The first results of what is said to be the most comprehensive study ever undertaken of the health effects of exposure to new technology diesel engines has found no evidence of gene-damaging effects in the animals studied, and only a few mild effects on the lungs,
according to a report issued by the Health Effects Institute.

The Advanced Collaborative Engine Study is exposing rats and mice for 16 hours a day to emissions from a heavy-duty diesel engine meeting stringent 2007 US EPA standards that reduce emissions of fine particles and other pollutants by over 90% from levels emitted by older engines.

The study was conducted by the Health Effects Institute in collaboration with the Coordinating Research Council. The Health Effects Institute is an independent, non-profit research institute funded jointly by the U.S. Environmental Protection Agency and industry.

The new study offers important new insights on the advancements in clean diesel technology and ultra-low sulfur diesel fuel, according to Allen Schaeffer, Executive Director of the Diesel Technology Forum.

The goal of ACES is to test the emissions and health effects of the new technology diesel engines to document the improvements that have been made and to ensure that there are no unintended emissions from this new technology.

The study found that exposures lasting one, three, and in some cases up to twelve months had effects on only a few of the many health markers tested; exposures will continue for the life time of the rats. The few effects that were reported for the rats were mild hyperplasia (cell proliferation) in the lungs and slightly reduced lung function, and were most consistent with exposure to nitrogen oxides in the engine exhaust, which are being further reduced under 2010 US EPA standards now in effect.

In their commentary on the study, the ACES Review Panel concluded: "Overall, these results showed few biologic effects related to diesel exhaust exposure."

"As this new study illustrates, the 2007 compliant diesel technology provided historic improvements in reducing particulate and nitrogen oxide emissions," Schaeffer says. "And the 2010 and newer diesel technology is even cleaner with near zero emissions."