Hygienic importance of soil Sanitary evaluation of soil

Hygienic importance of soil. Sanitary evaluation of soil in populated area Ph. D Maksimenko L. V.

Definition of SOIL • Soil is the external layer of rocks changed by water, air and various organisms (V. V. Dokuchayev - the eminent Russian naturalist, geologist and soil scientists ). • Soil is the special natural-historical body which has arisen on a land surface as a result of cumulative interaction of “soil forming factors”: climate, rocks, plants, animal, microorganisms and time. • Soil is the open spontaneous self-regulating system providing circulation of substances in nature. • Soil is a natural body consisting of layers (soil horizons) that are primarily composed of minerals, mixed with at least some organic matter, which differ from their parent materials in their texture, structure, consistency, color, chemical, biological and other characteristics. It is the loose covering of fine rock particles that covers the surface of the earth L. V. Maksimenko 2

Soil content Share (%) Component Mineral constituent 90 - 98 destroyed parent rocks Organic constituent 10 - 2 a) plant residues b) animal residues – corpse, faeces c) humus Other components Soil air Content Importance In pure soil: O 2 (18 -19%) + CO 2, In polluted soil: O 2 + CO 2 + H 2 + CH 4 Determines soil ability to autopurification, humification of organic substances (instead of rotting), prevalence of aerobic/ anaerobic microflora Soil moisture Free liquid and aqueous solutions of Determines microclimate at soil salts and water soluble organic surface and survival of compounds, water vapor and microorganisms chemically bound water

Soil physical properties applied at sanitary soil evaluation Importance Examples Porosity effects on soil moisture, the ability to retain contaminants, selfpurification coarse-grained soils – 25 % (sand, gravel), fine-grained soils - 85 % (chernozem), superfine-graned soil - 40 -45 % (alumina). Capillarity the ability to retain moisture Hydroscopicity the ability to draw out moisture from soil air Available water content (AWC) the range of available water that can be stored in soil and be available for growing crops

Humus • HUMUS is organic substances • have been formed due to decomposition of organic residues. • • Humus consists of humic acids, fulvic acids, humin, ulmin. • The ratio of humus share in organic matter is called • “SANITARY NUMBER” (SN). • SN is not dependent on soil type. • SN=1 at 100% of organic part • consist of humus; • SN=0 at 100% of organic part consist of organic residues The process of "HUMIFICATION" can occur naturally or at artificial production of “compost”. Humus is responsible for soil selfpurification and provides soils fertility in physical and chemical sense. HUMUS helps the soil retain moisture by increasing micriporosity and encourages the formation of good soil structure. Humus has a characteristic black or dark brown color, due to an accumulation of organic carbon.

Functions of humus as part of soil Accumulation Humus is a colloidal matter and increases the soil's cation exchange capacity, hence its ability to keep nutrients by chelat structures forming. Transport Formation of water-soluble salts of humic substances with metal cations resulting to the formation of geochemical flows Regulation Soil structure, physical and chemical properties, p. H, soil nutrients for plants Protection Formation of water-insoluble compounds of toxic and radioactive elements Physiological function Stimulation of seed germination

Soil types by clay, silt and sand composition

Constant (Anthrax, agent of gas gangrene, botulism, tetanus, actinomycosis; eggs of soil-transmitted helminths) Biological pathogens Hygienic importance of soil Temporary (intestinal infections, typhus-paratyphoid, dysenteric bacteria, Vibrio cholerae, eggs of biohelminths) Agents of tuberculosis and tularemia can be permanent and temporary soil inhabitants. Pathogenic viruses, polio, enteric viruses, germs serous meningitis ECHO, Coxsackie may also be present in soil Natural chemical composition Chemical pollution Biogeochemical endemic diseases Toxicosis of technologic nature

Activators of infectious diseases • The microorganisms survival rate depends on soil physical properties, climate and a microclimate, soil air, presence of a biological substratum, presence of antagonistic soil microorganisms. • Bactericidal factors: 1. Low daily both seasonal average air temperature, 2. Sharp fluctuations of average day-night air temperature, 3. Air low humidity, 4. Intensive insolation and UV-radiations. L. V. Maksimenko 9

