Assessment of Pesticide Residue Content in Polish Agricultural Soils

Abstract

Pesticides belong to a group of xenobiotics harmful to humans and wildlife, whose fate and activity depends on their susceptibility to degradation. Therefore, the monitoring of their residue level in agricultural soils is very important because it provides very valuable information on the actual level of soil contamination and environmental risk resulting from their application. The aim of this study was to evaluate contemporary concentrations of organochlorine (OCPs) and non-chlorinated pesticides (NCPs) in arable soils of Poland as an example of Central and Eastern European countries. The results were assessed in relation to Polish regulations, which are more restrictive compared to those of other European countries. The sampling area covered the territory of arable lands in Poland (216 sampling points). The distribution of sampling points aimed to reflect different geographical districts, conditions of agricultural production, and various soil properties. The collected soil samples were extracted with organic solvents in an accelerated solvent extractor (ASE 2000). The OCPs, including α-HCH, β-HCH, γ-HCH, and p,p’DDT, p,p’DDE, and p,p’DDD, were extracted with a hexane/acetone mixture (70:30 v/v) and determined by gas chromatography with an electron capture detector (GC-μECD). NCPs included atrazine, carbaryl, and carbofuran were extracted with a dichloromethane/acetone mixture (50:50 v/v), while maneb was extracted by intensive shaking the sample with acetone (1:1 v/v) and ethylenediamine-tertraacetic acid. The NCPs were identified by a dual mass- spectrometry (GC-MS/MS). The total content of individual OCPs ranged from 0.61 to 1031.64 µg kg−1, while the NCP concentrations were significantly lower, from 0.01 to 43.92 µg kg−1. DDTs were detected in all soils samples (p,p’DDD (23.60 µg kg−1) > p,p’DDT (18.23 µg kg−1) > p,p’DDE (4.06 µg kg−1), while HCHs were only in 4% of the analyzed samples (β-HCH (339.55 µg kg−1) > α-HCH (96.96 µg kg−1) > γ-HCH (3.04 µg kg−1)), but in higher values than DDTs. Among NCPs, higher concentration was observed for carbaryl (<0.01–28.07 µg kg−1) and atrazine (<0.01–15.85 µg kg−1), while the lower for carbofuran (<0.01–0.54 µg kg−1). Maneb was not detected in analyzed soils. Assessment of the level of soil pollution based on Polish regulations indicated that several percentages of the samples exceeded the criterion for OCPs, such as ∑3DDTs (14 samples; 6.5% of soils) and HCH congeners (α-HCH in one sample; 0.5% of soils), while NCP concentration, such as for atrazine, carbaryl and carbofuran were below the permissible levels or were not detected in the analyzed soils, e.g., maneb. The obtained results indicated that residues of the analyzed pesticides originate from historical agricultural deposition and potentially do not pose a direct threat to human and animal health. The behavior and persistence of pesticides in the soils depend on their properties. Significantly lower NCP concentration in the soils resulted from their lower hydrophobicity and higher susceptibility to leaching into the soil profile. OCPs are characterized by a high half-life time, which affect their significantly higher persistence in soils resulting from affinity to the soil organic phase.

Monitoring of DDT in Agricultural Soils under Organic Farming in Poland and the Risk of Crop Contamination

“…These results are partially in line with the outcomes of a previous environmental monitoring programme carried out on arable fields in Poland (Ukalska-Jaruga et al 2020 ). Indeed, 100% of the 216 sampled locations resulted contaminated with DDT, 55% of them contaminated at medium level (according to our classification), and with a wider range (from 0.006 to 0.485 mg/kg), but showing similar average amounts of ΣDDT (0.045 mg/kg) in comparison to the results of the present work (Ukalska-Jaruga et al 2020 ). The comparison is thus suggesting that fields managed according to organic farming practices are contaminated by DDT residues to a lesser extent than other arable areas.…”

“…The detection of DDT in the majority of the monitored soil samples strongly confirms the high persistence of this compound in soil (Lewis et al 2016 ) and a relatively diffused contamination of Polish agricultural soils (Ukalska-Jaruga et al 2020 ), similar to several agricultural areas across many European countries (Silva et al 2019 ). Besides contamination due to the use of DDT as an insecticide, another possible source of this diffused contamination could derive from underground landfills of pesticides (widely known as ‘tombs’) that were created in Poland from 1965 up to the early 1990s where about 200,000 kg of pesticides were buried (Gałuszka et al 2011 ).…”

“…DDT soil contamination in Poland was pointed out in the results of a general monitoring programme (GIOŚ Main Inspectorate of Environmental Protection 2015 ) and confirmed by a previous study (Tartanus et al 2017 ) as well as by a recent survey on arable soils (Ukalska-Jaruga et al 2020 ).…”

“…Furthermore, basic soil conditions have been reported to enhance the transformation of p,p′-DDT into p,p′-DDE (Nash et al 1973 ). Nevertheless, no relationship was found between soil pH and organochloride pesticides residues in the nation-wide monitoring of Polish soils (Ukalska-Jaruga et al 2020 ).

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Residues of Persistent Organic Pollutants (POPs) in Agricultural Soils Adjacent to Historical Sources of Their Storage and Distribution—The Case Study of Azerbaijan

“…Due to the negative environmental impact of POPs, many research projects or monitoring programs at the national or regional level were carried out to determine the content of their residue in soils, especially from rural areas [23,24]. Several studies [4][5][6]16,19,[23][24][25][26][27] characterized the distribution of pesticide residue in soil at the national or regional scale. Despite this, there is still a lack of data from many countries where POPs were emitted, distributed, stored and applied for many years.…”