The Department for Environment, Food and Rural Affairs issued a smog alert for England and Wales as the public get into their cars and drive around or fly out of the country. http://www.bbc.co.uk/news/uk-13161431#dna-comments
Sure enough, http://www.londonair.org.uk shows high levels of pollution in central London, particularly PM10 and PM2.5 particulates which are created by the car drivers leaving London and the flights out of the airports, leaving their filthy pollution in the air as a health hazard for those who remain. The pollution levels are getting worse by the hour and by 1pm there are many parts of London registering 7, 8 & 9 on a pollution scale of 1-10, with the main problem being particulates from car exhausts.
In Germany the health of people and the environment is taken much more seriously than in Sloppy Britain. Motor vehicles in Germany are strictly regulated and only models produced in the last few years to very low emission standards get a green display card allowing them into German towns and cities. By contrast, London laughably calls itself a ‘Low Emission Zone’ but I have never seen a motor vehicle exhaust check being done in the UK and our air is filthy. So filthy that heat recovery ventilation filters need changing every 2-3 months in London, but only once a year in a German city.
Already this year one site on the Marylebone Road has exceeded EU pollution rules for the whole year.
However Britain has managed to wriggle out of massive EU fines again, with an extension of the EU deadline to June this year to sort out this mess. So what is the British government and the London Mayor doing about this? With just weeks to go before the new anti-pollution deadline, the answer appears to be “absolutely nothing”. Perhaps our leaders are all oblivious to the problem, enjoying the fresh air in remote locations at the end of car or aeroplane journeys.
From Wikepedia, here is an extract on some of the many health hazards associated with particulate pollution from motor vehicles:
The large number of deaths and other health problems associated with particulate pollution was first demonstrated in the early 1970s  and has been reproduced many times since. PM pollution is estimated to cause 22,000-52,000 deaths per year in the United States (from 2000)and 200,000 deaths per year in Europe.
The effects of inhaling particulate matter that have been widely studied in humans and animals now include asthma, lung cancer, cardiovascular issues, and premature death. The size of the particle is a main determinant of where in the respiratory tract the particle will come to rest when inhaled. Because of their small size, particles on the order of ~10 micrometers or less can penetrate the deepest part of the lungs. Larger particles are generally filtered in the nose and throat and do not cause problems, but particulate matter smaller than about 10 micrometers, referred to as PM10, can settle in the bronchi and lungs and cause health problems. The 10 micrometer size does not represent a strict boundary between respirable and non-respirable particles, but has been agreed upon for monitoring of airborne particulate matter by most regulatory agencies. Similarly, particles smaller than 2.5 micrometers, PM2.5, tend to penetrate into the gas exchange regions of the lung, and very small particles (< 100 nanometers) may pass through the lungs to affect other organs. In particular, a study published in theJournal of the American Medical Association indicates that PM2.5 leads to high plaque deposits in arteries, causing vascular inflammation andatherosclerosis — a hardening of the arteries that reduces elasticity, which can lead to heart attacks and other cardiovascular problems.Researchers suggest that even short-term exposure at elevated concentrations could significantly contribute to heart disease. A study in The Lancet concluded that traffic exhaust is the single most serious preventable cause of heart attack in the general public, the cause of 7.4% of all attacks.
Researchers at the Johns Hopkins Bloomberg School of Public Health have conducted the largest nationwide study on the acute health effects of coarse particle pollution. Coarse particles are airborne pollutants that fall between 2.5 and 10 micrometers in diameter. The study, published in the May 14, 2008, edition of JAMA, found evidence of an association with hospital admissions for cardiovascular diseases but no evidence of an association with the number of hospital admissions for respiratory diseases. After taking into account fine particle levels, the association with coarse particles remained but was no longer statistically significant.
The smallest particles, less than 100 nanometers (nanoparticles), may be even more damaging to the cardiovascular system.
There is evidence that particles smaller than 100 nanometers can pass through cell membranes and migrate into other organs, including the brain. It has been suggested that particulate matter can cause similar brain damage as that found in Alzheimer patients. Particles emitted from moderndiesel engines (commonly referred to as Diesel Particulate Matter, or DPM) are typically in the size range of 100 nanometers (0.1 micrometer). In addition, these soot particles also carry carcinogenic components like benzopyrenes adsorbed on their surface. It is becoming increasingly clear that the legislative limits for engines, which are in terms of emitted mass, are not a proper measure of the health hazard. One particle of 10 µm diameter has approximately the same mass as 1 million particles of 100 nm diameter, but it is clearly much less hazardous, as it probably never enters the human body — and if it does, it is quickly removed. Proposals for new regulations exist in some countries, with suggestions to limit the particle surface area or the particle number.
A further complexity that is not entirely documented is how the shape of PM can affect health. Of course the dangerous feathery shape of asbestos is widely recognised to lodge itself in the lungs with often dire consequences. Geometrically angular shapes have more surface area than rounder shapes, which in turn affects the binding capacity of the particle to other, possibly more dangerous substances.