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

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.

Anthropogenic Transformation of the River Basins of the Northwestern Slope of the Crimean Mountains (The Crimean Peninsula)

“…K o = P 6 + P 5 + P 4 P 1 + P 2 + P 3 (6) where K a -coefficients of absolute tension of the ecological and economic balance of the territory; K o -coefficients of relative tension of the ecological and economic balance of the territory; P 6 -industrial, transport, communications, defense and other disturbed lands, landfills, dumps; P 5 -urban settlements; P 4 ¯arable land, rural settlements; P 3 ¯perennial plantations, pastures, recreational lands, forest lands; P 2 -hayfields, fallow lands, forested lands not used for logging, reserve lands; P 1 -protected areas, water fund lands and other conditionally unused lands. The calculation of the indicators was conducted both for the basin area as a whole and for the grid of hexagonal cells composing the study area.…”

“…More and more attention is being paid to this issue in the world. Various characteristics of anthropogenic impact are studied: microplastic pollution [3,4], pesticide pollution [5,6], oil pollution [7,8], heavy metal pollution [9,10], and land cover change [11,12]. At the same time, some authors suggest using various indicators for a comprehensive assessment of anthropogenic transformation [13][14][15][16][17].…”

Concentration of mercury levels in saliva, milk and hair of nursing mothers in southeastern Iran

“…After preparing the samples for mercury analysis, the instrument was calibrated with a NIST-traceable Hg standard solution (AccuTrace Single Element Standard; AccuStandard Inc., New Haven, CT, USA). Three standard reference materials (SRM, National Institute of Standards and Technology-NIST), namely SRM 1633b (Constituent Elements in coal y ash), SRM 2709 (San Joaquin Soil Baseline Trace Element Concentrations), and SRM 2711 (Montana II soil), each of them analyzed in seven replicates (Dahmardeh Behrooz et al, 2021).Standard solutions of mercury metal were prepared and injected into the device from low to high concentration of 0.03, 0.1, 0.3, 1 and 3 ppm, respectively. After calibrating the mercury analyzer with standard solutions and drawing the calibration curve, 1 ml of each sample was injected into the device.…”

Assessing Water Quality in Rivers Flowing into the Caspian Sea in term of pollution using Water Quality Indices and Remote Sensing indices

“…Investigating the water quality of rivers flowing into the Caspian Sea is of paramount importance because of its unique geopolitical and ecological significance Dahmardeh Behrooz et al (2021). The Caspian Sea is a closed basin, bordered by several countries with distinct geological and geographical features Pietkiewicz (2021).…”