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Dutch researchers may have found a chemical link between diesel fumes and altered brain activity.

In a small study published last March in the journal Particle and Fibre Toxicology, researchers from Zuyd University in The Netherlands observed a general cortical stress response in their test subjects.

During and after exposure to diesel fumes, subjects experienced an increase in fast wave (beta-2) activity in their left frontal cortex. The researchers suggested that inhaled nanoparticles in the diesel exhaust may travel to the brain, causing the increased beta-2 wave activity.

This type of brain activity has been associated with elevated cortical stress, which may be damaging. Consider that other studies using EEG (electroencephalogram) results have shown that subjects with serious conditions such as headaches, post-traumatic stress disorder, burnout, and traumatic brain injury have also exhibited increased beta-2 levels.

While researchers in the Netherlands were careful to assert that it’s not yet possible to predict the long-term brain damage of short-term exposure to diesel fumes, the implications from the study are troubling, especially as diesel consumption in North America is on the rise.

In recent years, our attention has been focused on reducing gasoline use and emissions. According to Statistics Canada, gasoline fuel sales have basically remained constant since 2002, while diesel fuel sales have steadily increased (see sidebar). Fuel sales in the United States also followed this pattern. Perhaps we’ve turned to diesel as an alternative to gasoline because we are told that diesel-powered vehicles produce less greenhouse gases and have better fuel economy.

Although diesel use has increased, the Dutch study suggests that we need to avoid diesel fumes because it stresses our brains, which may or may not lead to permanent damage. Because they have no protection, pedestrians, cyclists, and young children in strollers (at tailpipe level) might get the most exposure.

It’s difficult to know what to do. We’re encouraged to reduce personal vehicle use, use public transit, and walk or bike. This study’s findings suggest that we need to protect ourselves when we’re on or near the road. Choose routes with less traffic whenever possible to minimize exposure and to breathe easier when walking or biking.

About the Diesel Engine

In 1892 Rudolf Christian Karl Diesel patented his diesel engine. He wanted to create a highly efficient internal combustion engine, which he achieved with a high fuel-to-air ratio. Diesel believed that his engine could “be fed with vegetables’ oils,” meaning biodiesel.

Writer Rob Klettke takes transit, bikes, and walks whenever he can.

Source: alive #312, October 2008