Something in the air
Paul Suff assesses the progress being made in the UK to improve air quality in line with EU pollution prevention targets
Last October, the environmental audit committee (EAC) published damning criticism of successive governments’ inaction on improving air quality in the UK. It highlighted the continuing failure to meet European targets for safe air pollution limits in many parts of the country, and argued that the present government had also failed to get to grips with the issue.
The committee provided the startling reminder that, while 4,000 people died as a result of the Great Smog of London in 1952, which led to the introduction of the Clean Air Act in 1956, a similar number of people died in London from air pollution in 2008 and 30,000 died across the whole of the UK in the same year.
The EAC also reported that 40 of the UK’s 43 assessment zones are failing to meet EU targets and poor air quality was found to be shortening the lives of up to 200,000 people in 2008 by an average of two years.
Aside from the human cost, the financial cost of failing to improve air quality is staggering. Defra estimates this costs the UK up to £20 billion a year, while the European Environment Agency (EEA) reveals that industrial air pollution recorded by the European Pollutant Release and Transfer Register in 2009 cost the UK between £3.5 billion and £9.5 billion.
Poisonous atmosphere
The UK monitors harmful pollutants, such as benzene, 1, 3-butadiene, carbon monoxide (CO), lead, nitrogen dioxide (NO₂), particulate matter (both PM2.5 and the coarser PM10), sulphur dioxide (SO₂), ozone (O3), and PAH (polycyclic aromatic hydrocarbons) (see panel below for main causes of pollution). And Defra and the devolved administrations measure CO, PM10, NO₂, SO₂ and O3 to assess air pollution levels.
Progress in reducing some of these has been made over the past 25 years, although that advance may be stalling. In 2010, the previous EAC concluded that “air quality in the UK has improved over recent decades but improvements are now levelling off and are increasingly costly to achieve.”
It found the following three key pollutants are causing a major air-quality problem where the UK is failing to meet its domestic and European targets: nitrogen oxides (NOx), a mix of nitrogen monoxide and NO₂; ozone; and particulate matter (PM) – tiny particles from a variety of materials, including sulphates, ammonia, sodium chloride, carbon, mineral dust and water.
Main pollutants
Sulphur dioxide – from burning sulphur in fossil fuels, such as coal and oil.
Nitrogen oxides – from vehicle emissions and the generation of electricity.
Toxic organic micropollutants – from combustion activities, such as dioxins, furans, polyaromatic hydrocarbons and polychlorinated biphenyls.
Fine particles, including dusts, sulphates and nitrates – from combustible sources, such as road traffic and atmospheric reactions.
Butadiene – a chemical released in the atmosphere from the industrial burning of rubber and synthetics, as well as emissions from petrol- and diesel-operated machinery.
Carbon monoxide – from petrol engines.
Lead and heavy metals – from industrial emissions.
Ozone – pollutes the lower atmosphere. It is not emitted directly from any manmade source but is formed from chemical reactions between various air pollutants, primarily nitrogen oxides and volatile organic compounds. |
The UK national ecosystem assessment, which was published last year, reported some improvement, but concluded: “Although there have been significant improvements in UK air quality over recent decades, current concentrations and deposition rates still exceed thresholds for effects on human health, crop and forest production, and biodiversity over significant areas of the country.”
Industry and road transport are the main sources of air pollution, with the former a major source of emissions of NOx (46%) and PM10 (36%) and the latter contributing to significant emissions of NO₂ (30%) and PM10 (18%). Exposure to pollutants varies according to location, with road transport responsible for up to 70% of air pollution in urban areas.
Long-term trends reveal that, in urban areas, concentrations of PM10 declined from a peak of 35 micrograms per cubic metre (μg m3) in 1992 to 19μg m3 in 2008. Little has changed in the four years since, with 2011 levels at 20μg m3. Similarly, roadside particulate pollution has shown long-term improvement, but stagnated recently, with concentrations of PM10 declining from 39μg m3 in 1997 to between 19μg m3 and 23μg m3 for the past four years. By contrast, urban background ozone pollution is increasing, with concentrations rising from 38μg m3 in 1987 to 58μg m3 in 2011.
The latest figures from the environment department show that the UK exceeded the hourly limit value for NO₂ in 2010 in only three out of the 43 zones, but in 40 zones for the annual limit. The UK also reported exceeding the long-term ozone objective for human health in 41 zones, and the long-term objective for vegetation in six.
Much has been done to reduce air pollution from regulated industry.
In 2008, the Environment Agency reported in its 10-year assessment of progress that those sectors that had reported to it since 1998 had halved PM10 emissions, reduced emissions of NOx by 12% (largely because of controls at major power stations) and cut sulphur oxide releases by 69% (mainly due to flue gas desulphurisation at major coal-fired power stations). Over the same period, dioxin and volatile organic carbon releases from sites directly regulated by the agency declined by 58% and 57% respectively.
