Title: Monitoring of pesticide content in arable soils of Poland

Biography:

Aleksandra Ukalska-Jaruga is currently in the Institute of Soil Science and Plant Cultivation, Poland.

Abstract

Over the last 20 years, the use of pesticides in Poland significantly increased from 8848 to 24006 tons. The highest level of consumption was recorded for herbicides and fungicides, respectively 12190 and 7737 tons in 2019, which accounted for 83% of its total usage (Statistical Yearbook of Agriculture 2012-2019). The presented data show that the use of these substances in Poland is systematically growing, and people are increasingly exposed to the residues of these compounds in food products. Despite the occurrence of many threats and the possibility of including harmful substances in the biological chain, pesticides are still the most effective method of combating pathogens. Therefore, constant monitoring of the pesticide residue level in soils is necessary, and the information on the actual level of soil environment contamination by these toxic compounds is crucial for the proper assessment of the risk resulting from their application.

The aim of the research was to assess the content of pesticide residues in agricultural soils of Poland according to Polish Regulation (Dz.U. 2016 poz. 1395).

Soil was collected from 216 sampling points (0-25 cm) located throughout the country. The samples were dried, sieved, ground, and then subjected to extraction with organic solvents. Organochlorine pesticides: α-HCH, β-HCH, γ-HCH (Lindane), Aldrin, Dieldrin, Endrin, and 4,4'DDT and its metabolites: 4,4'DDE and 4,4'DDD were extracted in the Accelerated Solvent Extractor (ASE200) with a hexane mixture / acetone (50/50 v / v), purified on deactivated silica gel and determined by gas chromatography with the electron capture detector (GC-μECD). Non-chlorine pesticides such as: Atrazine, Carbaryl and Carbofuran were extracted in ASE200 with a dichloromethane / acetone mixture (50/50 v / v) and purified on deactivated silica gel. Maneb was extracted from the soil by shaking the sample mixed with ethyl acetate. Non-chlorine pesticides were determined using a dual mass spectrometry (GQ QQQ Agilent System) gas method operating in MRM (Multiple Reaction Monitoring) mode.

The research indicated that Polish soils do not contain a high concentration of pesticides, neither non-chlorine (Atrazine, Carbaryl, Carbofuran, Maneb) nor organochlorine compounds (α-HCH, γ-HCH, Aldrin, Dieldrin and Endrin). Nevertheless, the sum of 4,4'DDT / 4,4'DDE / 4,4'DDD was slightly above the limit (> 0.12 mg kg^-1), exceeding the permissible content of these compounds in soils in twelve samples. The higher concentrations of DDT may come from the period when DDT was authorized for use in agriculture as indicated by the proportion of 4,4’DDE / 4,4’DDT and high half-livesof these compounds in the soil.