A study conducted in California has found that living near a freeway may be hazardous to your health.

According to the Los Angeles Times, researchers from the University of Southern California (USC) and the University of California at Berkeley have found that residents of Los Angeles who live near a freeway experience a hardening of the arteries—known as atherosclerosis—at twice the rate of those who live farther away.

Atherosclerosis is a condition known to cause heart disease and stroke.
Researchers studied nearly 1,500 people who lived within 328 feet of a California freeway for a period of three years. The participants received ultrasounds every six months to measure the carotid artery wall thickness. The findings were then compared to the levels of toxic dust near their homes.

They found that living near a freeway contributed to a hardening of the arteries at a rate of 5.5 micrometers per year. That’s more than twice the average progression of the condition.

"For the first time, we have shown that air pollution contributes to the early formation of heart disease, known as atherosclerosis, which is connected to nearly half the deaths in Western societies," said the study’s co-author Michael Jerrett. "By controlling air pollution from traffic, we may see much larger benefits to public health than we previously thought."