Contamination of soils in historic apple and pear growing areas in Tasmania by lead arsenate spray

By Chris Harries Tasmanian Times, 12th July 2010

Comment by Chris Harries on Article: International spotlight on arsenic and lead poisoning in Australian lead mining town [re: www.lead.org.au/lanv10n4/LEAD_Action_News_vol_10_no_4.pdf ]

[Source: Tasmanian Times, according to its own website: “Tasmanian Times is a forum of discussion and dissent - a cheeky, irreverent challenge to the mass media’s obsession with popularity, superficiality and celebrity”, 12th July 2010  ]

This is a tangential issue but… what information is out there on contamination of soils in historic apple and pear growing areas in Tasmania?

As many of us remember, lead arsenate was liberally sprayed for decades throughout the Huon as a coddling moth poison and, as Rachel Carson noted in her seminal work Silent Spring, is one of the most persistent poisons used in agricultural practice.

More recent research shows that where lead arsenate has been widely used on Australian farm, soil analysis shows that those soils may have concentrations 30 times higher than normal. Nice to know, but what does that means in terms of on-going risk?

We do know that carrots, for instance, are good at absorbing heavy metals from soils, and have sometimes been grown as a throw away crop to try to rid a field of lead / arsenic contamination. 

Of particular concern, Tasmanian land owners who may wish to grow certified organic produce, can organic produce be grown on lead arsenate contaminated soils? 

There are many web references to standards set in US states where lead arsenate sprays were widely used, but I have failed to find much local data or regulation.

Some questions:

1. Is lead arsenate, where used as a pesticide, found in the soil at high enough levels to warrant concern?
2. What are the potential risks for families living in former apple growing orchard areas?
3. What are the potential risks for domestic animals, livestock, or wildlife?
4. What is the likely take-up in vegetables and fruit grown on those soils?
5. Can these chemical residues move off-site and pose a hazard elsewhere?
6. How do people who live on these lands deal with the issue?