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. 2018 Jul 2;84(14):e00287-18. doi: 10.1128/AEM.00287-18

TABLE 2.

Spearman's rank correlation between microbial indicators and environmental parameters, chemical tracers, and land use categoriesa

Correlation parameter Correlation coefficient
E. coli (MPN/100 ml) Enterococcus spp. (MPN/100 ml) PMMoV by qPCR (GC/100 ml) PMMoV _contig1 PMMoV_ reads mapped to reference genome
Microbial indicators
    E. coli (MPN/100 ml) 0.554 0.599
    Enterococcus spp. (MPN/100 ml) 0.859 0.588 0.541
    PMMoV (GC/100 ml) 0.612 0.549 0.788 0.888
Environmental parametersb
    Temp (°C) −0.344 −0.426 −0.209
    pH 0.432 0.394
    EC 0.521 0.588 0.394 0.565 0.543
    TDS (ppm) 0.507 0.585 0.358 0.516 0.495
    Salinity (PSU) 0.515 0.595 0.371 0.525 0.518
    DO (ppm) −0.345 −0.333 −0.440 −0.356
    Turbidity (PFU) 0.503 0.572 0.379
Chemical tracers
    ACE (ng/liter) 0.590 0.638 0.658 0.721 0.549
    ACT (ng/liter) 0.631 0.727 0.473 0.638 0.642
    CBZ (ng/liter) 0.530 0.717 0.712
    CYC (ng/liter) 0.564 0.590 0.609 0.811 0.792
Land use categories
    Residentialb 0.421 0.412 0.678 0.728 0.608
    Urban 0.497 0.503 0.473
    Green −0.588 −0.585 −0.702 −0.757 −0.705
    Weightage 0.583 0.583 0.728 0.766 0.713
a

Only significant correlations are shown (with Bonferroni correction, 2-tailed t test). All correlations were significant at P values of <0.01, except for values in boldface, for which P values were <0.05. Abbreviations: TDS, total dissolved solids; DO, dissolved oxygen; PSU, practical salinity units; ACE, acesulfame; ACT, acetaminophen; CYC, cyclamate; CBZ, carbamazepine.

b

For environmental parameters oxidation-reduction potential [ORP] (in millivolts), 24-h rainfall and 5-day rainfall (in millimeters), and antecedent dry period (in days) and for land use category “Agriculture,” no significant correlation was found; therefore, these parameters are not included in the table.