Photoprotection by clothing
英文原文
The increasing use and importance of clothing for sun protection for children is now a key elementin a range of protection strategies, where reducing ultraviolet radiation (UVR) exposures in early life is fundamental to skin cancer prevention programmes.Other applications of photoprotection by clothing are sun protection of outdoor workers in occupational situations, sun protection of the general population in ecreational situations, protection of photosensitive patients and protection of workers exposed to intense artificial sources of UVR such as welding. The broadest application and the one that this article will mainly concentrate on is clothing and sun protection, although there will be some discussion on the other areas.
对应中文
现在，越来越多的儿童衣物用于防晒，这是防护措施中的一个关键因素。减少早期生活中的紫外线（UVR）暴露是皮肤癌预防计划的基础。通过衣物进行光防护的其他应用包括在职业场合对户外工人的保护、在休闲场合对普通人群的防晒、对感光者的保护、以及对暴露在强烈紫外线辐射（UVR）源（如焊接）下的工人的保护。本文将主要集中在服装和防晒两个方面，其他方面也会有一些讨论。
Protection against solar UVR
太阳紫外线防护
英文原文
Providing protection against the sun is the most common application of photoprotection by clothing. Reducing solar UVR exposures in early life has been one of the main initiatives in skin cancer educationalcampaigns, such as in the SunSmart campaigns in Australia, with the aim of reducing the incidence of skin cancer in later life. Sun protective clothing for young children is now very popular among many parents who want to provide comprehensive UVR protection for their children in a range of outdoor situations, but most particularly at the beach. Clothing has the advantage over sunscreens in that it can provide high levels of UVR protection without any questions over whether it has been applied at adequate levels to achieve appropriate protection.
对应中文
通过衣服提供防晒是光防护最常见的应用。减少生命早期的太阳紫外线照射一直是皮肤癌教育活动的主要举措之一，例如澳大利亚的SunSmart活动，目的是降低晚年皮肤癌的发病率。现在，幼儿防晒服在许多家庭中非常常见，家长们希望在各种户外环境下为孩子提供全面的紫外线防护，尤其比如海边。与防晒霜相比，布料的优势在于它可以提供高水平的紫外线辐射防护，而不存在应用相关的其他问题、比如用量是否充足等。
Determining the UVR protection of clothingagainst solar UVR
确认服装的紫外线防护性能
英文原文
Measurements of UVR protection by clothinggenerally require the measurement of the spectral transmittance of both direct and diffuse UVR acrossthe wavelength range 290-400 nm. These spectral transmittance measurements are then used to calculate how much of the solar UVR spectrum measured at theearth’s surface would reach a person’s skin beneaththe clothing and then calculate the effect on human skin due to the erythemal effectiveness of this incident UVR using the CIE erythemal effectiveness actionspectrum. Spectral measurements require theability to discriminate individual wavelengths andtherefore utilize either a monochromator, spectrora-diometer or a diode array system for that purpose.Commercial instruments efficiently measure ultravio-let protection factors (UPFs) of standard fabrics;however, for special highly protective garments asused in welding, instruments with a greater dynamicrange are required in order to measure the extremelylow transmittance and therefore high protection.
对应中文
服装紫外线防护性能的测量一般需要测量直接照射和漫反射的UVR在290-400nm波长范围内的透过率。然后，通过测量这些光谱的透过率来计算在地球表面的太阳UVR光谱中有多少会到达穿着衣服的人的皮肤上，最后通过CIE红斑有效作用光谱来计算这种入射UVR对人类皮肤的影响。光谱测量要求具有分辨单个波长的能力，为此需要使用单色仪、光谱仪或二极管阵列系统。商用仪器通常可以有效地测量标准织物的紫外防护系数（UPF）；然而，对于焊接中使用的特殊高防护性服装，为了测量极低的透过率，必须使用具有更大动态范围的仪器。
Levels of solar UVR
太阳紫外线辐射水平
英文原文
The main aim of sun protective clothing is protectionagainst erythema or sunburn from solar UVR; hence,for much of the world UPFs of 30 for clothing wouldbe sufficient. However, the levels of solar UVR thatsun protective clothing is aimed at providing protec-tion against vary greatly. Solar UVR levels vary withgeographical location, generally depending primarilyon latitude, but also to some extent on where on acontinent they are and how that affects cloud cover.The factors that affect solar UVR at the earth’ssurface are solar elevation, ozone, atmospheric airpollution, aerosols, dust, water vapour, clouds, alti-tude and surface reflection. Only a brief description ofthese factors is given here, but more comprehensiveand detailed information is readily available.
