Summer is here and we need to protect our skin from excess UV Radiation. Short exposure (10 minutes) has therapeutic effects as it improves the production of Vitamin D and this increases calcium absorption however longer exposures can cause severe damage to skin including sunburn, skin cancers including the potentially deadly melanoma (Holick 2004).
Athletes spend many hours in the sun not just 10 minutes! One study of 290 high school students in 13 different sports found a mean outdoor training duration of 4 hours a day 10 months of the year, approximately 1,000 hours of sun exposure annually (Wysong 2012). Sweating also increases the sensitivity of the skin to UV radiation thereby increasing the sunburn risk.
The environment athletes train in also contributes to the exposure risk. UVB radiation increases 5 - 10% per 300 meters above sea; reflected UV radiation of snow can be as high as 60% compared to 10% off sand or 2 -3 % of grass (Chadysiene 2008). Water also reflects a significant portion of UV radiation and both UVA and UVB rays penetrate water to reach athletes.
The best defence to UV radiation after clothing is sunscreen. However Recent studies have shown that the organic and inorganic UV filters as well as other components of sunscreen reach the marine environment directly via water activities and indirectly from waste treatment plants.Â The toxicity of the UV fillers has been demonstrated in aquatic organisms. UV Fillers inhibit growth in plankton and bioaccumulate in the food chain (Sanchez-Quiles 2015)
Not all sunscreens are equal and fortunately there are brands that will safely protection your from UV radiation that do not contain the substances that are known to harm the marine environment
Sunscreens are products containing filters that help prevent the sun's ultraviolet (UV) radiation from damaging the skin. UV Filters can be organic or inorganic and many sunscreens will contain a combination of both. There are 50 organic compounds allowed as UV filters. The inorganic compounds are titanium dioxide and zinc oxide generally in the form of nanoparticles as they give an effective protection without whitening the skin.
Sun Screen impact on the Environment
On the skin organic UV filters should be photostable under sunlight, however in water these can undergo change and form undesirable by-products that compromise their UV absorption properties (Santos et al, 2012). Sunscreens are also a source of toxic chemicals into the environment, UV filters and other components such as UV stablizers have been found in the tissue of marine organisms. Sunscreens induce corals bleaching by promoting the lytic viral cycle, killing microalgae . (Danovara et al., 2008)
Nanoparticles are generally covered with an inert coating to avoid it breaking down in sunlight however this layer dissolves in aquatic environments (Boota et al 2011). More than 200 studies provide evidence of the toxicity of nanoparticles in aquatic organisms. (Sanchez-Quiles 2015)
The most common UVA filter is Oxybenzone and is in over 70% of sunscreens, Oxybenzone is a very fine substance that penetrates the skin, gets into the bloodstream and acts like estragon in the body. It can trigger allergic reactions has been rated as a moderately high health hazard by the Environmental Working Group. Oxybenzone is also the most commonly detected UV filter in marine water samples and considered is a marine hazard. Oxybenzone leaches the coral of it's nutrients and bleaches it white. It can also disrupt the development of fish and other wild life.
UV Filters can reach the marine environment in seawater, rivers and lakes directly through water activities or from waste treatment plants. (WTP) Showering, laundering, swimming in chlorinated swimming pools or even urinating are sources of sunscreen components discharged to the WTP where they are not completely removed (li et al., 2007).
What to look for in a sunscreen
Take the time to read the ingredients and avoid sunscreen that contain oxybenzone, nano particales and parabens.
Buy a broad spectrum sunscreen with an SPF 30 or SPF 50. The new Australian/New Zealand standard limits SPF claims to 50 in line with other international standards. Above SPF 50+ the additional protection is very small. High SPF values are a problem as people use them to stay out longer in the sun during which time they receive large doses of radiation.
Look for a sunscreen that is highly water resistant and for verified product reviews as not all water resistant sunscreens are equal. Sunscreen's receive the water resistant rating with exposure to water with moderate exercise only. The water resistant time stated on products is also unreliable as sunscreens made in Europe or the USA can only claim 80min water resistant even if it provides 4+ hours of protection.
Try to find a sunscreen that is also biodegradable as this is more likely to be reef friendly. There are no specific test to determine if a sunscreen is reef friendly but sunscreens that promote they are biodegradable must have certification of this from approved laboratories.
Also avoid sunscreens that contain Vitamin A (retinyl palmitate) as scientists have found that vitamin A can spur excess skin growth, known as hyperplasia and that in sunlight retinyl palmitate can form free radicals that damage DNA (NTP 2000).
Avoid sunscreens that contain insect repellents as they have has been shown to reduce the effectiveness of the UV fillers.
Finally Select lotions rather than sprays as it is easier to get an even coverage and they are generally kinder on the environment.
Further research is needed into the impact of sunscreens on the marine environment but we do know they are having an impact so select your sunscreen brand carefully.
Remember where possible cover up, if you can't avoid the midday sun put on a sun hat and sunglasses, wear a wetsuit or a long sleeved rash vest when swimming, apply your well considered sunscreen purchase generously 20 minutes prior to UV exposure, use lipbalm and check your skin regularly and have anything unusual seen immediately.
Author: Katherine Greer, Managing Director of Hydro Surf. When I started surfing 30+ years ago, there were no water resistant sunscreens on the NZ market. I sourced Aloe Up, a sports sunscreen made specifically for active people, to protect myself and my children while surfing. Hydro Surf now distributes Aloe Up in New Zealand. Aloe Up SPF 30 and SPF 50 lotions have the biodegradable certification and are reef friendly. For more information go to www.aloeup.co.nz.