Q) The last few weeks you reviewed the importance of using sunscreen to protect my skin. I am worried about the chemicals contained within sunscreens. Is there another way to protect myself and my kids from the damaging effects of the sun rays?
A) Other than staying out of the sun completely, the best way to protect oneself from the damaging effects of the sun such as burning, aging and cancer is through the use of clothing. In fact, some skin experts prefer this method to the use of sunscreens. This is not because of some perceived risk from the chemicals used in sunscreens but rather due to the undeniable fact that the vast majority of people fail to use adequate amounts of sunscreen or fail to reapply as frequently as is necessary (every few hours) to gain the full benefits.
As to the safety concerns regarding the chemicals used in sunscreen, experts consistently agree that there is no proof these are harmful even after many years of widespread use, whereas we definitively know that sun exposure will lead to many Canadians being diagnosed with some form of skin cancer of which nearly 10% will be of the potentially lethal melanoma variant.
Getting back to our garments, all clothing to some degree impacts the transmission of UV radiation. The amount of protection is measured by a UPF (ultraviolet protection factor) rating (sunscreens use SPF ratings). UPF measures blockage of both UVA and UVB rays whereas, an SPF only indicates the degree of protection from UVB rays. The higher the number, the greater the reflective qualities and the safer you will be. A UPF of 50 allows only 2% of the sun’s rays to pass through whereas a UPF of 25 would block all but 4% . This number also serves as an indication of how many times longer you can be exposed to the sun before it starts to damage the skin cells underneath it.
When fabrics and ultraviolet radiation meet, the energy from the UV rays is changed. The radiation is converted to heat, a conversion that renders most of the ray harmless. Clothing must have a UPF of at least 15 to be marketed as UV- protective. To put that in perspective, a white cotton t-shirt would have a UPF of between 5 and 8. Interestingly, laundering a shirt repeatedly can increase its protective factor since most detergents use optical brightening ingredients (these are the chemicals that allow your laundry detergent to make your whites “whiter than white”) that boost the disruption of ultra violet rays when they strike your garment.
There are a variety of factors that make some garments more effective at changing these rays than others. These include;
- Colour and thickness: The denser and darker the material, the higher the UPF. Recall from above, the white cotton T-shirt has an average UPF of 7 whereas dark denim has a UPF of about 1700.
- The weave: Clothing made with loose weaves allows for many holes for the sun’s UV rays to reach your skin as compared to tighter weaves.
- The dye used: It is the specific type of dye and the concentration used, not necessarily the colour, that impacts a fabric’s UPF
- The “treatments” added, if any: Chemicals added during manufacturing that further disrupt UV radiation
- The stretch/fit: A tight-fitting shirt that is stretched against your skin allows for more UV rays to reach your skin. If a garment is stretched beyond 10% it loses much of its protection. It is best to choose loose fitting clothing for a more optimum UPF.
- The fiber type: During hot summer days, people opt for lighter-weight clothing. A linen shirt offers less protection than a sunscreen with and SPF 15 and that white cotton T-shirt offers a UPF of about 7. Though more people have been choosing more natural fibres such as 100% cotton of late, in terms of sun protection, synthetics materials such as polyester and nylon are excellent fabric options for better UPF.
- Whether it’s wet: Damp clothing is less effective. For example, that white cotton t-shirt’s UPF drops to 3 when it gets wet.
- Coverage: The clothing will only work if it actually covers your skin.
- Its overall condition: Worn or faded clothing is less effective.
- Wide-brimmed hats: The head and neck are exposed to the sun and are often not protected from the UV rays thus are the sites where skin cancers are more commonly found. Baseball caps do not offer great protection. Neither do straw hats due to the large holes in its weave.
In summary, UVF clothing is not a must do, but given that much of it is lightweight, breathable and fashionable, it makes a nice alternative for those who would prefer to protect their arms and legs in the hot summer by a more natural means. For more information about this or any other health related questions, contact your pharmacist.