对应中文
防晒服的主要目的是防止太阳紫外线引起的红斑或晒伤；因此，对于世界上大多数国家来说，衣服的UPF30就足够了。然而，防晒衣所要提供的紫外线防护水平差别很大。太阳紫外线辐射水平随地理位置的不同而不同，通常取决于原始纬度，但在某种程度上也取决于它们所在的大陆以及大陆位置对云层的影响。影响地球表面太阳紫外线辐射的因素有太阳海拔、臭氧、大气污染、气溶胶、尘埃、水汽、云、海拔和表面反射等。这里只给出了这些因素的简要描述，但更全面、更详细的信息很容易获得。
The UV Index
紫外线指数
英文原文
Any discussion of the levels of solar UVR will focus on the intensity, which nowadays is denoted by the UV Index , promoted by the World Health Organization (WHO) in an effort to standardize the use and presentation of the levels of solar UVR around the world. The UV Index is important inraising awareness among the general public of the hazards of solar UVR. In many countries across theworld, both UV Index forecasts and measurements areavailable and can be used to estimate the potential hazards of sun exposure when outdoors. The CIE erythemal effectiveness is used to determine the protection against solar UVR, as in equations 1 and 2.The CIE erythemal effectiveness is also used togenerate the UV Index. With solar UVR, the UVR effas determined in equation 1 is multiplied by 40 to give the UV Index, a process that converts the levels of solar UVR into levels between 0 and maxima of about 12 or so for mid-latitude locations.
对应中文
任何关于太阳紫外线辐射水平的讨论都集中在强度上，其中的代表为由世界卫生组织（WHO）推动的UV指数（紫外线指数），该指数旨在促进世界各地的太阳紫外线辐射水平使用和呈现的标准化。UV指数对提高公众对太阳紫外线辐射危害的认识也非常重要。在世界上许多国家，UV指数的预测和测量都是可进行的，可用来估计户外暴露在阳光下的潜在危险。如方程式1和2所示，CIE红斑有效性用于确认太阳紫外线防护性能；同时，CIE红斑有效性也用于生成紫外线指数。对于太阳紫外线辐射，将方程式1中确定的紫外线折射率乘以40将得到UV指数，这个过程即将紫外线辐射水平转换为0到12左右的最大值（中纬度地区）之间的水平。
英文原文
The UV Index measurements and forecasts for citiesin many countries around the world are now routinely posted on the internet by various meteorological agencies. In summer in Europe, the solar UV Indextypically peaks at values from 5 at high latitudes (Scandinavia) to around 7 in central regions such as the United Kingdom, France or central Europe and up to 9 or 10 in Southern Europe. In the United States maximum measured UV Indices range from 10 to 12 in the Southern continental United States to 5 in Alaska while in Canada peak values reach 8 in the southern cities. Generally the highest reported UV Index measurements in the Northern hemisphere have been recorded at high altitude. For example, Bogota in Colombia, at over 2500m abovesea level, has registered a UV Index of 16 and for Mauna Loa volcano in Hawaii, at 3400m above sea level, a UV Index of 17 has been reported .
