Urbanization, also known as rural flight, is the movement of people from rural areas into cities, often motivated by economic or social factors.   Some of these desirable factors include less time and expense commuting, access to better job opportunities, education, housing, and entertainment. Currently, about 3 billion live in urban areas. We can see a huge increase in urbanization in the past 60 years. The number of urban dwellers has quadrupled between 1950 and 2000 from 733 million people to 2.587 billion people.  This rapid increase is expected to continue and by 2030 about 5 billion people will live in urban areas, that is 61% of the population. This chart below helps demonstrate the increasing trend and the distribution of urbanization over the past 60 years and into the future.

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There are no signs of this movement slowing down. This trend of increasing urbanization has already and will continue to create issues regarding human and environmental health.

Rapid and unplanned urban growth is often associated with poverty, environmental degradation, and population demands that exceed what can be serviced. These conditions put human and environmental health at risk. Crowding, air pollution, insufficient or contaminated drink water, inadequate sanitation and solid waste disposal services, industrial waste, and increased motor vehicle traffic are all aspects of increased urbanization that affect human and environmental health. Just looking at a picture of Los Angeles as it is cloaked in smog (caused when sunlight reacts with airborne pollution, including ash, dust, and ground-level ozone) makes me scared to visit.

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According to the Population Reference Bureau the effects of urbanization listed above increase respiratory and cardiovascular disease, increase tuberculosis incidences, cause stress related illnesses, discourage physical activity, and promote unhealthy food. I’m hoping you are beginning to worry about the negative effects of urbanization by now.

Environmentally speaking, urbanization creates heat islands and negatively affects air and water quality. Dense urban areas can change the local weather pattern from the heat island effect.  Let me explain. Roads, cement sidewalks, and buildings replace open land and vegetation in cities. These hard surfaces radiate heat back into the atmosphere 15 to 30 percent less than on the open land in rural communities. Higher energy consumption to cool down buildings within the city in addition to less albedo results in warmer temperatures in cities. This increased warming traps atmospheric pollutants close to the surface of the Earth. The graph below demonstrates as you move away from cities temperatures drop and as you move closer to cities temperature increase.

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Within urban areas there is an increase in air pollution due to an exponential increase in the number of vehicles registered. For example, professor J. P. Singh at Patna University in India noted that in the number of registered vehicles in the country have increased from 1.87 million in 1971 to 25.28 million in 1993. This air pollution is hazardous for any life forms and affects communities downwind of major cities. Lastly, many urban cities in developing and undeveloped countries don’t have proper treatment of sewage collection and disposal. The untreated and partially treated waste water contaminates local rivers, streams, lakes, and reservoirs. This disrupts surrounding ecosystems and threatens nearby biodiversity while simultaneously affecting human health. The polluted urban environment affects the health and quality of life of the urban population. Now it should be obvious to see that urbanization is taking a toll on public health and the environment. Enough of this gloom and doom talk though. I’m here to tell you that sustainable urban living is a possibility to help mediate all these issues.

Sustainable urban living helps cities become healthy viable communities for citizens. This way of living can increase the quality of life, create natural open spaces, reduce waste, increase access, build a sense of community, improve the quality of water and air, and create environmental diversity.