Lung cancer risk increases with diesel exhaust exposure

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(CBS/AP) Exposure to diesel exhaust increases risk for lung cancer, new evidence shows, and workers are especially at risk.

PICTURES - 10 worst jobs for your lungs

Diesel exhaust has long been thought to be a carcinogen. But the 20-year study from the National Cancer Institute took a closer look by tracking more than 12,000 workers in certain kinds of mines - facilities that mined for potash, lime and other nonmetals. They breathed levels of exhaust from diesel-powered equipment higher than the general population encounters.

The study - published Mar. 2 in the Journal of the National Cancer Institute - found the most heavily exposed miners had three times the risk of death from lung cancer compared to workers with the lowest exposures.

But even workers with lower exposures had a 50 percent increased risk, study author Debra Silverman, an NCI epidemiologist, wrote.

"Our findings are important not only for miners but also for the 1.4 million American workers and the 3 million European workers exposed to diesel exhaust, and for urban populations worldwide," Silverman wrote.

Silverman noted that some highly polluted cities in China, Mexico and Portugal have in past years reported diesel exposure levels that over long periods could be comparable to those experienced by miners with lower exposures.

One industry group said that the study looked back at mines using decades-old equipment, and there's far less pollution from diesel engines today.

"Diesel engine and equipment makers, fuel refiners and emissions control technology manufacturers have invested billions of dollars in research to develop and deploy technologies and strategies that reduce engine emissions, now ultimately to near zero levels to meet increasingly stringent clean air standards here in the United States and around the world," Allen Schaeffer, of the nonprofit Diesel Technology Forum, said.

More people in the U.S. die from lung cancer than from any other type of cancer - it's expected to kill more than 160,000 Americans this year. The most recent statistics, from 1998 to 2007, show a decline in lung cancer rates among men and level rates among women.

The National Cancer Institute has more on lung cancer.

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10 worst jobs for your lungs

[stemarhan]

The findings of the two NCI studies are now undergoing a detailed peer and scientific review of the methodology and the conclusions, which have been the subject of great question and controversy over the last decade.

The researchers based assumptions regarding exposure on previous studies with apparent errors in the accuracy and appropriateness of some of the test measures. There are serious concerns about fundamental aspects of study design and the conclusions of the study.

The NCI studies further fail to note the tremendous changes that have taken place in diesel engines and equipment over time. Diesel engines and equipment that were the basis of these studies are in some cases over 50 years old. Like any other technology, diesel engines have changed dramatically over the course of the last half-century based on advancements in engineering and emissions control technology and new fuels.

Over the last 10 years, emissions from heavy-duty diesel trucks and buses have been reduced by 99 percent for nitrogen oxides (NOx) - an ozone precursor - and 98 percent for particulate emissions.

In addition, the new ultra-low sulfur diesel fuel that has been required since 2010 has reduced sulfur emissions by 97 percent - from 500 PM to 15 PM.

None of these advancements are considered in the two studies. Instead, the studies focus on older engines that haven't been manufactured for decades.

[stemarhan]

The findings of the two NCI studies are now undergoing a detailed peer and scientific review of the methodology and the conclusions, which have been the subject of great question and controversy over the last decade.

The researchers based assumptions regarding exposure on previous studies with apparent errors in the accuracy and appropriateness of some of the test measures. There are serious concerns about fundamental aspects of study design and the conclusions of the study.

The NCI studies further fail to note the tremendous changes that have taken place in diesel engines and equipment over time. Diesel engines and equipment that were the basis of these studies are in some cases over 50 years old. Like any other technology, diesel engines have changed dramatically over the course of the last half-century based on advancements in engineering and emissions control technology and new fuels.

Over the last 10 years, emissions from heavy-duty diesel trucks and buses have been reduced by 99 percent for nitrogen oxides (NOx) - an ozone precursor - and 98 percent for particulate emissions.

In addition, the new ultra-low sulfur diesel fuel that has been required since 2010 has reduced sulfur emissions by 97 percent - from 500 PM to 15 PM.

None of these advancements are considered in the two studies. Instead, the studies focus on older engines that haven't been manufactured for decades.

[tomgillilan]

Diesel exhaust also causes cardiovascular disease. The cleaner they make diesel exhaust,the worse it is for humans to breathe.

Diesel exhaust is public enemy number one. Almost as bad as charcoal barbeque and wood smoke.

When they make diesel exhaust "cleaner" they reduce the amount of larger and medium sized particles, but in doing so they dramatically increase the amount of micron sized particles in the exhaust.

These micron sized particles readily enter our blood via the lungs and they ATTACK AND ENTER the mitochondria of the cells that line our lungs and blood vessels and cause hardening of the arteries with the multiple medical problems that causes.

The only solution is to get rid of diesel altogether.

The port of Long Beach California has switched all their diesel trucks to natural gas and it has made a difference. There is also a company that now produces a conversion kit that will convert existing diesel trucks to natural gas.