UK government not reducing pollution in line with legal limits

With all the concern over atmospheric pollution levels in China a story may have escaped notice. The UK government is facing a case in the UK Supreme Court over its failure to reduce air pollution in line with legal limits (http://www.bbc.co.uk/news/science-environment-21691784). The government admitted that limits would not be meet in 15 regions until 2020 (London will not comply until 2025). This comes on top of the government having to issue a severe pollution warning for London this week.

The response of the government has been to say that the laws are unrealistically strict and that the EU didn’t set proper limits on pollution from diesel exhaust in the first place. Why they view these limits are unrealistic is not clear. Do they mean given the current economic situation it is not realistic to expect pollution to be tackled? Do they mean the limits are to be meet in too short a timeframe? Does the comment imply that there is an expected time lag between introducing the limits and compliance – if so why? Does the comment relate to how the government expects such changes in polluting behaviour to be tackled within the particular political and economic context of the UK.

 

DEFRA stated that the government has acted to reduce emissions of nitrogen dioxide through trying to encourage behaviour changes in divers via tax breaks and subsidies for low emission vehicles. Likewise, there has been investment in green bus technologies  (£75million) along with £560m to encourage local sustainable transport. This is the government response to trying to improve the atmospheric levels of PM10s and nitrogen dioxide, key pollutants from road traffic. In other words responsible for implementing and resolving the issue has been delegated downwards to the local level, indeed even as far as down the individual driver. Action is also indirect via tax incentives to which individuals are meant to respond in the manner the government thinks they should.  Rather than direct action or legislation, the government has taken a ‘nudge’ approach to the problem, developing policies and the context or environment that they believe will provide the impetus to encourage change in the direction they want. Reduction in atmospheric pollution is a side-effect, an outcome of these nudges. The question could be asked will these nudges be effective? Likewise, how can you measure the impact of such nudges to assess if they have been effective?

 

The threat of court action also places the complaints over Chinese pollution in a different light. It could be argued that the atmospheric pollution levels in the UK are much lower than in China and so different criteria should be applied to the problems of the UK government. The UK is not dealing with dense smogs that clog lungs and increase death rates (although calculations do suggest that traffic pollution does cause excess deaths in the UK as noted in the above report). The pollution of concern in the UK seems to be focused on road traffic and so a linear pollution source whilst the Chinese are having to deal with point, linear and areal sources as they go through rapid urbanization and economic growth.  Indeed the Chinese are having to cope with multiple sources of differing magnitudes and with both private and official institutions involved. The magnitudes of the pollution maybe of different orders in the UK and China but both are struggling to balance the needs of economic development and the pollution it produces.  So is atmospheric pollution the unavoidable price for economic development?

 

 

 

Beijing Pollution: Continuing Highs

In January and February of this year the air quality in and north-eastern China has been reported to have deteriorated to the extent that the smog so thick that it was visible from space (http://www.nydailynews.com/news/world/china-pollution-bad-visible-space-article-1.1253838). The rise in pollution has reported caused increases in hospital admissions of respiratory problems and, according to the report above, even resulted in an official recognition of the problem, the article stating that the Chinese Ministry of Environmental Protection stating that the haze covering Chinese cities covered over 500,000 square miles. The problem has been officially identified as being caused by unregulated industries, vehicle emissions and cheap gasoline.

The identification of the ‘causes’ is interesting. The focus is upon the action of individuals with respect to vehicle emissions and the use of cheap gasoline. This implies that the cause is a matter of individual responsibility. Placing causation at the feet of individuals means that there is justification for taking action against individuals for not taking appropriate steps deemed vital to reduce pollution by authorities. The focus on unregulated industries implies that regulated industries are not contributing to he pollution level. Again responsible and fault is placed onto individuals who run firms that do not conform to state regulations. Politicians, according to the report, even closed these firms for 48 hours as well as urging individuals to stay off the road. The implication is that the pollution is an inevitable result of the outcome of ‘development’ or ‘progress’ with the individualistic bend of capitalism.  The pollution is as predictable a result of economic progress as were the dark satanic mills of nineteenth century Manchester were of progress in Britain. By implication, the more measured and responsible activities of the state have no role in producing this smog.  Despite the state setting the economic regulatory climate as well as enforcing regulations relevant to pollution production, the role of the state is regulated to a backseat in the internal pollution narrative that is emerging from these reports.

The pollution does, however, have a flip-side in the new China – the hazard is an economic opportunity for the few. Anti-pollution domes, with interiors of pollutant-free atmospheres have been jointly developed by a Shenzhen-based manufactuer of outdoor enclosures and a Calfornian-based company (UVDI) that specialises in air filtration and disinfection systems (http://wallstnews.blogspot.co.uk/p/asia-edge.html#!/p/asia-edge.html ). Combining these existing technologies it is possible to create a pollutant free environment within outdoor activities can continue. Additionally, face masks, ranging from high-tech neoprene masks to strips of cloth, have been increasingly sold to try to prevent inhalation of pollutants. Within homes air filtration units are being employed to ensure a clean supply of domestic air.  This, however, also means that there is increasingly a social, or even a class, aspect to this hazard. The emerging middle-class in China can afford to buy these new ‘must-have’ accessories to sustain urban life. The poor are left to cope using tatters of cloth across their mouths and noses to filter their domestic air.  How long before your income determines your ability to survive extreme pollution episodes?

One enterprising individual has even taken to selling cans of fresh air to hassled urbanites, for 80 cents a can. Although to be fair, Chen Guangbiao, although promoting himself says that the sale of the fresh air cans is a tactic to push ‘mayors, county chiefs and heads of big companies’ not to just pursue economic goals but also to consider the impact of their actions on the future.

