Consumer VOICE

Do sunscreens work?

Sunscreen brands have a fair bit of presence in the media these days. Going by their advice, Indians should not step out of their homes without a liberal application of the cream that is supposed to protect one from the harms of direct sunlight exposure. However, in a tropical country like India, which has always weathered summers, it remains to be seen whether people will take to sunscreens, or whether sunscreens can do any real good. While sunscreens may be essential for people living in Europe or America and those who spend a long time sunbathing, Indian conditions, with centuries of living with the Sun, are very different.

The manufacturers refrain is that everybody should use sunscreen, regardless of skin type or colour and that sunscreen should be applied any day a person is going to be exposed to the sun for more than 20 minutes. 

What is SPF?

The Sun Protection Factor (SPF) rating is calculated by comparing the length of time it takes for unprotected skin to turn red versus protected skin. For instance, a light-skinned person may burn after 10 minutes of unprotected sun exposure. Protected by sunscreen with an SPF of 2, the same person would burn in 20 minutes.

 

The higher the SPF number, the longer a sunscreen will offer protection. A sunscreen rated SPF 15 would provide the same fair-skinned person with protection for 15 times longer, or 150 minutes. By comparison, a typical white
t-shirt has an SPF of three. Heavier clothing typically offers an SPF of six.

The flip side of sunscreens

Nano-particles of titania (titanium dioxide) used in some sun creams can damage brain cells. Nano-particles (or small-sized particles) started to be used when an effort was made to reduce the white-mask look of sunscreens. Mineral sunblocks that contain titanium dioxide (TiO2) or zinc oxide (ZO) are preferable to chemical sunscreens, because rather than being absorbed into the skin, the minerals lie on top of the skin, reflecting UV rays before they cause damage. It is this white-mask that is worn as sunscreen by cricketers and lifeguards. 

But this is where problems with minerals arise. In order to reduce the visibility of sunscreen, many manufacturers use nanometer sized particles of TiO2 and ZO.
A nanometer (nm) is about a billionth of a meter-a unit so small that a single human hair is about 80,000 nm in diameter.

Nanoparticles are unpredictable because their small size and high ratio of surface area to volume can produce chemical or physical properties that are very different from their larger counterparts. For instance, once TiO2 nanoparticles enter the bloodstream, they are at risk of infiltrating the brain where they can damage cells, whereas larger micron-sized (millionths of a meter) particles of TiO2 are blocked by the blood-brain barrier, which protects the brain from harmful substances in the bloodstream. However, the scientific community is still at variance with each other over whether TiO2 or ZO can penetrate the skin deep enough to actually enter the bloodstream.

Alert

Further confusing the issue, some companies, in the USA for example, use the term "micronized" to describe micron-sized particles, while other companies use it to describe particles that undergo what some dictionaries define as "breaking into very fine particles." Since the FDA has no set definition for the term, some companies misleadingly advertise nano-sized particles as "micronized," which is why its important to verify particle sizes when youre purchasing a product that contains "micronized" or "nanoparticle" ingredients.

Benzophenone 

There are some troubling facts about benzophenone, a substance found in many sunscreens. The first relates to skin irritation and allergies. Generally, it is rare for people to have bad reactions to sunscreens, especially because PABA, a substance that used to be ubiquitous in sunscreens and that causes skin irritation and allergies in some users, has become increasingly rare. With PABA complaints on the decline, other substances are getting attention. Benzophenone is one of them. Those who get a rash after using sunscreen may be reacting to this compound. 

Less well researched but perhaps more important, benzo-phenone-3 appears to mimic the hormone estrogen. In one study, estrogen-sensitive breast cancer cells in test tubes multiplied when they were exposed to benzo-phenone-3, indicating that the substance was acting like estrogen. While research on this subject is preliminary, results suggest that benzophenone-3 has the potential to disrupt the endocrine system of people who use it.

Preventing skin burns

It is not impossible to avoid skin burns. Just covering oneself up adequately during peak sunlight hours, especially the back of the neck, wearing full-sleeves cotton clothes, sunglasses and a cap or a hat can reduce the damage caused by the sun. Alternatively, simply carrying a pretty umbrella should also do the trick. The Indian dupatta, the saree pallu, or the earlier pagdi were ways of protecting oneself from the Sun. 

We venerate the sun. Those of us who include the Surya Namaskar in our daily routine continue to build a healthy relationship with the sun and that is what we can recommend us Indians do, instead of plastering ourselves with chemicals

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