I stumbled upon this, and several others here.
Maple Syrup Smell is Really Bio-Weapons Testing
The first time the sweet fragrance wafted through the city in the fall of 2005, penetrating every stank corner, infiltrating every orifice—even overpowering the locker room B.O.—we tried to ignore it. “I thought I was having a stroke, and this was some phantom scent,” a guy admitted sheepishly after it turned out to be experienced by everyone with olfactory abilities in Manhattan, some locales in northeastern New Jersey and as far as Queens and parts of Brooklyn. Could it be a sweet-smelling dirty bomb? A syrup slick on the Hudson? We were later assured it was just some sort of leak from a factory that produces chemical scents, but the smell has turned up several times over the years—most recently this past May. Turns out it’s not so harmless after all but is a form of bio-“weapons” testing. The CIA has been testing New Yorkers with the smell of American breakfast over the years in an attempt to determine if it will pass unnoticed in Middle Eastern countries who don’t traditionally dine on pancakes or waffles during brunch (see halal carts). We’re still unsure if it’s simply a means of distraction or actually has some sort of paralyzing effect. As soon as the pigeons start dropping dead—the New York version of a canary in a coal mine—it’ll probably be too late.
Kind of reminds me of the time I was driving down the highway and a weird chemical smell came into the car. All of a sudden I started coughing and kept it up for 15 minutes, long after I passed the source of the smell. I was starting to wonder if I’d been gassed… aaaaghh! Chemtrails!