Polluted air threatens children

Air pollution may be putting children at risk of life-long health problems and radical measures are needed to tackle the issue, according to a study in the Lancet Public Health journal.

The study looked into the impact of London’s low emission zone and found that while it has improved air quality it has not been enough to benefit children’s lung health.

Low emission zones are in place in 200 cities across Europe but only modest reductions in the exposure of nitrogen oxides from diesel vehicles have been made in the capital. Little progress was found in the reduction of ultrafine particles (PM2.5) or course particulate matter (PM10) over the study period, which is a health concern due to their ability to reach deep inside the lung.

The observational study included more than 2,000 primary school children aged between eight and nine, living in areas of high pollution within the low emission zone. It linked chronic exposure to traffic-related pollutants to reduced lung function.

Despite improvements in air quality the study found no improvement in asthma symptoms or a reduction in the proportion of children with smaller lungs, over the five years since the zone was implemented.

Author of the report Professor Chris Griffiths from Queen Mary University of London 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.’

Average exposure levels of nitrogen dioxide over the five-year study remained high (median 40.7 µg/m³) and researchers estimated that children’s lung capacities were reduced by around 5 per cent.

Griffiths said: ‘Although changes of this magnitude are unlikely to cause problems in healthy children, we urgently need to know whether these lung deficits will impact lung function and health in later life.

‘Until longer-term impacts are known, doctors should consider advising parents of children with clinically significant lung disease to avoid living in highly polluted areas, or to adopt personal mitigation measures to limit their exposure. More research is needed to identify factors that lead to increased susceptibility or protection.’