In the 1980s and 1990s governments across Australia outlawed the use of the herbicide 245T. The ban was introduced for one very good reason - 245T contains dioxin, a chemical impurity with the potential to seriously harm people who are exposed to it.
But has the dioxin menace been tamed?
Four Corners reveals evidence that this potentially deadly chemical compound may still be present in weed control products and that authorities do not routinely test for it.
The program also reveals that this hands-off approach to regulation is entirely in keeping with the way governments have dealt with the lethal chemical dioxin over four decades.
Weeds are a scourge on country life, costing landowners up to $4 billion a year. In the 1960s and 70s the solution used in weed eradication often involved the spraying of herbicides 245T and 24D. Both substances contained dioxin. It was common practice for workers, in many parts of the country, to decant the herbicides from large drums into backpacks to apply the chemicals. In many cases they sprayed the liquid without using proper protective clothing.
Four Corners reveals the full extent of the problems caused by the chemicals. We meet the families of former government employees who have died almost certainly as a result of their exposure. The program also reveals the failure of successive governments to acknowledge the problems associated with the use of the chemicals and the refusal of those governments to pay adequate compensation to people who sprayed them and who have suffered massive health problems as a result. Four Corners reveals there are now reports of the children and partners of former sprayers also getting sick.
It is now widely accepted by experts that dioxin is the common factor that causes health problems in people who were exposed to herbicides. Although governments finally banned 245T, they continued to sanction the use of 24D as a herbicide, provided it did not contain anything more than trace levels of dioxin. The problem is authorities admit they do not routinely test for the potentially lethal chemical contaminant.
Four Corners has found evidence that herbicides containing 24D, currently being sold, do have levels of dioxin which could pose a potential health risk. Significantly, experts warn that cheap imports might be a source of herbicides contaminated with dioxin and yet those imports haven't attracted significant scrutiny.
To add to the problem posed by the lack of regulation enforcement, there is also evidence that farmers are spraying forms of 24D that drift across large tracts of neighbouring land creating a potential danger to other farm crops.