Soil contamination and health

Damage to health in the event of exposure

Living, working or recreation at a location with soil contamination almost never results in serious health problems. That is because insufficient quantities of these chemical substances from the soil actually enter people's bodies ('exposure'). However, contaminated ground can make illnesses more likely if we come into direct or indirect contact with contaminated soil or products which come from the soil. This could happen during gardening or digging work.

Direct and indirect exposure

People can come into contact with contamination in the soil or groundwater via various exposure routes. This not only involves direct contact with the soil, but also indirect contact such as inhaling contaminated articles, drinking contaminated groundwater or eating contaminated vegetables from the garden.

How contaminated soil is used determines the degree of exposure. For example, the consumption of cultivated vegetables grown on contaminated soil in a contaminated vegetable garden can cause health issues. Similarly, health issues can occur after breathing in volatile contaminants which move from the ground water to the surface of the soil or accumulates in people's homes. Another example of risks of health damage occurs if contaminated drinking water is consumed, for example from a private drinking water well. Lastly, chemical substances attached to soil particles can enter children's bodies through hand to mouth contact, for example while they are playing on contaminated soil.

The parties involved

The state, provincial governments and municipalities, including the Municipal Health Service, are working together to assess chemical soil quality and cooperate if the risks are excessive and action has to be taken (in the form of a soil remediation operation). The research institutes play a role in the development of the required instruments. The consultancies generally carry out the soil investigation which involves, for example, taking and assessing soil and groundwater samples.

Financing

In the first instance the party that has caused the soil contamination is held responsible. This means that it has to pay for the investigation and any remediation work. Often, several parties are responsible for an incidence of contamination and in many cases no one will know who actually caused it. The government only pays for the soil to be made suitable for use if no party can be held accountable.

Assessment of soil contamination

Chemical substances that have been detected are not always a problem and therefore do not, by definition, have to be removed. A risk assessment can be carried out to check whether, at a contaminated location, and excessive risk actually exists in terms of damage to people's health, effects on the soil ecosystem and the spread of substances via the groundwater. A standard instrument is available to do this, namely the decision support model called Sanscrit. Certainly if there is less intensive contact with ground and with products from the ground, for example, as on an industrial estate, the presence of chemical substances can often do little harm.

For policy

For people who want, or are going, to communicate about soil, both with regard to the possibilities which the soil offers and with regard to the threats facing the soil, there is a brochure entitled Communicate about soil: possibilities and threats. Clarification of the concepts of soil contamination risks and standardisation.

For residents

• Your provincial government or the municipal authorities can tell you which nearby locations are, or are suspected of being, contaminated. Sometimes the municipal authorities will have commissioned an operations unit or environmental authority to carry out this task.
• Are you buying a house or a piece of land? If so, you should check whether a declaration of suitability or a 'clean soil declaration' is available. If this is not the case, an assessment will have to be made to determine whether the site is contaminated.
• You yourself should also look out for indications that the soil is contaminated. For example, have any oil barrels leaked onto the site, or has a path been laid using rubble which may include broken pieces of asbestos?
• Make sure the soil is clean before you start a vegetable garden.
• If you are going to build or extend, a soil survey will often be necessary in order to obtain a building permit.
• Do you live on contaminated soil which is being cleaned up? If so, you can set up a residents group to represent your interests.
• You can also take steps yourself to prevent any new soil contamination. Be careful with substances which can cause contamination such as oil and petrol.
• If you suspect soil contamination, you should report this immediately to the municipal authorities.