Globally, the UV Index appears to be on the rise. Europe, North America, Africa and Asia seem to be a witness to the rising trends.
How is the weather today? This is the common question we ask when visiting a new town or meet a friend or relative. This is the topic we are going to discuss today as well— How is the weather?
Answer: Warmer than yesterday! Drastically warmer than years ago.
The current rate at which rivers and lands are drying, temperature rising and climate changing, could also reflect the state of our bodies.
Picture for representation only. Souce: Pexels
As our bodies are but the reflection of the environment in which we live. It may not be in India, but in many places in the world, when they ask about the weather, they also ask about the UV index. It has the following ranges:
- Low is less than 2
- Moderate is 3-5
- High is anything and above 7
- Anything above 8 is very high and then beyond 11 – extreme
Globally, the UV Index appears to be on the rise. Europe, North America, Africa and Asia seem to be a witness to the rising trends. What’s more disturbing is to see India’s contribution to the charts in the UV index. No doubt we are a tropical country, but the rising UV index surely is not a welcoming trend to our health either. Not only have we crossed the high mark, but also stepped beyond the extreme, something that is very conveniently neglected in our setting.
Now, the question is, why is this happening and what are the implications for the current generation and the next?
One thing is for certain, as the UV index rises, immunosuppression increases, cataracts rise and so does incidence of cancer.
Now, this has implications for nature as well as for humans and animals. Further, recent observations about the changing trends in migratory patterns of birds point to larger issues. Although migratory birds follow a very clear magnetic line, their geological pattern has been disturbed and they are unable to reach their homes. Additionally, changes in crop patterns have been attributed to bees being unable to reach their hives. These changes reflect a larger disturbance to the environment and the ecosystem.
There are three types of UV radiations. Typically, we call them VIBGYOR so the ones that are beyond the range of violet are called ultraviolet rays. The ones in the visible light spectrum, which are close to it, the UVA, the B and C. C is the farthest and A is the closest to visible light. Now, as the sun passes through the atmosphere, all of these UVCs are fully absorbed, 90% of the UVB rays are absorbed by ozone, water vapour, oxygen, carbon dioxide and the clouds. The UV ray that reaches the earth surface is largely UVA rays and a very, very little of B rays.
Now when you look at this energy given by the sun, the UVA ray is actually responsible for ageing, wrinkles and to an extent, cancers too.
The UVB ray causes sunburns and skin cancers. The UVC rays do not generally penetrate the atmosphere and hence we do not need to worry about them.
But there is one general rule that there are no safe UV rays, so we all worry about UV rays. About 90% of UV rays penetrate over the clouds and get reflected, and are received between 10 am to 2 pm.
They increase by about 4% for every 300 meters increase in altitude; it is true about depth in the same way.
The different skin types in humans contain melanin in different quantities, suggesting that their response to UV exposure also differs. The United Nations and WHO categorised skin into four types—the burner, the tanner, the naturally brown and the naturally black. This is based on the minimum exposure rates without producing any harm.
Now, our Indians fall in group 3, naturally brown. When our skin is exposed to a UV index of 10 or above (which is what we are exposed to) makes us highly vulnerable to the effects of UV rays. Health advisory in such instances often recommends usage of shade, sunscreen, shirts and cap.
They further divided the risk categories based into low rays, medium rays, high rays and very high rays. Currently, we are at the very high-risk category. Sunscreen lotions and other skincare products have come up but do not seem to be the logical solution to the problem. They are marketed very aggressively, but may not be the larger solution to the problem itself.
Question: Current reports say that these lotions are of no use. Is that right?
Answer: Absolutely, if you do not use the right one and for the right time.
We need to know that UV-A rays cause heat, and UV-B leads to burns. Here again, we need to differentiate between sunscreen lotions Vs moisturizers, and what SPF really denotes. SPF, in reality, tells you how long it can delay the burn if you apply it. Which means if the UV conditions outside mean that it would take just 10 minutes for unprotected skin to start going red, an SPF 30 sunscreen would theoretically prevent this for 300 minutes – 30 times longer at 5 hours. But the lotion would still need to be topped up at least every 2 hours to maintain this level of UV block. Moisturizers protect against UVA and not UVB unless they have an SPF, amid less effectively. (Ref: Photoprotection: Stephan et al: Lancet 2007; British Association of Dermatologists)
Bald patch on earth’s forehead
The ozone layer filters the UV rays. Today, it is called the ozone hole. Theoretically, we say that the ozone layer is depleting and that it is a worrisome fact. Pollution from industries and automobiles, deforestation and degardenisation with invading concrete jungles seem to be the key contributors of global warming.
We all need to take a collective responsibility of our ecology as much as we do for our economy. Governments, NGOs, civil society and media will need to rise to this occasion and take cohesive action to protect planet earth. For, the next five decades will be the defining years for us to accelerate future generations into destruction or pave the way for a brighter survival. #healthyearth
(Written by Dr Vishal Rao and edited by Shruti Singhal)