ER-L & ER-M Description
Why these sediment quality criteria?
These statistical guidelines, defined by NOAA, are based on large datasets
that include a range of sediment types and organisms to define toxicity.
Therefore, the concentrations defined as potentially toxic are irrespective
of sediment type and organism. They can be used on non-normalized data.
Effects Range Low (ER-L)
Long, et al (1995) took a large database of sediment toxicity
tests and screened it for samples labeled as toxic by the original investigators.
The lower 10th percentile of these concentrations is the ER-L.
Concentrations below the ER-L are within the defined "no effects range."
Effects Range Median (ER-M)
The ER-M is the median concentration of the database screened
for samples labeled as toxic by the original investigators.
Concentrations between the ER-L and ER-M are within the defined "possible
effects range," and concentrations above the ER-M are defined as the "probable
effects range."
From Long, et al 1995, Environmental Management, Vol 19: 81-97
(NOAA)
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