Living in a place with high vehicle exhaust may make asthma worse, but the evidence is "relatively weak," the researchers report.

It is overwhelmed by industrial emissions, smoke, vehicle exhaust and human waste.

Sources include gas cooking stoves, vehicle exhaust, and tobacco smoke.

He also believes that vehicle exhaust fumes have played a role.

Such a system would be challenging to ventilate without having to pump out clouds of vehicle exhaust.

Inside, the garage was filled with vehicle exhaust.

Emissions from vehicle exhausts are a significant source of air pollution.

When you live near a freeway, you are exposed to far more vehicle exhaust than normal.

Benzene is found in vehicle exhaust, and can cause leukemia.

"After smoking, vehicle exhaust and pesticides are probably the two largest carcinogenic exposures."