A man in the U.S. has been awarded US$7.2 million after contracting a lung disease he said was brought on by years of inhaling the artificial butter smell of microwave popcorn.

According to reports, a federal jury found food companies Gilster-Mary Lee Corp., The Kroger Co. and Dillon Companies Inc. liable in a suit brought by Wayne Watson after he developed respiratory problems in 2007.

Watson, a man from suburban Denver, Col., had long claimed that he had contracted “popcorn lung,” a respiratory disease formally known as bronchiolitis obliterans. The disease is associated with inhaling the chemical diacetyl, which is found in popcorn flavouring.

While popcorn lung has been documented in factory workers before, Watson’s was the first reported case of a consumer developing the illness.

Watson said he loved microwave popcorn so much that he would eat two bags a night, breathing in the steam from the freshly opened bags before consuming the snack.

Tests of his home found peak levels of diacetyl fumes matching those found in factories where workers tested hundreds of bags of microwave popcorn per day.

Watson argued that both the manufacturer and the supermarket failed to warn consumers that inhaling the buttery aroma could put them at risk of developing the lung disease.

Lawyers for the companies argued Watson’s respiratory problems were more likely the result of exposure to dangerous chemicals during his years as a carpet cleaner.