Air pollution is a major environment-related health threat, especially to children and the elderly, as it can cause respiratory diseases, lung cancer, and cardiovascular diseases. It has also been linked to low birth-weight, dementia, and damage to DNA and the immune system (WHO, 2017). Outdoor air pollution in both cities and rural areas was estimated to cause 3 million premature deaths worldwide in 2012 (WHO, 2016), and can also have substantial economic and social consequences, from health costs to building restoration needs and agricultural output (OECD, 2015). Of particular concern for outdoor air pollution are carbon monoxide, nitrogen oxide and ozone, but also fine particulates, or PM2.5, whose diameter is 2.5 μm or smaller. These are potentially more dangerous than the larger particulates (PM10), as they can penetrate deeper into the respiratory tract, and cause severe health effects. In 2015, particulate matter pollution was the cause of over 4.2 million deaths worldwide (Forouzanfar et al., 2016). The WHO has claimed that air pollution is one of the most pernicious threats facing global public health today and on a bigger scale than HIV or Ebola (WHO, 2017).