Forty-one City air samplers. One hundred forty-six days. Watch the asbestos plume over Lower Manhattan shrink, flare and settle, reading by reading, and read what officials said on the days it flared. Every figure is New York City’s own, from the records it released for the 25th anniversary.
Each dot is one of the City’s samplers. The surface between them is an estimate: each day’s readings, blended by distance, so the eye can follow where the air was over the standard and where it wasn’t. Red is over 0.01 fibers per cubic centimeter. Blue-grey is under it. Nothing is drawn where no sampler was close enough to say.
Press play or drag the day. Switch to Days over for a still of how many days each location read over the standard, or Under for good for the date each location last read over it.
The three zone chips are the City’s own: Z the restricted zone, E the edge of it, P the streets open to the public.
Method: a Gaussian distance kernel (σ 170 m) blends the readings present on each day; a location without a sheet that day carries its last reading forward for at most three days, then drops out. Non-detects are drawn as zero. The surface is a visual aid, not a measurement: the samplers are the data, the fill between them is an estimate. Positions are digitized from the City’s own location map (±25 m).
Forty-one rows, one per location, grouped by the City’s zones. One hundred forty-six columns, one per day. Every red cell is a day a City sampler read over the standard. Empty cells are days with no sheet for that location. Hover any cell for the number.
The red is dense in September, thins through October, and comes back in two bursts: December 3–4, when seven locations flared in one day, and December 20, the restricted zone’s last. A dashed line marks day 100.
Week by week, the share of the City’s asbestos readings that came in over the standard. Six in ten in the first week. A third in the second and third. About one in a hundred by the seventh week, then a long tail of flares that did not end until the last week of January.
The line is the City DEP’s daily sheets: every reading, detects and non-detects alike, so the share is a real rate.
The small panels are the EPA’s own draft tables and the DEP’s December extended-network sheets. The EPA tables report the readings the agency chose to tabulate, so they are shown as counts, not rates.
Eight dated statements from the City’s own files, each set beside the City’s asbestos readings for that day. The statements are quoted from the documents in the portal; the numbers are the DEP sheets for the same date.
The EPA statements addressed the general public and its own monitoring; the DEP sheets include samplers inside the restricted zone where only workers were. That is why each entry says how many of the day’s exceedances fell in the public zone.