Effects of pesticides on human health and environment

Abstract

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Full Text

Strategy for sustainable agricultural development involves improving farming system and involves rational use of pesticides. Pesticides are potentially dangerous to human health [1].
The most dangerous pesticides are characterized by chronic toxicity, which is associated with cumulativity — property of accumulating in all food chains (water, plant and animal food).
Cumulation is characterized by accumulation of toxins in the body as a result of incomplete decomposition and removal. Organophosphorus pesticides possess functional toxicity. After entering the organism, they damage nervous system and danger increases with repeated contacts [2].
Pesticides enter the human body both during plant protection work and through plant food when application regulations are violated. Even though pesticides are destructive to the environment, their rational use significantly increases crop productivity. Thus, the pesticide issue is acute and relevant nowadays, when the planet is on the verge of an environmental disaster [3].
An analysis of pesticide traffic showed that in 2020 there was a sharp jump in market volume growth, which amounted to 22 %. According to the Fertility Agency, in 2021 growth of the market for chemical plant protection products (CPPP) fell back to the world average of 5 %. Based on the results of 2021, the market volume amounted to 198 thousand tons, which is 5 % more than in 2020 (188 thousand tons). Over 5 years, market growth amounted to 31 % from 151 thousand tons in 2017. As in 2020, the reason for growth of chemical plant protection market is increase in cost of agricultural products, especially wheat. This allowed allocating additional money to obtain pesticides and agrochemicals [4, 5].
An analysis of pesticide production has revealed the complete dependence of Russian pesticide market on foreign supplies of active ingredients and products, imported from China and India. Due to increased environmental control in China, production of pesticides was partially suspended, which led to shortage of products on the world market and rising prices. Despite the available production capacity, ability of Russian chemical producers to fully meet the need for pesticides remains dependent on imported active ingredients [6, 7].
Chemical companies in the Russian Federation do not have the necessary technologies for production of active ingredients. Due to rising prices for imported pesticides and active ingredients, Russian market for producers and importers of chemical pesticides grew by 31 % to 17 billion rubles in 2021. The share of Russian producers of chemical pesticides in 2021 decreased compared to 2020, but remains dominant in Russian market — 52 %. Sales of domestic herbicides decreased from 70 in 2020 to 64 % in 2021. In 2021, herbicide sales market increased mainly due to imported products [8, 9].
Sales of insecticides produced in the Russian Federation continues to decline (from 74 in 2017 to 40 % in 2021). Increase in sales of Russian pesticides was recorded only for other pesticides (from 58 in 2019 to 87 % in 2021) [10].
Pesticides are used to protect agricultural crops against pests, diseases and weeds; their use greatly reduces losses in agricultural crop yields, reduces agricultural costs by 2–3 times, and allows savings of agricultural products by 10…12 billion rubles per year. But it is always worth remembering the risks and undesirable effects. Only few countries monitor pesticide use. All requirements are adopted in the Directive of the European Parliament and of the Council [11]. The main place of pesticide accumulation is the soil, from where harmful substances enter plants and the environment.
As part of implementation of Russian Government instructions, Rosselkhoznadzor monitored agricultural products for the residual amounts of pesticides in imported coffee and tea.
During July-­September 2023, Rosselkhoznadzor laboratories examined 290 coffee lots from 22 countries and 488 tea lots from 16 countries. As a result, 14 coffee lots were found to contain residual amounts of pesticides. The pesticide Permethrin was 2 and 2.5 times higher than the maximum allowable level (MAL) in two lots of coffee from India and Brazil. 7 active ingredients of pesticides that do not have Russian standards and are not registered for use on the territory of the Russian Federation were found in 13 lots.
The same situation was noted when analyzing tea for residual amounts of pesticides. In the analyzed 91 lots of tea, 6 active ingredients of pesticides regulated by Russian legislation and 36 active ingredients of pesticides not regulated by Russian legislation were identified. There were cases of detecting several tens of active ingredients of pesticides in small quantities in one sample, confirming facts of high-intensity treatments of tea in places of its production. Simultaneous entry of small amounts of pesticides with different modes of action into human body can lead to increase in negative effects due to synergism.
Residues of active ingredient of highly toxic organophosphorus pesticide (Methidathion) were found in three tea lots from Kenya, India and China. Methidathion is still produced in China, but since 2010 it has been completely banned by the US Environmental Protection Agency (US EPA), and in 2011 — by the European Union.
According to the China National Center for Food Safety Risk Assessment (Beijing), in 2021, 50 % of the tested samples of crop products contained pesticides that were prohibited for use or did not have MALs. Risk ranking of the detected pesticides showed that Methidathione and Dimethoate pose the greatest risk, since they are extremely toxic, and have the ability to accumulate in the body and cause tumors [12, 13].
Residues of organophosphate insecticide Monocrotophos were found in tea lot from India. Monocrotophos is banned in 129 countries due to proven mutagenicity and ability to cause mutations in humans. Circulation of the pesticide is regulated by the Rotterdam Convention on the Prior Informed Consent Procedure for Certain Hazardous Chemicals and Pesticides in International Trade [14, 15].
Lindane (organochlorine pesticide), which was internationally banned for use in agriculture by the Stockholm Convention on Persistent Organic Pollutants, was identified in tea lot from China.
Safety risk assessment of the identified active ingredients when they are consumed daily with tea and coffee cannot be fully carried out due to the lack of MALs.
Pesticide residue analysis of imported products (grapes) showed that all detected substances do not have standards. Moreover, for products based on these active ingredients, the registration in Russia has expired. The pesticide Ametoctradine (triazole fungicide) identified in fresh grapes is not standardized, registration in Russia has expired and there is no MAL [15]. Content of Biphenyl herbicide is also not standardized; it can remain in soil for up to two years; MAL in grapes has not been established. All detected pesticides (Metraphenone, Acetamiprid, Dimethomorph, Bupirimate, Diphenylamine, Fluvalinate, etc.) belong to the 2nd hazard class for humans and the 3rd hazard class for bees. Some of them degrade into several metabolites that are difficult to identify. Grapes are used fresh for food without heat treatment, which confirms pesticide danger to humans and the need to tighten control over their content and prioritize development of MALs. The active ingredients and their toxicological characteristics confirm their toxicity for humans, especially children.
All the above data require prompt actions in solving issue of importing high-quality crop products, especially those consumed fresh. This important indicator for human health is developed by Rospotrebnadzor and included in SanPiN no. 1.2.3685–21 (Hygienic standards and requirements for ensuring safety and (or) harmlessness of environmental factors to humans).
Unfortunately, it should be noted that only 28 MAL standards have been established for tea and 25 — for coffee in the Russian Federation. In the European Union, there are 498 MALs for pesticide active ingredients in tea and 499 — in coffee.
The analysis showed the need to regulate legislation for safe handling of pesticides and agrochemicals and development of MALs for pesticides, especially in plant products that are consumed fresh.
The data presented substantiate the use of integrated protection systems in production of plant products and the need for maximum replacement of chemical pesticides with Russian biological agents in conditions of import substitution.