Types of Shade Vary in Protection Just Like Sunscreens

Solar UV Measured under Built-Shade in Public Parks: Findings from a Randomized Trial in Denver and Melbourne

Reducing exposure to ultraviolet radiation (UV) is crucial for preventing UV-induced diseases of the skin and eyes. Shade may offer significant protection from UV. More empirical research to quantify the UV protection offered from built shade is needed to guide disease prevention practices and confidence in investment in shade. This study quantified UV levels under built-shade relative to unshaded passive recreation areas (PRAs) over summer months in parks in two cities. In a randomized controlled trial, n = 1144 UV measurements were conducted at the center and periphery of PRAs in a total sample of 144 public parks as part of pretest and posttest measures of use of the PRAs by park visitors for three recruitment waves per city during 2010 to 2014. Following pretest, 36 PRAs received built-shade and 108 did not. Regression analyses modelled pre-post change in UV (Standard Erythemal Dose (SED) per 30 min) at PRAs; and environmental predictors. Mean UV at the center of built-shade PRAs decreased from pretest to posttest (x¯ = 3.39, x¯ = 0.93 SED), a change of x¯ = -3.47 SED relative to control PRAs (p < 0.001) adjusting for the covariates of ambient SED, (cosine) solar elevation and cloud cover. Clouds decreased and solar elevation increased UV levels under shade. No significant differences in UV by shade design occurred. A substantial reduction in exposure to UV can be achieved using built-shade with shade cloth designs, offering considerable protection for shade users. Supplementary sun protection is recommended for extended periods of shade use during clear sky days.

Sun Protective Clothing and Sun Avoidance: The Most Critical Components of Photoprotection in Patients With Melanoma

BACKGROUND

Ultraviolet radiation is the main modifiable risk factor for melanoma which can be reduced by avoiding excess sun exposure.

OBJECTIVE

We sought to explore (1) sun protective practices, (2) effectiveness of these sun protective practices, and (3) vitamin D supplementation in patients with melanoma.

METHODS

Using the National Health Interview Survey, the authors conducted a cross-sectional analysis to investigate sun protective behaviors and sunburns among adults with melanoma compared with those without skin cancer. We calculated adjusted odds ratio (aOR), 95% confidence interval (95% CI), and p-values using logistic regression.

RESULTS

Patients with melanoma reported increased use of sun avoidance, shade, sunscreen, long sleeves, and hats, but had similar sunburn rates compared with those without skin cancer. Only sun avoidance and long sleeves were associated with decreased odds of sunburn. Patients with melanoma also reported decreased vitamin D supplementation.

CONCLUSION

Although it is reassuring that patients with melanoma practice sun protective behaviors, this does not always translate into reduced sunburns. Physicians should emphasize the importance of photoprotection, especially sun avoidance and sun protective clothing, to reduce future melanoma risk.