《预防医学导论》PPT课件.ppt

1 Environmental Health Science 环境卫生学概要 Department of Environmental Health Science School of Public Health and Tropical Medicine 环境卫生学系 周宏伟 61648327 B You cannot select your genome but you can change your environment 什么是环境卫生？ n环境卫生是指城市空间环境的卫生。主 要包括城市街巷、道路、公共场所、水 域等区域的环境整洁，城市垃圾、粪便 等生活废弃物收集、清除、运输、中转 、处理、处置、综合利用，城市环境卫 生设施规划、建设等。 文章来源：（ 淄博市党员干部现代远程教育中心 ） 一、环境卫生学定义 定义1 n研究自然环境和生活环境与人群健康的关系， 解释环境因素对人群健康影响的发生、发展规 律，为充分利用环境有益因素和控制环境有害 因素提出卫生要求和预防对策，增进人体健康 ，提高整体人群健康水平的科学。 n是预防医学的重要分支学科，也是环境科学不 可缺少的重要组成部分。 陈学敏，杨克敌 Definition 2 nIn its broadest sense, environmental health is the segment of public health that is concerned with assessing, understanding, and controlling the impacts of people on their environment and the impacts of the environment on them. -Moeller D.W. Environmental Health 二、环境对健康的影响到底有多大？ 通过健康环境预防疾病:对疾病的环境负 担的估计 Preventing disease through healthy environments: Towards an estimate of the environmental burden of disease WHO 2006 估计全球疾病负担的24%和全部死亡的23% 可归因于环境因素。 n最大绝对负担可归因于可改变的环境因素的疾病包 括：腹泻、下呼吸道感染、“其它”意外伤害和疟 疾。 n地区差异 q传染病和伤害给发展中地区造成极其沉重的负担 q在可归因于环境的非传染病的分值上，发达国家与发展中 国家的整体差异不明显 q发达国家，可归因于环境的心血管疾病和癌症负担较大。 n儿童承担了过分沉重的环境性健康负担（高4倍）。 三、环境卫生学研究内容 研究内容 n大气、水体、土壤与健康； n饮水卫生与健康； n住宅以及室内环境与健康； n公共场所卫生； n人居环境与健康； n家用化学物品、个人用品与健康； n环境质量评价和健康危险度评价； n环境卫生监督与卫生管理； n灾害卫生； n全球环境变化与健康。 环境卫生学课程内容 nThe Scope/ Toxicology/ Epidemiology/ The work place/ Air in the home and community/ Food/ Drinking water/ Liquid waste/ Solid waste/ Rodents and insects/ Injury control/ Electromagnetic radiation/ Environmental economics/ Environmental law/ Standards/ Monitoring/ Risk assessment/ Energy/ Disasters/ A global view Moeller DW Environmental Health 四、环境卫生学发展简史 环境卫生学形成（Environmental Hygiene) n19世纪后形成 q德国Max von Penttenkofer (1818-1901)首次提出肠 伤寒和霍乱等传染病的流行与空气、水以及食物 等生活环境有关； q1865年在德国慕尼黑大学开设卫生学讲座，以空 气、水、食物、住宅、土壤等为研究对象，采用 物理和化学方法，开展了空气中二氧化碳浓度测 定方法的研究，称为实验卫生学(experimental hygiene)。 q其后，卫生学的发展进入新阶段，实现了专业分 化，产生了环境卫生学等多种专门学科。 环境卫生学发展 n近几十年来，环境科学学科蓬勃发展，形成与传 统的环境卫生学在研究内容上相互交叉的学科： q环境工程学、环境化学、环境生物学、环境管 理学、环境毒理学 n环境卫生学的研究内容从强调hygiene逐渐转变为 以健康(health)为核心。 nEnvironmental Health Science q环境科学和公共卫生学（Public Health)的交 叉学科。 发展方向 n加强环境污染对人体健康影响的调查研究。 n加强对环境污染物在低剂量、长时间作用下的 健康效应研究 n加大环境因素与传染病发生和流行关系的研究 。 n开拓环境卫生研究和环境卫生工作的新领域。 n做好突发公共卫生事件应急处理的科学技术和 人才储备。 五、环境卫生学核心概念 The 5 Core Concepts A Toxic Word Game Toxic means _. Toxic_ is the study of poisons. Toxic_ is a measure of how dangerous a chemical is. poisonous or dangerous ology ity A Toxicity Scale Toxicity Rating Signal Words on Package Symbol on Package Highly ToxicDANGER or POISON Moderately ToxicWARNING Slightly ToxicCAUTION Not Toxicnone How would you rate these products? Toxicity Rating Highly Toxic Moderately Toxic Slightly Toxic Not Toxic And the answers are Toxicity Rating Highly Toxic Moderately Toxic Slightly Toxic Not Toxic Exposure （暴露） is The total amount of a hazard that comes in direct contact with your body. The 3 parts of exposure The Source of the hazard (bus exhaust) The Environmental Pathway (air) The Contact (inhaled fumes) Which route will the hazards take? Route #1: Inhalation （呼吸） Inhalation: Breathing. When chemicals enter the body through this route of exposure, they can get stuck in the lungs and/or be taken up into the bloodstream. Route #2: Ingestion （消化道） Ingestion: Swallowing (usually by eating or drinking). When chemicals enter the body through this route of exposure, they can easily be taken up into the bloodstream. Route #3: Dermal Absorption （皮肤） Dermal Absorption: Absorbing a chemical through any part of the skin, including the eyes. When chemicals come in contact with the skin, they can sometimes enter the bloodstream through this route of exposure. 南方医科大学公共卫生与热带医学学院 环境卫生学系 周宏伟 32 barrierArea (m2) Thickness (m) Weight (kg) Daily exposure (kg) Skin 210012-16variable GI tract20010-1273-4 Lungs1400.2-0.40.8-0.924 Exposure X X What is dose(剂量)? XX X X X X = hazard Dose Dose is the amount of a hazard that actually enters your body. X X X X X X Dose can depend on Duration of Exposure: How long? Frequency of Exposure: How often? Body Size: How big or small are you? M L SS Duration of Exposure might not have any harmful effects. 30 minutes of sun exposure Duration of Exposure might be very harmful indeed! But 4 hours of sun exposure The larger the dose, the more extreme the response will be. Dose/Response Relationship (剂量反应关系) 1 can of pop in 15 minutes 3 cans of pop in 15 minutes 不同化学物有不同类型剂量-反应关系 饮用水中氟含量和龋齿数、氟斑牙的关系饮用水中氟含量和龋齿数、氟斑牙的关系 三种化合物的剂量反应关系 n有阈值化合物 n无阈值化合物 n必需微量元素 Individual Susceptibility （个体易感性） Why are these people more likely to be harmed by exposure to a hazard than the man below? Individual Susceptibility Pregnant women and their developing babies Elderly people whose defense mechanisms are less efficient Infants and children who are still developing Sick people who have weakened immune systems Genes & Susceptibility Your genes can also make you more or less susceptible to harm from an environmental hazard. For example, some people are more likely to get sick when they are exposed to certain kinds of pesticides. Risks & Benefits （风险效益） What are the risks and benefits when grape growers use pesticides on their crops? Risks & Benefits RISKSBENEFITS No bugs! Better looking fruit that is more visually appealing Bigger crops so farmers can make more profit P