Broadcast on Today with Sean O’Rourke [24-08-2016]

Tax incentives for those buying diesel cars over the last decade has fueled a move to diesel on Irish roads, with diesel cars now outnumbering petrol cars.

This has been widely regarded as a welcome move, as diesel cars are considered ‘better for the environment’ because they produce less carbon dioxide gases than petrol cars – the gases that have been linked with causing global warming.

However, scientific evidence is emerging which shows that the level of diesel particulates, which are damaging to human health, has increased in line with the growing popularity of diesel and that Irish people are dying as a result of this. The European Environment Agency has, for example, estimated that 1,200 people in Ireland per year are dying as a result of diseases caused by particulate pollution.

Research

Until relatively recently, there has not been a significant amount of research into the impact of diesel pollution on public health, particularly in Europe, but the Volkswagen diesel emissions scandal certainly gave it an added push.

The evidence that is emerging from the US primarily – where research has been going on for longer – suggests that there is real reason for concern when it comes to health effects, and environmental effects, or air pollution from diesel engines. The US Environmental Protection Agency (EPA), the World Health Organisation and the UK Department of Transport have all produced reports in the last year or two which point to a real problem here.

As well as pointing to increased emissions of particulate matter (PM) and Nitrogen Dioxide gas, which are known to damage human health, the authorities in Europe and the US have started to make a direct link between an increase in numbers of people dying from respiratory diseases and cancers, and this increase in pollution.

The US EPA, who support a lot of work in this area, has led the way with publication of figures of increased numbers of premature deaths, cancers and respiratory diseases due to air pollution from diesel vehicles. There is a tangible link, a ‘smoking gun’ if you link that is linking cause and effect.

Ireland 

There has been little research into subject in Ireland until this year. In January 2016, a research project began at Trinity College Dublin, with funding from the Irish EPA, which is looking to precisely determine the amount of a certain type of damaging particulate, called PM 2.5 which is produced by diesel vehicles here.

It is a multi-disciplinary research effort, involving experts in air pollution, chemistry and transportation and will take place over 24 months. At the end of it, they say they will be able to determine precisely, using computer software modeling, how many deaths and illnesses here are caused by diesel vehicles.

One of the researchers involved, Dr Bidisha Ghosh, is a transportation expert, and said that the plan is to look at diesel particulates first, and to then to a follow up study where the impact of NO2 is measured and assessed.

Measuring 

The Irish EPA has a number of monitoring sites around Ireland that will be used as measuring points. One of the key challenges – and this is the first time anyone in the world has done this – will be to distinguish the percentage of PM 2.5 (particulate matter 2.5, a size of particulate) that is from diesel cars as opposed to other potential sources, such as sand, or the burning of coal.

The measuring sites will be near to roads as that is where diesel fumes are strongest, and another part of the study will determine how quickly dangerous diesel pollution dissipates as you move away from a busy road.

The researchers will be looking closely at what comes out of the diesel particulate filters that are attached to diesel cars. This is in order to get the chemical composition, or signature of PMs to better identify those PMs that are from diesel cars or other diesel vehicles. This is a difficult task and will involve using specialised machines to look at tiny quantities of polluting chemicals.

Dr Ghosh said that by the end of their project, in the latter part of 2017 they will be in a position to give precise numbers on the health effects of the growing use of diesel cars in Ireland. At that stage, she said they will have precise numbers on how many extra deaths, or premature deaths are being caused or what kind of extra number of lung cancers and other respiratory diseases are happening in Ireland due to us driving more diesel cars.

The calculations are based on knowledge of the car fleet, the type and age of cars on Irish roads, and knowledge of what the standard pollution emission from a certain vehicle of a certain age will be. This makes it possible to do comparison such as comparing the 2000 level of emissions versus the 2015 levels and matching the increase in pollution with the increase in deaths and diseases.

The project will also make it possible to predict, based on a number of scenarios – such as increasing use of diesel cars at the current rate – what Ireland can expect in 2020 or 2030 in terms of death rates from air pollution. This, it is hoped, will produce a solid basis for policy makers to address this problem.