对应中文
现在，世界上许多国家的城市紫外线指数测量和预报都由不同的气象机构定期发布在互联网上。在欧洲的夏季，太阳紫外线指数的峰值在高纬度地区（斯堪的纳维亚半岛）为5，在中部地区（如英国、法国或中欧）为7，在南欧为9或10。在美国，测量到的最大紫外线指数范围从美国南部大陆的10到12到阿拉斯加的5，而在加拿大，南部城市的峰值达到8。一般来说，北半球报道的紫外线指数最高的测量值都是在高海拔地区记录的。例如，哥伦比亚的波哥大，海拔2500米以上、紫外线指数为16，夏威夷的莫纳罗亚火山，海拔3400米、紫外线指数为17。
Cumulative exposures
累积暴露量
英文原文
While the UV Index is a measure of UVR intensity, it is the cumulative dose that is important for human exposures to solar UVR. In recent years, the CIE has introduced the concept of a standard erythemal dose (SED), where 1 SED is defined as 100 J/㎡ effective when weighted with the erythemal response function of the CIE . Both the UV Index and the SED are derived through weighting solar UVR with the CIE erythemal response function. Solar UVR with an intensity of 0.25 W/㎡ and a UV Index of 10 incident for 20 min (1200s) provides a dose of 0.2512005300 J/㎡, or 3 SEDs. In the past, the term minimum erythemal dose (MEDs) was oftenused as a measure of the cumulative UVR exposurerequired to induce erythema or sunburn in people. Forpeople with sensitive skin, a MED is about 200–300 J/㎡ or 2–3 SEDs.
对应中文
虽然紫外线指数是紫外线强度的一种衡量标准，但累积剂量对人体暴露在太阳紫外线下的评估是很重要的。近年来，CIE引入了标准红斑剂量的概念（SED），当与CIE的红斑反应系数加权时，1SED被定义为100J/㎡有效。紫外线指数和SED都是通过用CIE红斑反应系数加权评估UVR得到的。当太阳紫外线强度为0.25W/㎡，紫外线指数为10时，照射20分钟（1200s），剂量为0.2512005300J/㎡，或3SED。在过去，专业词语最小红斑剂量（MEDs）经常被用来衡量导致人们产生红斑或晒伤所需的紫外线累积暴露时间。对于皮肤敏感的人，MED约为200-300J/㎡或2-3SED。
英文原文
Solar UVR levels vary globally, with locations closeto the equator having very high levels and places closeto the equator and at high altitude having the highestlevels. Measured annual totals of solar UVR rangefrom 2500 SEDs (UK and Sweden) to 9000 SEDs (Spain) for Europe and from 6000 SEDs (Bismark)to 12 000 SEDs (El Paso) for the continental USA,although Mauna Loa in Hawaii at 3.4 km altitude has17 700 SEDs annually . Levels in Japan rangefrom 5800 to 10 000 SEDs while in Australia the rangeis 7300 to 16 800 SEDs.
对应中文
太阳紫外线辐射水平在全球范围内各不相同，靠近赤道和高海拔的地方非常高。全球常见太阳紫外线辐射水平范围为：2500SED（英国和瑞典），6000SED（俾斯麦），9000SED（西班牙），12000SED（埃尔帕索）；日本的水平在5800到10000SED之间，澳大利亚在7300到16800SED之间，而夏威夷海拔3.4公里的莫纳洛亚每年可高达17700SED。
Outdoor workers and solar UVR
户外工作者和太阳紫外线
英文原文
The other important area where sun protective cloth- ing plays a role is with outdoor workers. Australia has recently introduced a new occupational exposure standard for exposure to UVR (28), which is planned to eventually become a mandatory standard adopted across all states and legislatures. The standard requires that for artificial sources of UVR, exposures must be less than the exposure limits (29) of the International Commission on Non Ionizing Radiation Protection (ICNIRP) and recommends compliance of the exposure limits for outdoor workers by utilizing a risk management approach and the use of personal protective equipment (PPE). The implications for outdoor workers is that they will need to be provided with a range of items of PPE such as clothing, sunscreens, sunglasses and hats as well as possible scheduling of tasks outside times of peak solar UVR or the provision of shade. It is important that all of the PPE measures provide appropriate and adequate protection against solar UVR. For clothing, this means provision of garments that have been tested and rated to UPF 501, a practice that is becoming standard for companies with outdoor workers.
