The introduction of LEZ in London caused small improvements in air quality but was not associated with a decrease in the proportion of children with reduced lung volume for their age, according to an observation study.
Researchers who write The public health Lancet the magazine said it needed interventions that caused greater cuts in emissions to improve children's health.
Experts have indicated that the findings have highlighted that while public health policies aim to reduce overall levels of air pollution, more targeted initiatives are needed to protect the health of vulnerable people, such as children and the elderly.
The study, led by Queen Mary University of London (QMUL) and King's College in London (KCL), involved 2164 children aged 8 to 9 who attended 28 elementary schools in four London municipalities. Tower Hamlets, Hackney, Greenwich and the City of London were selected because they were inconsistent with the European Union's nitrogen dioxide (NO2) at the beginning of the study.
Between 2009-2010 and 2013-2014, participants received annual health checks for winter 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.
Reduction of lung capacity
The researchers found that children exposed to atmospheric pollution experienced a loss of about 5% in pulmonary capacity. This was linked to the annual report on NO2 and other oxides of nitrogen (NOX.) – both are in oil emissions – and in particulates (PM10).
Following the implementation of LEZ in London, small improvements were made to NO2 and noX. but PM did not improve10 levels, the study said.
"What we could not see in these children was an improvement in their pulmonary function," said co-author Ian Mudway, a lecturer in respiratory toxicology at KCL Medscape News UK. "Although atmospheric pollution is improving, it has not improved enough to see a signal from the point of view of the respiratory health of these children."
Other factors that could affect respiratory health, such as age, gender, height, body mass index, ethnicity, socio-economic status and exposure to environmental tobacco smoke, have been taken into account.
The researchers concluded: "Large-scale LEZs can improve the quality of urban air and can be linked to changes in children's respiratory health.
"However, more ambitious systems than those assessed here are needed to meet regulatory limits and improve respiratory health in many European cities."
Co-writer Chris Griffiths, from QMUL, said: "Some improvements in air quality have been made despite diesel vehicles that emit higher levels of pollutants in the real world than in tests.
"However, many internal and external London areas continue to violate EU air pollution standards and are unlikely to address them without a substantial limitation of current emissions controls."
Dr. Mudway said: "How your lungs grow, whether they achieve their maximum growth in adulthood, are very important in terms of how long you will live, the level of healthy life in later life, and so, effectively, this is saying there are impacts on our population that could now affect the quality of their lives during their lives for many years down the coast. "
Ask for new policies on air pollution
Commenting on the survey, Dr. Stein Reis, Head of Atmospheric Chemistry and Impact at the Center for Ecology and Hydrology, said: "This study highlights a key challenge for implementing policy interventions to improve air quality.
"So far, great emphasis has been placed on the achievement of air quality limit values in a few existing air quality monitoring sites. However, the envisaged measures aimed at reducing the exposure of the population to urban areas, in particular [in] vulnerable groups, such as children or the elderly, should be adequately assessed before applying them. "
Shirley Rodrigues, Deputy Mayor for the Environment and Energy at the London Mayor's Office, commented: "This shocking report is further evidence of how pollution is stifling the lives of young Londoners. taking decisive action. "
The mayor's office said that – in April 2019 – it will introduce the world's first low-emission zone to further reduce air pollution levels in central London.
A representative of the Department of Food, the Environment and Rural Affairs (DEFRA) said: "While air quality in the UK has improved significantly since 2010, we understand the continuing danger to human health and realizes that more needs to be done.
"For this reason, we have put in place a £ 3.5 billion plan to reduce harmful emissions and an ambitious clean air strategy that has been welcomed by the World Health Organization."
"We will soon proceed even more with the introduction of new legislation to give local authorities new powers to take action in areas with pollution problems."
The Impact of the London Low Emission Zone on Air Quality and Respiratory Health of Children: A sequential annual cross-sectional study, Mudway et al., The Lancet Public Health. Paper.