Soaring UV levels: Melting road tar a warning to 'slip, slop and slap'

Yesterday’s UV index chart from the National Institute of Water and Atmospheric Research. The UV level was the highest for Gisborne so far this summer. The temperature reached just under 33 in the shade at Makaraka.

If the tar seal on roads starts melting, then it is definitely time to use sunscreen on human bodies.

Research in recent years has shown just how seriously ultraviolet radiation can damage the tarseal component of road surfacing.

UV changes the structure of the tar and accelerates its chemical breakdown, leading to brittleness and cracking, which in turn makes the road more vulnerable to rain penetration and flexing from the weight of vehicles.

The same thing happens to human skin, which is why melting road tar is a warning to “slip, slop, slap”.

With clear blue skies over the past few days, not only have temperatures risen dramatically, but ultraviolet levels have soared.

For the time spanning 10.30 in the morning to 3.30 in the afternoon, Niwa’s ultraviolet index put the UV level  at 9 — very high or above.

At the worst part of the day from 11am to 2pm the UV index was over 11, hitting a maximum of 12.3 around 1pm.

As health authorities and the Cancer Society repeatedly advise, the best way to avoid skin cancers is to stay out of the sun during the heat of the day.

They also promote the wearing of sun-proof clothing, especially for children, and regular and plentiful applications of an approved sunscreen lotion to all skin exposed to the sun.

Roading engineers apply similar techniques to protect road surfaces from UV.

The latest science has identified additives for the tar which acts as the equivalent of sunscreen.

But much depends on other factors such as the age of the road and whether it is exposed to high rates of frictional pressure through heavy vehicles and high traffic numbers.

Many people are unaware that anti-UV additives are particularly used in mountainous terrain, where there is less atmosphere to soak up the UV rays, and more bendy roads with higher frictional loads.

So if you don’t want a face that ends up looking like an old cracked road, slap on the anti-UV warpaint!