You might want to be careful about the sunscreens that you use and how you use them when tanning this summer. Using them wrongly can be accompanied by potentially serious risks to your skin.
Using them correctly, however, can save millions of dollars in medical costs and spare our environment from potentially serious pollution.Read More »
Among those issuing warnings about sunscreen use is Dr. Win L. Chiou. He should know. He is a retired professor from the University of Illinois at Chicago and a former consultant to the Food and Drug Administration who has authored more than 200 publications and obtained six patents.
He says he wants to warn people about the misconceptions and potentially serious risks in the use of sunscreens when sunbathing. He points out that sunscreens with sun protection factors (SPFs) from 15 to 100 have been promoted for many years to reduce sunburn.
(The SPF indicates how long you can stay in the sun without being burned when using the sunscreen. If you would burn if you spent more than 15 minutes in the sun without protection, for example, an SPF of 30 would in theory allow you to stay in the sun for 450 minutes, or seven-and-a-half hours without burning.)
In spite of the use of these sunscreens, however, the incidents of skin cancer continue to increase. So, he asks, are the sunscreens as safe and effective as they are thought to be?
Areas are missed
The problem is that people often miss areas of their skin when they use high-rated sunscreens, Chiou explains. They also apply more sunscreen in some areas than in others. So even though the sunscreen protects those areas that are covered, it misses those that are uncovered.
The result is that unsuspecting users of the sunscreen think they are protected from sunburn for hours, but parts of their skin remain unprotected, he explains.
He cites a European study—titled “A Sun Holiday is a Sunburn Holiday”—in which all 25 sunbathers who were studied became sunburned after a week’s vacation at a resort even though they used sunscreen.
In another well controlled study researchers found that as much as 20% of the sunbathers’ skin remained unexposed and therefore was not covered with the sunscreen that was applied.
Chiou believes, therefore, that the increasing use of sunscreen might be causing increases in skin cancer—largely because of the areas that are missed.
The false feeling of protection even though areas are missed might also explain why it is futile to use sunscreens with higher and higher SPF values to avoid the increased incidences of sunburn and skin cancer in recent decades.
Chiou believes that severe sunburn is the root cause of most skin cancers. They are predominantly caused by ultraviolet B (UVB) rays. The need, therefore, to use broad-spectrum sunscreens containing ultra violet filters might need to be reevaluated.
He says, too, that the effects of sunlight on the skin vary with skin types. It therefore appears illogical to use a one-for-all SPF sunscreen for all people.
Anther warning comes from a study by researchers from the University of Oregon, Oregon State University, and the University of Leeds. A study there found that chemical reactions involving zinc oxide—a main ingredient in many sunscreens—cause it to become ineffective after only two hours of sun exposure.
They call for innovative new ingredients to be considered for use as ultraviolet filters in order to provide protection that is effective.
The problem is not zinc oxide itself, but the way in which it reacts with the other ingredients in many sunscreens, says Professor Richard Blackburn, professor of Sustainable Materials at the University of Leeds’ School of Design. He worked with the teams in Oregon on the study.
Once the zinc oxide is exposed to the sun for two hours it destroys the ultraviolet protection that the other ingredients provide, he explains.
The degradation of the ultraviolet filters not only decreases the sunscreen’s effectiveness, it also increases the toxicity in the formula, adds Professor James Hutchinson from the University of Oregon.
Therefore not only is the lack of effective protection an issue, but the product itself also might be causing harm when it is used in the sun.
So the use of sunscreen actually could make it worse because people believe that they are being protected from the harmful rays of the sun and might stay longer in the sun, he says.
The use of zinc oxide often is promoted as being a “natural ingredient” that is kinder to your skin. The team found that “mineral free” or “chemical-free” sunscreens that contain zinc oxide might be causing more harm than doing good in the sun.
Time in the sun is most important
What is the answer?
Chiou suggests avoiding peak hours when tanning without using sunscreen. You should also wear proper clothing and seek shelter to avoid too much exposure to the sun.
In other words, time spent in the sun is more important than trying to protect yourself with highly rated sunscreens. Doing so might result in your spending a long time in the sun and causing significant harm to those parts of your body that are not covered with sunscreen.
In addition the sunscreen itself might be causing you to suffer.
When using sunscreen Chiou suggests that people with colored and non-sensitive skin should use an SPF of 2 to 6. White people with sensitive skin should find a sunscreen with an SPF of 8 as adequate.
An SPF of, say, 6 would allow a person to stay in the sun for roughly an hour-and-a-half without suffering sunburn. If you are on the beach or at the pool for longer, you might want to opt for shade and clothing rather than sun.
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