NIDCD Investigates the Olfactory Impact of 9/11

April 20, 2010

Attendees of this year’s NIDCD Annual Meeting of the Association for Chemoreception Sciences Conference (April 21-25 at St. Petersburg’s Tradewinds Grand Isle Resort) are in for some unusually fascinating topics. Among the headliners slated for discussion are a newly discovered area of the brain where smell and sound converge (see the Whiff-Guys’ look into Smound) and a study into the long-term olfactory effects of toxic exposure on responders to the 9/11 terrorist attack.

Individuals involved in rescue, recovery, demolition, and clean-up after the World Trade Center disaster on September 11, 2001, were exposed to a complex mixture of airborne smoke, dust, combustion gases, acid mists, and metal fumes. The impact of this exposure on responders’ upper and lower respiratory function has been well documented, but little is known about its impact on their sensitivity to odor and irritants. Researchers supported by NIDCD and the Monell Chemical Senses Center studied 102 individuals who worked or volunteered at the WTC site by administering a battery of tests to measure sensitivity to odors, which are perceived by the olfactory receptors high in the nasal cavity. They also measured irritants, which are perceived by the trigeminal nerve, a nerve in the head that senses touch, temperature, and pain. The researchers found that, even two years after exposure, the loss of olfactory and trigeminal sensitivity was significantly greater in the exposed group in comparison to individuals who weren’t exposed. Thirty to 40 percent of the WTC group was significantly impaired in their ability to detect odors, while 75 percent were either partially or completely impaired in their ability to sense irritants. The most profound loss of sensitivity was found in people caught in the dust cloud after the buildings collapsed. The nose’s ability to sense potentially harmful irritants in the air is part of an early warning system that protects the respiratory tract from toxic exposure.