Don’t give up on berries. Eating berries is an important part of a balanced diet. And the APVMA is at pains to emphasise the risk of harm is low.
But this year-long suspension isn’t due to any new information about the pesticide itself. Rather, the Australian Pesticides and Veterinary Medicines Authority (APVMA) says it’s because we’re eating more berries so our potential exposure has increased.
To do this, you need to have estimates of how much residue is on food and how much food we eat.
The APVMA has a maximum limit for how much dimethoate we should be exposed to from our food. This is known as the acute reference dose (or ARfD), which is 0.02 milligrams per kilogram of body weight.
What is dimethoate?
So careful regulation of both application of dimethoate and levels of dimethoate residues on food are required so we are not exposed to harmful levels.
Australia’s regulator has suspended use of a common pesticide used on blueberries, raspberries and blackberries known as dimethoate.
The level of residues detected are unlikely to pose a serious risk to human health, but has proposed suspension of these specific dimethoate products as a precautionary measure.
Eating more berries is a good thing. But this means that current trace levels of dimethoate on berries (0.0033 micrograms per kilogram of body weight per day for a toddler) might potentially exceed the maximum limit for children aged two to six years.
This maximum dose includes a safety factor of ten. In other words, the maximum dose allowed is ten times lower than the lowest dose that has no effect.
How much is too much?
The amount of maximum permissible residues depends, in turn, on how much someone is exposed to from their food.
In particular, it says children aged two to six years may be at increased risk of exceeding maximum limits.
Here’s what we know about dimethoate and whether berries are still safe to eat.
So, what’s changed?
The APVMA states:
This dose was set in 2017. But it is consistent with current World Health Organization limits and Canadian regulations. Australia’s maximum dose is lower than
limits from the United States Environmental Protection Agency.
Mammals, including humans, also have the enzyme acetylcholinesterase, and can be poisoned by this class of pesticide.
Washing berries will not remove all dimethoate, but can substantially reduce the levels so you can continue to enjoy them and their benefits.
What can you do?
Dimethoate is a pesticide that has been used in Australia since 1956. It belongs to a class of pesticides that inhibits the enzyme acetylcholinesterase. This prevents the breakdown of a key neurotransmitter (chemical messenger) and so paralyses an insect’s nervous system, killing it.
The simplest approach is to wash your berries. You should be washing fruit and vegetables anyway. Washing helps get rid of soil, and potentially harmful microorganisms.
But our dietary habits have changed. Australian consumption of blueberries, blackberries and raspberries has increased substantially since the APVMA last assessed dimethoate. Consumption is up 285–962% compared to levels considered for its 2017 assessment.
