Jaiswal et al. 2022 — Heavy metal contamination across the full Yamuna river stretch with fuzzy-logic health risk assessment
This study reports concentrations of eight metals (As, Cd, Cr, Cu, Ni, Pb, Fe, Zn) measured at 13 sites distributed across the entire 1,376 km Yamuna river in Uttar Pradesh, India, over seven years (2011–2018) in both monsoon and non-monsoon seasons. Atomic absorption spectrometry (Varian AA240 Zeeman) was used for analysis. Except for iron, mean concentrations of all metals were within WHO and BIS drinking water limits in both seasons; children’s hazard indices exceeded 1 at most sites in non-monsoon season, indicating non-carcinogenic risk from cumulative multi-metal exposure. The paper introduces a fuzzy-logic hazard index (FHI) as a complement to the conventional hazard index, demonstrating that uncertain and imprecise data can be incorporated systematically into health risk frameworks.
Key numbers
Monsoon season concentrations (µg/L), n=13 sites:
| Metal | Min | Max | Mean |
|---|---|---|---|
| As | 0.79 | 6.21 | 2.55 |
| Cd | 0.072 | 0.875 | 0.30 |
| Cr | 0.385 | 18.28 | 7.45 |
| Cu | 1.80 | 19.47 | 5.37 |
| Ni | 1.97 | 10.98 | 4.79 |
| Pb | 0.485 | 3.95 | 1.80 |
| Fe | 26.9 | 412.0 | 117.4 |
| Zn | 4.93 | 279.3 | 45.3 |
Non-monsoon season concentrations (µg/L):
| Metal | Min | Max | Mean |
|---|---|---|---|
| As | 0.893 | 4.660 | 3.23 |
| Cd | 0.110 | 1.776 | 0.62 |
| Cr | 2.429 | 10.300 | 5.12 |
| Cu | 2.518 | 8.713 | 6.14 |
| Ni | 3.078 | 12.701 | 5.41 |
| Pb | 0.885 | 6.808 | 3.21 |
| Fe | 47.6 | 303.3 | 145.3 |
| Zn | 13.35 | 459.95 | 192.0 |
Non-monsoon concentrations generally higher than monsoon for most metals (except Cr), attributed to dilution during monsoon season. Highest Pb levels found at Delhi, Mohana, and Agra districts. Highest Cr at Pratappur, Agra, Hamirpur, Etawah.
Children hazard index (HI) exceeded 1 at most sites in non-monsoon season; adult HI remained below 1. Fuzzy-logic hazard index (FHI) showed similar patterns.
Methods (brief)
Water samples collected from 30–50 cm depth at center of river using grab method; 1 L volume; filtered, acidified with HNO3, preserved at 4°C. Acid digested with 20 mL concentrated HNO3 at 100°C to dryness; digests diluted and filtered (Whatman no. 42). Atomic absorption spectrometry (Varian AA240 Zeeman, USA). Standard operating procedures, reagent blanks, spiked controls, certified stock solutions from Merck (Germany). PCA and hierarchical cluster analysis used for source identification. Fuzzy-logic Mamdani-type model with Gaussian membership functions applied to derive FHI alongside conventional hazard quotient (HQ) and hazard index (HI). No speciation performed; total arsenic only; no distinction of inorganic vs. organic arsenic fractions.
Implications
Certification: River water used for irrigation of food crops creates a pathway for heavy metal uptake into agricultural produce. Yamuna basin supplies >90% of water demand for several districts including Delhi. Cd, Cr, Ni, and Pb concentrations in river water are relevant inputs for supply-chain screening where agricultural ingredients are sourced from Yamuna-adjacent farmland in India.
Courses: Demonstrates seasonal variability in surface water heavy metal concentrations; dilution effect of monsoon precipitation on most metals is a useful teaching case. Multi-metal co-exposure and cumulative hazard index calculation illustrates the standard HRA framework for waterborne metals.
App: River water matrices are upstream of the food supply but not direct food-matrix data; relevant for context on supply-chain risk from Indian agricultural regions rather than direct ingredient concentration data.
Microbiome: Not directly applicable; this paper measures water, not gut-relevant matrices.