防晒产品的使用方法和注意事项.doc

根据世卫组织（WHO）的统计，全世界每年发生约132 000例恶性黑素瘤(最致命的一种皮肤癌)病例和200多万例其它皮肤癌病例。世界每3例确诊癌症病例中有1例是皮肤癌。大多数皮肤癌是由于过度暴露于紫外线辐射中造成的 。 有关研究表明：过度的紫外线照射不仅会让皮肤变黑老化，而且还会损伤人体的免疫系统，导致皮肤癌的发生：主要包括基底细胞癌、鳞状上皮癌、恶性黑色素瘤；此外，过强的紫外线还可以引起眼部疾病，如晶状体混浊，引起视力减退和白内障，由此可见防晒的重要性。一、皮肤为什么会晒黑 说起皮肤晒黑的原因需要从皮肤的构成说起，这样对我们选择防晒方法和产品会有些帮助。我们的皮肤从外到内分为三层，最外层是表皮层，中间是真皮层，最内是皮下脂肪层，通常紫外线造成的损伤会出现在表皮和真皮层。表皮层从外到内由五层构成，其中第五层就是基底层，与真皮层相连，表皮层除了基底细胞外，还有黑色素细胞。 当皮肤暴露在紫外线时，有一些因素会促使黑色素细胞将黑素体（黑色素颗粒）注射入周围的细胞，紫外线强烈时，黑素细胞产生大量的黑（色）素体，这些黑（色）素体的形成，是为了保护细胞中最重要的结构即细胞核中的DNA。黑（色）素体在细胞核上面形成一个类似于帽的结构，象一把保护伞，这样就可以抵挡UV射线。所以黑（色）素体的形成是为了保护我们的面部和身体的肌肤免受阳光中紫外线的侵害。通过黑色素过滤阳光中的紫外线，阻止紫外线对肌肤的更深层的伤害，其结果是皮肤变黑。 如果紫外线过强，日晒过久，又没有做及时的防晒保护，我们皮肤的自我保护机制防不胜防，保护不过来的直接结果就是产生色素沉着（晒斑）、晒伤、或色素缺失，严重者导致真皮层受损，例如胶原纤维断裂，老化，使皮肤发生皮革样改变，更严重的就是皮肤癌变。二、防晒产品的防晒指数和种类 目前我们常见的防晒产品按照制造工艺不同分为油状、霜状、乳液状等，按照使用部位不同，又分为肤用和发用等。而且各生产厂家按照原料的不同又分为化学防晒和物理防晒品。我们先从防晒指数说起。1、关于SPF 第一代防晒产品主要是防止中波紫外线UVB的伤害，也就是防止皮肤晒伤的能力。对于UVB的防护采用SPF（防晒系数）来评价，SPF是指在强光照射下（例如正午阳光）使用防晒剂的最小红斑量与未使用防晒剂的最小红斑量的比值，通常SPF1指15分钟，如果涂抹了SPF30倍的防晒产品，理论上能防15分x30倍=450分的阳光照射带来的伤害。2、关于PA 随着人类防晒意识的增强，近些年对长波紫外线UVA的防护渐渐引起人们重视，所以很多防晒产品添加了防止皮肤晒老的成分，如PA指数，PA值是表示产品阻挡阳光中UVA长波紫外线的指数。UVA对皮肤的损伤是长期而慢性的，导致皮肤被晒黑、晒老。 PA的系数是以“+”来表示的。一般PA+表示低效防护；PA+是中效防护；PA+是高效防护。也有产品是以UVA来表示防晒黑系数的，如UVA12，数字值越高就表示越不易被晒黑。 使用含有SPF值的防晒产品可以帮助有效防晒伤，如果既想防晒伤又不致晒黑、晒老，最好选择同时含有SPF和PA两种系数的防晒产品。3、 防晒产品的种类 防晒产品按照用途来分，分为肤用和发用，肤用中又分为面部和身体，单以面部为例来说，很多品牌又按照不同使用部位来区分，有适合眼部，唇部、颧周、耳朵等不同部位的产品；还有根据不同皮肤类型研发的，例如干性肌肤、混合性肌肤，敏感性肌肤；剂型也不同，有油状、膏霜状、乳液状等，购买时需跟导购咨询，必须符合使用者的肤质，生活及工作环境以及要达到的效果来选择。 选择防晒产品时要了解防晒品的防晒性能，更重要的是要区分防晒产品是物理性的还是化学性的。（1）物理性防晒产品 物理性防晒产品的原理主要是在其中添加一些反射光的微小粒子，可以在涂抹后像镜子一样将紫外线反射出去，防止紫外线进入皮肤深层，其中大多成分来自无机物，如矿物粉氧化锌、二氧化钛。因其不含或少含有化学成分，所以对皮肤的刺激会相对小些，比较适合脆弱、易敏、以及偏干的皮肤，涂抹后皮肤较白，只要出汗量少，能起到较长时间的防晒效果，不足之处是睡前必须彻底清洁，易堵塞毛孔。（2）化学性防晒 化学性防晒产品的作用原理是吸收紫外线，降低能量等级，将紫外线的能量以热能的形式释放，也就是说化学防晒剂是在细胞受损前先吸收可能对肌肤有害的紫外线，再经过皮肤的转化降低紫外线对皮肤的伤害，最后的代谢物经过皮肤自身代谢循环出去。 化学性防晒剂的有效成分为有机化合物，通常为芳香族化合物，如氨基苯甲酸酯及其衍生物、水杨酸酯及衍生物、肉桂酸酯、樟脑类衍生物等。所以化学性防晒剂比较适合油性皮肤、健康不易敏感的肌肤。需要注意的是出汗多时，阳光强时需要补涂，睡前也要注意彻底清洁。 三、防晒产品的使用方法和注意事项1、出门前15分钟涂抹防晒产品，以便其充分发挥作用。游泳时需要考虑防晒品的防水效果，必要时需要补涂。2、防晒霜不能直接涂于皮肤，使用顺序是：洗脸后爽肤水乳液防晒（或有防晒作用的隔离霜）；身体皮肤使用时也是先用乳液，之后再使用防晒产品。3、正确选择适合自己皮肤和工作生活环境的防晒产品，在正规渠道购买，仔细读产品标签，注意生产日期，不要买即将到期的防晒产品，不要轻信广告。4、即使涂抹了防晒产品，夏季也要尽量避免正午阳光（10：00-16：00）出门，因为1次阳光灼伤，患恶性黑色素瘤的危险就增加一倍。5、一年四季做好对于来自沙子，水，雪和冰面反射的紫外线的保护，它们会反射或折射90%的紫外线，对于皮肤和眼睛都会有损伤。小结： 因紫外线可以穿透车窗，居室玻璃窗以及浅色的衣服照射我们的身体， 对于预防晒黑、晒老、晒伤，最好的措施是：减少暴露在阳光下的时间+正确使用防晒产品According to the world health organization (WHO), the world each year about 132, 000 cases of malignant melanoma () one of the most deadly skin cancer cases and 200 cases of other / cases of skin cancer. World each 3 cases diagnosed cancer 1 case of skin cancer. Most skin cancers are caused by excessive exposure to uv radiation. Studies showed that excessive ultraviolet irradiation not only can let the skin become black aging, but also can damage the bodys immune system, lead to the occurrence of skin cancer: basal cell carcinoma, squamous carcinoma, malignant melanoma; In addition, too much ultraviolet light can cause eye diseases, such as lens opacity, cataract, cause vision loss and this shows the importance of sunscreen. Why a, skin suntan About the cause of the