A legal matter
Measures to address air quality are largely the responsibility of the devolved administrations in the UK, although policy instruments to improve air quality, such as environmental standards for industry and vehicle manufacturers, tend to be agreed at European level. Nationwide objectives for air quality are set out in the 2007 strategy for England, Scotland, Wales and Northern Ireland.
EU legislation, such as the Directive on ambient air quality (2008/50/EC) and the Integrated Pollution Prevention and Control Directive (96/61/EC as amended), set caps, which are regulated through domestic legislation.
Under the 2008 Directive, for example, member states have to reduce exposure to PM2.5, which comes mainly from cars, trucks, planes and small industrial plants, in urban areas by an average of 20% by 2020 based on 2010 levels, bringing the exposure levels below 20μg m3 by 2015.
In non-urban areas, countries will need to respect the PM2.5 limit value set at 25μg m3 by 2015. The Directive also allows member states to postpone achieving PM10, NO₂ and benzene standards by five years, from the original 2010 deadline until 2015.
Despite the extension, lawyers acting for Defra confirmed in December that the UK was effectively already in breach of its legal obligations to lower air pollution levels in a number of locations. The lawyers were responding to a legal challenge to Defra’s plans to comply from campaign group ClientEarth.
The environment department’s plans to cut NO₂ reveal that it does not expect pollution levels to be cut in line with the Directive before 2020 in 17 of the 43 cities and regions affected. Central London, for example, will not meet the NO₂ limit until 2025, while some cities, including Birmingham, Cardiff, Glasgow and Manchester, should meet the targets in 2020.
ClientEarth wants the environment secretary to revise the plans so the UK does not breach the 2015 deadline. Hearing the case, Justice Mitting said any enforcement action was a matter for the European Commission. Should the commission instigate proceedings, it will not be the first time the UK has faced the possibility of legal action over infringements of EU air-quality legislation. Although eventually dropped, the commission started infringement procedures against the UK in 2007 for exceeding EU limits on ambient concentrations of SO₂ from industrial installations.
On the domestic front, UK regulators investigate several hundred air pollution incidents each year, prosecuting many companies that breach their permit conditions. In the past year, for example, Industrial Chemicals was fined £10,000 in November 2011 after pleading guilty to two breaches of its environment permit and allowing an estimated 194 litres of NO₂ to escape from its Hebburn plant in South Tyneside, while Maier UK was fined £26,500 in December, after it emitted 66 tonnes of solvents into the atmosphere during 2009–10, which was more than three times the legally imposed limit.
Constant challenge
Particulate matter and ozone are Europe’s most problematic pollutants in terms of human health (see diagram below), and, as Defra’s latest data indicate, keeping both in check is proving difficult.
Partly this is because of complex links between emissions and ambient air quality, which means that cuts in emissions do not always produce corresponding falls in atmospheric concentrations. This is particularly the case for PM and O3, as the EEA reported in 2011. It revealed that PM precursor emissions, such as sulphur oxides and NOx, declined considerably across the EU in the 10 years to 2009 (down 56% and 28% respectively), but primary PM10 and PM2.5 rates decreased by only 16% and 21% over the same period.
And while the regulatory and monitoring focus for PM has tended to be on PM2.5 and PM10, evidence is emerging that even finer particles – so-called black carbon, which is a product of the incomplete combustion of fossil fuels or biomass – are causing health problems and exacerbating climate problems.
“These tiny particles can act as sponges carrying small amounts of toxic species, such as PAHs and dioxins, which are adsorbed onto black carbon particles and transported deep into the body,” says Jim Mills, managing director at Air Monitors, which is supplying monitors for an EU-funded programme, Carbotraf, to measure CO₂ and black-carbon emissions from traffic in Glasgow and Graz, Austria.
Scientists also say that black-carbon emissions are the second largest contribution to global warming, after CO₂ emissions. Black carbon increases warming by absorbing sunlight, darkening snow and influencing the formation of clouds. But whereas CO₂ stays in the atmosphere for many decades, black carbon stays only for a relatively short period of time, from days to weeks, before falling to the ground as a result of dry deposition or precipitation.
Researchers from NASA and the Stockholm Environment Institute at the University of York (SEI) recently reported that keeping high-polluting vehicles off the road, installing particle filters in diesel vehicles, upgrading stoves, boilers, kilns and coke ovens, and banning agricultural burning, would cut emissions of black carbon and, in conjunction with measures to control methane emissions, could help reduce global temperatures by 0.5°C by 2050.
