The process of a society changing from rural to urban can be termed urbanization. As the number of people moving into cities soar, urban centers expand too, erasing rural, agricultural and forestland in their wake.

This year, the world’s urban population of over three billion people, has for the first time in history exceeded the number of those living in rural areas. Going by this trend, by 2030 around two-thirds of the world's people will be living in cities. According to a July 2006 estimate, in India around 30 percent of the population lives in urban cities.

Is urbanization bad? Not necessarily. Undertaking the correct approaches during urban planning can avoid most of the environmental problems associated with it. Obviously this has not happened. Among the many evils urbanization has unleashed, respiratory problem is one.

How Urbanization Causes Respiratory Problems

• Urban activities, such as combustion, industrial activities, mining, and drilling lead to higher levels of toxic Industrial and Vehicular Emissions.
• Global warming and the resultant Climate Change
• Poor Indoor Air Quality (from modern building materials and other household products)

The quality of the air we breathe has a profound effect on the health of our lungs and the entire respiratory system. In almost all the cities of the world, doctors warn that respiratory problems are on the rise.

One of the main culprits is the burgeoning of vehicular flow. Motor vehicle emissions include carbon monoxide, oxides of nitrogen, benzene, formaldehyde, etc. Along with these are diesel particulates; solid carbonaceous particles contribute to the total particulate matter. Such microscopic particles can be inhaled into the lungs where they remain lodged and bring about lung damage and other related disorders.

It is well known that carbon monoxide hampers the transport of oxygen to tissues. Exposure to oxides of nitrogen can cause respiratory infections, decreased lung function and increased airway resistance. While problems of the upper respiratory tract include a runny nose, sinusitis, sore throat, wet cough, hay fever and burning eyes, lower respiratory tract problems are indicated by wheezing, dry cough, phlegm, shortness of breath (dysponea), emphysema, chest discomfort and pain.

In addition to this are even graver illnesses, such as bronchiolitis, pneumonia, chronic obstructive pulmonary disease (COPD), congestive heart failure, lung cancer and even cardio-vascular mortality. The cardiovascular system can be affected when lungs cells release a variety of potent chemical mediators in response to respired toxins. In addition to compromising the function of other organs, this response causes lung inflammation and impairment of lung function. As the respiratory system is closely associated with blood vessels, soluble carcinogens could also be transported from the lungs to other parts of the body.

According to environmental specialists, children are highly vulnerable to respiratory problems brought about by air pollution. Bronchitis attacks in city-dwelling children are becoming very common. A chronic form of bronchitis could lead to diseases that cause obstructions in the lungs, also known as COPD.