tanning needs to start with the composition of the skin, so to we choose sunscreen method and the product will have some help. Our skin from outside to inside / is divided into three layers, the outermost layer is the epidermal layer, the middle is the dermis, subcutaneous fat is the most inner layer, uv damage often appear in the epidermis and the dermis. Cuticular layer from outside to inside consists of five layers, including the fifth layer is the base layer, connected to the dermis, epidermis layer in addition to the basal cells, melanocytes. When skin is exposed to ultraviolet light, there are some factors would lead to melanin cells will melanosomes (melanin granules) injected into the surrounding cells, strong ultraviolet ray, melanin cells to produce large amounts of black ferrite (color), the black (the color) ferrite formation, is the most important structure in order to protect the cells or DNA in the nucleus. (black color) on the ferrite / in the nucleus to form a structure similar to the cap, like an umbrella, so that you can resist UV rays. So black (the color), the formation of ferrite is to protect our facial and body skin from ultraviolet ray in sunshine. By filtering the ultraviolet ray in sunshine melanin, prevent ultraviolet damage to the skin deeper, as a result, the skin to become black. If the ultraviolet ray too strong, the sun too long, and didnt do a timely protection, our skins self protection mechanism available, not to be able to protect is a direct result of the produce / pigmentation (sunburn), sunburn, or pigment is missing, damaged serious result in the dermis, collagen fiber fracture, for example, ageing, make skin leather sample change, more serious is skin cancer. Second, sunscreen of SPF and species At present the common sunscreen products we according to the different manufacturing process can be divided into oily, cream, lotion, etc., according to the use of different parts, is divided into the skin and hair, etc. And the manufacturer in accordance with the raw material is divided into different chemical sunscreen and physical sunscreen. Lets start with SPF. 1, about the SPF The first generation of sunscreen products are mainly is to prevent the UVB rays UVB damage, is the ability to prevent sunburn skin. For UVB protection SPF (SPF) is used to evaluate, SPF is / refers to under the strong light irradiation (midday sun, for example) use sunscreen with minimal erythema dose not use sunscreen minimal erythema dose ratio, usually SPF1 refers to 15 minutes, if SPF30 times daub sunscreen products, in theory, can prevent 15 x x = 450 to the hurt of sunshine. 2, about the PA Prevent bask as human consciousness enhancement, to long wave ultraviolet UVA protection in recent years gradually to the attention of the people, so a lot of sunscreen products added to prevent the skin bask in with the old components, such as PA, PA is said the index of product block UVA long wave ultraviolet ray in sunshine. UVA is long-term and chronic damage to the skin, causing skin, sunburn, old. The PA of the coefficient is expressed as a +. General PA + said inefficiency protection; PA+ is effective protection; PA+ + is efficient protection. Also have product is UVA to prevent bask in coefficient of black, such as UVA12, numerical value as it is not easy to sunburn. Gao said Sunscreen with SPF protection products can help to effectively prevent bask in, if want to sunburn and not tan, tan old, had better choose contain SPF and PA at the same time coefficient of two kinds of sunscreen products. 