Biogeochemical provinces and biogeochemical endemic diseases • Biogeochemical provinces – are the terrioties with extremely low or high content of some chemical elements. • The reasons of changed soil chemical composition are natural or anthropogenic (industrial emission). • Biogeochemical endemic diseases are based on biochemical abnormalities in an organisme. • The soil chemical composition affects the public health indirectly by food chain - drinking water, food of plant and animal origin. L. V. Maksimenko 10

" Interaction of minerals in human organism ", Enslinger, 1983 г. • Excess or deficiency of any chemical element in vivo leads to a cascade of violations of metabolic processes Lines shows interaction of elements metabolism. L. V. Maksimenko 11

Role of mobile forms of chemical elements • Formation of mobile forms of chemical elements in soil can lead to excessive entry into human body, if these forms are easily absorbed by crops, and vice versa - insufficient uptake, if these forms are quickly eluated. • Chemical elements Ti, Zr, Hf, Th, Sn, Pt and many others do not form mobile soluble compounds and so do not cause BED. • Molybdenum forms mobile forms only in alkaline soil that lead to endemic moly gout. Deposits of molybdenum ores in another soil types does not give a similar effect. • Mobile forms of In (Indium) and Cu are formed only in dark fertile soil. L. V. Maksimenko 12

Examples of BEDs Endemia Iodine deficiency pathology, including endemic craw and mountain cretinism in children Chemical element in insufficient dose Iodine Soil type and promoting factors Podzolic soil, the aggravating factor – lack of copper in the soil and lack of social measures (delivery of products from regions with normal levels of iodine in food, sea fish and seafood), consumption of iodized table salt Endemic dental caries Fluorine Local sources of water (at centralized water supply fluoride content in drinking water is corrected by fluoridation of water) Keshan illness (endemic cardiomyopathy) in China Selenium Fertile soil with a high content of iron, preferential consumption of local wheat, the lack of imported cereals

Types of Keshan disease. • • A) Acute Keshan disease involves sudden onset with acute heart failure such as cardiogenic shock, severe arrhythmia, and pulmonary edema. ST‐T changes can be noted on electrocardiogram. B) Subacute Keshan disease, the most prevalent type at present, is predominant in children with generalized edema and heart failure of subacute onset. C) The chronic type involves moderate to severe cardiomegaly with a varying degree of heart failure. D) Latent disease involves mild cardiomegaly with normal heart function. Electrocardiographic changes of right bundle branch block (RBBB) and ventricular premature contractions (VPC) may also be present. L. V. Maksimenko 14

Examples of BEDs Endemia Kashin-Beck disease (Urove disease) in Urov river valley (southeast Siberia) Chemical elements in Soil type and promoting factors misbalanced equation entering the human body Calcium deficiency The excess of barium and strontium with a deficiency of selenium. Sick children over 4 years of age and adolescents, both male and female. The disease develops only in the period of growth, often at the age of 6 -14 years, when there is the greatest growth of the skeleton. It is generalized degenerative process in bone and joint with significant impairment of ossification. Mainly affects the metaphyses and epiphyses of long bones.

Kashin-Beck disease (Urove disease)

Endemia Chemical element in excess dose entering the human body Soil type and promoting factors Molybdenum gout (Armenia, a region of molybdenum ore deposits), molybdenum toxicosis among the animals Molybdenum Copper deficiency in the soil, water, food Poisoning with antimony (Uzbekistan, Sheravshan valley) Antimony Intrazonal endemic fluorosis, in India & China crippling forms of fluorosis Fluorine Volcanic emanation soil or in areas of F-containing minerals deposits - cryolite (Na 3 Al. F 6), fluorite (Ca. F 2); local sources of water (at centralized water supply fluoride content in drinking water is corrected by defluoridation of water) Arsenosis or illness " black foot" (Myanma, Bangladesh, Japan, USA, Mexico, Argentina); skin arsenious cancer (Argentina, Canada, China, Czechia and Slovakia, France, Germany, Israel, Japan, Southern Africa, Switzerland, Great Britain, USA). Arsenic containing pesticides in rice paddies Antimony ore (stibnite) deposits, lack of social measures

