Many pesticides are very persistent, bioaccumulative and toxic. Children with their increased vulnerability to chemicals are at greater risk from pesticide exposures.
Organochlorines
Organochlorine pesticides (OCs) include the persistent organic pollutants (POPs) – DDT, dieldrin, aldrin, endrin, heptachlor, chlordane and mirex. These pesticides are banned in Australia, yet their residues are still found in soil and sediment. Other OCs that continue to be used in Australia include lindane and endosulfan.
Endosulfan
The organochlorine insecticide, endosulfan is a highly toxic, ubiquitous environmental pollutant, causing long-term harm to humans and wildlife.
Endosulfan is:
- acutely toxic and has poisoned numerous people, livestock and wildlife
- an endocrine disruptor and threatens reproductive capacity, and increases risks of breast cancer
- volatile and contaminates environments far from where it is used
- persistent in the environment, and its main metabolite is even more persistent
- already deregistered or banned in many countries
- effective alternatives are available for all uses
Endosulfan is being assessed as a POPs by the POPs Review Committee .
For more information :
IPEN Adding New POPs
Endosulfan Monograph
Position Paper of Pesticide Action Network (PAN) Asia and the Pacific on Endosulfan
Organophosphates
Organophosphates (OPs) such as the pesticide chlorpyrifos and its metabolites are severe neurotoxins and damage the central nervous system. Chlorpyrifos is widely used both in agriculture and for termite and insect control.
The USEPA review of chlorpyrifos acknowledged that the insecticide and its metabolites had been found in the urine of 89% of children tested in one US study. Dow AgroSciences 1998 data showed the chlorpyrifos metabolite, TCP-3,5,6-trichloro-2-pyridinol in 100% of a sample of 416 US children (0-6 years ).
In 1998, a study in regional Australia had shown chlorpyrifos was present in the meconium (first bowel discharge) of 59% of new-born babies.
Chlorpyrifos is very toxic to freshwater fish, aquatic invertebrates and estuarine and marine organisms as well as birds, 21 and had been implicated in fish and bird kills. In1990, opportunistic sampling found Chlorpyrifos in three eggs of the Little Terns (0.06-0.36ppm), in a liver sample from Little Terns (0.02ppm) and in a Pelican egg (0.5ppm) from the Wallace Lake colony on the central coast of NSW.
Chlorpyrifos has a log Kow of 4.96 (14) meeting the criteria for bioaccumulation for a new POPs or persistent organic pollutants.
Its residues (breakdown product, 0,0-diethyl 0-(3,6-dichloro-2-pyridyl) phosphothioate) had been detected in the kidney and fat from cattle that had been dipped only once in a 0.025% emulsion of chlorpyrifos for cattle tick.
New research has demonstrated another impact of chlorpyrifos on the environment. It found that several species of freshwater fish have lower temperature tolerances when exposed to the widely used pesticides endosulfan and chlorpyrifos. Australian scientists have found that fish exposed to sub-lethal concentrations of endosulfan and chlorpyrifos showed significant reductions in the ability to survive in warmer waters. Affected fish displayed “erratic swimming…, uncoordinated movement with body quivering, rolling over on sides or back” and loss of the ability to swim upright.
The study predicts that global warming will make fish more susceptible to dying from pesticide-contaminated water. Both endosulfan and chlorpyrifos are commonly used in cotton, horticulture and sugar cane production.