June 13, 2012

Diesel Exhaust Labeled As Cancer Causing Carcinogen By WHO

Asbestos, secondhand smoke and mustard gas are all dangerous to our health, potentially causing life-threatening lung cancer; and now we can add diesel exhaust fumes to that list, according to the cancer arm of the World Health Organization (WHO) on Tuesday.

The overall risk of getting cancer from the exhaust fumes is small, but since so many people breathe them in, in some way, an expert panel said raising the status of diesel exhaust from group 2A (possible carcinogen) to group 1 (carcinogen) was an important shift.

“It´s on the same order of magnitude as passive smoking,” said Kurt Straif, director of the French-based International Agency for Research on Cancer (IARC) department that evaluates cancer risks. “This could be another big push for countries to clean up exhaust from diesel engines.”

Straif said diesel exhaust affects everyone from pedestrians on the street, ship passengers and crew, railroad workers, truck drivers, mechanics, miners, to heavy machine operators. Since so many people are exposed to it, there could be many cancer cases related to diesel exhaust contamination.

The ruling came after a week-long discussion on the matter in Lyons, France. The experts said their decision was unanimous and was based on “compelling” scientific evidence, and as such, have urged people around the world to reduce their exposure to diesel fumes as much as possible.

“The working group found that diesel exhaust is a cause of lung cancer and also noted a positive association with an increased risk of bladder cancer,” IARC said in a statement. The last time the agency considered the status of diesel exhaust was in 1989, when it was labeled a probable carcinogen.

Despite the WHO´s ruling, the US government still classifies diesel exhaust as a “likely carcinogen.” Most engines spew out fewer fumes than in the past, but experts say further study is needed to assess potential dangers.

“We don´t have enough evidence to say these new engines are zero risk, but they are certainly lower risk than before,” Vincent Cogliano, of the U.S. Environmental Protection Agency (EPA), told The Guardian.

Experts analyzed studies, evidence from animals, and research in humans in their quest to determine the fate of diesel fumes. One of the largest studies was published in March by the U.S. National Cancer Institute. That study analyzed more than 12,000 miners for several decades starting in 1947. Researchers found miners heavily exposed to diesel exhaust had a much higher risk of dying from lung cancer.

However, lobbyists for the diesel industry argued that the study wasn´t credible because researchers didn´t have exact data on how much exposure miners were subjected to in the early years of the study; the study simply asked miners to remember what their exposure was like.

Representatives for diesel engine makers maintain that major technological advances in the past decade have reduced emissions from many heavy duty vehicles by more than 95 percent.

Yet, some experts weren´t surprised by the ruling.

Ken Donaldson, a professor of respiratory toxicology at the University of Edinburgh, who was not part of the IARC panel, said too much exposure to diesel, a carcinogen, is never a good thing. He said thousands of particles, including some harmful chemicals, in the exhaust could cause inflammation in the lungs and over time, could lead to cancer.

Although, he acknowledged, lung cancer is caused by multiple factors and things like smoking are far more deadly. Those who are constantly exposed to diesel fumes are most at risk, he noted.

“For the man on the street, nothing has changed,” he said. “It´s a known risk but a low one for the average person, so people should go about their business as normal ... you could wear a mask if you want to, but who wants to walk around all the time with a mask on?”

In Europe and India, diesel passenger cars remain widely popular. However, in much of the rest of the world, diesel engines are almost entirely confined to heavy duty trucks and commercial vehicles, mainly due to fuel efficiency. German automakers are trying to raise awareness of the fuel in the U.S., stating that diesel engines are better for long distance traveling.

Center for Automotive Research in Michigan analyst Sean McAlinden said about 2.5 percent of light vehicles in the US had diesel engines, but he expects that number to rise to 8 percent by 2020.

The European Automobile Manufacturers´ Association (EAMA) said it was surprised by the WHO´s finding and said it would study the details closely.

“The latest diesel technology is really very clean,” EAMA spokeswoman Sigrid de Vries told Reuters, adding the industry had been working on technologies to address health concerns.

IARC director Christopher Wild in a statement said Tuesday´s finding “sends a strong signal that public health action is warranted“¦ this emphasis is needed globally, including among the more vulnerable populations in developing countries where new technology and protective measures may otherwise take many years to be adopted.”

Cancer risk, of course, depends on a number of variables, including the person´s genetic makeup and the length of time of exposure to dangerous substances.

Cancer killed 7.6 million people worldwide in 2008, the most recent year the WHO has full data for. And lung cancer was the most deadly type, accounting for 18 percent of all cancer fatalities.

IARC took recent advances in diesel technology into consideration when making its decision, and said it was not yet clear how these advances might translate into health effects. It added that more research is needed.

IARC also noted during the discussions that gasoline exhaust fumes should be uplisted to “probably carcinogenic to humans,” a finding that went unchanged from its previous assessment in 1989.