The basic chemical pollution of soil of anthropotechnogenic nature on modern stage • • Heavy metals, Mineral oil, Pesticides. Sources of pollution – emissions of motor transport, power installations, the industrial enterprises, unorganized dumps of toxic waste, agricultural works with application of pesticides. Entering of pesticides into a soil • Danger of pollution of soiles as a risk factor for health of the population is defined by its functional use. L. V. Maksimenko 18

List of chemicals required to validate when a routine sanitary inspection of soils in Russia • • • • Pesticides (residual quantities), Heavy metals, Oil and mineral oil, Phenols flying, Sulphurous compounds, Detergents (anionic and cationic), Cancerogenic substances, Arsenic, Cyanides, Polychlorinated biphenyl's (known as PCB), Radioactive substances, Macro chemical fertilizers, Micro chemical fertilizers. L. V. Maksimenko 19

Influence of complex pollution of soil on health of the population Categoria of polution of soil Zc Changes of populational health in sites of soil pollution Admissible < 16 Minimal frequency of morbidity, functional deviations and deviation in physical development among children Moderately dangerous 16 -32 Enhancement of common morbidity Dangerous 32 -128 Enhancement of common morbidity, increase of amount of frequent sick children, children with chronic diseases, violation of functional condition of cardiovascular system Extraordinary dangerous >128 Enhancement of morbidity of children, violation of reproductive function of woman (enhancement of frequency of toxemia of pregnancy, amount of L. V. Maksimenko premature birth, stillbirth, hypotrophy of newborn) 20

Parameters of a sanitary status of soil Epidemiological indexes • I. Sanitary-bacteriological indexes: • 1). Indirect indexes - coli-index, enterococcus-index - biological contamination of soil by feces. • 2). Straight indexes - the maintenance of infectious factors of intestinal infections, pathogenic enterobacteria and enteroviruses - epidemic danger of soil. • II. Sanitary-parasitological indexes: – Extensive index = a share of positive tests (%) from the general investigated soil samples; – Intensive index = the general maintenance of pathogenic agents in 1 kg (100 g) of the soil. – Direct danger to public health there is due to the presence of eggs of Ascarids, Trichurises, Toxocares, Ancylostome, larve of Strongyloidaes, oncospheres of Taenias, cysts of lamblias, isospores, a balantidium, amoebas, oocyst of cryptosporidium. – Mediated threat to public health there is due to the presence of eggs of Trematoda and Diphyllobothrium. • III. Sanitary-entomological: presence of preimaginal (larve and chrysalis) forms of synanthropic flies. L. V. Maksimenko 21

Criteria for hygienic evaluation of chemical contamination • Sanitary-chemical indexe N. I. Khlebnikov's sanitary number (SN) characterizes process of humification and autopurification of the soil. • Criteria for hygienic evaluation of chemical contamination • 1). translocation (ability of a chemical agent` transition into agricultural crops), • 2) water-migration • 3) air-migration • 4) common-sanitary (impact on the soil ability to clean itself = autopurification). L. V. Maksimenko 22

Hygienic reglamentation of chemical substances in the soil Parametrs of danger in toxicological experiment in a laboratory 1. Set the threshold (minimal) acting concentration Translocation to agricultural crops CT Watermigration CW Air-migration CA General sanitary parameter suppression of soil macro-and microflora CS 2. Select minimum concentration MPC 3. Select maximum concentration – Kmax 4. Establish class of danger

Parameters of danger of a chemical substance in a soil Parameter Class of danger I II III Toxicity, LD 50 mg/кg <200 200 -1000 Persistence in soil, months. >12 6 -12 <12 + +/- - ≥ 3 1 -3 <1 strong moderate no <0. 2 -0. 5 >0. 5 Migration Persistence in plants, months Influence on nutritional value of agricultural product MPC in soil, mg/kg L. V. Maksimenko 24

