Ned Ostojic's nose has led him to sites that range from odd to repugnant. He has inhaled the air of tuna canneries in American Samoa, whiffed gooey kibble at pet-food factories in Canada and sniffed sewage tanks in Brooklyn. Worldwide, there are only a handful of people like him: experts at diagnosing offensive odors. His clients are usually desperate to eliminate a stench that bothers neighbors or presents a hazard to workers. Trained as an analytical chemist, his job is to find the source of a smell and then figure out how to fix it.
Scientific thinking on olfaction posits that there are hundreds of odor receptors in the human nose, each responsible for detecting different odor molecules. Smells are the perception of combinations of these molecules and as such are tricky to manipulate and record. The act of smelling itself has long been an “orphan sense,” especially compared with a more dominant faculty such as sight, Ostojic says. “We can represent the whole world on our TVs using just three colors, we can see to the end of the observable universe and we can see a single atom,” he asserts, but smell remains elusive.
As a result, Ostojic approaches his job with a mix of science and art. In the field, he employs an olfactometer with an aggressive brand name: Nasal Ranger. Held up to his face, it works like a gas mask at first. Once his nose adjusts to that confined odorless environment, Ostojic adds controlled amounts of the surrounding air to map the intensity and spread of a stink.
Thousands of New Yorkers can thank Ostojic and his Nasal Ranger for rendering the city's largest sewage treatment plant scent-free (above). “We had a horrendous record,” says Jim Pynn, who recently retired as the superintendent of Newtown Creek Wastewater Treatment Plant in Brooklyn. “We had such a disgusting, putrid smell that even I was left to retch by some of the odors in the plant.” In this case, everyone knew where the stench was coming from: aeration tanks. So Ostojic developed a way to cover the tanks and then ventilate the fetid air through wide cylinders of porous carbon, which absorbs odor. Now the site smells neutral enough to serve as a shooting location for movies, such as Salt, starring Angelina Jolie; film crews have had no idea they were shooting at a sewage plant, Pynn says. “When someone has to ask me what goes on here, we've met out goal,” says Pynn, who calls Ostojic a “silent hero.”
Ostojic's next projects include mapping the odor footprints of paint fumes at car factories in Michigan and of decomposing garbage buried in landfills in Kentucky. Advances in gas chromatography now allow him and other engineers to separate odor compounds and quantify them, but those data shed no light on whether people will tolerate particular nasal assaults. After all, an odor only becomes a problem when people complain about it. “It all leads back to the human nose,” Ostojic says.