Table 1 ANODEV table summary of GLMMV models.

GLMMV models were fitted to the response of experimental freshwater benthic communities exposed to selected PPCP low-dose mixtures and sequential analysis of deviance (ANODEV) was performed. MV data used to build each GLMMV include the six community-level metabolic end points measured: F0, the dark-adapted basal fluorescence; F, the light-adapted steady state fluorescence; Ymax, the maximum photosynthetic efficiency of photosystem II (PSII); Yeff, the effective quantum yield of PSII; β-Glu, β-glucosidase; and Phos, alkaline phosphatase. The experiment included two factors: treatment (four levels) and time of exposure (three levels). Treatment levels were as follows: control (n = 5); Mix 16 (n = 3), PPCP mixture 16; Mix 16-4 (n = 3), mixture 16 without the four most important PPCPs from GSA results; and Mix 16/10 (n = 3), mixture 16 diluted 10 times. Time levels were as follows: 24, 36, and 120 hours of exposure for each treatment (n = 4). Therefore, the total number of samples was n = 42. The null hypothesis (H0) for the Wald test is that the reduction in model residual deviance is 0. Res. df, residual degrees of freedom; df diff., degrees of freedom difference added by the sequential inclusion of each term of the model.

GLMMV modelRes. dfdf diff.WaldP (>Wald)
Model 1 (full model): treatment × time
Intercept41
Treatment3836.590.45
Time36213.050.86
Treatment × time30617.160.01**
Model 2 (control only): time
Intercept14
Time12210.030.01**
Model 3 (Mix 16 only): time
Intercept8
Time6215.750.54
Model 4 (Mix 16-4 only): time
Intercept8
Time62162.20.04*
Model 5 (Mix 16/10 only): time
Intercept8
Time6218.180.61

Significance values: *P < 0.05 and **P < 0.01.