UNITED STATES.- Modest reductions in air pollution can prevent the deaths of tens of thousands of infants in sub-Saharan Africa each year, according to a new scientific study that investigated the link between breathable air pollutants and premature deaths in 30 countries across the continent.

Although few pollution monitoring systems exist in Africa, the researchers combined satellite-based data estimating the concentration of air pollutant particles with household health survey data on the location and timing of almost 1 million infant births — and any subsequent deaths — between 2001 and 2015.

There is a “robust relations- hip” between breathable particulate matter and infant mortality in some of the world’s poorest countries, according researchers from Stanford University and the University of California, San Diego published Wednesday in the journal Nature.

Particulate matter, one of many air pollutants, is believed by many experts to be the most harmful to human health. The term refers to small particles suspended in the air, including dust and black carbon originating from such sources as fossil fuel and biomass burning. Air pollution contributes to the global burden of heart disease, lung cancer, as well as respiratory diseases such as asthma and pneumonia, according to the World Health Organization.

Many people in Africa, where the process of rural electrification has been slow, still burn wood to cook or heat their homes. Other sources of pollutants may be natural, including large amounts of dust from the Sahara Desert.

Every 10-microgram-percubic-meter increase in the concentration of breathable particulate matter is associated with an increase of about 9 percent in infant mortality, an effect consistent over the 15- year study period, the study’s authors say. They also estimate that a decrease in air pollution of 5 micrograms per cubic meter across Africa might have averted around 40,000 infant deaths in 2015.