A listener asks:
“I live in an older suburb in Perth (Freo) in the past they have used chemicals in the ground (DDT) will growing vegetables at home even having chickens at home will any toxic chemicals that had been used in the past be found in the vegetables eggs etc….Thanks have a great day”
Tony from Freo
It’s a good question.
DDT spread quickly in popularity after World War II, and was eventually used right across the world, including Australia. It was an incredibly effective insecticide, wiping out mosquitoes bearing malaria, and in doing so has saved millions of lives.
Unfortunately, it also affected marine life and birds, and in a massive overreaction, it was banned in 1972 in the US, and 1987 in Australia.
The ban was lifted in 2006, and it is now being used in Third World countries where no alternative is available. It’s a bit of a funny one, as neither its effectiveness in saving lives, or its impact on marine life and birds are called into question. So in a way it is hero and villain at the same time.
The problem with it is that it is an organochlorine insecticide, and as such it is essentially nonbiodegradable. It’s half life is something like 50 years – compare that with the half life of modern day insecticides like pyrethrins, which are measured in months.
So to come to the original question – is it possible that we may have DDT in our soils, if we live in an area where it was used in the past? The answer is that yes it is a possibility.
To answer Tony’s specific question, his chooks may be able to help. One of the effects of DDT in birds, is that it results in eggs being laid with weak shells – so weak, for example, that they often break when their mother sits on them. So if the eggs that Tony’s chooks lay appear okay, there is every chance that there is minimal DDT in his soil.
But if you want to be sure, there are three labs in Perth that can test a soil sample for you: SGS in Newburn, ALS in Malaga, and the Chemistry Centre in Bentley.