More than 50 percent of people worldwide live in cities, and the World Health Organization predicts that this proportion will continue to increase. People migrate to cities for many reasons, including family ties and job opportunities. Urbanization changes the economic, social and political setup of a country or region and has several major negative impacts.

Lack of Jobs

Urbanization leads to a deficit in jobs. Businesses and governments cannot produce enough jobs to meet the demand of a fast-growing population. Unemployment rates soar as a result, causing people to apply for government-funded programs and benefits. The government loses money, reducing the amount of energy, health care, education, public transportation, waste management and physical security offered. Poverty spreads and stunts economic growth.

Air Pollution

Suspended particulates in the air come from motor vehicle fuel combustion. Soot, dust, lead and smoke make up the particulates. They pose a serious threat to health. Lead alone can cause brain damage, learning disabilities and premature death in children. The World Health Organization stated suspended particulate concentration should add up to less than 90 micrograms per cubic meter. The suspended particulate concentration soars over that measurement in cities with a population of 8 million or more.

Biodiversity Threatened

City growth destroys natural areas flowing with new and endangered animal and plant life. No matter how small, each species plays an important role in how the Earth works. Without this variation in life, humans suffer. Biodiversity protects water and soil from contamination, stores and recycles nutrients, breaks down and absorbs pollutants and helps areas to recover faster from disasters. Biodiversity also provides people with medicine, food and air. Urbanization limits our access to these resources.

Disease

Urbanization has led to reduced physical activity and unhealthy nutrition. The World Health Organization predicts that by 2020, noncommunicable diseases such as heart disease will account for 69 percent of all deaths in developing countries. Another urbanization-related threat is infectious diseases. Air travel carries bacteria and viruses from one country to the next. In addition, people relocating from rural areas are not immune to the same diseases as long-time city residents, which puts them at a greater risk of contracting a disease.

Crime

Rapid urbanization affects crime rates. Residents of different beliefs and behaviors thrown together suddenly do not have time to adjust or adapt to different viewpoints, leading to violence. The government's inability to prevent widespread poverty causes an increase in theft and other crimes. Frustration and alienation linked to a lower status, limited access to education, money and other resources push young people to join organized crime.