The Public Health Hazard Of Metropolitan Sprawl

After World War II,the US metropolitan area developed rapidly,and low-density spread became a major feature of the US metropolitan area.The traditional view is that the suburbs are the best place to raise a family and provide a clean and healthy place to live.However,with the disorderly spread of metropolitan areas,the suburbs,instead of providing people with a healthy lifestyle,have created a series of environmental,social and economic problems,which have caused numerous health problems and caused extensive damage to residents' health.This paper is divided into four parts.The first part mainly introduces the background of American metropolitan sprawl.This part mainly introduces the characteristics and automobile dependence of metropolitan area.The low-density spatial structure of the metropolitan area and the discrete distribution of infrastructure have led to the choice of private cars for people to travel.Infrastructure includes schools,shopping centers and community service centers.Over-reliance on car travel has created public health problems.The second part introduces the threat to the public health caused by metropolitan sprawl from the aspects of air pollution and water pollution.As the disorderly spread of metropolitan areas intensifies,it has caused serious pollution to the ecological environment,which in turn poses a potential threat to public health.First of all,the harmful gases and harmful substances emitted by automobiles will cause serious harm to people's health.These harmful gases and substances can cause heart and respiratory diseases,and even cancer,especially for vulnerable groups such as the elderly and children.Urban sprawl has also caused water pollution,mainly in the form of source pollution and non-point source pollution.Point source pollution refers to the source with fixed point of discharge,septic tank is the main source of point source pollution.Non-point source pollution is mainly rainwater runoff pollution.Contamination ofdrinking water sources increases the incidence of traditional diseases such as typhoid,hepatitis,dysentery and gastrointestinal disease.The third part introduces the impact of driving on people's health.On the one hand,people's dependence on cars means that they walk less and sit still for a long time.If there are no other fitness activities,people will become fatter and their health will be affected.On the other hand,the stronger people's dependence on cars means that the more they drive,the greater the possibility of traffic accidents.There are many accidents on America's highways each year,causing great casualties.At the same time,driving can also cause physical symptoms such as disc herniation and back pain.The fourth part mainly discusses the impact of the metropolitan sprawl on public mental health.First,the low-density and disorderly spread of metropolitan areas often requires long-distance commuting for long periods of time.More and more research shows that driving increases heart rate and is a source of stress.Second,the spread of metropolitan areas has also left Americans feeling lonely,a loneliness that can make them more vulnerable to heart disease,colds,strokes,depression,cancer and all kinds of diseases that can lead to death,and even increase the suicide rate in the United States.The negative effects of urban sprawl are more harmful to some vulnerable groups,such as the elderly,women,children and the disabled.