A Special Report . . .

PUBLIC HEALTH HAZARDS
TO LIFEGUARDS
FROM SUN EXPOSURE

In general, there is evidence that excessive ultraviolet radiation (UVR) exposure from sunlight, both in recreational and occupational settings, can have deleterious health effects, including increasing the risk of skin cancers. However, data specifically dealing with the risks of skin cancer in lifeguards are not available. Of concern is that:

Skin cancers are preventable by reducing the exposure to the UVR from sunlight. In 1972, the National Institute for Occupational Safety and Health (NIOSH) issued criteria for a recommended standard entitled Occupational Exposure to Ultraviolet Radiation which advised that ". . . susceptible persons working outside in strong sunlight should be protected."³ But there are currently no State or Federal requirements providing outdoor workers with shelter, protective clothing/hats, sunscreens, or sunglasses.

Studies have shown an association between excessive sun exposure and both premature skin aging and skin cancer (Table l).⁴

Melanoma is the least prevalent of the three skin cancers but has the greatest risk of fatality, accounting for 85% of skin cancer deaths. The American Cancer Society estimates that over 53,000 Americans will be diagnosed with melanoma in 1998 with 7300 deaths.⁵ Melanoma is likely to be related to excessive sun exposure (although the relationship is complex); it seems to be associated with severe sunburns during childhood.

Basal cell carcinoma and squamous cell carcinoma are more clearly related to sun exposure, probably as a result of cumulative exposure over a long time period (e.g. as found in outdoor workers). Together, basal and squamous cell cancers make skin cancer the most common cancer diagnosed in the United States with up to 1 million Americans affected each year (with over 2000 deaths).

The UVR in sunlight is responsible for sun-related skin disease. UVR reaches the earth's surface as two main components, ultraviolet A and ultraviolet B (UVA and UVB); although UVB is clearly linked to skin damage and contains more energy, UVA penetrates more deeply and can cause harm as well.⁶

The key is

The peak hours of UVR exposure are 10 a.m. to 4 p.m., when the sun is highest. Less obvious is that the same is true on a cloudy day, since up to 80% of UVR can pass through clouds.

Shade. While it's true that these are peak working hours, sun exposure can still be reduced for the outdoor worker by providing shade when possible. Shade can be provided using protective awnings, umbrellas, hats and clothing.

Hats. The typical "baseball cap" provides some shade for the eyes, but does little to protect the ears, neck, and much of the face. Researchers in Australia (which has the highest rates of skin cancer in the world and where skin cancer prevention has become an important public health priority) studied the use of hats with full brims and found that UVR exposure of the head and neck decreases with increasing size of the hat brim. A 4 inch hat brim leads to about 70% reduction of UVB to the head and neck; this may need to be modified in work settings where visibility (especially from above) is important. Hats are also available which protect the ears and neck by "foreign legion"-type cloth flaps. Hats should be chosen to allow adequate air circulation for cooling.⁸

Clothing, too, varies in the amount of sun protection provided. Clothes should protect sun-exposed areas of the body. Densely woven fabrics provide more protection than those with open weaves, although clothing made of densely woven fabrics should be designed for a loose fit in order to allow adequate air to circulate and perspiration to evaporate. Among fabrics with open weaves, fabrics with darker colors absorb more radiation and therefore have less radiation penetration (but are also hotter to wear).⁸ Also available is clothing made of special sun-protective fabrics, which get their protective effect from a combination of fabric thickness, the composition of the fiber, and the weave tightness.⁹

Sunscreens. In addition to protection by shade-producing devices, sunscreens may also provide protection. However, there has been much debate over the protection offered by sunscreens. It is best to use sunscreens in combination with the other preventive measures.

SPF. Sunscreens are rated by SPF (solar protection factor) to tell how much they reduce exposure to sunlight. For example, a person wearing a sunscreen with an SPF rating of 4 takes four hours for the skin to absorb the same amount of UVB as it would in one hour with no sunscreen. However, the SPF rating was devised only for UVB.

The American Academy of Dermatology recommends sunscreens of at least SPF 15 but which also contain chemicals that block UVA (including benzophenone, oxybenzone, sulisobenzone, titanium dioxide, zinc oxide, and avobenzone).⁹ In order to protect the layers of the skin, sunscreen needs time to soak in to the skin, not just sit on the top, so it should be applied at least 20 minutes before going outside. Sunscreens should be applied liberally; it takes about an ounce per application over the body. Even the "waterproof" varieties eventually start to come off with enough sweat or water play, so some authorities recommend putting on another coat after about 2 hours, or every 45 to 60 minutes when swimming. The lips, too, are susceptible, and lip balms with appropriate SPF ratings are available.

