Studies point to air quality impacts in infants and over-60s
Dec 06 2017 by Kathy Alvarado
The research was carried out in collaboration with United States colleagues from Duke University.
Researchers estimated average monthly concentrations of traffic-related pollutants by looking at the mother's home address at the time of birth.
The results suggest that poor air quality can cancel out exercise benefits and demonstrate the health impacts of even short-term exposure to air pollution.
According to the authors, cutting the average concentration of fine particle pollution emitted by the city's road traffic by just 10% could prevent around 90 babies a year (3% of cases) being born with low birth weight.
Fumes from vehicles in London is linked with a rise of up to six per cent in the odds of a low birth weight and a rise of up to three per cent in the risk of being small for the baby's gestational age, Imperial College London found.
"Exercise is crucial in reducing the risk of a heart attack or stroke, but it seems unsafe levels of air pollution could be erasing these benefits in older adults".
All the participants, recruited through London's Royal Brompton Hospital, were either healthy or had a stable lung condition or non-progressing heart disease.
London Mayor Sadiq Khan has pledged to make reducing air pollution one of his top priorities and announced a global network to tackle the issue while on a trip to Delhi this week.
For the new study 119 volunteers over the age of 60 were asked to walk for two hours in a relatively quiet part of Hyde Park and along a busy section of Oxford Street.
"People like outdoor exercise". Data analysis was carried out at the MRC-PHE Centre for Environment and Health at Imperial College London and Kings College London, and the Rutgers School of Public Health in New Jersey.
The study found everyone in the park group benefited, with lung capacity improving within an hour and persisting for 24 hours.
Physical measurements taken before and after the walks revealed the effects activity had on each volunteer's cardiopulmonary health, including lung capacity, blood pressure, blood flow, and arterial stiffness. Eighty participants had mild heart or lung disease.
The British Heart Foundation says the cardiovascular benefits of a brisk walk along Oxford Street are completely negated by exposure to air pollution for the over 60s.
Walking in Hyde Park reduced arterial stiffness by more than 24 percent in healthy and COPD volunteers and more than 19 percent in heart disease patients.
Because the research also showed that volunteers who walked for two hours in a large city park-away from direct exposure to street-side traffic fumes-experienced significant improvements in lung and vascular functions, "we call for greater access to urban green spaces for people to exercise", Zhang adds.
The authors add that it is possible that stress could account for some of the physiological differences seen between the two settings, with the increased noise and activity of Oxford Street having an effect. When exercising it's best to avoid highly-polluted areas, swapping them for green spaces or even back streets where pollution is lower. Funding came from the British Heart Foundation.