Living in countries with higher levels of air pollution, such as India and China, may be associated with an increased risk of developing kidney diseases, a study suggests.
Researchers from the Johns Hopkins University School of Medicine in the US said the findings may be especially important for parts of the world with higher air pollution, like India and China, where fine particulate matter levels are 5 to 10 times higher than in the US.
It is known that breathing in air pollution can have detrimental health effects beyond the lungs, but few studies have shown how it impacts the kidneys, which act as filters for the blood, they said. The study, published in the Journal of the American Society of Nephrology (JASN), examined information on 10,997 adults across four sites in the US who were followed from 1996-1998 through 2016.
The researchers estimated the monthly average levels of tiny particles of air pollution -- called fine particulate matter -- based on participants' home addresses. They noted that fine particulate matter comes from a variety of sources including fossil fuel combustion, industrial processes, and natural sources.
They found that exposure to higher amounts of fine particulate matter was associated with a higher degree of albuminuria -- a marker of kidney dysfunction -- at the start of the study as well as a higher risk of developing chronic kidney disease over time.
"As rates of chronic kidney disease rise worldwide, it is important to understand whether and how exposure to air pollution plays a role," said Matthew F Blum from Johns Hopkins University School of Medicine.
Future studies should examine whether efforts to improve air quality yield health benefits, including reducing rates of chronic kidney disease, the researchers said.