Classes of danger of the chemical substances getting in a soil from emissions, dumps & waste Class of danger Chemical element (substance) I Arsenic, cadmium, mercury, lead, selenium, zinc, fluorine, benz(а)pyrene II Boron, cobalt, nickel, molybdenum, cuprum, stibium, chromium III Barium, vanadium, wolfram, manganese, strontium, acetophenon L. V. Maksimenko 25

• • • Estimation of danger of the polluted soil 1) Unicomponent pollution: Inorganic substance 1. Factor of danger Кi = Сi/MPCi and degree of its exceeding 1 2. Class of danger 3. MPC is the minimal value of an admissible level on 1 from 4 parameters of danger 4. Кmax is the maximal value of an admissible level on 1 from 4 parameters of danger Organic substance 1. Class of danger 2. MPC • 2) Multicomponent pollution: • A total parameter of pollution Zc is the sum of Factors of concentration for each substance Кci = Сi/Cbi, where Ci - concentration of the chemical element (substance) found in the soil, Cbi - the background concentration of the same chemical substance in the soil of the region). L. V. Maksimenko 26

Accumulation of chemical elements in soile in a zone of influence of the industrial enterprises and other sources of pollution (part of document) SOURSES OF SOIL POLUTION Factors of concentration for each substance Кci = Сi/Ci background of region (Degree of excess of background concentration) 2 -10 Более 10 Solid common waste of city, used as fertilizer Lead, cadmium, tin, cuprum, silver, stibium, zinc Mercury Sediments of sewerage (system) Lead, cadmium, vanadium, nickel, tin, chromium, cuprum, zinc Mercury, silver Impure water for agricultural watering Lead, zinc Cuprum Mercury, strontium, zinc Cement plant L. V. Maksimenko 27

1. 2. 3. 4. 5. 6. Improvement of a sanitary status of the soils in populated areas. Preventive maintenance of organic pollution Equipment of the occupied places by public toilets, dustbins and urns both their duly clearing and sanitation. Covering of the roads and foot zones by asphalt or concrete and their constant cleaning. Liquidation of dumps, destruction of unorganized landfill of household waste. Sanitation - collection, removal, destruction of municipal solid waste; implementation of a centralized system of removal and sewage treatment. Organization of sewer system. The sanitary control of soil contamination (first of all in zones of the raised risk). L. V. Maksimenko 28

Common prophylactic measures 1. The proof of the endemic nature of disease and revealing of its reason. 2. Official recognition of endemic diseases. 3. Development of programs both their state financing and realization on this basis of hygienic and medico-social measures. 4. The constant control of morbidity of the population living in provinces. 5. Organization of public events for the prevention of diseases caused by endemic factors. 6. Propagation of a healthy way of life in view of factors of harm of the territory. L. V. Maksimenko 29

Lab work Hygienic estimation of soil • 1. Indexis of epidemiological dangerous of soil: – Coli-index - the number of specimens of E. coli in 1 kg of soil – Enterococcus-index – Pathogenic bacteria (Salmonella, …) – Geohelminthes eggs - ex. /kg of soil – synanthropic flies larvae, pupae in a soil sample collected at the soil surface (20 cm x 20 cm)

Estimation of a degree of chemical pollution • 1. Ability of soil to recovery: Sanitary number – a share of humus (count by equation on nitrogen of humus and nitrogen of soil) • 2. Factor of concentration of a chemical substance: • КСi = Ci/Cb, • where – Ci – the revealed content of a chemical in soil samples withdrawn in the survey area, – Cb – background level of a chemical element in the geochemical province.

• 3. Total parameter of concentration: Zс = ∑ КСi – (n – 1), where n - quantity of chemical contaminants, Ксi - factors of concentration of the chemical contaminants. 4. At evaluation of chemical pollution the important toxicological characteristics of chemical substances are: - MPC – maximum permissible concentration, - class of danger, - K max.