6.5 Stories of Toxicity and Contamination

Note that:

\[\begin{equation} \text{Risk} = \text{Exposure} \times \text{Toxicity} \end{equation}\]

Acute toxicity refers to the effects from a single exposure or repeated exposure of a pesticide over time - for instance, accidents during the application or the mixing of pesticides. A pesticide with a high acute toxicity can be fatal even if a small amount is ingested (this can be measured via oral toxicity, acute dermal toxicity, or acute inhalation toxicity).

Chronic toxicity refers to the effects of long term exposure or repeated lower level exposures to a toxic substance. The effects of chronic exposure do not appear immediately after the first exposure and make take years to produce symptoms. Some examples of chronic toxicity include:

  1. Mutagenicity - ability to cause mutations
  2. Tetratogenicity - ability to cause birth defects
  3. Oncogenicity - ability to cause cancer
  4. Liver damage
  5. Reproductive disorders - lower sperm count, miscarriage, and infertility
  6. Nerve damage - cholinesterase depression associated with organophosphate insecticides.
  7. Allergenic sensitization

6.5.1 Needle found in strawberries

“It was a crisis driven by social media and the only real victims were the strawberry growers, and to some extent other Australian fruit growers and exporters…”

– Queensland Strawberry Growers Association

A 50-year old woman was charged in a strawberry needle contamination case - this sparked a major food scare.

The strawberry industry (worth 160 million Australian dollars) was rocked; farmers had to dump crops amid warnings of widespread bankruptcy. The suspect was believed to have an axe to grind with her previous employers - she allegedly had discuss with others on seeking revenge.

6.5.2 High levels of pesticides found in lettuce

Pasar and other Iceberg lettuce brand names were pulled off the shelves after the AVA detected a high amount of fipronil - a wide-spectrum pesticide - in the lettuce.

The AVA stated that consumers should take extra care to wash their vegetables prior to cooking and consumption to remove pesticide residues.