对应中文
防晒布发挥作用的另一个重要领域是户外作业。澳大利亚最近出台了一项新的职业紫外线暴露标准，该标准计划最终成为所有州和立法机构采用的强制性标准。该标准要求，对于人造紫外线源，曝光量必须低于国际非电离辐射防护委员会（ICNIRP）的曝光量限值，并建议利用风险管理方法和使用个人防护装备（PPE）来遵守户外工作人员的曝光量限值。对户外工作者的影响是，他们将需要准备一系列个人防护用品，如衣服、防晒霜、太阳镜和帽子，以及在太阳光峰值时间以外安排户外工作任务或做好遮阳。重要的是，所有的个人防护措施都要针对太阳紫外线提供适当和充分的保护。对于服装而言，这意味着必须使用经过测试并评定为UPF50+的服装，这一做法已成为户外作业公司的标准。
英文原文
Also shown in Table 1 for different values of UV Index are the times Tmax, which denotes the time to exceed the ICNIRP exposure limit of 30J/m2, andTerythema, the time required to exceed 2SEDs and achieve erythema for people with sensitive skin. Examination of Table 1 shows that for high levels of solar UVR, e.g. UV Index values of 10–12, people with sensitive skin will exceed the occupational ex- posure standard in 6–8 min and will achieve erythema in 11–13 min. Thus, if the exposure limits are complied with, people should not see short-term detrimental effects such as erythema. For anyone outside for periods exceeding 10 min, including outdoor workers, use of sun protection is therefore both necessary and advisable.
对应中文
（文中包含的）表1显示了不同紫外线指数值的时间Tmax，Tmax代表了超过国际非电离辐射防护委员会（ICNIRP）暴露限值30J/m2并出现红斑的时间，即超过2SEDs导致敏感皮肤出现红斑所需的时间。表1的检查表明，对于高水平的太阳紫外线，例如紫外线指数为10-12，敏感皮肤的人将在6-8分钟内超过职业暴露标准，并将在11-13分钟内达到红斑。因此，如果遵守了暴露值，人们应该不会受到红斑等短期有害影响。对于任何户外时间超过10分钟的人，包括户外工作人员，使用防晒措施是必要的，也是可取的。
Personal exposure to ultraviolet radiation
个人紫外线照射
英文原文
Personal exposure to the sun is the link between the ambient levels of solar UVR and health effects. Personal exposure to solar UVR is determined mostly by behaviour, for example when an individual chooses to be outside and whether they use items of personal protection such as hats, sunscreens, sunglasses, shade and, the main topic of this article, sun protective clothing. Numerous studies have measured the UVR exposures of various population groups when outside. It is possible to relate these personal UVR exposures to the ambient solar UVR at the location where the study was carried out to determine what fraction of ambient the subjects received. Given the importance of solar UVR exposures in early life, many UVR exposure measurement studies have focussed on children, particularly school children. Results for measurement studies in the United Kingdom , Australia and South Africa found UVR exposures were in the range 4–8% of daily total ambient. However, if personal exposures are compared against available ambient, i.e. the amount of ambient solar UVR incident while the subjects were actually outside, then these figures increase and are generally of the order of 25–40% of available ambient. These exposures need to be considered when choosing appropriate clothing for adequate solar UVR protec- tion. Evidence that clothing can provide a protective effect is mounting, as study looking at children in day- care centres in Germany found that children who wore more clothing had lower numbers of melanocytic naevi but indicated that more randomized trials were necessary to confirm these findings. An ongoing intervention study using sun protective clothing with children from child care centres is examining whether sun protective clothing helps in preventing the development of fewer melanocytic naevi in the high solar UVR environment of Queensland.
