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, weeds and molds.
Based on these calculations, we suggest the following definitions for low, moderate, high and very high concentration levels:
|1 – 6499||Low||1 – 4||Low||1 – 14||Low||1 – 9||Low|
|6500 – 12999||Moderate||5 – 19||Moderate||15 – 89||Moderate||10 – 49||Moderate|
|13000 – 49999||High||20 – 199||High||90-1499||High||50 – 499||High|
|>50000||Very High||>200||Very High||>1500||Very High||>500||Very High|
* These mold levels were determined based on outdoor exposure to natural occurring spores in the environment and should not be applied to indoor exposure which may represent an entirely different spectrum of spore types.
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.