Other than the intrinsic aging, environmental exposure contributes additional insults on the skin. Knowing these 3 biggest environmental factors that cause skin aging, you can avoid them and slow down skin aging as much as possible.
Ultraviolet Radiation
Sun exposure is the biggest cause of environmentally induced skin aging. Studies show that there is an overall loss of 1% per year of collagen bundles when photo-aged skin is examined microscopically. Here I’d like to remind you of the following situations where you need to particularly protect yourself.
-
Cloudy days: Solar radiation is composed of infrared radiation and UV radiation. Clouds attenuate infrared radiation much more than UV radiation. So there is less heat sensation on a cloudy day. But it is NOT much safer to have outdoor activities on a cloudy day because UV radiation is not significantly reduced. For example, a very heavy cloud can prevent about 50% UVB and allow most UVA to pass through. Remember that UVA makes up to 90 to 95% of UV energy in the solar spectrum.
-
Noon: During summer, about 75% of the total daily UV radiation is received from 9AM to 3PM. So avoid outdoor activities during this time period.
-
Fun time: Sand reflects about a quarter of UVB so you still need sunscreen while sitting under an umbrella on the beach. Snow reflects 50-95% of sunlight so protect yourself very well while skiing. Water is a good transmitter of UV radiation. About 75% of UV radiation is transmitted through 2 meters of clear ocean water. Reapply your water-proof sunscreen when swimming outdoors.
Heat and Infrared Radiation
The effects of heat and infrared radiation (IR) on skin aging are less researched and not fully understood. Generally the damage to skin caused by heat and IR is similar to the damage induced by UV radiation. Infrared radiation comprises approximately 40% of earthbound solar radiant energy. Since people start to suspect that the amount of IR is enough to cause skin aging, some companies have developed sunscreens against IR as well. As far as I know, this is not reliable. There is not as much research on IR as on UV and we don’t know the ingredients or mechanisms to fight again IR yet. In this case, having physical protections, such as hats, umbrellas, etc, is helpful. Some home appliances, a kind of space-heater for example, also emit IR. It is good to avoid this type of appliance.
Heat problems to skin are mainly from open fires, cook ovens, heating pads etc.. That is why bakers and kitchen workers exposed to direct heat for many years tend to have faces and arms that appear older. So try to keep enough distance to ovens when you cook. And eliminate the use of fireplaces and space heaters.
Free Radicals
Free radicals contain one or more unpaired electrons, making them highly unstable. They cause random and irreversible damages of tissue by getting electrons from biological molecules. Free radicals can be a result of UV radiation, petrochemical pollutants, oxygen, and ionizing radiation (tobacco, construction materials, gas, coal, televisions, luminous watches, X-ray, electron tubes, fluorescent lamp starters). Sounds like everywhere, right? But we live in a read world and cannot completely avoid these things. So the best way is to eat antioxidant-rich foods and use skin care products with antioxidants. Antioxidants can either act as scavengers to provide electrons for free radicals or enzymatically hasten biochemical reactions.
References
Anthony V. Benedetoo, Do. The environment and skin aging, Clinics in Dermatology 1998; 16: 129 – 139.