Sanitary indicators point to a change in the number, species diversity, the optimum ratio of different types of soil macrofauna and microorganisms in the soil contamination with pathogens. In large cities with a high population density of the biological load on the ground is very high and, as a consequence, indices are high sanitary-indicative microorganisms.
Chemical and biological pollution of soils reduces their biological activity and reducing soil self-purification processes. Contaminated soil, typical of urban areas, is a favorable environment for the preservation of viable pathogens.
In a survey of the sanitary-epidemiological indicators from the site soil samples are selected to determine the presence in them:
- Sanitary-bacteriological parameters - the presence of any pathogens intestinal infections, pathogenic bacteria, enterovirus;
- Sanitary-parasitological indicators - the presence of intestinal parasitic diseases, geohelminthes eggs, cysts (oocysts), enteric, pathogenic protozoa;
- Sanitary-entomological indicators - the presence of immature forms of synanthropic flies.
Coliform bacteria (coliform) inhabit the feces and not peculiar to unpolluted soil and other objects in the environment. The presence of E. coli in samples of soil and water indicate their fecal contamination.
Of great importance to the viability of E. coli has, in particular, the acidity of the soil. In an acidic environment (pH 2,9-3,7) E. coli almost dies within 10 days, and in a neutral medium (pH 5,6-6,3), it can exist and multiply within 110 days. Reproduction decays rapidly at the surface under the influence of UV rays than in the deeper layers of the soil. In sandy soils the viability of the bacteria Escherichia coli is lower than in loamy soils.
Enterococci inhabit the intestines of humans and animals. Their presence is also unusual for uncontaminated soil and water. In this connection, the presence of enterococci can serve as an indicator of fecal pollution. Viability enterococci, in particular, depends on the temperature: at 20 ° C they are killed within 10 days at lower temperatures - there are up to several months.
Pathogenic bacteria of the family of intestinal pathogens are a number of human and animal diseases for which they are excreted in faeces. This family includes rod-shaped bacteria of the genus Salmonella.
Bio- and geohelminthiasis have a significant impact on the formation of the negative impact on public health. On the territory of the Russian Federation the most common bio- and geohelminthiasis: opistorhoz, diphyllobothriasis, echinococcosis, toxocariasis. Life cycles biohelminthes is much more complex than bacteria and protozoa, and many species associated with a mandatory change of developmental stages and habitats throughout the individual life of the individual.
Commensal lifestyle and character of the imaginal power of many species of flies are responsible for their epidemiological and epizootiological role as one of the main vectors of human and animal infections. Flies are vectors, the following human diseases: poliomyelitis virus, dysentery, typhoid, paratyphoid, dysentery, cholera, tuberculosis, tularemia, brucellosis, botulism, and stafillo- micrococcal infections eggs of parasitic worms - roundworm, pinworm and broad tapeworm. Fighting synanthropic flies is an important measure of prevention of intestinal infections and parasitic infestations.