How Does Pollution in Large Cities Affect Human Health?

How does pollution in large cities affect human health?
It is generally believed that the development of industrialization and urbanization brings about not only the rapid progress of economic growth, but also the widespread of multiple kinds of pollution, especially in large cities where the speed of development is extraordinarily fast, which poses an acute threat to human health. A variety of investigations have explored the effects on human health in a number of urban areas all over the world. As the impacts of pollution on human health are of significance, it is worthwhile to examine them deeply. This essay will introduce three major types of pollution, namely air pollution, land pollution and water pollution, along with their effects on human health.
The first kind of pollution is urban air pollution, which is considered to be a central environmental problem. Ever-increasing emissions from factories and automobiles are released into the atmosphere as the society develops, which have direct effects on human health through inhalation in both the short term and the long term. Inhaling polluted air only causes minor health issues in the short run, such as headaches, eye irritation and upper respiratory infections. Long-term effects including lung cancer and heart disease, however, pose a serious risk to urban people (Lawrence Berkeley National Laboratory n.d.). There are various air pollutants, of which sulfur dioxide and particulate matter are the primary ones in large cities (Enger & Smith, 2004).
Enger and Smith (2004) define sulfur dioxide as a chemical substance combining sulfur with oxygen that is produced when fossil fuels are burned. As Middleton (2008) points out, sulfur dioxide in high concentration is closely related to the ascending mortality, morbidity among citizens. For example, during the period of 1990 to 1996, a study was carried out focusing on how sulfur dioxide affected the prevalence rate of cardiovascular diseases in seven European cities...