Lecture
Sources of contamination of food products and food raw materials with heavy metals. 60-70 thousand chemical
compounds are produced in the world, a significant part of which are potential carcinogens. In Ukraine
more than 1.5 thousand enterprises are operating that contain, process and
store chemical substances; 1 thousand enterprises process or store explosive substances. 11% of the country's territory falls within the zone of possible contamination by chemical
toxic substances, where 35%
of Ukraine's population lives.
Food products are contaminated with toxic heavy metals
through gaseous, liquid, solid emissions and waste from industrial enterprises,
power plants, transport, municipal household waste, wastewater, plant protection products [2, 5, 10, 11].
Due to the intensification of industry and agriculture, an accumulation of heavy metals in soils at high concentrations, toxic to plants and living
organisms, is observed over significant territories.
Heavy metals enter plants through soil, air and water, parts of which we use as food raw materials and food products. Contamination of the biosphere with toxic and carcinogenic chemical
compounds causes the emergence of known and new, still unknown diseases.
In Japan, Western Europe and the USA, an ailment has recently become widespread, in particular, one called the "fatigue syndrome", from which thousands of
people die. The number of births of disabled children is growing, and nature is perishing.
The situation is aggravated by the fact that no mechanisms of natural self-purification exist for heavy metals, and treatment facilities practically completely
"let through" mineral salts, including compounds formed by toxic and carcinogenic heavy metals. Only the best treatment facilities
can extract from 10 to 40% of inorganic compounds, and there are very few such facilities in
Ukraine. Therefore, cases of illness and poisoning of the population have become more frequent [2, 5, 10, 11].
About 70 heavy metals enter the human body with food products,
of which many belong to trace elements. The most
toxic are considered to be mercury, lead, cobalt, copper, nickel, beryllium, selenium, cadmium, bismuth, etc. But some of these metals in small doses
are vitally necessary, since they participate in various forms of metabolism, transport, synthesis of substances, and are part of enzymes, vitamins and various body tissues. Indeed, zinc, copper, chromium, cobalt, selenium and manganese are called
the "metals of life", therefore the daily requirement for these elements is standardized for different
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groups of the population. In some countries (USA, Germany, Finland), based on modern research into the effects of heavy metal ions on the human body, daily norms are being revised and increased. For example, in the USA the daily consumption norm for selenium is 10 mg (in Ukraine – 0.5 mg), which is explained by its blocking effect on harmful and carcinogenic heavy metals: cadmium, mercury, lead, etc.
At concentrations above the maximum allowable levels, heavy metals become harmful. In total there are about twenty of them, including:
mercury, lead, selenium, vanadium, antimony, bismuth, chromium, manganese, iron,
cobalt, nickel, silver, copper, zinc, cadmium, arsenic, etc. [6, 7].
Measures to reduce the content of heavy metals in food products and food raw materials. First of all, measures must be taken at the
state level before the biosphere is contaminated with harmful substances. Mere
monitoring of products for toxic heavy metals and other contaminants
does not protect consumers from hazardous goods. It is necessary to eliminate not
the consequences, but the causes that generate them. It is necessary to ensure an ecologically
clean cycle of production of agricultural products, raw materials and
food goods, to prevent the entry of substandard and harmful goods of foreign production into the domestic market, and to begin a resolute fight against illegal producers of food goods.
The removal of heavy metals from the body and the strengthening of immunity
is facilitated by adherence to the principles of optimal nutrition. Pectin, dietary
fiber, carotenoids promote the removal of heavy metals from the body.
Specialists of the German Institute for Consumer Information believe that
the occurrence of a third of all cancers is directly related to
improper nutrition. They recommend consuming food rich in
ecologically clean vegetables, and predominantly raw or unheated. Fruits and vegetables contain about 10 substances with anticarcinogenic action
(Table 2.3), therefore their systematic consumption within physiological norms
will help remove heavy metals and prevent the formation of malignant
tumors [2, 5, 10, 11].
Table 2.3 – Anticarcinogenic substances of fruits and vegetables
Name of substances Products in which they are found
Carotenoids Vegetables, fruits
Phytosterols Vegetables, fruits, legume vegetables
Flavonoids Vegetables, fruits, legume vegetables
Protease inhibitors Potatoes, cereals, legumes
Isothiocyanates All types of cabbage, bulb vegetables, salads, radish
Phenolic acids Potatoes, fruits, cereals
Indoles All types of cabbage
Monoterpenes Citrus fruits
Acedol Beetroot
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