Guy Robinson stands underneath two monitors on West 41st Street, next to the New York Times. Photo by Patrick Verel

If you want to know what kind of pollen is drifting around outside, it’s not that hard to fashion a collection device out of a Frisbee, a jar, and some glycerol.

But to help Kate Weinberger track the pollen levels of 45 locations around New York City, Guy Robinson, Ph.D., needed to come up with something different.

Robinson, a lecturer of biology at Fordham College at Lincoln Center, has monitored pollen levels at the Lincoln Center campussince 2009, when Fordham’s pollen monitoring was expanded from a single station at the Louis Calder Biological Field Station. In April, he started tweeting his weekly counts at @FordhamPollen.

Weinberger, a Ph.D. candidate at Columbia University’s School of Public Health, sought out Robinson to help her develop a project to systematically measure how pollen is dispersed around the five boroughs.

Unlike the monitors that Robinson deploys on the roof of Fordham Law School and the Calder Center, these had to be compact enough to piggyback on the 150 light poles where the Department of Health maintains air pollution monitoring equipment. The design mimics the way that pollen gets trapped in lake floors and bogs.

“We needed a design that’s not nearly so bulky. It had to be compact and be able to be strapped to a pole. So we just took a screw end cap, and a slip cap for schedule 40 PVC piping, which you can get a hardware store, and is quite thick and sturdy,” Robinson said.

His final version looks a little like a squat cocktail shaker with a hat. The screw that attaches the bottom to the carrier also connects to a mounting brace, allowing for easy removal. Weinberger installed the first ones in late February and early March; they will be taken down for analysis in December.

The installation followed a successful pilot project that Weinberger ran from August through December at ten locations. What made the pilot intriguing for Robinson was the fact that at some locations, even when ragweed was observed nearby, very little of the plants’ pollen accumulated in the trap. Robinson attributed this to the vagaries of air currents, which are influenced by structures big and small.

“It’s not always as easy to predict, but the detectors can pick up what people are actually exposed to,” he said.

“Even if theoretically, we should say ‘This is going to be a high exposure site,’ it doesn’t necessarily turn out that way.”

One of Robinson’s pollen traps, ready to be mounted to a pole. Photo by Patrick Verel

Pollen counts have not been undertaken on a scale of this size since 1935, when the Works Progress Administraion (W.P.A.) organized a city-wide survey of air pollution. And while modern day New Yorkers do not have to worry about the amount of coal dust they inhale the way previous generations did, they are afflicted by asthma and allergies, often in geographically distinct ways.

Asthma has been found to be more prevalent in poorer communities, although Robinson said he’s not convinced that pollen plays a significant role in that difference.

“We had a monitor at the South Bronx, and we ran it concurrently with several others, including one right here at Lincoln Center, but we found little difference in the pollen influx among these sites. There was a bit of a change in the composition, mainly different tree types, but that’s it,” he said.

“Our main contact at the Department of Health said the one parameter that pediatric asthma correlates with is poverty, and all the things that go along with it, like poor medical care and only getting treatment when it’s already an emergency.”

A project like Weinberger’s is still valuable though, to people who suffer from seasonal allergies.

“Are people out in Brooklyn, like those near the coast, really getting exposed to what we’re reporting to the clinics, the media and everybody else? Is this really what they’re getting exposed to? In one sense, yes, the flowering times of all these plants don’t change that much,” Robinson said.

“But from day to day and from neighborhood to neighborhood, there could be a lot of variability. That’s what we’re trying to get a handle on now.”