The deodorants, perfumes and soaps that keep us smelling good are fouling the air with a harmful type of pollution — at levels as high as emissions from today’s cars and trucks.

That’s the surprising finding of a study published Thursday in the journal Science. Researchers found that petroleum-based chemicals used in perfumes, paints and other consumer products can , taken together, emit as much air pollution in the form of volatile organic compounds, or V.O.C.s, as motor vehicles do.

The V.O.C.s interact with other particles in the air to create the building blocks of smog, namely ozone, which can trigger asthma and permanently scar the lungs, and another type of pollution known as PM2.5, fine particles that are linked to heart attacks, strokes and lung cancer.

Smog is generally associated with cars, but since the 1970s regulators have pushed automakers to invest in technologies that have substantially reduced V.O.C. emissions from automobiles . So the rising share of air pollution caused by things like pesticides and hair products is partly an effect of cars getting cleaner. But that breathing room has helped scientists see the invisible pollutants that arise from a spray of deodorant or a dollop of body lotion.