The silent killer
What is it that according to the United Nations annually kills more people than AIDS and Malaria put together worldwide and in the United Kingdom kills far more than road deaths?
It’ is air pollution – the silent killer!
A 2012 World Health Organization study showed that 3.3 million people were killed around the world annually by outdoor air pollution which causes cardio-pulmonary (heart and lung) diseases and cancer.
In comparison, AIDS kills around 1.7 million a year and malaria 660,000. We may no longer see the “pea souper” fogs which caused thousands of deaths, principally in our cities in the 1950s, but just because the pollution appears invisible it can be, and still, is present in our towns, cities and villages.
Yes we have Clean Air Acts. The days when coal fires were the norm, with their smoking chimneys down every street, are long gone (at least in Britain), but the problem has not.
So what does this pollution today consist of and where does it come from?
Well obviously there are the local hotspots from heavy industry and power generation but visible and toxic emissions from the latter are now very tightly controlled and modern technology has reduced these drastically (it should be noted that we are not talking here about carbon dioxide emissions, linked to global warming, which are not lethally toxic emissions).
What affects us most here today are the emissions from petrol and diesel fuelled motor vehicles.
Motor vehicle emissions consist of hydrocarbons, nitrogen oxides, carbon monoxide, ozone and particulates. Many of these are reduced, but not completely eliminated, by catalytic converters or filters fitted to modern vehicles but catalytic converters only work when hot. If your vehicle is used mainly for short journeys of say a few minutes duration your catalytic converter will have negligible effect in reducing toxic emissions. In addition to pollutants from exhausts every time a vehicle drives past it leaves microscopic particles of tyre in the air and every time a driver hits brakes it distributes microscopic elements of brake pads into the air you are breathing.
Considering the effects on our health of these various pollutants let us consider first nitrogen oxides, NO and NO2 being the principal offenders. One effect is that they can react with moisture in the atmosphere to form nitric acid vapour which can penetrate deeply into lung tissue, damaging it and causing or worsening respiratory diseases such as bronchitis and emphysema and in extreme cases causing premature death.
The dangerous and lethal effects of carbon monoxide are of course well known and there is no need to elaborate on them here.
One of the most noxious hydrocarbon emissions is benzene, known to be a highly carcinogenic compound where prolonged exposure can depress the immune system and cause directly several cancers. Particulate matters (known as PM10 and PM2.5 emissions) are principally caused by diesel engines and they are known to cause asthma, lung cancer and cardiovascular problems and premature death.
The large increase in asthma amongst children seen in recent years is believed to be caused by the vast increase in these particulates due to the increasing volumes of road traffic. The respected medical journal The Lancet has stated “the adverse effects of air pollution are of increasing concern.
Many studies show that air pollution causes not only unfavourable respiratory effects in patients with asthma and chronic obstructive pulmonary disease and other lung disease but also cardiovascular effects such as myocardial infarction and stroke. Of the different air pollutants particulate matter has emerged as the component most strongly related with health effects”.
The same journal has also indicated that exposure to traffic fumes has adverse effects on children’s lung development which may result in problems of lung function in their later life.
Ozone too can be a problem. Whilst it is beneficial in the upper atmosphere, at ground level it irritates the respiratory system causing coughing, choking and reduced lung capacity and is also believed to cause asthma in children. It also has an effect on plant growth reducing food crop yields. Finally another Lancet paper on air pollution in 3 European countries (France, Switzerland and Austria) showed that air pollution caused 6% of total mortality or 40,000 deaths per year in those countries. About half of this pollution was due to motor vehicle emissions and it caused around half a million asthma attacks per annum.
So what’s being done about it?
The European Union Ambient Air Quality Directives set limits for concentrations of various pollutants in outdoor air for the protection of health and ecosystems. These directives have been set in law in England through the Air Quality Standards Regulations and the National Air Quality Objectives For The Protection Of Human Health from the Department for Environment, Food and Rural Affairs (DEFRA). These set maximum limits for benzene, 1.3-butadiene, carbon monoxide, nitrogen dioxide, PM10 particulates, PM2.5 particulates, sulphur dioxide, ozone, polycyclic aromatic hydrocarbons and lead.
Meanwhile the Environment Act 1995 gave local authorities a duty to review and monitor air quality in their areas and localities and St Helens Council monitors this by the use of 4 continuous analyzers (real time monitors) and 33 diffusion tubes at various locations within the borough.
Air Quality in the OLV region.
All three authorities Wigan, Warrington and St Helens monitor air quality throughout their boroughs. But there an area has severe air quality that might be of risk to public health the authority must declare an Air Quality Action Plan. (AQMA).
The AQMA’s on our region are
Leigh and Wigan town centres and the M6.
Warrington town centre (generally in the area of Bank Quay Station) and Chester Road and Bridge Foot.
Newton Le Willows High street and Southworth Road. Borough Road and the Linkway in St Helens.
Due to the air quality AQMA’s in the OLV region being ostensibly in the Newton Le Willows areas the others being geographically out of scope.
The mitigation measures are therefore described in the page OLV local air quality management action plan (OLV LAQMA’s) page on this website.