May 28, 2019

expert reaction to study on air pollution and mouse development

Research published in PNAS demonstrates that maternal exposure to ultrafine aerosols impacts prenatal and postnatal organogenesis in offspring and predisposes metabolic syndrome in adult life.

Dr Mark Miller, British Heart Foundation Senior Research Scientist, University of Edinburgh, said:

“There is a growing body of evidence showing that exposure to air pollution during pregnancy has detrimental health effects on mothers and babies. This study by Wu and colleagues is an intricate study in mice showing that exposure of minute particles of ammonium sulphate causes increases in the likelihood of stillbirth, smaller babies and a range of other effects on the babies which could be harmful to their health. Some of these effects were long-term, with the babies showing early signs of diabetes and circulatory diseases as they grew up. These effects add to the now lengthy list of the many different ways air pollution could potentially affect health.

“It is worth noting, though, that not all particles in air pollution are the same. This study looks at ammonium sulphate particles which could behave differently from the more commonly studied mixture of particles in cities and near roads. Forms of ammonia are especially relevant to the pollution caused by farming, which has been on the rise in the UK over recent years. It is worth bearing in mind that the investigators used quite high levels of particles for several weeks. Levels like this can be reached in some countries in Asia, however, the relevance of these levels to the UK needs further investigation. Nonetheless, more studies like this are needed so that we can get a better idea of the full risk caused by agricultural pollution and what policies might be needed to regulate levels.

“The authors of the paper conclude that ‘therapeutic strategies are needed to prevent the health effects of air pollution’. While such therapies could be useful, ultimately, it is essential that we reduce levels of harmful air pollution in the first place”

Dr Stefan Reis, Head of Atmospheric Chemistry and Effects, Centre for Ecology and Hydrology (CEH), said:

(Commenting on the type of particulate matter rather than the specific health aspects of this study)

“At this point in time, we know that exposure to particles in the air causes a wide range of impacts on human health, as two recent reviews into air pollution and non-communicable diseases have demonstrated^{1, 2}. The contribution of individual components that make up these particles to health outcomes is still rather uncertain, however.

“The outcomes of this study, if they can be confirmed by further research into the same mechanisms in humans, could present a vital step towards a better understanding of how prenatal exposure to air pollution can affect child health. A focus on ammonium sulphate aerosols, a component of fine particulate matter that can be transported through the air over very long distances, is especially relevant for the current discussion on which components of fine particles have the largest health impacts.

“If future research is able to demonstrate substantial health effects from exposure to secondary aerosols formed from ammonia and sulphur dioxide, this could strengthen the argument for reducing exposure to allfine particulate matter. As a consequence, rather than prioritising primary emissions of particles from combustion sources, this would add further weight to tackling ammonia emissions at the same time.” 

¹ Air Pollution and Noncommunicable Diseases: A Review by the Forum of International Respiratory Societies’ Environmental Committee, Part 1 DOI: 10.1016/j.chest.2018.10.042

² Air Pollution and Noncommunicable Diseases: A Review by the Forum of International Respiratory Societies’ Environmental Committee, Part 2 DOI: 10.1016/j.chest.2018.10.041

‘Adverse organogenesis and predisposed long-term metabolic syndrome from prenatal exposure to fine particulate matter’ by Guoyao Wu et al. was published in PNAS at 20.00 UK time on Monday 27 May 2019.

Declared interests

Dr Mark Miller: “I have no conflicts of interest to declare.”

Dr Stefan Reis: No declarations of interest.