the Earth's surface by 98.7%. A positive effect of UVB exposure is that it induces the production of vitamin D in the skin. An effect of vitamin D deficiency is poor absorption of calcium which can lead to bone diseases Also there has been a rise in cases of Rickets in children in built up areas such as New York where sunlight can be blocked. During the Industrial Revolution, rickets appeared in epidemic form in temperate zones where the pollution from factories blocked the suns ultraviolet rays. Thus, rickets was probably the first childhood disease caused by environmental pollution. Some studies show that most people get adequate Vitamin D through food and Incidental exposure. Many countries have fortified certain foods with Vitamin D to prevent deficiency. Eating fortified foods or taking a dietary supplement pill is usually preferred to UVB exposure, due to the increased risk of skin cancer from UV radiation.
Medical applications
Ultraviolet radiation has other medical applications, in the treatment of skin conditions such as psoriasis and vitiligo. UVA radiation can be used in conjunction with psoralens (PUVA treatment).
Harmful effects
An overexposure to UVB radiation can cause sunburn and some forms of skin cancer. In humans, prolonged exposure to solar UV radiation may result in acute and chronic health effects on the skin, eye, and immune system.

SPF
SPF stands for Sun Protection Factor and is used to help understand how much protection you receive for different sun creams. SPF comes in different levels designated by a numeric system.
Factor 15, only 7% of the harmful UVB rays will get through
Factor 30, only 4% of the harmful UVB rays will get through
Factor 60, only 2% of the harmful UVB rays will get through
Sunscreens with an SPF of 15 or higher provide the best protection from the sun's harmful rays.

Pollen count
The pollen count examines the amount of a particular type of pollen grain in an air ample, measure per cubic metre. To smooth out blips, it averages this number over the 24 hour period of a day. Although a few hay fever sufferers are allergic to mould spores, for most of us it's an allergic reaction to pollen that causes the runny nose, watery eyes and bouts of sneezing. So knowing how much pollen is in the air on any given day is crucial to managing your hay fever symptoms. About 95% of hay fever sufferers in the UK are allergic to grass pollen. The season for grass pollen starts towards the end of May and goes through to August, peaking in June and early July.

Editor: Ryan Cranston
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