Residual contents of persistent organic pollutants in the agrogenic soils of the Novosibirsk Region
A. A. NEFEDOV1,2, P. A. BARSUKOV1,3, A. E. OSECHKOVA1,2, E. A. KHOKHRINA1, O. A. RUSALIMOVA3, YU. S. SOTNIKOVA1,2, A. S. KIL’MET’EV1,2, A. V. SOTNIKOV1, D. N. POLOVYANENKO1, E. G. BAGRYANSKAYA1
1Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
2Novosibirsk State University, Novosibirsk, Russia
3Institute of Soil Science and Agrochemistry, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
Keywords: persistent organic pollutants, organochlorine pesticides, gas chromatography-mass spectrometry, chernozem, soil, agrochemical indicators, soil monitoring, DDT transformation products, Stockholm Convention
Abstract
The study was carried out on 100 samples of agrogenic soils collected in 2025 from nine districts in the Novosibirsk Region to determine the residual amounts of organochlorine pesticides (OCPs) and other persistent organic pollutants (POPs). Analysis of basic characteristics (particle size distribution, acidity (pH), salinity level, soil organic matter content) of the soil samples has shown that they form a high-quality representative set of samples for the chernozem soils of the West Siberian forest-steppe zone, which are the basis of arable land found in the Novosibirsk Region. The list of POPs and OCPs under determination included the compounds subject to monitoring under the UN Stockholm Convention on Persistent Organic Pollutants: aldrin, dieldrin, 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT) and its derivatives, hexachlorobenzene (HCB), hexachlorocyclohexanes (HCHs), heptachlor, polychlorinated biphenyls (PCBs), chlorpyrifos, as well as a candidate substance for inclusion in the monitoring list - methoxychlor. It has been demonstrated that the substances that had been long included in the Stockholm Convention monitoring list are not currently in use on the studied agricultural fields. However, there remain “background” levels of HCB, PCBs, DDT concentrations averaging between 0.001-0.050 of the maximum permissible concentrations (MPC) or tentative permissible concentrations (TPC). Several substances (aldrin, dieldrin, methoxychlor) were not detected. Special attention was given to studying DDT and its transformations in natural environments into 4,4'-dichlorodiphenyldichloroethane (DDD) and into 1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene (DDD) and 1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene (DDE). It has been established that since the discontinuation of DDT-based pesticide application, on average, approximately 60 % of initially introduced DDT had already transformed into DDD and DDE.
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