Health Hazards of Modern Diesels Remain Unknown


LYON, FRANCE – The World Health Organization (WHO) announced this week that diesel engine exhaust can be linked to cancer.

However, the ramifications of the findings are not as clear as they first might seem.

In a statement released Tuesday, the WHO said “There has been mounting concern about the cancer-causing potential of diesel exhaust, particularly based on findings in epidemiological studies of workers exposed in various settings.”

“The scientific evidence was reviewed and overall it was concluded that there was sufficient evidence in humans for the carcinogenicity of diesel exhaust. The Working Group found that diesel exhaust is a cause of lung cancer (sufficient evidence) and also noted a positive association (limited evidence ) with an increased risk of bladder cancer.”

However, in an interview following the announcement, the Director of the International Agency for Research on Cancer (IARC), Dr. Christopher Wild, said that newer low-emission diesels are not the prime culprit.

In response to the question: “Can you say that the new diesel engines are now so clean that the findings from this monograph meeting are no longer relevant to today’s situation?” Wild said scientists don’t yet know if there’s a connection between modern low-emission diesels and health.

“It’s certainly true that with the newer diesel engines that the exhaust contains far fewer of the particulates and chemicals compared to the older technology engines,” he said in a press conference.

“In addition to that quantitative change there’s qualitative changes such that the composition of the mixture in the exhaust is different.

“What we don’t know at this stage is whether this altered composition – the decreased levels of these components – translates into a different health effect in exposed people and that’s something we can only encourage further research upon in the future.”

“We must remember that in many developing countries in particularly, the transition from the old technology to the new technology will certainly take time. For many parts of the world and for many people in the world the exposures that are relevant are still the exposures to the exhaust from the old diesel technology engines.”

Click here for more on the WHO findings.

UPDATE: Diesel Makers to WHO: “Brake and tire wear worse than diesel smoke.”

 The diesel engine makers of North America have wasted no time responding to the World Health Organization’s (WHO) denunciation of the fuel.

On Tuesday, hours after the WHO released findings liking diesel emissions to human-health hazards, the non-profit industry-based Diesel Technology Forum’s executive director Allen Schaeffer issued the following statement.
“The Diesel Technology Forum welcomes and supports scientific inquiry and discussion regarding diesel fuels and emissions. The industry’s commitment is underscored by its funding for independent peer-reviewed, multi-stakeholder Advanced Collaborative Emissions Study (ACES) by the Health Effects Institute (HEI).  

As recently as April 12, 2012, findings of this landmark study sponsored by U.S. Environmental Protection Agency (EPA), the California Air Resources Board (ARB), industry and HEI suggest ‘few biologic effects to diesel exhaust exposure’.
 “New technology diesel engines, which use ultra-low sulfur diesel fuel, advanced engines and emissions control systems, are near zero emissions for nitrogen oxides, hydrocarbons and particulate matter.  In the U.S. for example, diesel exhaust is only a very small contributor to air pollution.  EPA’s most recent data indicates that diesel accounts for less than six percent of all particulate matter in the air.  And today in Southern California, more fine particles come from brake and tire wear than from diesel engines.
 “For example, in the United States, emissions from heavy-duty diesel trucks and buses have been reduced by 99 percent for nitrogen oxides (NOx)- an ozone precursor – and particulate emissions.  A key part of reducing emissions has been the shift to ultra-low sulfur diesel (ULSD) fuel that has been available since 2006.  That change in fuel specification reduced sulfur emissions by 97 percent – from 500 PM to 15 PM, and enables the use of advanced emissions control technologies.  Similar advancements are taking place in off-road engines and machines.”

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