Frequently Asked Questions

In this section you will find an answer to frequently asked questions on the topic of water, plant and animal health.

1. What is soil?

Soil is a mixture of organic matter, minerals, gases, liquids and organisms that support a diversity of life. It provides the medium for plant growth; a habitat for many insects and other organisms; acts as a filtration system for surface water; stores carbon; and contributes to the maintenance of atmospheric gases.

2. What is soil pollution?

Soil pollution is the degradation of soil due to the presence of natural or man-made contaminants which compromise the growth and development of plants and may poison animals or humans. These contaminants include chemicals, microbes or parasites. The prominent chemicals of concern include heavy metals, pesticides, phosphate fertilisers and drugs; while protozoa, fungi, bacteria and viruses are among the soil-borne microbes.

3. What impact do heavy metals have on soil health?

When a soil is contaminated with heavy metals it is difficult to be remediated. Heavy metals are highly hazardous to the environment and organisms because they can be enriched through the food chain. Heavy metals may affect soils by impacting on microorganisms and enzymatic activity; or by poisoning the plants. They may also affect human health both through the inhalation of gases and dust particles and by ingestion of contaminated food causing serious illnesses.

4. What are the main sources of water pollution?

The main sources of water pollution include both inorganic and organic wastes, heat from industries, petroleum compounds, urban wastes, agricultural wastes, pesticides, and acid mine drainage. Among these pollutants mercury, perflouoroalkyls (PFAs e.g. perchlorate), tributyiltin, dioxins and polychlorobiphenyls (PCBs) are present.

5. Is water pollution a concern?

Water pollution may affect health since many of them are highly lipophilic, and bio-accumulate along the food chain. However, in developed countries water quality is monitored at each step of the food chain to ensure it is suitable for human consumption. Control measures include regular execution of and response to sanitary surveys; maintenance of irrigation water reservoirs and distribution systems; adequate water treatments to gain better water quality; and faecal indicator tests to monitor water quality.

6. What are microplastics?

Microplastics are pieces of plastic with a diameter of less than 55mm. This small size is of concern in the marine environment because it is small enough to be taken up by the marine environment. The potential consequences of plastics and microplastics are well documented, from their physical obstruction in the marine environment to ingestion and physiological effects.

7. Why are plants important?

Plants provide many important ecosystem functions, including providing oxygen and food for animals, as well as providing wood and fibres for human use.

8. Are pests a concern to plant health?

Pests damage plants and make them vulnerable to disease. Plants and pests in their natural setting have evolved in an arm race type scenario, where the evolution of a new offensive trait in the pest is usually matched by the evolution of defensive trait in the plant. However, when a pest meets a plant it has never encountered before, the plant does not possess the traits needed to defend against the pest. This can lead to the pest becoming very damaging to the unprepared plant.

9. What is Integrated Pest Management?

Integrated Pest Management is advocated as a sustainable approach to managing pests by combining biological, cultural, physical and chemical controls in a way that minimises economic, health and environmental risks.

10. What are mycotoxins?

Mycotoxins are toxic secondary metabolites produced by filamentous fungi growing on grains before harvest and in storage which can contaminate food and feed worldwide. Mycotoxins can enter the food chain at any point, particularly during production and storage, with varying severity. Policies and procedures are in place to ensure mycotoxins do not pose a significant threat to human health; and to safeguard the economic interests of producers and traders.