1. SOIL CONTAMINATION

2. What are Wastes?
Wastes are defined as “substances or objects which are disposed of or are intended to be disposed of or are required to be disposed of by the provisions of the law”

3. Kinds of Wastes
Solid wastes: domestic, commercial and industrial wastes
Examples: plastics, bottles, cans, papers, scrap iron, and other trash
Liquid Wastes: wastes in liquid form
Examples: domestic washings, chemicals, oils, waste water from ponds, manufacturing industries and other sources

4. Classification of Wastes according to their Properties
Bio-degradable
can be degraded (paper, wood, fruits and others)
Non-biodegradable
cannot be degraded (plastics, bottles, old machines,
cans, styrofoam containers and others)

5. Classification of Wastes according to their Effects on Human Health and the Environment
Hazardous wastes
Substances unsafe to use commercially, industrially, agriculturally, or economically that are shipped, transported to or brought from the country of origin for dumping or disposal.
Non-hazardous
Substances safe to use commercially, industrially, agriculturally, or economically that are shipped, transported to or brought from the country of origin for dumping or disposal.

6. Sources of Wastes
Households
Commerce and Industry

7. Sources of Wastes
Agriculture
Fisheries

8. TYPES OF CONTAMINANTS
Organic contaminants have a carbon base, e.g., petroleum hydrocarbons, dioxins, chlorophenols.
Inorganic contaminants refer to metals & other molecular compounds, e.g., metals, major ions & nutrients.
Non-reactive contaminants are dissolved contaminants that are not influenced by chemical reactions or microbiological processes.
Reactive contaminants are those contaminants in which the transport processes are considered along with various chemical mass transfer & microbial degradation processes.

9. Basic concepts
Contaminated land defined as “Any land which appears to the local authority or in whose authority it is situated to be in such a condition, by reason of substances in, or under land that significant harm is being caused or there is significant possibility of such harm being caused” (Part IIA of the Environment Protection Act (1990, Section 78(A))

10. Land contamination may impact on health or the environment
Contamination may affect people’s perceptions of their local environment and it may affect the use of land
Contamination may also affect people’s personal finances

11. Risks to humans posed by contaminants on land:
Increased levels of illness have not been observed in people living on contaminated land
However ill effects, which may be undetectable using current epidemiological and analytical methods, may occur
Impact from contaminated soil can be difficult to separate from other types of pollution
Possible health effects of the contaminants are difficult to establish because there are many confounding factors
Risks to humans posed by contaminants on land:
Despite fact that biomarkers have shown exposure to soil contaminants does occur in many cases, increased levels of illness have not been observed in people living on contaminated land.
This does not rule out the possibility of ill effects, which may be undetectable using current epidemiological and analytical methods
Impact from contaminated soil can be difficult to separate from other types of pollution or contaminants that we are exposed to in our daily lives, this makes extremely difficult to demonstrate a cause-effect relationship
Possible health effects of the contaminants are difficult to establish because there are many confounding factors (pre-existing health of people being studied, wealth or poverty of the people, availability of health or social care services, etc)

12. SOURCES OF CONTAMINATION
Sources originating on the ground surface
Infiltration of contaminated surface water
Land disposal of solid and liquid waste
Accidental oil spill
Fertilizers and pesticides
Disposal of sewage and water treatment plant sludge

13. 2. Sources originating above water table
Waste disposal in excavation
Landfills
Leakage from underground storage tanks
Leakage from underground pipelines
Septic tanks

14. 3. Sources originating below water table
Waste disposal in wet excavations
Deep well injections
Mines
Abandoned or improperly constructed wells

15. Most common contaminants

16. CADMIUM
Cadmium can be found in cigarettes, fertilisers used in agriculture and in low levels in all foods (highest in shellfish, liver, and kidney meats)
Breathing or eating air or food contaminated with cadmium over a long period of time can cause health effects including:
Renal dysfunction
Growth disturbances
Lung disturbances (bronchitis, obstructive lung disease)
Skeletal damage
Reproductive disturbances
Anaemia