New-car smell can pose serious health risks, according to a new study.

Researchers at Harvard University and the Beijing Institute of Technology tested the air inside new vehicles and discovered high levels of chemicals linked to cancer.

The study, published last week in the journal Cell Reports Physical Science, found formaldehyde levels 35 percent higher than Chinese national safety standards and acetaldehyde levels more than 60 percent higher than Chinese standards.

The familiar smell associated with newly built vehicles is produced by off-gassing of plastics and adhesives. Although many Americans enjoy it, the smell is disliked in China and many automakers take measures to neutralize the aroma before selling vehicles there.

The researchers tested vehicles that had been parked outside and sealed for 12 days “under varying environmental conditions.” They found that warm weather resulted in a higher concentration of chemicals in the cabin air but that opening a window could “rapidly reduce” the toxicity.