Alison Bleaney
There is now substantial evidence that certain chemicals (e.g. estradiols, nonylphenol, bisphenol A, PCBs and some pesticides) can impact on the health of wildlife, influencing hormonal and reproductive functions. Chemicals that interfere with the normal functioning of endocrine systems are generally referred to as Endocrine Disrupting Chemicals (EDCs).
http://www.apvma.gov.au/media/mr0802.shtml
CSIRO classify atrazine and simazine as endocrine disruptors and call for the precautionary approach and to minimise unnecessary discharge of EDS to the environment. (The Black Mountain Declaration 2007)
They also state:
“Research on the outcomes of contaminants has tended to focus on single chemicals tested under highly controlled conditions. In reality, ecosystems are complex environmental matrices (eg. water, sediments, soil and air) and mixtures are the norm.
The effect of a contaminant when assessed in isolation may be very different to the effect of a mixture. There are combined effects that may be described as additive, antagonistic or synergistic, and there are various chemical interactions, which may result in dramatically different fate, effects and risk profiles.
There is now substantial evidence that certain chemicals (e.g. estradiols, nonylphenol, bisphenol A, PCBs and some pesticides) can impact on the health of wildlife, influencing hormonal and reproductive functions. Chemicals that interfere with the normal functioning of endocrine systems are generally referred to as Endocrine Disrupting Chemicals (EDCs).
The ecological risks associated with EDCs, pharmaceuticals and personal care products (PPCPs) in the Australian environment are not clear. This is largely due to a lack of knowledge about their incidence in the Australian environment and the impact of exposure for our unique native species.
CSIRO is developing bioassays and biomarkers for assessing ecotoxicological impacts on native species. We seek to understand stress impacts throughout the system (from the molecular to the population level) for integrated environmental risk assessment. ”
Professor Tyrone Hayes (2002) demonstrated chemical castration of frogs (similar enzyme and hormone systems to humans) with atrazine concentration at 0.1 ppb.
Professor Bernard Stewart on his recent visit (4/2008) to Tasmania stated that atrazine should not be in drinking water and should be phased out from use due to its properties.
The Australian Drinking Water Guidelines (ADWG) 2004, states:
“Atrazine should not be detected in drinking water.
Pesticides should be authorised for use in water or water catchment areas only where necessary.
Water suppliers should adopt a preventive risk management approach, as stipulated in the ADWG, to maintain the supply of water at the highest practicable quality.
The guideline values should never be seen as a licence to degrade the quality of a drinking water supply to that level.
It is the responsibility of drinking water suppliers to keep the community fully informed about water quality, existing problems and needs for improvement.”
So,
when is the use of atrazine “necessary”?
Who gets to make these decisions?
Why is Tasmania in its recent 6/5/2008 “A review of the provisions for aerial and ground spraying agricultural chemical products” allowing an atrazine guideline value of 5ppb for pescribed water bodies?
( Note that the exception to this is for pescribed water bodies that are regularly used to provide drinking water for humans, when the specified guideline value is 0.1 ppb.)
How did ASCHEM come to this figure of 5 ppb?
Who decides and on what basis, what is termed a ” water body that is regularly used to provide drinking water for humans”?
Where is the community consultation as described in the ADWG re water quality, existing problems and needs for improvement?
Dr Alison Bleaney
7 May 2008
