Some foods we eat contain toxins or poisons. Explain why we do not normally suffer from the effects of these toxins. Do not discuss bacteria.

Some natural toxins can be formed in food as defense mechanisms of plants, through their infestation with toxin-producing mould, or through ingestion by animals of toxin-producing microorganisms.

Natural toxins can cause a variety of adverse health effects and pose a serious health threat to both humans and livestock. Some of these toxins are extremely potent.

Adverse health effects can be acute poisoning ranging from allergic reactions to severe stomachache and diarrhoea, and even death.

Long-term health consequences include effects on the immune, reproductive or nervous systems, and also cancer.

A scientific expert committee jointly convened by WHO and the Food and Agriculture Organization of the United Nations (FAO) – called JECFA – is the international body responsible for evaluating the health risk from natural toxins in food.

International standards and codes of practice to limit exposure to natural toxins from certain foods are established by the Codex Alimentarius Commission based on JECFA assessments.

compost can be added to topsoil as a:

pesticide

there are so many examples for that in different areas, like biology experiment carried out in our lab recently.

here's one link: