Integrated Risk Assessment of Herbicides and Fertilizers in Agricultural Drainage Systems Using Multivariate Environmental Modeling

Abstract

Agricultural intensification has significantly increased the application of herbicides and fertilizers,
resulting in the widespread occurrence of agrochemical contaminants in agricultural drainage systems.
These contaminants pose serious risks to aquatic ecosystems, water quality, and human health due to
their persistence, mobility, and potential toxicity. The present study aimed to evaluate the integrated
environmental risks associated with herbicide and fertilizer contamination in agricultural drainage
networks using chemical analysis and ecological risk assessment models. Water samples were
collected from multiple drainage locations across different seasons to assess spatial and temporal
variations in contaminant levels. Target herbicides, including atrazine, glyphosate, and 2,4-
dichlorophenoxyacetic acid (2,4-D), were analyzed using High-Performance Liquid Chromatography
(HPLC), while nutrient concentrations such as nitrate, ammonium, and phosphate were determined
using spectrophotometric techniques. Risk assessment tools, including Hazard Quotient (HQ),
Pollution Load Index (PLI), and Ecological Risk Index (RI), were applied to evaluate contamination
severity and ecological risks. The results indicated elevated contaminant concentrations in downstream
locations, particularly during monsoon seasons due to intensified runoff. High phosphate levels and
moderate herbicide residues were identified as major contributors to eutrophication and ecological
stress. Overall, the study highlights the importance of integrated monitoring approaches for sustainable
agricultural management and environmental protection.