how does air pollution affect the traveler?

I read an article recently in the Economist about the 25 most polluted cities in the world. It made me think about polluted cities that I have visited over the years and Cairo was at the top of this list. A thick smog was hanging over the city each morning and traffic pollution was almost unbearable. Most days I ended up with a huge headache.

Air pollution,Air Pollution information,25 most polluted cities,how to prevent air pollution,signs of air pollution — Early morning in Cairo and the smog hanging thick over the Nile river

There are different kinds of pollution. Some or visible and some invisible. Fact is they are both dangerous and contribute to global warming. It is estimated that more than 2 million people die prematurely each year due to the health risks of air pollution.

Air pollution,Air Pollution information,25 most polluted cities,how to prevent air pollution — 25 most polluted cities in the world – The Economist 2013

What are the symptoms of air pollution?

Short-term effects includes:

Itchy eyes, nose and throat.
Wheezing,coughing and shortness of breath.
Chest pain, headaches, nausea, bronchitis and pneumonia.
Asthma can get worse.

How can the traveler protect himself and what precautions can be taken?

When you plan your trip do a bit of research and try to answer the following questions:

Cities visited: Are you going to visit any of the cities that are known to be heavily polluted?
Length of your trip: How long will you be exposed to these conditions?
Health Status: What is your current health status? Do you have asthma, allergies, chronic bronchitis, heart or lung disease?
Age: Are you an elderly person or travelling with young children. The elderly are more susceptible to air pollution due to pre-existing chronic conditions and newborns and children take in more air (higher level of pollutants) than adults for their body weight.
Season: What time of year are you going? Depending on seasonal weather patterns, smog tends to occur during hot and humid days. If you suffer from asthma or allergies, also consider the occurrence of pollen season at your destination.

What precautions can be taken?

Purchase a mask that you can wear over your mouth and nose. You often see Chinese locals wearing them. They wear it for a reason!
Be on the lookout for smog alert days. Many newspapers warn people as well as the radio and television.
Avoid strenuous physical activity on these days.
Consult with your doctor if you are at risk.
For older travelers, get a physical exam that includes a stress and lung capacity test prior to departure.
If you are travelling with newborns or young children, minimize exposure or consider not travelling to areas with low air quality