Table 3.
Eigenvalues, percentage, and total variance of factors obtained from PCA analysis of chemical and biologic parameters of the land snail H. aspersa.
| Axis | Eigen-value | Percent variance | Cumulative variance | Contaminant/biomarker | Axis 1 (PC1) | Axis 2 (PC2) | Axis 3 (PC3) | Axis 4 (PC4) |
|---|---|---|---|---|---|---|---|---|
| Cu | 0.790705† | 0.539160 | 0.165378 | 0.238207 | ||||
| PC1 | 17.70858 | 59.02861 | 59.0286 | Pb | 0.715212† | 0.500997 | −0.542411 | −0.110842 |
| Cd | 0.313324 | 0.752549† | −0.005360 | −0.579197 | ||||
| PC2 | 6.91878 | 23.06260 | 82.0912 | Cr | 0.997280† | −0.008272 | −0.070683 | −0.019186 |
| Ni | 0.784127† | 0.126048 | −0.399784 | −0.457635 | ||||
| PC3 | 3.02699 | 10.08994 | 92.1812 | Mn | 0.900092† | −0.161097 | 0.377186 | 0.147014 |
| Fe | 0.595581 | −0.764651† | 0.238275 | 0.061795 | ||||
| PC4 | 2.34565 | 7.81885 | 100.00 | Zn | 0.917575† | 0.341097 | 0.113295 | 0.169924 |
| Naphthalene | 0.922264† | 0.331423 | 0.198704 | 0.010255 | ||||
| Fluorene | 0.920068† | −0.215378 | 0.108228 | −0.308827 | ||||
| Phenanthrene | 0.516094 | −0.722838† | 0.174026 | −0.561636 | ||||
| Anthracene | 0.913881† | −0.204078 | −0.170257 | −0.306899 | ||||
| Fluoranthene | 0.475363 | 0.353075 | 0.626410 | 0.506930 | ||||
| Pyrene | 0.846901† | −0.382454 | −0.355005 | −0.102269 | ||||
| Total lmw PAHs | 0.946469† | 0.257876 | 0.190068 | −0.039624 | ||||
| Total hmw PAHs | 0.920453† | 0.156682 | 0.158835 | 0.320918 | ||||
| Total PAHs | 0.949531† | 0.250606 | 0.188443 | −0.008797 | ||||
| MT | 0.948667† | 0.145167 | 0.175937 | −0.219096 | ||||
| AOX | 0.693021† | −0.716261† | 0.065546 | 0.048953 | ||||
| EROD activity | 0.158404 | −0.108723 | −0.921801† | 0.336705 | ||||
| ECOD activity | 0.786172† | −0.549701 | −0.281625 | 0.021227 | ||||
| Catalase | 0.939616† | −0.299041 | −0.163484 | 0.031132 | ||||
| GR | 0.867874† | 0.105793 | 0.137845 | 0.465404 | ||||
| GST | −0.354490 | −0.917779† | 0.134982 | 0.117469 | ||||
| GPx | 0.309859 | 0.901686† | −0.284869 | 0.098988 | ||||
| Total glutathione | 0.171919 | 0.840484† | −0.437953 | 0.268751 | ||||
| TOSC (ROO•) | 0.865488† | −0.434499 | −0.099349 | 0.228628 | ||||
| TOSC (HO•) | 0.821282† | −0.464366 | −0.320765 | 0.083491 | ||||
| Lysosomal NRRT | −0.555389 | −0.556256 | −0.400064 | 0.471244 | ||||
| DNA TD | 0.947211† | −0.181370 | −0.170131 | 0.202365 |
Abbreviations: PC, principal component; PC1, axis 1; PC2, axis 2; PC3, axis 3; PC4, axis 4. Factor loadings are given for each parameter.
†
Values ≥ 0.7.