Living close to a major road may increase the risk of women dying from sudden cardiac arrest, new research shows.

Previous studies have found a modest increase in coronary heart disease among people who live near major roadways, but this is the first study to examine the impact of road proximity on the risk of sudden cardiac death. The association is related to increased air pollution near busy roads.

The research, carried out by Harvard Medical School, shows environmental factors can be a fatal as lifestyle choices such as smoking, diet or drinking.

"It is important for health care providers to recognise that environmental exposures may be under appreciated risk factors for diseases such as sudden cardiac death and fatal coronary heart disease," lead author Jaime Hart told Nature World News.

"On a population level, living near a major roadway was as important a risk factor as smoking, diet or obesity."

For the study, researchers examined data from 107,130 women with an average age of 60. The group were part of the Nurses' Health Study from 1986 to 2012.

In 523 cases of sudden cardiac death, living within 50 metres of a major road increased the risk of death by 38%, compared to living at least 500 metres away.

For every 100 metres closer to roadways, there was a six percent increased risk of sudden cardiac death.

In 1,159 cases of fatal coronary heart disease, risk increased by 24%.

"Regardless of where you live, adopting heart healthy habits, such as maintaining a healthy weight, being physically active, eating nutritious food, quitting smoking, and managing stress, can help decrease your risk of heart and blood vessel disease," Hart added.

Researchers noted that further studies are needed to establish a cause-and-effect relationship.

Coronary heart disease is the leading cause of death both in the UK and worldwide. It is accountable for around 74,000 deaths in the UK each year, with around one in five men and one in eight women affected.

According to the Centers for Disease Control and Prevention (CDC), heart disease is the leading cause of death for women in the US and accounts for one in four female deaths.

The study appeared in the journal Circulation.