Lecture
Use of pesticides and pathways of their entry into food products and food raw materials. Pesticides are chemical substances used as means of protecting plants and animals from harmful organisms. They are widely used in agriculture to reduce crop losses and improve product quality [2, 5, 10, 11].
In some farms pesticides are used without proper regulation. This
leads to food products containing pesticide
levels higher than those provided for by the maximum allowable levels, the content of which is
determined in milligrams per 1 kg. Acceptable daily doses have also been established.
(ADD) of pesticide intake relative to human body weight.
With an increase in the range of pesticides and the volumes of their use, the number of cases of harmful effects of these substances on the human body is somewhat decreasing. In Ukraine it is permitted to use about
300 kinds of pesticides. By purpose, pesticides are divided into groups:
for controlling weeds – herbicides;
for rodents – zoocides;
for insects – insecticides;
for roundworms – nematocides;
against causative agents of bacterial diseases – bactericides;
causative agents of fungal diseases – fungicides;
mites – acaricides;
for destroying larvae, caterpillars and insects – aphicides [3, 4, 9, 13, 14].
Pesticides have different chemical natures, therefore they are divided into classes.
(organophosphate, organochlorine, copper, sulfur, etc.):
depending on the degree of hazard to humans and animals, pesticides
are divided into highly toxic – 50-200 mg/kg, moderately toxic – 200-1000,
low toxic – more than 1000 mg/kg;
by accumulation in food products: super-accumulative, with pronounced, moderate and weakly pronounced accumulation;
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by persistence: very persistent – decomposition time into non-toxic components – more than 2 years, persistent – 0.5-2 years, moderately persistent – 1-6 months, low-persistent – up to 1 month.
Pesticides are distinguished as contact (harmful organisms die on
contact with them) and systemic – substances penetrate the tissues of plants and there
cause the death of harmful organisms.
The degree of harmfulness of pesticides is determined by their intake and level of content in food products. The residual amount of pesticides in food products is determined by their physico-chemical properties: solubility in water, fats, etc., which is related to the degree of penetration of substances into plant tissues, the rate and nature of transformation; properties of the preparations (emulsion, suspension, solution, particle size, solution concentration, etc.); the method of application to the treated object (temperature, outlet pressure, dispersion, etc.); the consumption rate and frequency
of treatment; the characteristics of the treated object (surface smooth,
rough, waxy coating, density of leaf coverage, configuration);
soil-climatic and meteorological conditions (temperature, air humidity, rain, dew); the nature of farming (dry-land, irrigated) [3, 4, 9, 13, 14].
Pesticides can persist in vegetative crops from one
week to 5 months. Some organochlorine substances are very persistent – they are found in
soil and food products 4-12 years after application.
Content of organochlorine pesticides in food products, food raw materials and their effect on the human body. Organochlorine pesticides are most used in agriculture to control pests of grain, legume, industrial and vegetable crops,
fruit trees, vineyards. However, these pesticides accumulate very well, so prolonged consumption of food products containing them is very
dangerous [2, 5, 10, 11].
Organochlorine compounds (preparations) affect various organs, especially the central nervous and endocrine systems, liver, kidneys, blood.
In people with acute poisoning, headaches, dizziness, loss of appetite, nausea, sometimes vomiting, pain in the abdomen, muscles,
limbs occur, and body temperature rises.
When organochlorine compounds are present in food products above
the established norm, they must not be consumed. Fruits and berries are permitted to be processed into juices and wine with mandatory filtration, pears – into fruit paste,
jam, preserves, dried fruits (without peel), potatoes – used to produce starch
or used as seed material. Vegetable greens containing
organochlorine compounds are disposed of. The pesticide content can be partially
reduced by washing fruits and vegetables.
Content of organophosphate pesticides in food products,
food raw materials and their effect on the human body. Organophosphate
pesticides break down rapidly under the influence of environmental factors –
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sun, rain (sunlight, ultraviolet radiation, temperature,
acidic environment), and in food products they are destroyed by cooking. If the rules for treating plants and animals with pesticides and the intervals from the time of treatment to harvest are observed, poisoning by organophosphate substances is practically impossible. This can occur
only in the case of a significant increase in the doses of the preparation during treatment and
a reduction of the established interval between the last treatment of plants and
animals with potent preparations and the harvest or slaughter of animals [2, 5, 10, 11].
The toxicity of organophosphate compounds is due to the fact that they
inhibit the activity of a number of enzymes, and acetylcholine accumulates in the blood, which leads to disruption of the functions of the central nervous and cardiovascular systems.
Fruits and vegetables contaminated with organophosphate compounds above
the maximum allowable levels must not be consumed fresh. They
are consumed only after processing.
Use of inorganic preparations, their content in food products, food raw materials and effect on the human body. Inorganic preparations, including copper, iron, sulfur, phosphorus, etc., are widely used to protect orchards, fruit crops
from pests and diseases, etc.
Of the organomercury compounds, only granosan is used, which is used
to treat grain. It is persistent, volatile, highly toxic and acts on the proteins
of human body tissues, as a result of which metabolism in
tissues is disrupted, the condition of the central nervous system, heart, vessels and
other organs changes. Poisoning is possible when working with it and consuming bread products made from treated grain. Cases of poisoning by
these products have been described, including fatal ones. In case of poisoning there occur
a metallic taste in the mouth, nausea, vomiting, diarrhea with mucous
discharge and blood, bleeding from the gums, unsteady gait, trembling
of the limbs, decreased vision and hearing. Kidneys may be damaged, fatigue develops, headache occurs, drowsiness or, on the contrary, insomnia, dizziness, memory impairment, etc. [6, 7].
Compounds containing copper (copper sulfate (blue vitriol), Bordeaux mixture, coppernaphthenate, copper oxychloride), are widely used to
protect orchards, vineyards, fruit crops and vegetables from pests and
diseases. These are very toxic preparations, especially blue vitriol.
When copper preparations enter the human body, poisoning can occur. This is accompanied by a metallic taste in the mouth, salivation, nausea, vomiting. The vomit is colored blue-green.
Crampy pains in the abdomen, diarrhea with blood are observed,
and hemolytic jaundice may also develop [6, 7].
Sulfur and its preparations are used to control mites
and powdery fungi as insecticides, fungicides, acaricides. Especially toxic are sulfur anhydride and carbon disulfide, which act on the mucous
membrane and skin. Upon entering the body, these compounds can cause poisoning due to the release of hydrogen sulfide from them [6, 7].
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