3, sunscreen products Sunscreen products, in accordance with the purpose to points, divided into the skin and hair, the skin in use is divided into the face and body, single face, for example, many brands and according to the different parts to distinguish, is suitable for the eyes, lips, zygomatic weeks, ears and other parts of the product; And according to different skin type research and development, such as dry skin, mixed skin, sensitive skin; Dosage form is also different, there is oil, cream, lotion, etc., need when buying guide and consultation, must conform to the users skin, living and working environment and to achieve the effect of the choice. Choose when understanding the sunscreen sunscreen sunscreen products performance, more it is important to distinguish between the sunscreen is physical or chemical. (1) physical sunscreen products Principle of physical sunscreen products mainly add some tiny particles of reflected light, can be in the daub after like a mirror reflect ultraviolet light out, prevent ultraviolet rays into the deep skin, mostly ingredient from inorganic matter, such as mineral powder, zinc oxide, titanium dioxide. Because it does not include or contain chemical composition, less stimulation to the skin will be relatively small, so more suitable for weak, Yi Min, and partial dry skin, apply after the skin is white, as long as the sweat less, can have a long time to prevent bask in effect, the deficiencies is before bed must be thoroughly clean, easy to jam the pores. (2) chemical sunscreen Chemical sunscreen action principle is to absorb ultraviolet light, lower energy level, the uv light energy in the form of heat release, i.e. chemical sunscreen is absorbed before cell damage may be harmful to the skin of the ultraviolet ray, again through the skin into reduce uv damage to skin, finally the metabolites of metabolic cycle itself out through the skin. Active ingredients of chemical sunscreen for organic compounds, usually in the form of aromatic compounds, such as amino acid ester and its derivatives, salicylic acid ester and derivatives, cinnamic acid ester, camphor derivatives, etc. So chemical sunscreen is suitable for oily skin, health is not easy to sensitive skin. When to note is sweating, sunny need filling besmear, also should pay attention to thoroughly clean before sleep. Third, the use of sunscreen products method and the matters needing attention 1, 15 minutes before going out daub sunscreen products, in order to give full play to the role. Need to consider the waterproof sunscreen effect while swimming, need filling besmear when necessary. 2, sunscreen can not directly apply to the skin, the use of the order is: after wash your face