对应中文
个人暴露在阳光下是太阳紫外线辐射环境水平和健康影响之间的联系。太阳紫外线辐射的个人暴露主要是由个人行为决定的，例如，某特定个人是否选择外出，外出时是否使用帽子、防晒霜、太阳镜、遮阳板等个人防护物品，以及本文的主要主题——防晒服。许多研究已经测量了不同人群在户外的紫外线辐射暴露，可以将个人紫外线辐射暴露与进行研究地点的环境太阳紫外线辐射综合起来，以确定受试者的环境紫外线辐射比例。鉴于太阳紫外线暴露在生命早期的重要性，许多紫外线位置测量研究都集中在儿童，特别是学龄儿童身上。在英国、澳大利亚和南非进行的测量研究结果显示，紫外线照射位置在每日总环境辐射的4-8%之间。然而，如果将个人暴露与总环境辐射进行比较，即取受试者处于室外时的环境太阳紫外线辐射事件为总环境辐射，上述比例即增加、通常可达到25–40%。在选择适当的衣服以充分保护太阳紫外线时，需要考虑这些暴露。越来越多的证据表明，穿衣服可以起到保护作用，因为对德国日托中心儿童的研究发现，穿衣服更多的儿童黑色素细胞痣的数量较少，但表明需要更多的随机试验来证实这些发现。一项正在进行的干预研究对来自托儿所的儿童使用防晒衣，研究防晒衣是否有助于预防昆士兰州强太阳紫外线环境中黑色素细胞痣的发生。
Standards for clothing and UVR protection
服装和紫外****线防护标准
Australian/New Zealand standard
澳大利亚/新西兰标准
英文原文
The first standard covering clothing and UVR protection was issued in Australia and New Zealand in July1996. This standard defined the test method as measurements of the spectral transmittance of scattered, diffuse and direct UVR through the fabric.These transmittance measurements are then used tocalculate how much of the solar UVR spectrum measured at the earth’s surface would reach a person’s skin beneath the clothing and also subsequently calculate the effect on human skin due to the erythemaleffectiveness of this incident UVR using the CIE erythemal effectiveness. The standard uses theterm UPF to designate the amount of protection provided by fabrics and garments rather than SPF,which is used to denotein vivotesting in the sunscreen standard AS/NZS 2604.
对应中文
澳大利亚和新西兰于1996年7月发布了第一个涵盖服装和紫外线防护的标准。本标准将试验方法定义为测量直接通过和散射穿过织物的紫外线散射光光谱透射率。然后用上述透射率测量值来计算在地球表面测量的太阳紫外线光谱中，有多少会到达衣服下面的皮肤，并根据入射紫外线的红斑效应、用计算机测算对人体皮肤造成的影响。SPF在防晒标准AS/NZS 2604中用于表示活体测试；本标准使用术语UPF来表示织物和服装提供的保护量，而不是SPF。
United States standards
美国标准
英文原文
In 2000 and 2001 in the United States, the American Society for Testing and Materials (ASTM) and theAmerican Association of Textile Chemists and Color-ists (AATCC) introduced a set of three standards thatfully cover the testing of fabric swatches and the ratingand labelling of clothing and garments and theirprotection against solar UVR.
对应中文
2000年和2001年，美国材料与试验协会（ASTM）和美国纺织化学家和着色剂协会（AATCC）推出了一套由三个标准组成的标准，全面涵盖了织物样品的测试、服装和服装的等级和标签以及对太阳紫外线的防护。
European standard
欧洲标准
英文原文
In 2001 the European standard EN 13758 ‘Textiles –Solar UV protective properties’ was issued in two parts . This standard includes the condition ingrequirements introduced in the British Standard while the test methods are similar to AS/NZS 4399.
