Assessing Diazinon Pollution in the Three Major Rivers Flowing into the Caspian Sea (Iran)

Reza Dahmardeh Behrooz,Abbas Esmaili-Sari,Magdalena Urbaniak,Paromita Chakraborty

doi:10.3390/w13030335

Abstract

The aim of this study was to investigate the seasonal and spatial variations in the concentrations of a widely used organophosphorous pesticide (OPP), diazinon, and the associated risk posed by this OPP in the surface water from the three largest rivers located in the northern province of Iran: the Haraz, the Talar and the Babolrood rivers. These rivers are located in the agriculture province of Mazandaran, and are exposed to high doses of organophosphorus pesticides, especially diazinon. The concentration of diazinon was determined using gas chromatography, while the potential risk posed by diazinon was elucidated using a Risk Quotient (RQ) calculated for general (RQm) and worst-case (RQex) scenarios. The obtained results demonstrated that the average diazinon concentrations ranged from 41 ± 76 ng/L in the Talar River and 57 ± 116 ng/L in the Haraz River, to 76.5 ± 145 ng/L in the Babolrood River, with a significant difference noted between summer and autumn seasons for all three rivers. For some stations, the concentration of diazinon is higher than the standard guidelines of Australian/New Zealand Guidelines for Fresh and Marine Water Quality (FMWQ) and the United States Criteria Maximum Concentration (CMC). The calculated RQs indicated a medium risk of diazinon, RQm = 0.73 and RQex = 2.27, in the Talar River; RQm = 1.02 and RQex = 2.49 in the Haraz River; and RQm = 1.35 and RQex = 4.54 in the Babolrood River. The overall exposure of diazinon was defined to have a high risk (RQm and RQex > 1); however, the summer sampling revealed a high risk (RQm and RQex > 1), while the autumn had a medium risk (RQm and RQex < 1). The obtained results revealed not only elevated concentrations of diazinon in the studied rivers but most importantly the high risk posed by this OPP for the aquatic organisms and the wellbeing of the whole river ecosystem. The current study showed that development and implementation of appropriate standards and regulations toward diazinon in countries such as Iran are required to reduce the pollution levels and risks related to elevated concentrations of the studied pesticide.

Highlights

IntroductionAround 2,540,117 tons of pesticides are consumed every year across the world to protect crops against pests and diseases, to shelter human from insect and pest bites, and to preserve agricultural products in warehouses (commercial applications) and in homes [1]
Considering the above, our objectives were to (i) evaluate the pollution status of the three main rivers in Iran, the Haraz River, the Talar River and the Babolrood River, in terms of the diazinon concentrations; (ii) demonstrate the seasonal and spatial changes in the pesticide concentrations; and (iii) assess the potential risk aquatic organisms associated with the presence of the pesticide in the three river ecosystems
River was observed in spatial distribution of diazinon, our results showed that more than 44% of Regarding spatial distribution of diazinon, our results showed that more

Summary

Introduction

Around 2,540,117 tons of pesticides are consumed every year across the world to protect crops against pests and diseases, to shelter human from insect and pest bites, and to preserve agricultural products in warehouses (commercial applications) and in homes [1]. Such a high usage of pesticides can threaten the health of consumers in addition to the environment [2,3]. Caterpillars, moths, butterflies, various worms, locusts, grasshoppers and scale in pastures, orchards, vegetables and field crops

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