Assessment of pesticide contamination in Akkar groundwater, northern Lebanon

Abstract

According to its high production and value, Akkar is considered as the second agricultural region in Lebanon. Groundwater constitutes the principal source of water in Akkar including drinking water of local inhabitants in Akkar. As such, the contamination of groundwater by organic pollutants can impact directly the population health. In this study, we evaluated the contamination status of groundwater in this region. Three classes of pesticides including 19 organochlorine (OC) pesticides, 8 organophosphorus (OP) pesticides, and 6 organonitrogen (ON) pesticides were monitored in 15 groundwater samples collected from different villages on the Akkar plain. Samples were extracted by using solid phase extraction (SPE) and analyzed by gas chromatography coupled with mass spectrometry (GC-MS). The results showed high contamination of Akkar groundwater by OCs with levels that can reach 58.9 μg/L. They were detected in the majority of the sample and represent 95-100% of ∑pesticides. Our results showed the recent use of these molecules with an average level of 0.3 and 0.39 μg/L for ∑HCHs and DDTs, respectively. Their concentrations were higher than those observed in the same region in 2014 and other regions elsewhere. OPs were also detected at high levels and among them, methylparathion was the predominant OP detected (44.6 μg/L). For ONs, lower levels were measured in all samples with a mean value of 5.6 μg/L. As a conclusion of this work, groundwater on the plain of Akkar was remarkably contaminated by the studied pesticides; indefinitely, more efforts should be taken to manage the pesticide use in this region, assess, and reduce their effects on human health. In the future, the application of organic farming can be a great solution to the groundwater contamination problem.

Suggested policy and legislation reforms to reduce deleterious effect of pesticides in Lebanon

“…(2017) on apiaries in North Lebanon, 10 pesticides were detected with a total level up to 1753.92 (ng g-1) in collected honey samples among which long time banned organochlorines, penconazole, pyraclostrobin, and diflufenican, the latter was never registered for use in Lebanon ( Al Alam et al., 2017 ). Furthermore, soil tests in Aakkar regions revealed the presence of organochlorines pesticides, though banned years ago ( Helou et al., 2019 ), in addition to heavy metals, mainly Nickel and a moderate pollution with Cadmium ( Chaza et al., 2018a b ). In another study conducted later that year, tests on groundwater samples in Aakkar revealed the presence of organochlorines, with levels reaching up to 58.9 μg/L, exceeding the limits set by the European Union, in addition to other organophosphates, mainly methyl-parathion, with levels ranging from 18.2 μg/L to 98.29 μg/L ( Chaza et al., 2018b a ).…”

“…Furthermore, soil tests in Aakkar regions revealed the presence of organochlorines pesticides, though banned years ago ( Helou et al., 2019 ), in addition to heavy metals, mainly Nickel and a moderate pollution with Cadmium ( Chaza et al., 2018a b ). In another study conducted later that year, tests on groundwater samples in Aakkar revealed the presence of organochlorines, with levels reaching up to 58.9 μg/L, exceeding the limits set by the European Union, in addition to other organophosphates, mainly methyl-parathion, with levels ranging from 18.2 μg/L to 98.29 μg/L ( Chaza et al., 2018b a ). This last study, also demonstrated a recent use of dicofol (2,2,2-trichloro-1,1-bis(4-chlorophenyl)ethanol), in which DDT was only an impurity, by, calculation of (DDD + DDE)/DDT ratios that were lower than 0.5 and 2,4′-DDT/4,4′-DDT ratios that ranged from 0.81 to 2.31, and by comparing levels with a 2 years older study ( El-Osmani et al., 2014 ).…”

Environmental Occurrence, Toxicity Concerns, and Degradation of Diazinon Using a Microbial System

“…Because of the trend towards large-scale usage of pesticides, the pollution sources of pesticides are not only limited to the intensive use of pesticides in urban areas but can also be linked to the chemical industry and farmland ( Liu et al, 2015 ; Wee et al, 2016 ; Zainuddin et al, 2020 ). Pesticides and their residues (metabolites) can condense into rain through surface runoff, soil leaching and transpiration, be deposited on the surface or in tissues of plants, enter drinking water and groundwater, and eventually reach nontarget organisms, including humans ( Palma et al, 2014 ; Chaza et al, 2018 ; Sumon et al, 2018 ; Villiot et al, 2018 ; Triassi et al, 2019 ). The levels of diazinon in several water sources have been found to exceed the standard, and the treatment processes used in diazinon agrochemical plants and sewage treatment plants still cannot fully degrade pesticide residues ( Fadaei et al, 2012 ; Arellano-Aguilar et al, 2017 ; Hamad, 2020 ).…”

Investigating Atrazine Concentrations in the Zwischenscholle Aquifer Using MODFLOW with the HYDRUS-1D Package and MT3DMS

“…Uncontrolled and improper pesticide applications have led to their presence in the environment exceeding permissible limits [1][2][3][4]. It has been observed that groundwater is most affected by pesticide applications in agricultural fields [5][6][7][8][9]. The pesticide contamination of groundwater is generally assessed through pesticide monitoring programs (e.g., [10][11][12]).…”