Poor air quality is not solely an urban problem. It also severely affects many small cities, suburbs and rural areas. Air pollution sources in rural areas typically differ from those in urban areas. 24 Solid biofuel used for cooking and heating, forest fires and agricultural burning are common sources in rural areas. But air pollution never remains where it is emitted. Pollutants (especially fine particles) can travel over long distances due to dispersion from the stratosphere and regional transport of pollutants by prevailing winds from urban sources to rural areas and vice versa. An example of the regional transport of air pollution is the transboundary haze pollution arising from forest and land fires in Indonesia that affect neighbouring Malaysia, Singapore and Brunei.
Cars are usually the major source of air pollution
While cars are often considered an important source of air pollution, other emission sources that can contribute significantly to air pollution include heat and power generation, industrial facilities, agricultural waste or biomass burning, shipping and aviation, and residential cooking with polluting fuels.9 The contribution of air pollution from different emission sources varies with seasons and time of day. For example, Hong Kong reports higher pollution concentrations emission from wood/biomass burning and coal combustion in power plants and industrial facilities in the adjacent Pearl River Delta region during winter months. 10 Therefore, long-term inter-sectoral and inter-state control strategies are needed to adequately address emissions. Studies have generally shown that the odd-and-even traffic restriction policies alone do not yield significant reduction in overall traffic volume 11, 12 or air pollutant concentrations across cities in China, India and Mexico. 13, 14
Air quality is better indoors than outdoor
Indoor air pollution is an important public health threat, as people typically spend over 90% of their daily time indoors. Indoor air pollution is caused by both outdoor air pollution penetrating into the indoor environment, and by pollutants generated by indoor sources such as household solid fuels used in cooking, environmental tobacco smoke, paint, carpets, and cleaning products. The U.S. Environmental Protection Agency reported that indoor air pollution concentrations can be on an average 2-5 times higher than outdoor concentrations, and in some instances, levels of certain pollutants can even be 1,000 times greater indoors than outdoors.6 In 2016 it was estimated that 3.8 million deaths occur globally each year as a result of household cooking that use solid fuels and inefficient stoves; this estimate is closely trailing 4.2 million deaths from outdoor air pollution.3
Only ‘Sensitive’ people are affected by air pollution
Air pollution damages health and wellbeing from womb to death.1 Not only has air pollution been associated with individuals at the extremes of age (e.g., infants or elderly) or those with pre-existing diseases (e.g., chronic respiratory diseases or heart disease), growing evidence has linked air pollution exposure to new-onset cardiovascular, cancer and pulmonary disease in previously healthy individuals. 2 Exposure in childhood has lifelong impacts on cognitive and physical development. Everyone is at risk from the health effects of air pollution.
If the air isn’t hazy then it’s safe
While air pollution at very high concentrations can form visible haze and smog, most of the air pollution we experience is at concentrations that are invisible and odourless. Nine out of ten people worldwide live in places where air quality exceeds World Health Organization (WHO) guideline limits.
You can get used to air pollution
Long-term exposure to ambient air pollution (particularly PM2.5) is associated with serious adverse health effects that include worsened respiratory symptoms, cancer incidence, heart attack stroke and premature death. 10 18 19. In fact, studies consistently report considerably larger cumulative health effects from long-term exposures than those from short-term exposures after taking into account other individual risk factors. 20 21 The longer one is exposed to air pollution, the greater the risk of serious adverse health impact.
All you need is a good air filter or mask to protect yourself from air pollution
Most air filters are designed to remove either particulate matter or gaseous pollutants; though some combine filters to achieve both (read more on how to select air filter/cleaners here). Particulate and gas filters require frequent filter replacement, and higher the pollutant concentrations, the more frequent the replacement and the higher the maintenance costs. Without proper maintenance, the efficacy of air filters declines. 7 The effectiveness of respirators and face masks depends on the type of pollutants, mask design and how they are used. 8 Simple paper dust masks are generally useless when it comes to reducing pollution exposure. Even better designed respirators like N95 masks may offer inadequate protection when worn, primarily due to poor facial fit. 8 It is important to keep in mind that no air-filter or face mask will eliminate all the air pollutants from the air, especially ultrafine particles (e.g., 0.3 microns in diameter). A better solution is to remove air pollution emission sources.
Taking vitamins reduces your risk from air pollution
While some vitamins and minerals may have health benefits for some people who are deficient in specific nutrients, direct evidence linking supplements to protection against air pollution is scarce. It is difficult to study whether supplements reduce the risks from air pollution. There are hundreds of vitamins and minerals on the market, their quality and dose varies dramatically, animal studies do not necessarily translate to humans, and it difficult in human studies to control the role of diet, physical health, co-morbid illness, medication use and other environmental exposures. 22, 23 Dietary supplements are not without their own risks, and can cause metabolic, kidney, liver and other health problems. For these reasons, the best solutions are those that reduce exposure to air pollutants.
Air pollution in a city can be controlled by moving polluting industries to outside the city limits
Zoning solutions that help separate polluting companies from dense urban populations have helped reduce local exposures to air pollution. But power plants, waste facilities and heavy industry that are large emitters of particulates, sulfur and other pollutants can still affect urban air pollution. Because of long distance transport of pollutants, cities can suffer from emissions located hundreds of miles away. Regional regulations and emission control strategies are needed to adequately address air pollution problems.
Controlling air pollution will hamper economic growth
Ambient and household air pollution imposes tremendous public health and environmental burden and constrains economic growth of any society. Each year, 7 million people die prematurely as a result of air pollution; 3 and it is estimated that the welfare losses of premature deaths related to air pollution worldwide was over US$5 trillion in 2013, and this cost in East and South Asia can be as high as 7.5% of its Gross Domestic Product. 15 While environmental measures entail certain pollution control expenditures, these costs have been demonstrated to be significantly offset by the economic benefits and savings in healthcare, premature mortality, and improved social and development outcomes, with conservative estimate of the benefit-to-cost ratio exceeding 14 to 1, and the ratio could reach 50 to 1. Thus, air pollution control is an imperative matter to tackle without delay.