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Tasmania may get cold, but sunburn is still very much a threat   

Tasmania may get cold, but sunburn is still very much a threat   https://www.abc.net.au/news/2022-02-14/uv-rays-not-heat-the-cause-of-sunburn/100774662, By Glen Perrin  If you think you cannot get sunburnt in chilly old Tasmania, you are sorely mistaken — the island state has more than its fair share of dangerous ultraviolet rays.

What is sunburn? What is UV?

Sunburn occurs when skin exposed to ultraviolet (UV) radiation is damaged.

The exposed skin becomes red, hot, and often painful.

If you think you cannot get sunburnt in chilly old Tasmania, you are sorely mistaken — the island state has more than its fair share of dangerous ultraviolet rays.

Additional melanin, the skin’s natural protector, is produced when the skin is exposed to UV radiation.However, when the levels of UV radiation exceed the protecting abilities of melanin, sunburn occurs.This can occur in less than 15 minutes depending on the time of year, the location and skin type.

Skin can turn red from sunburn within two to six hours of being burnt.Long-term excessive exposure to UV radiation may also cause skin damage, eye damage, premature ageing or even skin cancer, with Australia and New Zealand having the highest rates of melanoma in the world. UV radiation is a type of energy that we cannot feel (it does not make us feel hot) or see.Three bands of UV radiation are emitted by the sun: UVA, UVB and UVC.

UVB radiation is the main contributor to sunburn, despite the fact most UVB radiation (around 85 to 90 per cent) is absorbed by the ozone layer in the stratosphere about 15 to 30 kilometres above the surface of the earth.Australia has some of the highest UV levels in the world.

Why is sunburn a concern in Tasmania?

Many people relate getting sunburnt to temperature and incorrectly believe that in Tasmania, being generally cooler, means they won’t get sunburnt.Sunburn can occur on hot and cool days. It is intensity of the UV that is important.Such levels of UV are seen in Tasmania throughout most of the year, except for the winter months. It is also possible to burn in the morning and early evening, not just in the middle of the day.

Although cloud can decrease the amount of UV reaching the surface (with thick unbroken cloud reflecting and absorbing more UV than thin cloud), a break in or thinning of the cloud will still allow enough UV through to cause damage.Partly cloudy conditions can even increase the amount of UV at the surface by reflecting it towards the ground from the sides of the clouds.

Pollutants in the air can absorb some UV radiation or reflect it away from the surface.By comparison, air free from pollutants, such as in Tasmania, results in more UV radiation reaching the surface. Although the ozone hole occurs well to the south of Tasmania, ozone depletion can play a role in sunburn.

The ozone hole typically occurs between August and mid-December.When the ozone hole has broken down, it is possible for pockets of ozone-depleted air to mix with mid-latitude air.This air may then move over Tasmania, resulting in more UVB radiation reaching the surface.

What is the UV Index? How does it work?

The UV Index describes a daily UV radiation intensity and ranges from 1 (low) to 11+ (extreme).

A computer model generates the Index considering ozone concentrations, date, time of day, latitude and altitude and assumes a cloud-free and pollution-free sky.

Temperature is not considered.

Sun protection is recommended when the Index reaches 3 and above.

Sunburn occur any time of the year and at any location

UV levels, and therefore the UV Index, do change through the year, being lowest in winter (below 3 and in the low range in Tasmania) and highest in summer (mostly between 10 and 12 in Tasmania and in the very high to extreme range).

But exposure to excessive UV radiation can occur at any time of the year and can be enhanced by being at alpine locations (where the atmosphere is thinner, allowing more UV radiation to reach the surface), in the snow, swimming, or near other reflective surfaces such as concrete.

UV levels are higher towards the equator, as a result of having to travel though a smaller column of the atmosphere to reach the surface than at higher latitudes.

The UV Index is provided by the Bureau of Meteorology as part of city and town forecasts and through UV maps, tables and the BOM Weather App.

You can use the Cancer Council’s SunSmart app to view sun protection times and current UV levels.

The UV Index in city and town forecasts is also accompanied by a sun protection time when the UV Index is 3 or above.

This represents a time-period in which it is recommended that you slip, slop, slap, seek and slide to protect yourself from sunburn.

Remember you can still get burnt on cool or cloudy days – so think UV, not heat.

More information about UV and sun protection times can be found on the BOM website.

Glen Perrin is a senior meteorologist with the Bureau of Meteorology in Tasmania

February 14, 2022 - Posted by | health, Tasmania

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