Air pollution is a major public health concern that affects millions of people around the world. It is associated with various adverse health outcomes, including respiratory diseases, cardiovascular diseases, and cancer. However, recent research has also linked air pollution to kidney diseases, including glomerulonephritis and chronic kidney disease (CKD). In this blog, we will discuss the relationship between air pollution and kidney health.
By Majd Isreb, MD, FACP, FASN, IFMCP
Air pollution is defined as the presence of harmful substances or contaminants in the air that negatively affect human health, the environment, or the quality of life. These substances can be both natural (e.g., dust, pollen) and human-made (e.g., emissions from vehicles, industrial processes, and power generation). According to a new report from the American Lung Association, nearly 1 in 5 Americans live in communities with harmful air quality.
Air pollution and kidney health
Particulate matter (PM)
When it comes to health, air pollution is typically measured based on the concentration of specific pollutants in the air. One of these measures is particulate matter (PM). These are tiny particles suspended in the air, typically measured in two size categories – PM10 (particles with a diameter of 10 micrometers or smaller) and PM2.5 (particles with a diameter of 2.5 micrometers or smaller).
PM2.5 is of particular concern as these tiny particles can penetrate deep into the lungs and cause respiratory and cardiovascular issues. It is what I will focus on in this blog.
Air pollution and glomerulonephrites
Glomerulonephritis is a type of kidney disease that affects the glomeruli, the small blood vessels in the kidneys that filter waste and excess fluids from the blood. Various factors, including infections, autoimmune disorders, and exposure to toxins, can cause it. Air pollution has been identified as a potential risk factor for glomerulonephritis, particularly in urban areas where levels of air pollution are high.
One study published in the Journal of the American Society of Nephrology found that exposure to PM2.5 was associated with an increased risk of developing membranous nephropathy in China. Each 10 μg/m3 increase in PM2.5 concentration was associated with 14% higher odds for membranous nephropathy.
Another study found that PM2.5 is an independent risk factor for the progression of kidney disease in patients with IgA nephropathy. Air pollution has also been implicated in the epigenetic changes that promote the development of lupus.
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Air pollution and CKD
Chronic kidney disease (CKD) is a progressive disease in which the kidneys gradually lose their ability to filter waste and excess fluids from the blood. It is a major global health problem, affecting an estimated 10% of the adult population worldwide. Air pollution has also been linked to an increased risk of CKD.
One study published in the Journal of the American Society of Nephrology found that exposure to high levels of PM2.5 was associated with a higher risk of CKD in China. A recent study in Minnesota found that higher PM2.5 was also associated with an increased incidence of CKD.
The largest to date study on the link between PM2.5 and CKD linked the Environmental Protection Agency and the Department of Veterans Affairs databases. The study, which involved more than 2 million adults in the United States, found that those who were exposed to higher levels of PM2.5 were more likely to develop CKD, have a faster decline in eGFR, and need dialysis than those who were not exposed to high levels of air pollution.
How does air pollution damage the kidneys?
The exact mechanisms by which air pollution causes kidney diseases are not fully understood. However, it is believed that air pollution may damage the kidneys by causing inflammation, oxidative stress, and endothelial dysfunction. Air pollution can also affect the kidneys indirectly by promoting hypertension (high blood pressure), insulin resistance, and diabetes.
Preventing the effects of air pollution on the kidneys
Reducing air pollution is, therefore, an important strategy for preventing kidney diseases. There are big societal measures that can be used to achieve that goal. These include reducing emissions from vehicles and industry, promoting clean energy sources, and increasing access to public transportation.
However, on the individual level, there are many strategies that can be used to decrease exposure. This reference contains detailed recommendations. I summarized them here:
- Verify the air quality in your area. You can check it in the US on this website.
- Avoid outdoor activity when and where the air pollutant levels are higher.
- Avoid high traffic and industrialized areas as much as possible.
- Maintaining good indoor air quality by using air filters and air purifiers.
- Use personal protective equipment when necessary.
- A diet high in antioxidants can also be protective.
The bottom line
Air pollution is a significant risk factor for kidney diseases, including glomerulonephritis and CKD. It is, therefore, important for individuals, communities, and policymakers to take action to reduce exposure to air pollution and promote clean, healthy environments.
