- ● Indicates that the sample was analyzed for all effect-based parameters except micronucleus assay. Ø Indicates that the sample was analyzed for Nrf2 activity, but not the other parameters. MN indicates that the sample was analyzed in the micronucleus assay. The two samples from November 2022 were collected early and late in the month, respectively. All BAC filters were filled with used activated carbon from full-scale filters that had been in use for 10–15 years and expected to have no remaining adsorptive function