Pathways of exposure include emissions, auto exhaust, and cigarette smoke that can expose the human subject directly if they inhale or smoke.

Indeed, the virtual elimination of lead bromide emissions from auto exhaust has been a major victory for environmentalists in the United States.

Police wear masks to protect themselves from auto exhaust.

He said that carbon monoxide from auto exhausts and other sources remained a threat to health, particularly to fetuses.

Carbon monoxide, a component of auto exhaust, blocks the body's ability to absorb oxygen and can cause heart problems.

A hot breeze that felt like auto exhaust drove many into "cooling centers," senior citizens' gathering places or libraries.

The odor of hot pavement and auto exhaust blew into the car.

He ran a hose from his auto exhaust into the passenger compartment and fired up the motor.

He fought for air and found it foul with ancient auto exhaust.

Reported triggers include tobacco smoke, auto exhaust, perfume, insecticide, new carpet, chorine, and countless others.