Air pollution – both outdoor (ambient) and indoor (household) – is a major environmental risk to health affecting everyone in developed and developing countries alike, although with important geographical differences in exposure. Many of the world’s poorest people living in developing African and Asian countries breathe higher levels of air pollutants, as they are heavily exposed to toxic fumes when cooking, heating and lighting their homes. Among the major air pollutants, particulate matter (PM) is the most damaging to human health, and sulphur oxides (SOx), nitrogen oxides (NOx) and ozone are associated with a range of diseases.
A recent report released by the World Health Organization (WHO) confirms that 92% of the world’s population lives in places where air quality levels exceed WHO limits. An estimated 6.5 million premature deaths are associated with outdoor and indoor air pollution together (nearly 12% of all global deaths in 2012).
The energy sector is by far the largest source of air pollution emissions from human activity, including inefficient modes of transport, household fuel and waste burning, coal-fired power plants, and industrial activities. An increased use of natural gas in people’s daily lives can create significant improvements to public health and the environment: when burned to heat homes of for industrial uses, natural gas releases 25-30% less CO than oil and 40-50% less CO than coal (per unit of energy produced); replacing an old coal-fired power plant with a combined-cycle gas turbines (CCGT) plant can reduce CO emissions by up to 70%; in road transportation, vehicles powered by natural gas would reduce emissions of CO by about 40%, NOx by about 94%, and PM by about 95% with respect to the vehicles replaced, thus significantly lowering emissions.
Sources: IEA (International Energy Agency), Energy and Air Pollution: World Energy Outlook 2016 Special Report; WHO (World Health Organization), Ambient Air Pollution: A global assessment of exposure and burden of disease; Ambient Air Pollution Database 2016 version [Accessed 13 November 2017]