All the health benefits of walking for exercise along busy city streets may not be as beneficial as one would think. A recent study done in London found that lung capacity and other health markers improved within an hour when going for a two hour walk in a park, while a similar walk along a street in a busy shopping area barely showed any benefit. This means that breathing in the traffic fumes may well cancel out most of the potential health benefits derived from exercising.
The study aimed to compare the effects on cardiovascular and respiratory responses between walking down a highly polluted city street versus walking in an area with low pollution levels away from traffic. Men and woman 60 years and older from three distinctive health groups were recruited – either healthy (40 participants), or with stable chronic obstructive pulmonary disease (COPD) (40 participants), or with stable coronary heart disease (39 participants). Participants were randomly assigned to do a two hour walk at midday either along the very busy Oxford Street in London or in an urban park, Hyde Park in this case.
Participants underwent baseline physical measurements (including lung volume exhaled, blood pressure and the extent to which blood vessels dilate) before and after the walk; while air pollution levels of black carbon, particulate matter concentrations, ultrafine particles, and nitrogen dioxide concentrations were measured in both the street and in the park during each walking session.
And the conclusion? To quote from the study (as published in The Lancet): “Short term exposure to traffic pollution prevents the beneficial cardiopulmonary effects of walking in people with COPD, ischaemic heart disease, and those free from any chronic cardiopulmonary diseases.”
Sources:
Respiratory and cardiovascular responses to walking down a traffic-polluted road compared with walking in a traffic-free area in participants aged 600 years and older with chronic lung or heart disease and age-matched healthy controls: a randomized, crossover study. Research led by Imperial College London and Duke University. Published on 27 January 2018 in The Lancet, Volume 391, No 10118, p339-349.
City air pollution cancels positive health effects of exercise in over 60’s. Published 6 December 2017 in ScienceDaily.
Does air pollution make outdoor exercise risky? What if you have asthma or another health problem? Published 12 April 2017. Mayo Clinic.
Walking for fitness? Avoid traffic-clogged streets. Published March 2018 I Harvard Heart Letter. Harvard Medical School.
HEALTH INSIGHT. MARCH 2018