Contaminated land basics

Types of contaminant

A wide range of substances may be responsible for the classification of land as contaminated. They can generally be characterised according to the hazard they introduce.

Table 1: Hazards and contaminants
Hazards Contaminants
Toxicity to humans or animals by ingestion of soil (particularly children) or home-grown produce Heavy metals, hydrocarbon compounds,
pesticide residues
Toxicity to humans or animals by direct contact Oils, tars, phenols and other hydrocarbons, acids
and alkalines
Toxicity to humans by inhalation Contaminated dust and particles, carbon dioxide, carbon monoxide, hydrogen sulphides and other gases, Asbestos fibres
Attack on services, e.g. plastic pipes, or building materials, e.g. concrete Phenols, oils, coal tars, sulphates, sulphides
and chlorides
Risk of explosions or fire Landfill  and mine gas, flammable or
combustible materials
Phytotoxicity Zinc, copper, nickel, sulphates