Diesel cars 

The new new diesel cars on the market have very good particle filters and if you are sitting inside one of these cars you wouldn’t get a whole lot of this PM pollution, and the newer models may not pollute the atmosphere that much. The old diesels is where the big problem lies, and there are still a lot of old diesel cars being driven on Irish roads today, as they have vastly inferior emissions control technology to more modern cars.

It is also true that the bigger diesel car engines are far more polluting. The researchers at TCD, who have access to pollution figures in Ireland between 2010 and 2015 said there was a very significant increase in diesel PMs in those years, and this finding was what prompted a more detailed air pollution study.

The researchers also strongly suspect that the VW scandal wasn’t just a VW issue, and that many other diesel car makers have been cooking the books, in the sense that the emissions reported in the car manual does not bear much resemblance to the real on road emissions. The real figures, I was told, are likely to be far, far higher than what we see in the new diesel car manuals.

Supports

The Irish government started to actively support diesel from 20o8, with various tax incentives, in order to help Ireland meet its carbon dioxide ‘greenhouse gas’ targets. In fairness to the Irish government back then, the extent of the public health risk from diesel cars was not widely known.

It was initially thought that certain types of PMs were not harmful, but that thinking has changed, and now scientists are looking at the damage caused by diesel particulates that can remain wedged in the lungs. For example, the particulate, PM 1, is very hard to remove from the lung once in.

The evidence that is now emerging, however, is that not only is diesel bad for public health, it is also, by producing NO2, bad for the environment.

The science around this is all still quite new, and emerging. It is only in 2015 that a report was published by the UK authorities which stated that NO2 can also be very harmful to children, their respiratory development, their lung development and that it can cause irreversible changes.

The initial findings about the problem with diesel took time to emerge, as they didn’t perhaps fit with the green image of diesel, especially in Europe. However, the more research on this that is being done, the clearly the scientific picture becomes, and eventually, governments will have to act on the results.

NO2 

Nitrous oxide, and nitrous dioxide gases from diesel cars and vehicles are also linked with health problems, and the data can be collected again by using standard emissions and examining the national car fleet. This is likely to be supported by specific EPA funded research in future, which will, like the TCD project looking at PMs, look into NO2 levels at certain EPA monitoring sites, near busy roads around the country.

Aside from being linked with respiratory disease and death, NO2 is known to have a negative impact on vegetation and acts to break down the ozone layer.

Alternatives? 

There are emerging fuels out there, such as hydrogen gas, which is being made available at existing petrol stations in the UK this summer.

However, experts believe that because the infrastructure and global distribution network is built for diesel and petrol cars, and that huge investment has been made in this system, that it will be impossible to envisage a change to any other fuel or transport type in the near, or even distant future.

Electric cars are still rare in Ireland despite significant government support, as people don’t like some of the unanswered questions that remain on it, such as how long does an electric car last, and what to do should a battery die out?

There is also the fact that a very high amount of energy can be liberated from diesel or petrol, and there is nothing that can rival petroleum on that score.

The solution, some suggest, is to truly move towards a sustainable transport system, where people walk if they can, and only use a car when they have to. Those countries that do this, and that promote public transport have far less emissions from petroleum car engines. It is also very important to think about where we locate our busy roads, as studies have shown that irreversible damage can be done to schoolchildren from air pollution in schools near such roads.

For those that need a car, the advice is to look at getting rid of the old diesel and replacing it with a new one, with better a particulate filter. Also, to avoid buying one of the high performance diesel cars and go for a more modest option.

There is also the issue in Ireland of people removing diesel particulate filters when they start to affect car performance. They can be expensive to replace, and some garages in Ireland are openly offering services on the internet to remove and not replace the filters.

 

A diesel car can run without a filter, and not replacing a malfunctioning filter can save hundreds if not a few thousand euros. However, from a public health and environmental perspective removing a filter is “disastrous, really, really bad” according to Dr Ghosh.

Actively preventing the removal of diesel particulate filters from diesel cars, and insisting on a high standard of operation of diesel filters as part of the NCT test, might be how the Irish government might start trying to tackle this important public health issue.