Urban environments can have high‐risk spaces that can provide excess personal sun exposure, such as urban or street canyons, and the spaces between buildings, among others. In these urban spaces, sun exposure can be high or low depending on several factors. Polysulphone film (PSF) was used to assess possible daily solar ultraviolet radiation (UVR) exposure in urban canyons in Venice, Italy and, for the first time in Africa, in Johannesburg, South Africa. The photodegradation of PSF upon solar exposure was monitored at a wavelength of 330 nm by ultraviolet‐visible spectrophotometry, and the resultant change was converted to standard erythemal dose (SED) units (1 SED = 100 J m−2). Mean daily ambient solar UVR exposure measured for Venice and Johannesburg ranged between 20–28 SED and 33–43 SED, respectively. Canyon‐located PSF exposures were lower in Venice (1–9 SED) than those in Johannesburg (9–39 SED), depending mainly on the sky view factor and orientation to the sun. There was large variation in solar UVR exposure levels in different urban canyons. These preliminary results should be bolstered with additional studies for a better understanding of excess personal exposure risk in urban areas, especially in Africa.

中文翻译：

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意大利威尼斯和南非约翰内斯堡城市峡谷中太阳紫外线辐射的比较

城市环境可能有高风险空间，可以提供过多的个人阳光照射，例如城市或街道峡谷，以及建筑物之间的空间等。在这些城市空间中，阳光照射可高可低取决于多种因素。聚砜薄膜 (PSF) 被用于评估意大利威尼斯城市峡谷中可能的每日太阳紫外线辐射 (UVR) 暴露，并首次在非洲的南非约翰内斯堡进行。通过紫外可见分光光度法在 330 nm 波长下监测 PSF 在日光照射下的光降解，并将由此产生的变化转换为标准红斑​​剂量 (SED) 单位 (1 SED = 100 J m-2)。威尼斯和约翰内斯堡的平均每日环境太阳 UVR 暴露量分别介于 20-28 SED 和 33-43 SED 之间。威尼斯 (1-9 SED) 位于峡谷的 PSF 暴露低于约翰内斯堡 (9-39 SED)，这主要取决于天空视角因素和太阳方向。不同城市峡谷的太阳 UVR 暴露水平存在很大差异。这些初步结果应得到更多研究的支持，以更好地了解城市地区，尤其是非洲的过度个人暴露风险。