They should not be added inappropriately to the plants that are going to be edible. There should be adequate period before harvesting so that they are washed off by rain or other means so that the residue fall below the ADI (Acceptable Daily Intake) level for that particular chemical.

Large quantities of agrochemicals that are not permitted in developed countries are produced in industries and exported to countries that do not regulate their farming to the same standard.

There is no safe level for non-bio-degradable synthetic chemicals which cause further chronic illness. Commercial farming also utilises antibiotics in animals which are added to the human food chain. They prevent and treat common diseases, and relieve stress so that they will grow faster and bigger and produce more milk and eggs etc.

Three antibiotics promote growth. They are also regularly used in animal food to wipe out ammonia producing bacteria in their intestines.

Antibiotics contaminate livestock, including poultry, cattle, pigs and veal calves. It is also possible for them to contaminate milk.

There are regulations stipulating a minimum time before milking or slaughtering to permit the antibiotics to be administered. The widespread use of antibiotics causes drug resistant strains of bacteria.

Canthaxanthin is added to food which is fed to farmed salmon and trout to enhance the colour of their pink flesh. Similarly the yellow colour of egg yolks can be enhanced.

Fertilisers, which contain nitrate, potash, and phosphates, are used to increase the growth and yields of crops. They 'flood out' the other necessary nutrients that are required for healthy crops and the welfare of animals.

The heavier plants have an increased need for zinc, magnesium, chromium and selenium. When they are not replaced, the soil becomes depleted. They are deficient in most soil even before farming.

The solution to maximise mineral intake and minimise toxin exposure is to use organic foods.

The European Union (EU) has set standards for the production, processing and control of organic farming - the fertility of the soil needs to be built; chemicals and non-renewable resources have to have minimum usage; environmental damage and pollution have to be minimised; the work must be in accordance to nature; the welfare of the animals being farmed must be taken in account; minimum processing and additives must be used.

Genetically modified foods have the potential to create new toxins in crops and animals.

Pasturing livestock and poultry is conventional practice.

In biodynamic farming, the soil and crops are fertilised utilising natural methods.

Freshness is important. If they do not reach the consumers in time they may lose nutritional value. The loss of vitality and vitamins will negate the advantages of being grown without chemicals.

The writer is a student of Life Science and Nutritional Medicine.