This year’s record-breaking wildfire season has brought renewed attention to the dangers of pollution. Poor air quality has been linked to worsening symptoms of respiratory and cardiovascular diseases in adults and children. But, a recent study shows that the dangers to infants may be even more dangerous. An international team of researchers found that air pollution, both inside and outside the home, contributed to the deaths of about 500,000 newborns.

Why is pollution so dangerous to infants?

Fine particulate matter, or PM 2.5, are tiny particles in the air that can cause a variety of health issues such as hospitalization, disability,  respiratory diseases, heart disease, stroke, lung cancer, and diabetes, and even contagious illnesses like pneumonia. Increasingly, research is showing that exposure to PM2.5 also elevates the likelihood of premature birth and infant mortality.

That’s because inside the bloodstream of pregnant women, PM2.5 pollution acts similarly to tobacco smoke by triggering inflammation in the blood. This inflammation can decrease the transfer of oxygen and nutrients across the placenta and potentially result in preterm labor. Babies born early are more susceptible to health complications that, in the worst cases, can lead to death.

Unfortunately, over 90% of the world’s population lives in areas where  PM2.5 levels are above the WHO guideline for healthy air.

And it isn’t just about outdoor air quality. 49% of the worldwide population uses fossil fuels for cooking, resulting in 2.31 million deaths from indoor air pollution, with young children and infants being hit especially hard.

Worldwide, about 2.42 million infants die within the first 27 days of life each year. The new study suggests that about 20% percent of those deaths are linked to air pollution.

In what areas of the world are babies most susceptible?

Sub-Saharan Africa accounted for almost half of these deaths, largely because of indoor pollution from burning coal and oil for heat and cooking. Many, though not all, of the other deaths occurred in other developing nations.  But, pediatrician Susan Niermeyer warns that the air pollution problem is not restricted to low-income areas or places where people burn fossil fuels indoors.

“I think you can easily dismiss this finding as something that only happens to people who live far away in thatched-roof houses and not to us. But air pollution affects our babies, as well.”

Niermeyer explains that families in the United States who live near highways or airports are exposed to large amounts of PM2.5 and carbon monoxide, leading to an increased risk of premature births and deaths.

Epidemiologist Xueying Zhang at the Icahn School of Medicine at Mount Sinai believes that the findings may help bring attention to what many consider an unknown, invisible killer of infants.

“Doctors will never say a person died of air pollution,” Zhang says. “They will say the cause of death is cancer, a stroke or respiratory disease. But air pollution is an important cause of cancer, strokes, and respiratory syndromes.”

Zhang hopes that if people understand that pollution is also a factor in premature and low-weight births, more can be done to address the issue.

“Once people see how much air pollution threatens babies, they are more likely to look for ways to protect them.” Zhang said.

What can we do to help protect babies?

For developing nations, the most helpful thing may be to provide education on the dangers of cooking indoors over coal or wood fires and the benefits of ventilation.

In the US and other industrialized countries, the problem is more complex.  Obviously, living outside of urban areas, and away from highways and airports is the best way to reduce exposure to outdoor PM2.5. But, unfortunately, that isn’t a realistic option for everyone.

To minimize your family’s exposure to outdoor pollutants:

  • Check your air quality before going out.
  • Go outside in the mornings, when ozone levels are lower.
  • Walk away from traffic.
  • Stay near trees or shorelines.

To reduce your family’s exposure to indoor pollutants:

  • Ensure that gas stoves are well ventilated
  • Reduce the use of harsh cleaners and scented products
  • Keep windows and doors open as much as possible

While all of these measures can help reduce pollutants, perhaps the most important step to improving indoor air quality is to purchase an air purifier.  Not only will a high-quality air purifier remove pollutants such as dust, mold, and smoke from the air, there is also increasing evidence that HEPA filters may play a role in reducing COVID transmission.