Diesels cause cancer: WHO

The United Nations' peak health body has dumped on diesel -- just as well we ride motorcycles I suppose...

Breathing diesel engine fumes can cause lung cancer, the World Health Organization (WHO) insisted yesterday.

The WHO’s International Agency for Research on Cancer also suggested there was an association between diesel fumes and bladder cancer and maintained that petrol exhausts were possibly carcinogenic.

“The scientific evidence was compelling and the Working Group’s conclusion was unanimous: diesel engine exhaust causes lung cancer in humans,” Dr Christopher Porter, Chairman of the IARC Working Group, said.

“Given the additional health impacts from diesel particulates, exposure to this mixture of chemicals should be reduced worldwide,” he declared.

Yet while the WHO was sure diesel particulates caused cancer, the Volkswagen Group – one of the world’s largest manufacturers of diesel engines – insisted the issue was more to do with fuel quality rather than diesel engines themselves.

“They put all diesel engines together in one study, even the vintage ones,” Volkswagen European-based spokesman Pietro Zollino said.

“There is simply no comparison between the emissions of a modern diesel engine and a diesel engine built 20 years ago… Or one that was designed 40 years ago and is still being produced.

“The main issue is filtering the particulates but that depends on the fuel quality. You can’t do it with high-sulphur diesel. That’s one of the reasons we don’t sell diesel-powered vehicles in China -- because they have low-quality diesel,” he said.

The European Union’s rules on diesel passenger car emissions are based around particulate filters trapping carcinogenic emissions, while US laws add urea via an injection process to reduce soot before it arrives at the particulate filters. Yet much of the developing world -- and, critically, heavy industry -- uses diesel engines without these technologies. This in part led the WHO to conclude there was “sufficient evidence” to conclude that diesel emissions could lead to cancer.

Diesel emissions were originally classified as “probably carcinogenic” in 1988 and were put on high-priority list for re-evaluation 10 years later.

WHO was quick to point out that the declaration didn’t single out motor vehicle makers, as it stated: “Large populations are exposed to diesel exhaust in everyday life, whether through their occupation or through the ambient air.

"People are not only exposed to motor vehicle exhausts, but also to exhausts from other diesel engines, including from other modes of transport (eg: diesel trains and ships) and from power generators.”

Yet the classification has rung alarm bells at major carmakers, especially in Europe where diesels account for nearly 60 per cent of all passenger car sales.

The only major exclusion to the diesel dominance, especially in small cars, is Greece, where a) they don’t buy many cars now anyway and b) diesel passenger cars are banned.

VW Group Technical spokesman Harthmuth Hoffmann told motoring.com.au: "While we will be conducting our own careful analyses of these results and findings, one thing has now become clear -- in its assessements, the IARC used what were in particular old diesel engines without filter systems. These engines pre-date the EU4 standard.

“Because of that, these engines no longer represent in any way whatsoever the current state of the art in diesel technology, as it has been available on the market since 2004.”

Mr Hoffmann insisted VW had constantly developed its diesel technology since the late 1970s and has paid special attention to reducing exhaust emissions.

“In this regard, our technical developments centre on the optimization of the internal combustion, the after-treatment of exhaust gases with effective oxidizing catalytic converters and diesel particulate filters, in addition to the latest developments in NOx exhaust after-treatment.

“The diesel particulate filter has contributed significantly to minimizing the particulate matter emissions regarded as being harmful to health,” he said.

Older style diesel engines emit massive volumes of particulates through their use of prechamber-style indirect fuel-injection. In the history of the diesel engine’s more modern systems, Fiat introduced the first direct-injection diesel in the Croma in 1986, while Alfa Romeo introduced the common-rail fuel delivery system in the 156 in 1997.

Diesel-powered passenger cars have almost universally switched to both direct-injection and common-rail systems, along with adopting the particulate filters demanded by EU regulations. They have also become consistently the most economical cars on sale for their sizes in most world markets.

“The diesel engine is and remains a significant component within the Volkswagen drive stem and fuel strategy,” Mr Hoffmann said.

"We also regard the reduction of possible risks to health due to exhaust emissions and healthy ambient air as a fundamental requirement. The diesel engine is highly efficient and, particularly with regard to the global CO2 reduction targets, offers a reduction potential that we cannot ignore.”

Yet WHO remains unconvinced that such steps will be enough to stop diesel motors causing cancer.

“Increasing environmental concerns over the past two decades have resulted in regulatory action in North America, Europe and elsewhere with successively tighter emission standards for both diesel and gasoline engines,” the UN heath body pointed out.

“There is a strong interplay between standards and technology – standards drive technology and new technology enables more stringent standards. For diesel engines, this required changes in the fuel, such as marked decreases in sulfur content, changes in the engine design to burn diesel fuel more efficiently and reductions in emissions through exhaust control technology.”

But while admitting that particulates and chemicals had been reduced on current models, it warned it needed years more research to determine if they could receive a clean bill of health. Besides, the body warned warned, the older-style engines in less developed countries could take years to replace.

“It is notable that many parts of the developing world lack regulatory standards, and data on the occurrence and impact of diesel exhausts are limited,” WHO said.

While diesel passenger cars are the highest profile target, there are far 'dirtier' diesel-powered emitters skating free of emissions regulations, including international shipping, freight trains, stationary engines, compressors and heavy trucks.

WHO’s actual target in its research has been industry, insisting the most-exposed and most at-risk people worked closely with heavy diesel machinery --particularly in the mining industry.

“The main studies that lead to this conclusion were in highly exposed workers,” the Head of the IARC’s Monographs Program said.

The IARC’s initial concerns were based on epidemiological studies of highly exposed workers. These concerns were backed up by a large US National Cancer Institute/National Institute for Occupational Safety and Health study which showed an increased risk of death from lung cancer in underground miners.

“However, we have learned from other carcinogens, such as radon, that initial studies showing a risk in heavily exposed occupational groups were followed by positive findings for the general population. Therefore actions to reduce exposures should encompass workers and the general population.”

Rudolf Diesel built the first prototype diesel engine in 1897. Diesels were powering boats by 1903, submarines by 1904, trains and ocean-going ships by 1910 and Packard even had a passenger-car version in 1930.

However, it was the Mercedes-Benz 260D of 1936 that showed passenger car makers the way forward, then this was boosted further when Peugeot built the first transverse-engined passenger diesel in 1968.

Today, no major mainstream carmaker is without a diesel presence in its passenger car lineup in Europe.

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Diesels cause cancer: WHO

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