对应中文
2001年，欧洲标准EN13758“纺织品-太阳紫外线防护性能”分两部分发布。本标准包括英国标准中引入的条件要求，而试验方法类似于AS/NZS4399。
Factors that affect the UVR protection offabrics and clothing
影响面料和衣物紫外线防护的因素
英文原文
What makes a good sun protective garment? A number of factors determine how effective garmentsare at reducing UVR.
对应中文
什么是好的防晒衣？许多因素决定了防晒衣减少紫外线辐射的有效度。
Cover factor or weave density
覆盖系数或组织密度
英文原文
The term cover factor is defined as the percentage offabric surface area containing fibre or yarn . The more surface filled with material, the less space there is for the incident UVR to pass directly through and this is demonstrated in Fig. 3, which shows fabrics with different cover factors but with the same fibre strand thickness. As the fibres are woven together moreloosely and the spaces between fibres through which UVR can easily pass become larger, the measured UPF decreases. The closer the weave, the lower the UVR transmittance and the higher the protection.
对应中文
术语覆盖系数定义为含有纤维或纱线的纤维表面积的百分比。表面填充的材料越多，空间就越小。图3显示了具有不同覆盖系数但具有相同纤维绞合厚度的织物。随着纤维编织得更加松散，纤维之间的空隙（纤维很容易穿过）变得更大，测量值减小。织物越密，紫外线透过率越低，防护效果越高。
Construction of the fabric
织物的构造
英文原文
How a fabric is constructed and the geometricalar rangement of the yarns and fibres in the material can influence how close together the fibres can be andthus determine the cover factor of the fabric. Mostapparel fabrics are either woven or knit construction.The construction influences whether the amount ofopen area in a fabric changes when tension is applied.The construction also plays a role in determining the amount of shrinkage that occurs when the fabric is laundered, which can reduce the space between fibresand there by increase UVR protection .
对应中文
织物的构造以及纱线和纤维在材料中的几何排列会影响纤维之间的紧密程度，从而决定织物的覆盖系数。大多数服装面料要么是机织的，要么是针织的。这种结构会影响织物的开放面积在施加张力时是否发生变化。结构也会决定织物在洗涤时的缩水率；缩水这个变化本身减小了纤维之间的间距，从而增加紫外线的防护。
Weight per unit area
单位面积重量
英文原文
Given that the cover factor or the amount of materialor fibre blocking the UVR plays such an importantrole, increasing the weight perunit area would also be expected to increase the measured UPF. Assuming the same type of fibre, increasing weight of fibre perunitarea will mean more fibre in the path of the radiationand thus more absorption and higher UPFs.
对应中文
考虑到覆盖系数或阻挡紫外线的材料或纤维的数量起着如此重要的作用，增加单位面积的织物重量也将增加测量的UPF值。假设相同类型的纤维，每单位面积纤维重量的增加将意味着辐射路径中的纤维更多，因此吸收更多，UPF更高。
Fabric thickness
织物厚度
英文原文
Provided other variables remained constant, as fabric thickness increased it was found that measured UPFvalues increased.
对应中文
在其他变量保持不变的情况下，随着织物厚度的增加，发现测量的UPF值增加。
Composition of the fabric
织物的组成
英文原文
Different materials such as cotton, polyester, silk,rayon and nylon have different natural UVR absorbing properties . Some materials naturally absorb UVR very strongly while in others the fibres canactually transmit varying quantities of UVR. The UVR transmission of fabrics can be changed by increasing the concentration of absorbers in the fibre when it is made.
