So we have to break some bad news first: This is not a problem that can be solved at an individual level. As much as you do good work reducing electricity usage, lowering emissions as able, moving to public transport, cycling, being greener the reality is we as individuals don’t have the power to make big change.
We have to look to large and influential organisations and governments, and encourage them to act and act with coordination, while taking realistic action to protect our own health. Perhaps we can encourage them to act by pointing out that cost to health means economic cost, through both medical treatment and days of productivity lost.
Generally, it’s agreed that areas most contributing to the problem are:
- fuel-consuming forms of transport
- energy production and distribution
- waste management
- commercial and institutional buildings, and homes
So transport, energy, urban planning, rural development, agriculture, and many more departments must work together and work internationally for strong solutions.  
So what is happening? I won’t go into detail here, just broad strokes, but the WHO and EEA have plenty of resources if you wish to read through the nitty gritty.
In 2016, the WHO set out a “roadmap”  for addressing air pollution. There were four main areas:
- improving understanding and awareness
- improving our ability to monitor the situation and any progress made
- aiming to raise awareness at all levels of health sector leadership, i.e. from local to global
- helping those health sectors to address the issues through training, guidelines, and national action plans.
However, that’s a bit grandiose and vague, and focusses on knowledge and awareness. I enjoyed this more practically-orientated, holistic approach for a multifactorial problem in the developed world, and have adapted it to include suggestions from elsewhere (primary source , additional sources  ) –
We must improve the existing systems and introduce legislation requiring better standards for the new. Standards which look to the long term and are inherently sustainable.
Housing: ensure clean fuel for heating and cooking, no mould or pests
Schools and playgrounds: provide safe sanitation and hygiene, build away from major sources of air pollution such as busy roads, factories and power plants
Urban planning: create more green spaces, safe walking and cycling paths, reduce the amount of waste that is burned within communities and thereby reducing ‘community air pollution’.
Transport: reduce emissions and increase public transport; introduce new green methods of public transport. An example from the shipping industry:
- “The global shipping fleet is rushing to meet a 2020 deadline imposed by the International Maritime Organization (IMO) to reduce air pollution by forcing vessels to use cleaner fuel with a lower sulphur content of 0.5%, compared with 3.5% as currently used.”
Agriculture: reduce the use of hazardous pesticides and look at transport methods
Industry: manage hazardous waste and reduce the use of harmful chemicals, also look at transport methods
Health sector: inform, educate, provide resources to health professionals, and engage in inter-sectoral policy making. Monitor health outcomes and engage in policy making.
Miscallaneous government: work towards meeting WHO global air quality guidelines… invest in improvements in energy efficiency and facilitate the uptake of renewable energy sources.
In terms of the developing world, we must aid countries to develop alternative energies and continue to aim for access to healthcare for all.
There is some good news: although ambient air pollution have generally remained high and stable over the last 6 years , a recent EU report shows declining levels of particulates, although still often above recommended levels .
Meantime, individuals can take some actions to protect their health. These range from closing windows during peak pollution hours, seeking to live away from traffic-high areas, and wearing masks. In general, avoid creating smoke in the home, and look at the sectors contributing to air pollution and act as you can to reduce your use.
And as always, vote, and get in touch with your politicians. In the United Kingdom you can contact your Member of Parliament through this page: https://www.parliament.uk/get-involved/contact-your-mp/
“The cost of action is high, the cost of no action immeasurably greater” – Opening remarks, first WHO Global Conference on Air Pollution and Health 
- European Environment Agency, “EEA Report No 12/2018,” 29 October 2018. [Online]. Available: https://www.eea.europa.eu/publications/air-quality-in-europe-2018. [Accessed 15 December 2018].
- World Health Organisation, “Enhanced global action on air pollution approved at WHA69,” 27 May 2016. [Online]. Available: http://www.who.int/sustainable-development/news-events/wha69-roadmap-ap/en/. [Accessed 4 November 2018].
- World Health Organisation, “The Cost of a Polluted Environment,” 6 March 2017. [Online]. Available: http://www.who.int/en/news-room/detail/06-03-2017-the-cost-of-a-polluted-environment-1-7-million-child-deaths-a-year-says-who. [Accessed 30 October 2018].
- M. Sofiev, J. J. Winebrake, L. Johansson, E. W. Carr, M. Prank, J. Soares, J. Vira, R. Kouznetsov, J.-P. Jalkanen and J. J. Corbett, “Cleaner fuels for ships provide public health benefits with climate tradeoffs,” Nature
- World Health Organisation, “More than 90% of the world’s children breathe toxic air every day,” 29 October 2018. [Online]. Available: http://www.who.int/news-room/detail/29-10-2018-more-than-90-of-the-world%E2%80%99s-children-breathe-toxic-air-every-day. [Accessed 4 November 2018].
- World Health Organisation, “9 out of 10 people worldwide breathe polluted air, but more countries are taking action,” 2 May 2018. [Online]. Available: https://www.who.int/news-room/detail/02-05-2018-9-out-of-10-people-worldwide-breathe-polluted-air-but-more-countries-are-taking-action. [Accessed 4 November 2018].
- World Health Organisation, “First WHO Global Conference on Air Pollution and Health, 30 October – 1 November 2018,” 2018. [Online]. Available: http://www.who.int/airpollution/events/conference/en/. [Accessed 4 November 2018].