August 17, 2009
Pollen Count
Trees
1/m3
Grass
1/m3
Weeds 17/m3
NAB:
Reading the Charts
The following Aeroallergen Network calculations are based on the data (per cubic meter) reported
by all certified counting stations for trees, grasses and weeds.
NAB SCALE
TREE
0 Absent
1 - 14 Low
15 - 89 Moderate
90 - 1499 High
>1500 Very High
GRASS
0 Absent
1 - 4 Low
5 - 19 Moderate
20 - 199 High
>200
Very High
WEEDS
0 Absent
1 - 9 Low
10 - 49 Moderate
50 - 499 High
>500 Very
High
These definitions would allow comparison between sites across the country. They are based on ecological
measurements, not health effects. However, assuming dose/response relationships are the same across the country, the definitions
are probably more appropriate than a definition based on local numbers. This does mean that, for some stations, some categories
will never be high.