Sunglasses. The development of eye cataracts is also associated with exposure to sunlight. Protection may be afforded by sunglasses that block 99 to 100 percent of UVR, as will be indicated on the manufacturer's label.⁹ Wrap-around or side-shield styles protect against light entering from the sides, but glasses should not reduce the worker's vision to the side, especially when critical for safety.

UV Index. In many areas, during the summer months the National Weather Service, in cooperation with the Centers for Disease Control and Prevention and the Environmental Protection Agency, issues daily predictions for UVR exposure called the Ultraviolet Index.¹⁰ On a scale of 1 to 15, higher numbers mean UV exposure is greater. The daily Index is reported on weather radio and by some commercial broadcasters. An explanation of the Index is available on the Internet at http://www.cpc.ncep.noaa.gov/
products/stratosphere/uv_index/uv_what.html, which indicates the degree of protection recommended at each level of the Index. Literature ¹¹ is also available similarly explaining the Index.

Prevention and Control Initiatives. Public health messages and programs on the prevention of skin cancers have been introduced by the Centers for Disease Control and Prevention, the National Institute of Arthritis and Musculoskeletal and Skin Diseases, the National Cancer Institute, the Environmental Protection Agency, the American Cancer Society, the Skin Cancer Foundation, the American Academy of Dermatology, and other groups. National health objectives set forth by the Public Health Service in Healthy People 2000 identifies the following goal in an effort to promote preventive behaviors: "Increase to at least 60 percent the proportion of people of all ages who limit sun exposure, use sunscreens and protective clothing when exposed to sunlight, and avoid artificial sources of ultraviolet light."¹²

References 1   Holman CDJ, Gibson IM, Stephenson M, Armstrong BK. Ultraviolet radiation of human body sites in relation to occupation and outdoor activity: field studies using personal UVR dosimeters. Clin Exp Dermatol 1983;8:869-871. 2   Vitasa BC, Taylor HR, Strickland PT, Rosenthal FS, West S, Abbey H. Association of nonmelanoma skin cancer and actinic keratosis with cumulative solar exposure in Maryland watermen. Cancer 1990;65:2811-2817. 3   NIOSH. Criteria for a recommended standard: Occupational exposure to ultraviolet radiation. USHEW 1972. 4   DiGiovanna JJ. Prevention of skin cancer due to sun exposure. In: DiVita VT, Jr, HelIman S, Rosenberg SA. Cancer prevention. Philadelphia, Pennsylvania: JB Lippincott Publishers, August 1991:1-9. 5   American Cancer Society. Cancer statistics 1998. CA-A Cancer Journal for Clinicians: Jan/Feb 1998. 6   Sunlight, Ultraviolet Radiation, and the Skin. NIH Consensus Statement Online. 1989 May 8-10 [cited 1996 June 17];7(8):1-29. 7   CDC. Survey of knowledge of and awareness about melanoma-United States, 1995. MMWR 1996;45 :346-49. 8   Marks R, Hill D, eds. The public health approach to melanoma control. International Union Against Cancer, 1992. Pgs 115-7. 9   Strange C. Thwarting skin cancer with sun sense. FDA Consumer Magazine, July-August 1995. 10   EPA. The experimental ultraviolet index fact sheet: explaining the index to the public. EPA 430-F-94-0l7. 11   EPA. What is the ultraviolet (UV) index? EPA publication 430-H-94-003, February 1995. 12   Public Health Service. Healthy People 2000: National health promotion and disease prevention objectives. Washington, DC: DHHS publication (PHS) 91-50212. [ Top of the Page ]

HERE ARE SOME
BASIC OCEAN SAFETY TIPS:

• Swim in LifeguardedAreas
• Never Swim Alone
• Don't Dive Into Unknown Water or Into Shallow Breaking Waves
• Ask a Lifeguard About Beach and Surf Conditions Before Swimming
• If You Are Unable to Swim Out of a Strong Current, Signal for Help
• Rely on Your Swimming Ability Rather Than a Flotation Device
• Look For, Read and Obey All Beach Safety Signs and Symbols
• If In Doubt, Just Stay Out !

Return to the Hale (Home) Aloha Page. You can also use the following links to continue your beach and ocean tour of Oahu's North Shore, South Shore, East Shore, or West Shore.

Or, you can go to the Beach Directory for a listing of all the beaches covered in these pages.

Suggestions, comments and recommendations are welcomed. These pages are a project of the Hawaiian Lifeguard Association, a not for profit, professional association of Hawaii's lifeguards devoted to the advancement of lifesaving services and public education on beach and ocean safety.

Webmaster: This page is maintained by J. B. Lee. You can reach me by e-mail at: jblee@aloha.com. Last modified: 07-Jul-2001 06:35 PM HST

ALOHA . . . malama i ke kai!