Polluted air caused the early death of nearly half a million babies in the first month of their lives across the globe last year, a new study has found.
The majority of newborns who lost their lives to air pollution were in the developing world, with indoor air quality to blame for two-thirds of the deaths, according to the State of Global Air 2020 report. Scientists discovered that polluted air has an impact on the health of babies while they are still in the womb and could lead to premature birth or low birth weight - both factors associated with infant mortality.
The report states: "Air pollution is linked with an increased risk of low birth weight and preterm birth. Babies born too small or too early are more susceptible to health problems such as lower-respiratory infections, diarrheal diseases, brain damage and inflammation, blood disorders, and jaundice. Low birth weight and preterm birth are leading risk factors for death in the first month of life, contributing to an estimated 1.8 million deaths worldwide.
"The smaller the baby or the earlier they are born, the higher the risk of complications. If these babies survive infancy, they remain at a higher risk not only for infectious diseases throughout early childhood but also for major chronic diseases throughout life. We estimate that, in 2019, 476,000 infants died in their first month of life from health effects associated with air pollution exposure."
The report, published by the Health Effects Institute, found that in 2019 over 90 percent of the world's population experienced fine particle air pollution that exceeded the World Health Organisation's air quality guidelines. Air pollution is now the fourth highest cause of death globally, just below smoking and poor diet, with more than 6.67 million killed by dirty air in 2019 alone. Air pollution contributes to a large percentage of deaths globally from diabetes, stroke, chronic obstructive pulmonary disorder, lung cancer, ischemic heart disease, and lower respiratory infection.
But this year for the first time, scientists examined the impact on infant mortality. The report examined data on deaths around the world and found that of the 500,000 deaths of infants due to dirty air, around 330,000 were associated with indoor air pollution, particularly from burning solid fuels such as charcoal, wood, and animal dung for cooking.
The findings are supported by a growing body of evidence surrounding the impact of dirty air on babies in the womb. Katherine Walker, principal scientist at the Health Effects Institute tells Newsweek: "For many years, we've known that in general, a mother's exposure to any number of toxicants can affect unborn children. In the case of air pollution, there are now multiple studies in different countries around the world, that have found associations between a mother's exposure to air pollution and to lower birth weights and higher incidence of pre-term birth.
"What these individual studies alone don't tell us is how many babies might be affected and where. What is significant about the analysis provided in the State of Global Air is that it is the first major effort to answer this question on a global basis in relation to air pollution. It can give physicians and policymakers insights into how important these exposures are relative to other factors that also put babies at risk.
"It was surprising to me that as much as 20% of neonatal mortality is attributable to air pollution."
Babies born with a low birth weight are more susceptible to childhood infections and pneumonia and vital organs including the lungs may not be fully developed. The problem gets worse in densely populated areas such as developing cities where outdoor air pollution from vehicles and industry is likely to be higher. It means there is no escape from polluted air, indoors or outdoors, the study authors found.
The State of Global Air report focussed on data from 2019 but researchers said there is reason to believe that air pollution could also increase susceptibility to COVID-19 - though the impact is not yet clear.
As the world plunged into lockdown and people were forced to stay home, many cities across the globe saw their air pollution drastically drop. Dramatic reductions in travel and industrial activity saw substantial reductions in nitrogen dioxide and some reductions in fine-particle air pollution.
When Europe's original epicenter Italy was thrown into full lockdown smog hanging over the Grand Canal in Venice and the Italian Alps in Milan visibly cleared. The India Gate war memorial in New Delhi, India - one of the most polluted cities in the world - was pictured in April during a 21-day nationwide lockdown in clear view with no haze, while the Himalayas were seen from north India for the first time in 30 years.
Despite the early drop, the researchers say there has been little sign of improvement in air pollution over the past 10 years, despite increased warnings of the risks. Exposure to air pollution has been shown to affect the body's immune defense, making an individual more susceptible to respiratory and other infections. In addition, many of the health conditions that have been associated with increased vulnerability to COVID – such as diabetes and cardiovascular disease – are also caused by long-term exposure to air pollution.
The authors said: "With time and a continued focus on tracking outcomes and possible contributing factors such as air pollution, the world will learn more about COVID-19 and how to reduce its toll. Just as the COVID-19 crisis has demonstrated the need for multiple strategies to manage the pandemic, solutions to air pollution will require multifaceted ongoing efforts to bring attention to its health threats, to identify the policy changes necessary to control it, and to monitor progress over time."
The State of Global Air study was conducted as part of the broader Global Burden of Diseases project at the Institute for Health Metrics and Evaluation at the University of Washington.
Update 10/21/20 08:15 EST: This story has been updated to include quotes from Katherine Walker provided after publication.