LIVING ENVIRONMENT AND HEALTH Qiaoyuan Yang Department of Preventive Medicine Guangzhou Medical College
Living environment is concerned with all the factors,circumstances and conditions in the environment or surroundings of a human being which can influence the human health and well-being. • The environment provides man with the essential life support systems;but it also presents him with a variety of hazards which may prejudice his health. • Living environmental conditions include air,water,soil,food and shelter.
Section 1 air sanitation • Section 2 watersanitation • Section 3 geological environment and soil
1.Air • No element of the natural world is more essential to life than air. • The chemical and physical characters are obviously related to the human health and desease.
Atmospheric sphere • Definition：the air layer which surround the surface of earth and circumrotate with earth. • The thick is around 2000km～3000km.(no evident upper bound） • Character:physics and chemistry of atmospheric sphere is change with height.
according to the vertical change of air temperature troposphere stratosphere intermediun layer hot layer exosphere There are three delamination methods of air vertical structure.
According to air ionized condition ionosphere nonionosphere • According to chemical composition • homosphere • nonhomosphere
Upright structure of atmospheric sphere thermosphere umbrella of earth mesphere Ozone layer 25 ~35km, 20km stratosphere troposphere
stratosphere：including of ozone layer(the air temperature inversion) • troposphere：including of air,water vapour,fume,micro-organism. (the air temperature decrease progressively ) 1. Nearness earth 2. The temperature is change 3. Upright and horizontal move 4. Mostly climate changes happen in this layer 5.Contain mostly pollutants
There is a intimate relationship between the troposphere and the mankind. The pollutants concentrate mainly in the troposphere. The air pollutions often happen in this layer. People’s living condition will be importantly effected by the troposphere,especially the range near to the ground.
(1) chemical composition • Pure air is colorless, odorless, and tasteless. (mixing gas) • Air is mainly composed of nitrogen,oxygen,argon. (99.96%) • Some water vapor，(below 4%) • Free radical （source：ptotochemical reation of ozone）
Changeable composition：CO2 and water vapor unconstant composition： 1.dust,hydrogen sulfide (H2S),nitrogen oxide(NOX),foul gas produced by volcanic eruption,earthquake and so on. 2.coom,power dust, nitrogen oxide(NOX) produced by human activities Constant composition： nitrogen,oxygen,orgen,noble gas(Ne,He,etc)
(2)Physical state • Including of solar radiation,air ionization and meteorologic factor which are closed to human health.
pigmentation黑色素沉着作用 Erythema effect红斑作用 Anti-rachitic effect抗佝偻病作用 Germicidal effect杀菌作用 Heat effect • Ultraviolet UV-A（320~400 nm) UV-B（275~320 nm) UV-C（200~275 nm) • Infrared lay（760~30000 nm) • Visible light（400~760 nm) solar radiation help to form sense of sight
The adequate solar radiation could prevent people from eyes fatigue and near sight. • People is easy to get tired because of the weak light.
Light ion：neutral gas element sticking to ion, 10-15 molecule Heavy ion：light ion binding with dust and smog. air ionization Positive ion Negative ion (beneficial)
hygienic assessment of air ion • Quantity of air ion：negative ion ，cleaning degree • Heavy ion / light ion> 50 : air is muddy
meteorologic factor • air temperature,humidity,air current,air pressure • Meteorologic factor can adjust many physiologic function. (cold and thermal sensation,body heat regulation,nervous system funtion,immune function,etc) • Meteorologic factor make a important role in the diffusion process of air pollutants。
2.Air pollution • The quality of the air we breathe can have a significant impact on our quality of life. • The Industrial Revolution in Europe in the 19th century saw the beginning of air pollution as we know it today, which has gradually become a global problem.
Air pollution is aggravated because of four developments: increasing traffic, growing cities, rapid economic development, and industrialization. • Many countries have a "serious" air pollution problem.
