Air Quality and coronavirus: a glimpse of a different future or business as usual Contents

---

1Changes in UK air pollution

6.In this chapter we briefly explore how air quality has changed in recent decades and the progress, or lack of it, prior to the pandemic; before turning to the impact of the spring lockdown on air quality and its implications.

Box 1: Common types of air pollution and their effects on health10

Particulate matter (PM) mainly comes from burning fuels, tyre and brake wear, wind-blown soil and dust, sea spray and fires from burning vegetation. PM is classified by size: PM10 are coarse particles <10 microns (µm) in diameter; PM2.5 are fine particles <2.5 µm in diameter; and PM0.1 are ultrafine particles 0.1 µm in diameter. Particles bigger than PM10 are mainly deposited in the nose or throat. Smaller PM are a bigger health risk as they can be drawn deep into the lungs, and long-term exposure increases mortality and morbidity from cardiovascular and respiratory diseases and may cause lung cancer. Nitrogen dioxide (NO2) and nitric oxide (NO) (together known as NOx) are produced by combustion, with 80% of NOx emissions occurring in areas where the UK exceeds legal limits on NO2 because of transport, especially diesel-powered vehicles. Other sources are power generation, industrial processes and domestic heating. Short-term exposure to NO2, especially at high concentrations, causes inflammation of the airways. It is associated with reduced lung development, respiratory infections in early childhood, reduced lung function in adulthood and reduced life expectancy. Sulphur dioxide (SO2) comes from burning sulphur-containing fuels (e.g. coal). Chemical reactions of SO2 can produce sulphates in the air as secondary particles contributing to PM; and SO2 irritates the lining of the nose, throat and airways. Ammonia (NH3) comes from natural and man-made sources. Atmospheric NH3 reacts with acid gases to form secondary PM2.5. Agricultural emissions of NH3 can be a key contributor to short-term episodes of high PM pollution. Ground-level ozone (O3) is formed by heat and sunlight reacting with NOx and volatile organic compounds (VOCs) which produces smog and can affect people’s respiratory and cardiovascular systems. Non-methane volatile organic compounds (NMVOCs) come from industrial processes, agriculture and household products. In sunlight they react with NOx to form ground-level O3.

7.Air pollution is known to affect people’s health from before birth and to old age. It affects the vital organs including lungs, heart and brain, and is linked to physical and mental health problems including, asthma, lung cancer, heart disease, strokes, dementia, depression, anxiety, and poor concentration in children.11

8.It has been estimated that every year up to 64,000 of all premature deaths may be linked to air pollution, with up to 40,000 premature deaths linked to exposure to particulates and nitrogen dioxide.12 This was starkly highlighted by the Coroner’s verdict in December 2020, into the death of Ella Roberta Adoo Kissi-Debrah who died aged nine on 15 February 2013 who lived near the South Circular Road in south-east London.13 He concluded that Ella “died of asthma contributed to by exposure to excessive air pollution” and the medical causes of death were recorded as, “acute respiratory failure”, “severe asthma”, and, for what is believed to be the first time, “air pollution exposure.”14 He continued that:

Air Pollution was a significant contributory factor to both the induction and exacerbations of her asthma. During the course of her illness between 2010 and 2013 she was exposed to levels of [NO2] and Particulate Matter in excess of World Health Organisation (WHO) Guidelines. The principal source of her exposure was traffic emissions. During this period there was a recognized failure to reduce the level of NO2 to within the limits set by EU and domestic law which possibly contributed to her death.15

9.Nationally there has been a long-term decline in overall emission levels in the last 50 years as emissions controls were implemented “on energy production and vehicles in the 1980s and 90s”.16 The National Centre for Atmospheric Science (NCAS) explained the reduction in emissions had slowed in recent years as it is “proportionately more and more difficult to reduce ambient concentrations as air quality improves,” and past “easy wins” like phasing out coal power, better fuel quality and catalytic converters on petrol cars, meant there were “few easy sectors left to tackle”.17 Urban NOx have fallen since 2015 as issues with diesel vehicles are “now being slowly addressed”, and should fall further with a new emissions standards for cars, and more electric vehicles.18 PM2.5 concentrations have remained flat as “so many different primary sources and precursor emissions contribute to PM2.5”, including new petrol and electric vehicles’ brakes and tyres, although different particulates of the same size have different levels of toxicity. Meanwhile, little progress has been made in reducing NH3 emissions, despite the agricultural sector’s efforts.19

Figure 1: Trends in UK emissions 1970–201620

UK targets

10.The UK is a party to the Gothenburg Protocol which sets national emissions ceilings for sulphur dioxide (SO2), NOx, volatile organic compounds (VOCs), ammonia (NH3) and PM2.5.21 These are translated into UK law as annual emissions reductions targets via the National Emission Ceilings Regulations 2018.22 The EU Air Quality Directive, which along with other EU air quality legislation is now incorporated into domestic law as EU retained law, set “limit values” on the levels of permissible outdoor air pollution which must not be exceeded.23 However, the European Commission can no longer enforce these limits through the European Court of Justice since the UK has left the European Union.

