Natural occurrence of 1080
Fluoroacetate, the active ingredient of 1080, occurs naturally in several toxic plants in Australia, South Africa, and South America. At least 40 such species occur in Australia, with most confined to the south-west of Western Australia. All of these species are legumes but most are from the genus Gastrolobium, with one Acacia, and two species of Nemcia. Some of the Gastrolobiums can produce considerable amounts of 1080 (e.g. G. bilobum, G. parviflorum; >2500 mg per kg dry weight of leaves). Fluoroacetate also occurs at very low concentrations in tea leaves, and guar gum, a common constituent of a variety of foodstuffs.
Biodegradation
1080 is highly water soluble, and therefore readily leaches from most baits. However, mainly due to the activity of a number of fungi and bacteria (at least 24 different species) which can degrade 1080 into harmless by-products, accumulation in, or contamination of, soil or the environment does not occur. 1080 does not attain harmful levels and/or persist in waterways, even when quite high natural concentrations of fluoroacetate are present in the surrounding environment. Furthermore, as most 1080 is eliminated from living animals within three days, 1080 residues do not persist in meat, blood, the liver, or fat. (This is in contrast to the anticoagulant, brodifacoum and several other pesticides). Thus, bioaccumulation of fluoroacetate is very unlikely because biodegradation or elimination of fluoroacetate occurs at many levels in the food chain. This includes microorganisms, invertebrates, birds, mammals and reptiles.
The longevity of 1080 in baits, or of the baits themselves, depends upon the prevailing weather conditions. In the presence of rain, baits may only remain toxic for a matter of days, particularly with the grain-based baits. In contrast, some baits used to control pest canids can remain toxic for several months under dry conditions. The loss and degradation of 1080 from baits and carcasses is mainly dependent upon leaching, and the activity of microorganisms. However, it is not only the longevity of baits and their active ingredient (i.e. 1080) which determines a potential risk profile. How quickly baits are taken, the rate of lay, and where baits are located all influence these assessments.
For safety reasons (e.g. restocking paddocks), however, it is best to assume that baits will remain toxic for at least 4 weeks, and end-users must make their own decisions based on the local conditions regarding restocking of baited paddocks. Some bait trails can be covered with soil to reduce any potential hazard.