“All [the] measures can be implemented immediately, so they do not require long development processes. The measures maximise climate benefits but would also have important ‘win-win’ benefits for human health and agriculture,” said Dr Johan Kuylenstierna, co-author and centre director at the SEI.
A local issue
Having lambasted the government for providing no meaningful evidence to indicate that it was making headway towards meeting air-quality targets, the EAC recommended several measures to reignite progress, including establishing a national framework for low-emission zones (LEZs), retrofitting abatement certification for heavy vehicles and immediately implementing a cross-departmental action plan overseen by the Cabinet Office.
Like its predecessor, the committee also called for a public awareness campaign to drive air quality up the political agenda and inform people about the positive action they could take to reduce emissions and their exposure to these.
The government’s response to the earlier EAC report on air pollution was to place more responsibility on local authorities to improve quality. It also rejected – on cost grounds, even though savings from improved air quality would be significant – a specific awareness campaign.
Nonetheless, companies involved in air-quality monitoring expect to see a big increase in awareness in the UK and a renewed focus on solving the problem. Enviro Technology, for example, predicts the whole issue of air pollution will move up the national agenda in the next 12 months and beyond, as more and more people are affected by poor air quality, and the government faces the potential prospect of EU fines for breaching pollution limits.
The presence of the Olympics in London this summer could also trigger more progress as the government is unlikely to want the event to be remembered for poor air quality, something that dogged the 2008 games in Beijing.
To ensure the games were largely smog-free, the Chinese authorities imposed measures to restrict traffic and close factories around the city. Having been postponed in the previous year, the extension of London’s LEZ from 3 January 2012 is, in part, to help ensure the capital satisfies European and Olympic air-quality targets, and does not incur substantial fines. However successful this measure may be, it is clear the race to improve air quality in parts of the UK needs to speed up.
Monitoring industrial emissions going forward
Industrial emissions are largely governed by the Integrated Pollution Prevention and Control Directive (96/61/EC as amended) (IPPC), which covers about 4,000 industrial installations in the UK, and Directives on large combustion plants (2001/80/EC) (LCP Directive), solvent emissions (1999/13/EC), waste incineration (2000/76/EC), and the production of titanium dioxide (78/176/EEC, 82/883/EEC and 92/112/EEC). From the start of next year, these will be amalgamated into one Directive, the Industrial Emissions Directive (2010/75/EU) (IED).
Much of the new Directive mirrors the IPPC Directive, although it is more prescriptive in places and covers new sectors, such as the wood preservation industry. In terms of controlling emissions, the IED contains new reduction limits for large combustion plants (LCPs) and adopts a more prescriptive approach in the reference documents accompanying the use of best available techniques (BATs), the state-of-the-art techniques that achieve a high level of environmental protection and which are also economically and technically viable. The documents are known as BREFs – best available techniques reference notes.
In the UK, regulators already apply BATs in the way intended by the IED, so its strengthened provisions will mean little or no change. “It’s a continuation of what is already in IPPC,” says John Tipping at the Environment Agency. “There is more prescription about BATs and more guidance. Other than that very little has changed.”
The impact of the IED will be greater on LCPs. The emission limit values (ELVs) for nitrogen oxides, particulate matter and sulphur dioxide will be stricter from 2016, and ELVs for carbon monoxide will be introduced. It will mean that large coal-fired plants and some old gas-fired plants will have to either install new abatement equipment, reduce operating hours or close. However, in line with the LCP Directive, the IED also includes a number of derogations to extend the compliance period.
Another sector that may eventually experience a change is waste incineration. Although the IED does not substantially alter the scope of the existing Waste Incineration Directive (there is mention in the text of gasification and pyrolysis plants, which are already regulated in the UK), the strengthening of BATs could mean the introduction of so-called “continuous” monitoring of dioxins, for example. Most existing plants in the UK use periodic sampling – once or twice a year – to measure dioxin levels, which involves collecting a sample of emissions manually over six hours, and sending it away for laboratory analysis. According to Dominic Duggan, sales director at the specialist environmental instrumentation company Quantitech, other EU countries, including France, are beginning to use “continuous” sampling, which usually provides an average reading over a two-week period.
“BATs mean introducing the highest possible standards, so the UK may have to follow suit,” warns Duggan. Duncan Mounsor at Enviro Technology agrees. “The technology exists to measure things like dioxins online, so it will have to be considered.” He points out that the existing manual testing technique is subject to a very wide tolerance level and believes the implementation of online continuous monitoring will improve the quality of the data.
The IED has to be implemented in the UK by 6 January 2013 and will apply to new installations immediately. It will apply to installations already in existence before that date (with the exception of LCPs) on 6 January 2014. Industrial activities not subject to the current IPPC Directive will have to comply with the IED by 6 July 2015