Definition • 由于人类活动或自然过程，使得排放到大气中物质的浓度及持续时间足以对人的舒适感、健康，对设施或环境产生不利影响时，称大气污染
Sources of air pollutants 1. Natural sources 2. Man-made sources • Industrial pollution • Living pollution • Traffic transportation
Natural sources • Probably the most important natural source of air pollution is volcanic activity(火山爆发), which at times pours great amounts of ash and toxic fumes into the atmosphere. • Dust storms in desert areas and smoke from forest fires and grass fires contribute to chemical and particulate pollution of the air.
Man-made sources --1 Industrial pollution Industry and enterprise may be chiefly responsible to the air pollution. 1.Combustion of fuel（coal & oil） 2. Emission from working process （native material & finished product）
The following industries are among those that emit a great deal of pollutants into the air: thermal power plants, cement, steel, refineries, petro chemicals, and mines.
Man-made sources --2 Living pollution Living cooking range &heating boiler Combustion of fuel coal
燃烧一吨煤排出的各种有害物质的重量(kg） 有害物质 电厂锅炉 工业锅炉 取暖锅炉 SO2 60 60 60 CO 0.23 1.4 22.7 NO2 9.1 9.1 3.6 HC 0.1 0.5 5 Dust 一般燃烧11 11 11 燃烧良好时3 6 9
Man-made sources --3 Traffic transportation result from the combustion of mobile vehicle fuel Mobile pollution source(流动污染源) the pollution range is related to it’s race.
从油箱和汽化器中挥发的汽油 碳氢化合物20% 汽 车 排 气 一氧化碳 100% 碳氢化合物 60% 氮氧化物 100% 从曲轴箱漏出的气体 碳氢化合物 20%
How can air pollution hurt our health? • Air pollution can affect our health in many ways. • Different groups of individuals are affected by air pollution in different ways. • The extent to which an individual is harmed by air pollution usually depends on the total exposure to the damaging chemicals, i.e., the duration of exposureand the concentration of the chemicalsmust be taken into account.
How can air pollutants intrude into our body? ingressive pathway of air pollutant Respiratory passage(major) Digestive tube Skin A small quantity
The effects of air pollution on human health Direct harm Indirect harm
direct health hazard of air pollution • Acute poisoning • Chronic and long-term effect
(一) Acute poisoning • The concentration of pollutants rapidly increase in short-term，a lot of pollutants (fume, exhaust gas) have been absorbed by population induced acute poisoning.
Examples of acute effects include irritation to the eyes, nose and throat, and upper respiratory infections such as bronchitis and pneumonia. • Other symptoms can include headaches, nausea, and allergic reactions. • Short-term air pollution can aggravate the medical conditions of individuals with asthma and emphysema.
Major type • Coal smog(London) • Photochemical smog(losangeles) • Smog episode • productive accident
Productive accident • Toxic gas leakage accident in Bphopal, india （印度博帕尔毒气泄漏事件，异氰酸甲酯 ） • Explosion of unclear power plant in USSR （前苏联切尔诺贝利核电站爆炸事件） • Special disasters: fire, explosion of volcano, leak of gas, the use of chemical weapon.
Smog incident • Coal smog incident: Physical: primary pollutants • Photochemical smog incident: Chemical: secondary pollutants
Coal smog incident SO2 + fluoride SO2 + metal dust
The major pollutant of London smog incident sulfur dioxide and fog (created by burning coal and heavy oil that contain sulfur impurities in power plants, industrial plants, etc... )
Photochemical smog incident • Definition:Nitrogen oxides from motor vehicle exhaust gas and hydrocarbons from industry process emission are converted to ozone and other photochemical species form light blue smog through photochemical reaction under sunlight ultraviolet ray. • Los Angeles photochemical smog incident : The first time of this phenomena was occurred in Los angles (1943).
Los Angeles photochemical smog incident • Pollutant: nitrogen oxides + • hydrocarbons • Photochemical reaction
Graph of photochemical reaction Over 85% 10% SO2----SO3 ------ H2SO4
Smog incident • Coal smog incident: • Physical: primary pollutants • London smog incident • Photochemical smog incident: • Chemical: secondary pollutants • Los Angeles photochemical smog incident