FOODBORNE DISEASES - Environmental Engineering: Prevention and Response to Water-,Food-,Soil-,And Air-Borne Disease and Illness - page 175

diarrhea, vomiting, nausea, or fever. Additionally, this chapter addresses some
related diseases and conditions, including nutritional deficiencies, as well as
investigation and control of disease outbreaks.

SURVIVAL OF PATHOGENS

The survival of pathogens is affected by a number of factors, including the type of
organism, temperature, moisture, nutrients, pH, and sunlight. Since these factors
are quite variable, the survival data in Table 3.1 should be used only as a guide.
For some waterborne pathogens, the amount of clay and organic matter in the
soil may affect the movement of pathogens, but porous soils, cracks, fissures,
and channels in rocks permit pollution to travel long distances.
Despite variations in environmental resistance among pathogens, some gen-
eralities can be made. Soil moisture of about 10 to 20 percent of saturation

TABLE 3.1 Survival of Certain Pathogens in Soil and on Plants

Organism Media Survival Time (days)

Ascaris ova Soil Up to 7 years

Vegetables and fruits 27 - 35

Coliforms Soil surface 38, greater in soil

Vegetables 35

Grass and clover 6 - 34

Cryptosporidium oocyst a

Moist environment 60 - 180

Entamoeba histolytica cysts Soil 6 - 8

Vegetables 1 - 3

Water 8 - 40

8 or longer b Enteroviruses Soil

Vegetables 4 - 6 or longer

Salmonella Soil 1 - 120

Vegetables and fruits 1 - 68

Up to 85, 2 years at 0 ◦ C

Salmonella typhosa Peat soils

Shigella Grass (raw wastewater) 42

Vegetables 2 - 10

Water containing humus 160

Tubercle bacilli Soil 180

Grass 10 - 49

Source : D. Parsons et al., “Health Aspects of Sewage Effluent Irrigation,” Pollution Control Branch,
British Columbia Water Resources Services, Victoria, 1975, cited by E. Epstein and R. L. Chancy,
“Land Disposal of Toxic Substances and Water-Related Problems,” J. Water Pollut. Control Fed .
(August 1978): 2037 - 2042.
Note: The survival of pathogens can be quite variable. a A. S. Benenson (Ed.), Control of Commu-
nicable Diseases in Man , 15th ed., American Public Health Association, Washington, DC., 1990, p.
113.
b One or two years at 40 ◦ F(4 ◦ C).