Centre for Behavioural Research in Cancer, Cancer Council Victoria, Melbourne, VIC 3004, Australia.
Klein Buendel, Inc., Golden, CO 80401, USA.
Int J Environ Res Public Health. 2022 Aug 25;19(17):10583. doi: 10.3390/ijerph191710583.
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, = 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 ( < 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.
减少紫外线（UV）暴露对于预防 UV 引起的皮肤和眼睛疾病至关重要。阴影可能提供显著的 UV 防护。需要更多的实证研究来量化建筑阴影提供的 UV 防护，以指导疾病预防实践并增强对投资阴影的信心。本研究在两个城市的公园中，量化了夏季建筑阴影下的 UV 水平与无阴影的被动娱乐区（PRA）相比。在一项随机对照试验中，在 2010 年至 2014 年期间，每个城市进行了三轮招募，在每个城市的三个招募波中，对公园游客使用 PRA 的预测试和后测试措施中，在 PRA 的中心和周边共进行了 1144 次 UV 测量，共有 144 个公共公园作为样本。预测试后，36 个 PRA 获得了建筑阴影，108 个没有。回归分析模型化了 PRA 中 UV（每 30 分钟标准红斑剂量（SED））的预-后变化；和环境预测因子。建筑阴影 PRA 中心的平均 UV 从预测试到后测试降低（x¯ = 3.39，x¯ = 0.93 SED），与对照 PRA 相比，变化量为 x¯ = -3.47 SED（<0.001），调整了环境 SED、（余弦）太阳仰角和云覆盖率的协变量。云层减少和太阳仰角增加了阴影下的 UV 水平。阴影设计对 UV 没有显著影响。使用遮阳布设计的建筑遮阳可以显著减少 UV 暴露，为遮阳使用者提供相当大的保护。建议在晴朗天气下长时间使用遮阳时补充防晒。
