New York : Inhaling fumes while micro waving popcorn appear to cause harm, a leading lung expert has warned.
The food-flavouring fumes contain a butter-flavour chemical called diacetyl used by some of the companies who produce microwave popcorn. This chemical when inhaled appears to cause this harm, the expert said.

A man complained of a worsening cough and increasing shortness of breath. Lung function tests and imaging studies showed he has a lung disorder -bronchiolitis obliterans- obliteration of the tiny airways in the lung.

His only exposure was to the two or more bags of microwave popcorn that he consumed every day. Lung expert Cecile Rose took a team to the man's house and tested the air while micro waving some popcorn.

Air levels of diacetyl were similar to those in the area of a microwave popcorn factory where workers were affected, Rose and team found.

Bronchiolitis obliterans is a rare disease, first seen in 1985 in workers in food-flavour factories. In 2002, the disease was seen in workers making microwave popcorn in particular.

There have been many other reports since then, with at least three deaths and many patients awaiting lung transplants, reported the online edition of health magazine WebMD.

Many foods other than popcorn contain diacetyl. There is no indication that eating these foods is dangerous.

But breathing fumes containing diacetyl appears to be very dangerous, Rose, an associate professor of pulmonary medicine at the University Of Colorado School Of Medicine said.

Rose reported the case in a July 18 letter to the US Food and Drug Administration (FDA) and other organizations such as Centre for Disease Control and Prevention (CDC), Environmental Protection Agency (EPA) and Occupational Safety and Health Administration (OSHA). None of these agencies have yet issued a public health alert. (With Inputs from ANI)