Rush Hour Pollution Worse Than Previously Thought

A new study that measures exposure to rush hour pollutants found that the levels of some harmful particles are twice as high as previously believed.

Experts say that most traffic pollution sensors are placed on the ground alongside the road and take continuous samples for a 24-hour period. Exhaust composition, however, changes rapidly enough for drivers to experience different conditions inside their vehicles than these roadside sensors. Long-term sampling also misses variables caused by road congestion and environmental conditions.

To better determine what drivers are actually exposed to during rush hour, researchers from Duke University, Emory University and the Georgia Institute of Technology put specially designed devices into the passenger seats of cars during 60-minute rush hour commutes in Atlanta. The devices draw in air at a similar rate to human lungs to provide detectable levels of pollution.

The devices detected up to twice as much particulate matter as the roadside sensors. The team also found that the pollution contained twice the amount of chemicals that cause oxidative stress, which is thought to be involved in the development of many diseases including respiratory and heart disease, cancer, and some types of neurodegenerative diseases.

"We found that people are likely getting a double whammy of exposure in terms of health during rush-hour commutes," said Michael Bergin, professor of civil and environmental engineering at Duke.

"If these chemicals are as bad for people as many researchers believe, then commuters should seriously be rethinking their driving habits.

"There's still a lot of debate about what types of pollution are cause for the biggest concern and what makes them so dangerous," Bergin said. "But the bottom line is that driving during rush hour is even worse than we thought."

The results were published on June 27 in the journal Atmospheric Environment.

A study from Columbia University found that  B vitamins may be a weapon in the fight against the damage pollution does to the body. Scientists found that B vitamins reduce changes to the epigenome — the chemicals that regulate and direct genes — caused by air pollution.

The study reveals that even small amounts of the vitamins could counteract the damage caused by pollutant particles called PM2.5, which include toxins such as black carbon that cause inflammation in the lungs and throughout the body. These harmful particles can turn off cells in the immune system, but supplementing with B vitamins can reduce their effect by up to 76 percent.