June 28 , 2002

Shining a Light on the Risks of UV Exposure for Outdoor Workers

Peter Greaney, MD
Board-Certified Occupational Physician
President, WorkCare

Skin cancer is the most common type of cancer in the United States .  There are an estimated 1 million skin cancer cases annually [1] .  It is one of the 10 types of cancers whose rate is increasing, despite a decline in the rate of most other forms of cancer [2] . Since the primary cause of skin cancer is exposure to ultraviolet (UV) radiation, occupational health experts recommend that outdoor workers take preventative measures to safeguard their health.  This article provides information to the employee and employer on effective prevention measures.

Skin Cancer Types

There are three main types of skin cancer:  basal cell carcinoma and squamous cell carcinoma, both which are known as nonmelanoma types.  The third form is melanoma, which is less common, but potentially much more serious.

Both basal and squamous cell cancers are found mainly on the areas of the skin that are exposed to the sun – the head, neck, hands and arms.  These types of cancers vary in appearance, taking the form of a small, smooth, shiny, pale, or waxy lump.  The lump can also bleed or develop a crust.

The third form is melanoma , a skin cancer that is on the rise and responsible for an estimated 9,800 deaths in 2001.  Signs and symptoms include changes on the skin, especially in the size or color of a darkly pigment growth or spot.  This type of cancer arises from the melanocytes in the skin, and is considered the most serious because it can spread to other areas in the body.  According to the National Cancer Institute (NCI), evidence suggests that cutaneous melanoma may be related to sunburns, especially those occurring in early childhood. 

Causes of Skin Cancer

Solar UV radiation at the earth's surface consists of UVA and UVB rays.  These rays can directly damage the cells (DNA) of your skin.  The NCI states:  “UVB rays are more likely than UVA rays to cause sunburn, but UVA rays pass deeper into the skin. Scientists have long thought that UVB radiation can cause melanoma and other types of skin cancer.  They now think that UVA radiation also may add to skin damage that can lead to skin cancer and cause premature aging.”

Detection

The NCI reports that the cure rate for skin cancer could be “100 percent if all skin cancers were brought to a doctor's attention before they had a chance to spread.”  A regular self-examination is a good way to check for new growths or other changes in the skin. Learn how to do a Skin-Self exam.

Risk Factors

The single most important thing you can do to lower your risk of skin cancer is to avoid direct sun exposure. The risk of developing skin cancer is affected by where a person lives. People who live in areas that get high levels of UV radiation from the sun are more likely to get skin cancer.

Other risk factors for skin cancer include:

-Fair to light skin complexion

-Family history of skin cancer

-Personal history of skin cancer

-Chronic exposure to the sun

-History of sunburns early in life

-Atypical moles

-A large number of moles

-Freckles (an indicator of sun sensitivity and sun damage)

Protective Measures for Workers

If you work outdoors, it may not be possible to avoid sun exposure, so there are a series of recommendations by OSHA that can help protect you:

1.       Cover up:  Wear clothing to protect as much of your skin as possible. Wear clothing that does not transmit visible light.  To determine if the clothing will protect you, try this test:  Place your hand between the fabric and a light source.  If you can see your hand through the fabric, the garment offers little protection against sun exposure.  

2.       Use a sunscreen with a Sun Protection Factor (SPF) of 15 or higher.  Experts recommend products with a SPF of at least 15.  The number of the SPF represents the level of sunburn protection provided by the sunscreen.  An SPF 15 blocks out 93 percent of the burning UV rays; a SPF 30 blocks out 97 percent of the burning UV rays.  Products labeled “broad spectrum” block both UVB and UVA radiation.  Read directions on label and do not depend on sunscreens alone.  Combine sunscreens with wide-brimmed hats, UV-protective sunglasses, and tightly woven clothing to increase protection.

3.       Wear a hat.  A wide brim hat is ideal because it protects the neck, ears, eyes, forehead, nose and scalp.  A baseball cap provides some protection for the front and top of the head, but not for the back of the neck or ears where skin cancer commonly develops. 

4.       Wear sunglasses that block UV rays.  UV-absorbent sunglasses can help protect your eyes from sun damage.  Ideal sunglasses do not have to be expensive, but they should block 99-100 percent of UVA and UVB radiation.  Check the label to make sure they do.  Darker glasses are not necessarily the best.  UV protection comes from an invisible chemical applied to the lenses, not from the color or darkness of the lenses.

5.       Limit direct sun exposure.  UV rays are most intense when the sun is high in the sky, between 10 am and 4 pm .  If you are unsure about the sun's intensity, take the shadow test:  If your shadow is shorter than you, the sun's rays are the strongest.  Seek shade whenever possible. 

Recommended Strategies for Employers

If feasible, employers may consider the following engineering, administrative and PPE controls:

--Ensure that persons occupationally exposed to sunlight are aware of the risks and the appropriate control strategies

--Consider engineering controls, such as using natural shade or working indoors. Temporary shade can be provided by using canopies, tents, or other portable means of shade

--Consider administrative and procedural measures such as relocating the outdoor work to a shady area, or alternatively rescheduling the work outside the hours of 10 am to 2 pm .

--Encourage (or provide) use of personal protective measures--hats, broad spectrum sunscreens, sunglasses and appropriate clothing

[1] Cancer Facts and Figures 2001.  American Cancer Society.

[2] , 3 Annual Report to the Nation on the Status of Cancer, 1973-1998.  Journal of the National Cancer Institute:  Vol. 93, Issue 11, 824-842, 2001