Displaying items by tag: sun
Sun Protection Advice for Sailors
#sunprotection – Sailors and boaters are constantly outdoors pursuing their sport, so it is essential they are aware of the great increase in melanoma and skin cancer due to exposure to the sun's radiation.
They need to taking the most appropriate precautions to avoid getting skin diseases such as melanoma or skin cancer which can be fatal.
Leading dermatologist, Dr Patrick Ormond, a Board Member of the Irish Skin Foundation and a leading Consultant Dermatologist in St James Hospital, Dublin writes here about how the skin and the sun interact, and offers practical sensible advice is to be given on how to protect their skin in the sun.
The skin and the sun
The skin is the interface between the self and the environment, and as such protects us from many of the outside world's insults. One of the most important functions of the skin is protection from the sun's radiation. As the force of evolution pushed humans to become a relatively hairless organism, our skin had to develop strategies to protect our DNA from the damaging ultraviolet rays of the sun. Melanin is the primary protective mechanism used by the skin to protect. There are two types of melanin – eumelanin and phaeomelanin. The latter is far less effective in photo protection, but the mixture of these two types of melanin that has resulted in the diversity of human colour and, subsequently, an individual's ability to protect itself from UV radiation.
A person's skin type is important in advising on sun protection methods. Paler, fairer skin needs more protection that darker skin. Other visual clues include hair – red/fair hair, colour of eyes – blue/green, and presence of the freckles. All these indicate increased risk.
Ultraviolet radiation
Ultraviolet radiation (UVR) from the sun damages the skin. There are two types of UV radiation that affect the skin – UVA and UVB. UVR varies with the time of day, season, latitude and altitude, and is higher in the middle of the day, in the summer months, proximity to the equator, and further away from sea level.
Avoiding sun exposure when the radiation levels area at their highest – the middle of day between 11and 3, and particularly between May to September in Ireland.
If your shadow is shorter than you are tall, seek the shade. Be aware of reflection off water, sand and snow.
Don't forget the nearer to the sun, the more intense the radiation,due to loss of atmospheric diffraction filtering. Mountain climbing, skiing and other high altitude activities all need to be sun aware.
Be aware that on a cloudy day, up to 80% of the sun's radiation can penetrate through, and that UVA can penetrate glass.
The sun and skin cancer
UVB has been strongly associated with the development of many forms of skin cancer, including the three most common – basal cell carcinoma, squamous cell carcinoma and malignant melanoma. UVA penetrates deeper into the skin and has been long associated with premature aging of the skin, but its vital role in carcinogenesis of the skin has been recognised more recently.
Sun damage can be either acute or chronic. Malignant melanoma is strongly associated with acute sun damage. Reducing melanoma risk is about avoiding sun burning and sun bathing. Chronic sun damage has been associated with all forms of skin cancer. Minimising the risk from all types of skin cancer is about reducing total sun exposure over a lifetime.
Avoid sun burning and sunbathing.
You can't avoid the sun, but you can reduce the amount you get.
Sun behaviour
In Ireland, public awareness of the damage the sun can do to your skin has increased greatly over the last few decades. People's behaviour in the sun and more specifically their sun protection behaviour has improved. In practice most will use some form of "sun protection" strategy while on holiday abroad, commonly the use of a sun protection factor ( SPF). However the use of an SPF should be only one of a number of measures used. There is a perception that using an SPF allows one to sun bathe "guilt free". This is not the case. A tan simply shows the skin has been damaged.
The sun in Ireland is also the same sun as in Spain, but many of us forget to use sun protection/reduction behaviour on an everyday basis. This is slowly changing, particularly in the context of preventing skin aging.
There is no such thing as a safe tan.
It's the same sun here as on holiday.
How sun protection factors work
Sunscreens work by reflecting, absorbing or scattering the sun's radiation. Most sunscreens contain a mixture of compounds and work by a combination of these methods. Some contain chemicals that either interact with the skin to reduce the damage inflicted by UVR on the skin, or reduce the degradation of the photo protective compounds by the UVR. Modern sunscreens have changed, and most have both UVB and UVA protection levels. They both have slightly different methods of quantifying and declaring the protection level offered. The "SPF factor" refers to the UVB protection. The SPF number indicates the length of time taken to burn using that factor. SPF15 – in laboratory conditions, would increase the time taken to burn by a factor of 15. In other words, for a person whose non sun exposed skin would normally burn in 10 minutes, then using SPF15 correctly, it would take 150 minutes to burn. UVA protection is beginning to be standardised, and the most commonly used rating systems are either a "star" rate or low/medium/high protection level.
Sunscreens have an expiry date – usually retaining their original strength three years from manufacture. Sunscreens will degrade in sunlight, and extremes of temperature. Although correct usage of a sunscreen would make it unlikely that a bottle would not be used in a short time, in reality many people under apply sunscreens, use and store them in hot environments and subsequently may not retain their efficacy.
Use a sunscreen with both UVA and UVB protection.
Make sure it is in date.
The use of sun protection factor
Studies have shown that in real life, as opposed to laboratory conditions, most people apply sunscreens incorrectly. We apply between 25 – 50% of the recommended amount, effectively reducing the protection factor by 40 – 70%. We sweat off the sunscreen and there is a variable degree of photo degradation of the sunscreen whilst out in the sun. Sunscreens need to be applied liberally and frequently. Most dermatologist have difficulty reconciling with "once a day" sunscreens as a result. In my opinion the only reliable "once a day sunscreen" is what is commonly called a tent.
A guide to the correct amount to use is" a teaspoon to the face, and a shot glass to the body". Many will not use this amount, and is why most dermatologists advocate using factor 30 or greater. - it allows for a degree of " diluting" the level of protection. SPF number and the amount of UV screened out is not a linear relationship – the difference in amount of protection offered by SPF5 and SPF 15 is much larger than the difference between SPF15 and SPF50.
Apply a sunscreen of factor 30 or higher. Apply to dry skin, at least 15 minutes before being exposed to the sun
Generously coat any areas of skin that are not covered and reapply every two hours, or more frequently if swimming/exercising/towelling.
A water resistant formulation is preferred, as it won't be sweated off as easily, but remember there is no such thing as a waterproof sunscreen. Nor is there such a thing as a 100% total sun block.
Even though you are using SPF30 – it does not mean you can stay out in the sun 30 times longer!
Formulations of sunscreen
The range of sunscreens has greatly improved, and many formulations are available with a variety of practical and cosmetic acceptability. Micro-particles have reduced the "white mask" appearance, most commonly associated with titanium dioxide and Zinc oxide, particularly for those used on the face. Creams are more acceptable on the face or on dry skin, whilst sticks are useful for around the eyes and on the lips. Gels and mousses are good for hair bearing areas such as the scalp or male chest, and sprays are particularly useful for balding scalps.
Sprays are also useful for children – easy to apply, but there is still some improvement needed in standardisation of these formulations, and knowing the amount to apply can be difficult. Sunscreens can be used over the age of 6 months, and there are special sunscreens, containing predominantly Zinc oxide or titanium dioxide, which are less likely to irritate sensitive skin. Avoid exposing babies less than 6 months, and instead use shade, clothing etc as protection.
Summary of advice
Be sensible in the sun
Stay out of the sun if possible, most particularly when the radiation levels are high – 11 to 3, May to September.
Short shadow - Seek the shade
Cover up with clothing as much as possible – long sleeves, long trousers
Wear a wide brimmed hat and wrap around sunglasses
Apply sunscreen to any areas of exposed skin – factor 30 or higher, apply generously and frequently
