Scots findings drive call to speed up fumes ban.
Expectant mothers who live in the world’s worst air pollution hotspots risk causing almost as much harm to their unborn child as those who smoke, according to scientists.
A study by Edinburgh and Aberdeen universities found that babies exposed to toxic gases and particulates, such as those belched out through car exhausts, were born with smaller heads and shorter bodies.
A similar outcome was observed in babies whose mothers smoked during pregnancy but were exposed to less pollution.
Dr Tom Clemens, who led the study, has called on the World Health Organisation (WHO) as well as nations to urgently review their definition of “acceptable” emissions levels amid concern they are still too high.
He said the findings are particularly worrying because the study – the largest of its kind so far conducted – only examined the effects of pollution in the northeast of Scotland, where air quality is relatively good compared with congested areas such as Glasgow, Edinburgh and London.
“Our findings suggest that there may not be a truly ‘safe’ level of exposure during pregnancy,” said Clemens. “A foetus with a non-smoking mother exposed to high pollution levels is only slightly better off than one with a smoking mother exposed to low levels of pollution. This implies that the effect of exposure to the highest levels of pollution may be almost as bad as smoking.”
Poor air quality is one of the biggest environmental risks to public health. It has been estimated that many towns and cities have nitrogen dioxide that pollution breaches 40 microgrammes per cubic metre of air.
“Since the 2008 Beijing Olympics, outdoor air pollution has been recognised as a problem and the evidence we need to tackle it continues to pile up. It is time to do something about it,” said Steve Turner, a co-author of the study.
Indoor air pollution is often a problem as well, primarily due to poor ventilation that allows outdoor pollutants to enter indoor settings then remain there. Air conditioning units can decrease the level of pollution in homes and improve the air quality, though such units require maintenance to ensure that air filters are clean and efficient (see here https://homeserviceheroesfl.com/ for more AC maintenance information).
Another way to decrease air pollution both indoors and outdoors is for the inclusion of more plants. Homeowners can acquire potted plants that trap pollutants and town/city authorities can commit to planting trees and creating wildlife spaces that do this on a larger scale.
The study, published in the scientific journal Environment International, has prompted calls for bans on certain pollutants as well as diesel and petrol cars to be enforced as soon as possible.
Data on foetal growth was gathered from ultrasound scans and maternity records for almost 14,000 pregnancies between 2002 and 2011. Lifestyle factors, such as smoking, were considered.
Unlike previous air pollution studies, the investigation by Clemens and his team looked at the effect on developing foetuses of PM2.5 particulates – microscopic specks of dust and soot that can enter the lungs and bloodstream.
They detected average concentrations of 7.2 micrograms per metre cubed – well below the annual average of 10 micrograms per metre cubed that is deemed acceptable by WHO.
Nevertheless, they found that particulates were “consistently related” to babies born with heads that were almost 3mm smaller than those exposed to lower levels of pollution. There was strong evidence that PM2.5s stunt a baby’s growth.
Clemens stressed that smoking will always result in poorer pregnancy outcomes “no matter what else is going on”, but Chris Dibben, a co-author of the study, added: “Although most parents will be aware that their smoking may be harming their unborn child, we wonder whether there is an equal awareness that air pollution can have a similar level of impact on the growth of the child in the womb, even in relatively unpolluted regions like countryside areas.”