对应中文
不同的材料，如棉、涤纶、丝、人造丝和尼龙，具有不同的天然紫外线吸收性能。有些材料对紫外线的吸收很强，而另一些材料的纤维则能传递不同数量的紫外线。织物的紫外线透过率可以通过增加纤维中吸收剂的浓度来改变。
Colour
颜色
英文原文
Many dyes absorb UVR. In general, darker colours and higher dye concentrations absorb more UVR . Figure 4 shows the spectral transmittance across the UVR (280–400 nm) and visible (400–770 nm) regions for the same cotton material (identical weave, weight etc.) but for a range of colours. The transmit- tance in the visible is included here to show the effect of colour, where the blue fabric has maximum trans- mittance in the blue region of the spectrum (400–450nm), the green peaks in the green region (500 nm) and the red peaks in the red (650 nm). The UPFs of the various colours are determined by the transmittances below 400nm and can vary substan- tially. Dark colours of the same fabric type (blue, black, red etc.) all absorb more strongly than lighter shades (white, oatmeal, pale blue etc.) and will conse- quently have higher measured UPFs, e.g. blue, UPF 80; green, UPF 81; red, UPF 157 ; black; UPF 256 and consequently achieve UPF ratings of 50+ in the excellent protection category. This can be compared with the lighter colours such as natural, UPF 6 and pale blue, UPF 13, both less than UPF 15, which is insufficient to achieve a UPF rating. The oatmeal UPF 16 and the white UPF 22 both have low-rated UPFs of 15 and 20, respectively. The white fabric has an optical whitening agent (see next section) that absorbs strongly in the UVR, particu- larly in the UVA (315 to 400 nm) and so has a slightly higher UPF than the other pale samples. The same effect due to colour is also true for polyester materials (identical weave, weight, etc.).
对应中文
许多染料吸收紫外线。一般来说，颜色越深，染料浓度越高，吸收的紫外线越多。图4显示了光谱透过率，对于相同的棉料（相同的组织、重量等），但对于不同的颜色，UVR（280–400nm）和可见光（400–770nm）区域是相同的。这里包括可见光的透过率以显示颜色的影响，其中蓝色织物在光谱的蓝色区域（400–450 nm）具有最大透过率，绿色区域（500nm）具有最大透过率，红色区域（650 nm）具有最大透过率。同一织物类型的深色（蓝色、黑色、红色等）都比浅色（白色、燕麦片色、淡蓝色等）吸收更强烈，因此具有更高的UPF，例如蓝色、UPF80；绿色，UPF81；红色，UPF157；黑色；UPF256，因此达到了优良保护类别中的50+UPF额定值。这可以与较浅的颜色相比较，如自然色、UPF6和淡蓝色、UPF13，两者都小于UPF15，这不足以达到UPF等级。燕麦片色UPF16和白色UPF22的UPF等级分别为15和20。白色织物有一种光学增白剂（见下一节），它在紫外线中有很强的吸收能力，特别是在紫外线（315到400nm）中，因此它的UPF略高于其他白色样品。同样的效果，由于颜色也适用于聚酯材料（相同的组织，重量等）。
Additives
添加剂
英文原文
Chemical compounds such as optical whitening agents (OWAs) and UV-cutting agents can be added to fabrics to increase the UVR protection, either in the mill or later as wash in additives. The main reason for adding OWAs is to whiten and brighten fabrics although they also reduce UVA transmittance. UV- cutting agents can strongly absorb in the UVB and, depending on how well they are taken up by the specific fabric types they are applied to, can dramati- cally increase a fabric’s UPF. Some fabrics can be treated to improve the UPF rating. This is usually done if the base fabric has a low absorbance of UVR. Treatment with a UVR inhibi- tor, generally during manufacture, can result in a fabric with a higher UPF rating that still retains the comfort properties of the original. There are many dyes that absorb UVR and therefore increase the UPF rating of the fabric.
