SEASONAL VARIATION AND ECOLOGICAL RISK ASSESSMENT OF HEAVY METAL CONTAMINATION IN SURFACE WATERS OF THE GANGES RIVER (NORTHWESTERN BANGLADESH)
Bibliographic record
Abstract
The present work is evaluating the seasonal variation in metal pollution and the ecological risk indices of surface water of the Ganges River (Northwestern Bangladesh).Concentrations of Cr, Pb, Ni, Cd, As, Cu and Zn in surface water samples were determined by Flame Atomic Absorption Spectrophotometry.The level of heavy metals did not exceed the permissible limits of drinking water according to Department of Environment (DOE), Bangladesh and World Health Organization (WHO).Only Cr and Cd concentrations exceeded the permissible limits for aquatic life standards of the United States Environmental Protection Agency (USEPA) and Canadian Council of Ministers of the Environment (CCME).The heavy metal pollution index (HPI) showed that the seasonal contamination level followed the order: summer (136.13 (DoE), 220.72 (WHO) and 163.95 (USEPA, CCME)) > winter (57.38 (DoE), 91.36 (WHO) and 72.81 (USEPA, CCME)) > monsoon (16.49(DoE), 25.36 (WHO) and 19.44 (USEPA, CCME)).Additionally, the HPI value crossed the critical index value (100) for drinking and aquatic life standard during summer season.The metal index (MI) value showed that the water was moderately (DoE), strongly (WHO) and seriously affected (USEPA, CCME) by heavy metals during summer season (3.15, 4.79 and 9.99 according to DoE, WHO and USEPA, CCME, respectively).While the ecology of the river is presently at low risk, this study suggests taking necessary measures to prevent the present pollution rate of contaminants from rising in the future.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".