LOS ANGELES, Dec. 12 (Xinhua) -- A large study found that greater exposure to long-term air pollution was linked to increased risks for blood clots that can occur in deep veins, according to the U.S. National Institutes of Health (NIH).
If untreated, the condition can block blood flow and cause serious complications, even death, said NIH in a release on Thursday.
These findings came from a longitudinal study funded by NIH that included 6,651 U.S. adults who were followed for an average of 17 years between 2000 and 2018.
Participants lived in or near one of six major metropolitan areas in the United States: New York, Baltimore, Chicago, Los Angeles, Minneapolis, and Winston-Salem, North Carolina.
Throughout the study, 248 adults, 3.7 percent of the study sample, developed blood clots in deep veins that required hospital care.
The likelihood of this outcome was linked to anywhere from a 39 percent to a more than two-fold increased risk based on long-term exposure to three different types of air pollutants, according to NIH.
Blood clots in deep veins, collectively known as venous thromboembolism (VTE), include deep vein thrombosis, which occurs when a blood clot forms in a deep vein of the legs, arms, or an internal organ, and pulmonary embolism, which occurs when a blood clot breaks off from a deep vein and travels to the lungs.
VTE affects up to 900,000 Americans each year. Many cases occur after surgery, but other factors, including age, long periods of inactivity, heart disease, pregnancy, and genetics, can increase risks, according to NIH.
