6.1. Pollution of the environment with pesticides
6.1.1. Pesticides. Classification of pesticides by use
Among all foreign chemicals found in medicinal plants, pesticides and heavy metals are the most dangerous and toxic! The major pollutants of medicinal plants are organochlorine pesticides. Even those pesticides that are currently banned (for example, DDT, aldrin) slowly decompose and their amount in the soil is still equals to tons. Most organophosphate pesticides are destroyed when dried in raw materials. However, once in the body, remaining pesticides may turn into more active toxic substances. Obviously, pesticides enter the body with medicinal substances not constantly, but we must ensure that medicinal products are not a source of any poisons entering the body.
Pesticides-biocides, or toxic chemicals, are a chemical means of control of harmful or unwanted contaminants, plants and animals (from Latin pestis — infection and caedo — kill).
Pesticides are divided into groups, depending on organisms they infect. Classification of pesticides according to the effect on living organisms and plants is presented in table 6.1.
Table 6.1. Classification of pesticides by their designation
| No. | Pesticide | Direction of pesticide action (control) |
| 1 | Insecticides | Against insects that eat crops and products, and are carriers of human and animal pathogens |
| 2 | Herbicides | Against unwanted vegetation, weeds |
| 3 | Fungicides | Against fungi, mould |
| 4 | Bactericides | Against bacteria |
| 5 | Acaricides | Against mites |
| 6 | Algicides | Against algae |
| 7 | Molluscicides | Against snails and slugs |
| 8 | Nematocides | Against nematode |
| 9 | Zoocides (rodenticides) | Against vertebrate animals (mice, rats) |
| 10 | Desiccants | Pesticides that dry growing plants |
Pesticides also include repellents (from Latin repellentis — frightening or disgusting); chemosterilants — agents causing infertility of insects; defoliants — agents causing plant leaf fall; attractants — attractive substances that are used for disorientation, etc.
Composition of pesticides
Pesticides are usually used in a form of various compositions with diluents and surfactants, where pesticides or, more often, synthetic substances are used as an active ingredient or primary nutrient.
Sometimes the so-called propesticides are used; these are substances, which are transformed into pesticides only during their application or after entering a living organism.
Over 80% of industrial pesticides are used as plant protection chemicals; the rest are used in everyday life, in health care, as well as in industry as antiseptic agents.
About 20% of pesticides are used in developing countries for cosmetic purposes: to treat pineapples, bananas, oranges, coffee and other crops exported to industrial developed countries.
There are over 700 types of pesticides.
The annual global production of pesticides, more specifically, of active substances, is about 2 million tons. The average amount of pesticides per inhabitant is 2–3 kg.
Currently, there are 2 generations of pesticides.