I was impressed to see this recent New York Times ‘heads-up’ featuring a fellow chemical engineer from University of Minnesota, Chuck McGinley, who operates a lab just a few miles down the road from my home in Stillwater, MN. They got a great shot of Chuck using his Nasal Ranger to sniff around in South St. Paul, last summer. That area of the Twin Cities has emitted unpleasant odors throughout my lifetime—it being founded as a regional stockyard and still the home of a stinky rendering plant.*
“Some of the most recognizable and potent odors, like hydrogen sulfide (think rotten egg) can be sensed at even the tiniest concentrations, like 1 part per billion. ‘If you were to map out the distance from New York to Los Angeles, 1 part per billion would account for only a few inches along that route’.”
– New York Times quoting Professor Jacek Koziel, Iowa State
It turns out that there’s a surprising amount of science behind detecting and characterizing odors as detailed in this blog by St. Croix Sensory, where Chuck works as Technical Director. Unfortunately, the main focus of these experts on smelling must, by necessity, be on detection of ‘off-odors’, such as that emanating from kitty litter (yuk!). If I had a Nasal Ranger, it would be aimed at a rose garden or at a barbecue grill, that is, “on” odors.
PS: Sadly, the current coronaviruses not only cause the loss of smell but also a perverse reversal of olfactory senses called “parosmia.” This can make savory foods smell like rotting sewage as noted in a 1/18/22 report by CNBC on how Covid can turn kids into ‘fussy eaters’ if it changes their sense of smell.
*As reported in 11/22/21, Des Moines Register, ‘You can’t escape it’: Stench spoils downtown experience for some in Des Moines , the residents of South St. Paul won a settlement in 2020 for $750,000 for putting up with the off-putting odors.