11.Defra’s stated that the UK was currently complying with the emission ceilings for annual emissions of NO2, NH3, SO2 and NMVOCs; and annual emissions for all fell between 2010–18 except for NH3, which rose by seven per cent.24 The only EU Air Quality Directive limits the UK was failing to comply with were the hourly and annual mean limit values for NO2.25 The UK has been in breach of the limit on NO2 since 2010, leading to European Commission infraction proceedings against the UK in 2014 and 2018.26 Separately, the legal charity Client Earth brought three successful judicial reviews against the UK Government, with the courts ordering Ministers to publish new or updated air quality plans in 2015, 2016 and 2018 to bring NO2 levels under legal limits.27 The failure to meet legal limits on NO2 was raised by several witnesses. The British Medical Association (BMA) said that, whilst the UK Government had “made good progress […] over the past two decades” this had “plateaued in recent years”, referencing the lack of compliance on NO2 reported across the UK’s air quality assessment zones.28 By 2019, of these 43 zones that cover the UK, only 10 were meeting the mean annual limit on NO2 (see figure 2 below).29 However, it has been reported that between 2016 and 2019, London saw a reduction in NO2 which was five times greater on average than in the rest of the UK.30

Figure 2: Compliance with the annual mean limit value for NO2 between 2010–2019 across 43 air quality zones31

The impact of covid-19 lockdown

12.In June, Defra’s Air Quality Expert Group (AQEG) confirmed that, as expected, the lockdown introduced on 23 March 2020 to control the covid-19 pandemic had led to some improvements in air quality.32 Up to 30 April, “NO2 [was] lower everywhere, but the picture for PM2.5 [was] mixed compared to previous years”.33 Professor Alastair Lewis, the Chair of AQEG, explained that NO2 saw “the largest change” mainly because of reductions from road transport, and by 30–40% in urban areas.34 However PM-concentrations “did not change by really dramatic amounts”, as “far more of PM2.5 comes from things that are not related to road transport”, including industry, central heating, cooking, agriculture and other sources.35 AQEG also reported that there was a growth in urban ground-level ozone because of “reducing nitrogen oxide emissions [during] the peak of the lockdown”.36

13.Some people experienced a noticeable improvement in air quality; Asthma UK and the British Lung Foundation surveyed over 14,000 people living with a lung condition and found “1 in 6 reported having reduced symptoms, likely due to the reductions in air pollution over this period”. A survey of 2002 adults by Global Action Plan and Guy’s & St Thomas’ Charity (GSTC) found that “18% of all people have found it easier to breathe during the lockdown, which increases to 21% for residents of any urban area, and 36% for London residents”.37 The figures rose to “29% for those with asthma and 30% for those with a cardiovascular disease”.38

14.By July, traffic and emissions had not yet returned to normal although lockdown restrictions had been eased in June. Whilst car use had increased, the patterns and timing of traffic had changed with different working patterns and school closures.39

15.By the autumn, air pollution had returned to more normal levels. Analysis by the Centre for Cities found that by September 2020, in 39 of the 49 cities and large towns they looked at, “the pollution levels were at least back to pre-lockdown levels” but economic activity was not yet fully recovered indicating a risk that air pollution might start to exceed pre-pandemic levels.40 The Centre speculated that “the long-term impact of the pandemic may be to make pollution worse as changed behaviour becomes entrenched even as economic activity is restored”.41

Indoor air pollution

16.We did not include indoor air pollution within our inquiry’s terms of reference, but it was covered in several submissions. Professor Stephen Holgate, Royal College of Physicians Special Advisor on Air Quality, and UK Research and Innovation Clean Air Champion, argued that evidence is growing about its risks to health in public buildings and homes, including because of exposure to chemicals for cleaning that contain VOCs, reduced ventilation to conserve energy and the interaction of indoor and outdoor pollutants.42 The Royal College of Paediatrics and Child Health said that it can also lead to health inequalities as poor housing linked to social deprivation can increase exposure to bad ventilation, moisture and mould triggering respiratory conditions.43 Existing government guidance on indoor air quality may be out of date, and concerns were raised that the current Clean Air Strategy (see chapter 3) contains few measures to address the issue, especially given the increased time many people are spending at home during the pandemic,44 with people spending 90–95 per cent of their time indoors.45

17.Defra’s evidence highlighted that little was known about the impact of the lockdown on people’s exposure to indoor pollution, and said that it was rapidly seeking to fill in its “knowledge gaps”.46 This included commissioning research and a roundtable led by the Chief Medical Officer and the Government’s Chief Scientist.47

18.Before the pandemic, the UK had made limited progress in improving air quality, with less than a quarter of air quality assessment areas meeting the annual mean limit for nitrogen dioxide (NO2). Lockdown restrictions from March 2020 led to less traffic and changing travel patterns and many people experienced better air quality. But by September 2020, most towns and cities saw a return to pre-lockdown levels of air pollution. However, the temporary improvement in air quality in the spring does not mask the need for faster progress on air pollution. Longer term changes to how people live, work and travel as a result of the pandemic will bring opportunities, but also risks, and will require changes to policy which we discuss in the following chapters.

19.The noticeable improvement many people had in their experience of air quality and their wellbeing following the initial lockdown illustrates the benefits of action to tackle air quality for all of us. The tragic death of Ella Kissi-Debrah, and thousands of others each year, shows the costs of the failure to do so. This highlights the need for legally binding air quality limits and the Committee recommends that the Office for Environmental Protection (see chapter 3) be empowered to enforce them.