While the most serious personal air pollution is smoking, the most important source of external air pollution in Philippines, UK and elsewhere is now motor vehicles, especially in cities. Air pollutants are usually present in a mixture :-
• Carbon monoxide – interferes with oxygen carriage in blood.
• Volatile Organic Compounds – most important is benzene.
• Particulate Matter – mainly from diesel, inhaled deeply into lungs.
• Nitrogen dioxide .
• Ozone - from action of sun on nitrogen oxides – “ photochemical smog “ which can spread to rural areas.
• Short-term problems - cough, shortness of breath, especially in those with asthma or chronic bronchitis/emphysema.
• Long-term problems - may increase risk of lung cancer, asthma, chronic bronchitis/emphysema.
• Compared to many countries, air pollution levels in UK are low.
• An estimated 1/8 deaths in Metro Manila may result from air pollution ( around 5,000 premature deaths, mainly cardiovascular and lung diseases ). Next are Cebu , Davao , Zamboanga, and Iloilo cities.
• China has seen the largest human migration in history. Air pollution contributes to disease both in urban and in rural areas, and traffic-related accidents are a major public health threat as the country becomes increasingly motorised. In 2011, the proportion of China's population classified as urban reached 51%.
• China's air quality standards have been hard to meet. Outdoor air pollution may be associated with more than 400 000 premature deaths per year. Rapid increases in motor vehicle use— the number of vehicles in Beijing is growing by more than 1000 per day— contribute to serious air pollution in many cities.
• How to minimise risks from air pollution ? Easier said than done, but :-
1. Avoid strenuous outdoor exercise in polluted areas.
2. Carry inhalers if needed ( masks probably don’t help ).
3. Walk, bicycle, or use public transport. Air conditioning helps if available.
4. At least in UK, nobody should fear going outdoors because of air pollution. Give up smoking instead !
5. A continuing hazard of public transportation in Philippines is passive smoking from passengers who smoke in jeepneys and non-air-conditioned buses. Drivers themselves still smoke despite stickers and signs saying “No Smoking” and Republic Act 9211 / Tobacco Regulation Act of 2003 which prohibit smoking inside public vehicles.