对应中文
化学化合物，如光学增白剂（OWA）和紫外线切割剂，可以添加到织物中，以增加对UVR的保护，无论是在洗涤过程中还是稍后作为添加剂洗涤。添加OWA的主要原因是为了使织物变白和增亮，尽管它们也降低了UVA的透过率。紫外线切割剂能很强地吸收紫外线，并且根据它们被应用到的特定织物类型吸收的程度，能显著地增加织物的UPF。一些织物可以进行处理以改善UPF。这通常是这样做，如果基础织物有一个低吸收紫外线。通常在制造过程中，用紫外线抑制剂处理，可以使织物具有更高的UPF等级，仍然保持原始织物的综合性能。有许多染料能吸收紫外线，从而增加织物的上色。
Tension
张力
英文原文
Stretching a fabric will normally cause a decrease in the UPF rating as the spaces in the fabric open up.This is common in knitted or elasticised fabrics and care should be taken to select the correct size for the wearer.
对应中文
拉伸织物通常会导致UPF等级降低，因为织物中的空隙打开了。这在针织或弹力织物中很常见，应该注意为穿着者选择合适的尺码。
Moisture content
水分含量
英文原文
Many fabrics have lower UPF ratings when wet. The drop in UPF rating depends on the type of fabric and the amount of moisture it absorbs when wet. Test sconducted by ARPANSA showed that the mean measured UPF when wet reduced to 50% of the dry value for 12 different sample lots (five examples ofeach) of white T-shirts.
对应中文
许多织物在潮湿时具有较低的UPF等级。UPF等级的下降取决于织物的类型和潮湿时吸收的水分。ARPANSA进行的测试表明，12个不同批次（每批5件）的白色T恤潮湿时测得的平均UPF降至干值的50%。
Design
设计
英文原文
As well as considerations of fashion and comfort,selecting garments that are sensibly designed for sunprotection can make a large difference to over all UVR exposure. A shirt with long sleeves and a large collaroffers more protection than a short-sleeve shirt without a collar. Loose-fitting garments give better protection than garments that are worn close to the skin and also may be more comfortable to wear on hot days.Hat design is also important in UVR protection. Alegionnaire style cap with a flap protects the ears and back of the neck. A broad-brimmed hat or bucket hats hades the face and neck .
对应中文
除了考虑时尚性和舒适性，选择合理设计的防晒服装对整体紫外线照射也有很大影响。长袖大领的衬衫比没有领子的短袖衬衫提供更多的保护。宽松的衣服比紧贴皮肤的衣服提供更好的保护，而且在炎热的日子穿起来可能更舒服。帽子设计在紫外线防护中也很重要。有盖的军团帽子可以保护耳朵和脖子后部。宽边帽或桶帽遮住脸和脖子。
Condition
条件
英文原文
Unless otherwise stated, UPF ratings are performedon fabric that is in new condition. The UPF rating ofmany cotton based fabrics can improve over the ‘new’rating after they have been washed at least once. Pailthorpe found that the mean UPF of a group of garments was 20.6+-1.6 when new, and this increased to a mean UPF of 38.2 after one wash and then to 39.8 after 36 washes. Shrinkage in the fabric closes minute gaps between the threads and allows less UVR to pass through. However, old, threadbare or faded garments may have a reduced UPF rating.
对应中文
除非另有说明，UPF等级是在新状态的织物上进行的。Pailthorpe发现，许多棉基织物的UPF等级在至少洗过一次后就可以提高到“新”等级。新衣服的平均UPF为20.6+-1.6，洗一次后平均UPF为38.2，洗36次后平均UPF为39.8。织物的收缩缩小了线与线之间的微小间隙，允许穿透的UVR减少。然而，旧的、破旧的或褪色的衣服可能会降低UPF等级。
英文原文
Figure 5 also shows that the peak of the UPF distribution for nylon- elastane fabrics is at a higher value than those for cotton and polyester fabrics, which in turn are higher than the peak for polyester/cotton fabrics.
对应中文
（文中包含的）图5还显示，尼龙-弹性纤维织物的UPF分布峰值高于棉和涤纶织物，而棉和涤纶织物的UPF分布峰值又高于涤棉织物的UPF分布峰值。
REFERENCES
1.Morison WL. Photoprotection by clothing. Dermatologic Therapy. 2003;16(1):16-22.vi.