Black carbon released by diesel cars has been linked to various respiratory diseases, such as asthma and cardiovascular disease. After comparing the peak exhaust rates between busy and back roads, researchers recommend that pedestrians take the longer route rather than cross busy streets. Their findings on traffic pollution and air quality was recently presented at the European Respiratory Society's International Congress meeting.

Researchers compared emission levels monitored along both main roads and quieter routes between two areas in London. From this, they were able to determine which route exposed commuters to more air pollution.

"We know that short-term exposure to black carbon is associated with increased hospital admissions due to respiratory symptoms, and that long-term exposure is associated with exacerbations and increased prevalence of asthma," Lee Koh, a researcher at the Blizard Institute at Queen Mary University of London, said in a news release. "Since London is one of the most polluted cities for black carbon in Europe, ways that people might be able to reduce their own exposure are of interest, and we wanted to see whether walking quieter, side-street routes might help to do this."

From their study, researchers concluded that there was no exposure to peaks of black carbon when using quieter routes. However, when using busy roads, there were three occasions when exposure significantly increased.

"The peaks are when a much higher levels of pollution are present. For example, when you stop to cross a busy road and so you are subject to a higher level of pollution compared to when walking away from the traffic," Koh added. "Our study suggests that, in London, it is possible to reduce exposure to peaks of black carbon particles (mainly from diesel soot) by choosing to walk a less polluted route. Government action will be required to further improve the general air quality around us."

For more great nature science stories and general news, please visit our sister site, Headlines and Global News (HNGN).

-Follow Samantha on Twitter @Sam_Ashley13