Children's Lung Health 'at Risk' Despite Pollution Curbs

Peter Russell

November 15, 2018

The introduction of a low emission zone (LEZ) in London brought about small improvements in air quality but has not been associated with a reduction in the proportion of children with reduced lung volumes for their age, according to an observational study.

Researchers writing in The Lancet Public Health journal said that interventions that delivered larger cuts in emissions were needed to improve children's health.

Experts said that the findings underlined that while public health policies were aimed at reducing overall levels of air pollution, more targeted initiatives were required to protect the health of vulnerable people such as children and older adults.

The study, led by Queen Mary University of London (QMUL) and King's College London (KCL), involved 2164 children aged 8 to 9 years who attended 28 primary schools in four inner city London boroughs. Tower Hamlets, Hackney, Greenwich, and the City of London were chosen because they were non-compliant with European Union nitrogen dioxide (NO2) limits at the start of the study.

Between 2009-10 and 2013-2014, participants were given yearly winter health checks that included measuring the volume and function of their lungs with a spirometer. Parents were also asked to complete a medical history questionnaire for their child.

Lung Capacity Reduction

The researchers found that children exposed to air pollution showed a loss of approximately 5% in lung capacity. This was linked to annual exposures to NO2 and other nitrogen oxides (NOx) – both found in diesel emissions – and in particulate matter (PM10).

Following the implementation of London's LEZ, there were small improvements in NO2 and NOx levels, but no improvements in PM10 levels, the study found.

"What we were unable to see in those children was an improvement in their lung function," co-author Ian Mudway, lecturer in respiratory toxicology at KCL, told Medscape News UK. "Although air pollution was improving, it hadn't improved enough to see a signal in terms of those children's respiratory health."

Other factors that could affect respiratory health including age, sex, height, body mass index, ethnicity, socioeconomic status, and exposure to environmental tobacco smoke, were taken into account.

The researchers concluded that: "Large-scale LEZs can deliver improvements in urban air quality and these can be linked to changes in childhood respiratory health.

"However, more ambitious schemes than those evaluated here are required to meet legislative limits and deliver improvements to respiratory health in many European cities."

Co-author Prof Chris Griffiths, from QMUL, said: "Some improvements in air quality have been made despite the diesel vehicles emitting higher levels of pollutants in the real world than in tests.

"Even so, many areas of inner and outer London are still breaching EU air pollution standards and are unlikely to meet them without a substantial tightening of current emission controls."

Dr Mudway said: "How your lungs develop, whether they attain their maximum growth in adulthood, is critically important in terms of how long you're going to live, the level of healthy life in later life; and so, effectively, this is saying there are effects occurring in our population now which could have impacts on the quality of their life, on the length of their life, many years downstream."

Call for New Air Pollution Policies

Commenting on the research, Dr Stefan Reis, head of atmospheric chemistry and effects, at the Centre for Ecology & Hydrology, said: "This study highlights a key challenge for the implementation of policy interventions to improve air quality.

"Much emphasis has been placed to date on the attainment of air quality limit values at few existing air quality monitoring sites. However, planned measures aiming to reduce population exposure in urban areas, and in particular [in] vulnerable groups such as children or older adults, need to be adequately assessed prior to implementation."

Shirley Rodrigues, deputy mayor for environment and energy at the office for the Mayor of London, commented: "This shocking report is further evidence of how pollution blights young Londoners' lives. The Mayor and I refuse to ignore this public health crisis and are already taking firm action."

The mayor's office said it would – in April 2019 – introduce the world's first ultra-low emission zone, to further reduce air pollution levels in central London.

A spokesperson for the Department of Environment, Food, and Rural Affairs (DEFRA) said: "While air quality in the UK has improved significantly since 2010, we understand the risk it continues to pose to human health, and realise more needs to be done.

"For that reason, we have introduced a £3.5bn plan to reduce harmful emissions and an ambitious clean air strategy, which has been welcomed by the World Health Organisation.

"We will soon be going even further with new legislation to give local government new powers to take action in areas with a pollution problem."

Impact of London's low emission zone on air quality and children's respiratory health: a sequential annual cross-sectional study, Mudway et al, The Lancet Public Health. Paper.


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