 

Using St Paul’s Erosion Data to Predict Future Stone Decay in Central London

In a recent blog I mentioned a research project just completed on a 30-year remeasurement of stone decay on St Paul’s cathedral in central London. A second paper looks at how this data might be used to model decay into the future (http://www.sciencedirect.com/science/article/pii/S1352231012007145  - you need to have an account to get access to the full paper in Atmospheric Environment). Modelling erosion rates into the future tends to use relationships derived from erosion data of small (50x50x10mm) stone tablets exposed in different environmental conditions. Using such data and regression analysis a statistical relationship can be derived between stone loss and changing environmental conditions. These relationships are often referred to as dose-response functions.


Two equations stand out – the Lipfert and the Tidblad et al. does response functions. Using these two equations for the decades 1980-2010, they predict an erosion rate of 15 and 12 microns per year as opposed to the measured losses on St Paul’s of 49 and 35 microns per year. The ratio between the measured and the dose-response erosion rates varies from 3.33 in the decade 1980-1990 to 2.75 in the decade 2000-2010, so fairly consistent. The difference between the two measures of decay may result from differences in what they are actually measuring. The dose-response function uses small stone tablets, exposed vertically in polluted environments. The weight loss of these tablets is measured and then converted to a loss across the whole surface of the tablet. The micro-erosion meter sites measure the loss of height of a number of points across the same surface on a decadal time scale. Both measures are changes in height but derived in different ways. What is important is that both methods indicate the same patterns of change in relation to declining sulphur dioxide levels. Both measures of erosion show a decline and both show it in the same direction and, by and large, in proportion to each other. Interestingly, when the dose-response functions are used to work out erosion on the cathedral since it was built the long-term erosion rate (as measured by lead fin heights relative to the stone surface) is only 2.5 times greater than that predicted by the does-response functions. This is a similar ratio, more or less, to those indicated over the last three decades.

The St Paul’s data does not imply that dose-response functions do not work – if anything it confirms the patterns in decay they indicate – but the St Paul’s data does suggest that using these dose-response functions to model decay into the future may require a correct function, equivalent to the ratio of about 2.5-2.75 to convert the losses to those that will be found on St Paul’s Cathedral.

Atmospheric Pollution and Stone Decay: St Paul’s Cathedral

I have recently published a paper with colleagues from Oxford, Cambridge, Sussex and York on a 30-year measurement of erosion rates on St Paul’s Cathedral, London (http://www.sciencedirect.com/science/article/pii/S1352231012008400  - you need to have an account with the journal to access the paper). Pleasingly, the academic work did get some press (http://www.independent.co.uk/news/uk/home-news/pollution-erosion-at-st-pauls-cathedral-in-record-300year-low-8205562.html , http://www.stpauls.co.uk/News-Press/Latest-News/St-Pauls-safer-from-pollution-than-at-any-time-in-its-history , ) and I even did a very short radio interview on local radio (distracted during it because they just started their afternoon quiz to which I knew the answer!)


The paper outlines how the rates of erosion (and the rates of surface change) of five micro-erosion meter sites around the cathedral have changed over the decades since 1980 and how this has mirrored a dramatic fall in pollution levels in central London.

Figure 1 Micro-erosion meter site with protective caps being removed for remeasurement

Figure 2 Erosion rates, rates of surface change and environmetnal variables for central London 1980-2010

The erosion rates have dropped since the closure of Bankside power station in the early 1980s with atmospheric pollution, as indicated by sulphur dioxide levels dropping from 80ppb in 1980 to about 3ppb in 2010. Erosion rates fell from 49 microns per year in the decade 1980-1990 to 35 microns per year in the decade 2000-2010. Erosion rates in the 1980-1990 were statistically significantly higher than erosion rates in both the decades 1990-2000 and 2000-2010. Erosion rate in the decade 1990-2000 and 2000-2010 were statistically similar. Although the decline in erosion rates was not as steep as the fall in pollution levels, erosion rates are now at a level that could be explained by the action of the acidity of ‘normal’ or ‘natural’ rainfall alone. ‘Normal’ rainfall is a weak carbonic acid, produced by the reaction of carbon dioxide and water in the atmosphere, meaning that ‘normal’ rainfall has an acidity of about pH5.6.

Erosion rates represent the loss of material from a surface but not all points’ measured lost material, some gained height over the measurement periods – this is surface change. Points can gain height for a number of reasons; slat in the stone could distort and push the surface up, lichens and bacteria could form crusts that raise the surface and eroded material might be deposited in depressions in the surface causing an apparent raising of the surface. The rates of surface change were 44 microns per year in the decade 1980-1990 but fell to 26 microns per year by the decade 2000-2010 (and were only 25 microns per year in the decade 2000-2010). This suggests that rats of surface change fell in a similar manner to rates of erosion and match the drop in sulphur dioxide levels as well.

Back in the 1980s the long-term rates of erosion, since the early 1700s were also determined using lead find. These lead fins were produced when the holes used to raise the stone blocks into the balustrade were filled with lead. Over time the fins became proud of the surface as the stone around them eroded. By measuring the height difference between the fins and the stone (and then dividing by the time of exposure) the long-term rates of erosion can be calculated. The long-term rates from 1690/1700 to 1980 were about 78 microns per year. This suggests that the cathedral has experienced much higher erosion in the decades before 1980. This does suggest that the erosion rates we have managed to measure from 1980 onwards, and the associated pollution levels, were not as damaging to the cathedral as those experienced in the years up to 1980.