A Working Document
General comments on the toxicity of agricultural chemicals
List of general comments:
Rachel's Environmental News
The Human Burden of Environmental Toxins and their Common Health Effects
A Short Review of the Problems Posed by Xenobiotics in chemical mixtures and the role of mixed function oxidases
Specific information about the toxicity of individual agricultural chemicals
List of chemicals:
The Triazines
Dangers of Nitrite Combining with Triazines
Atrazine
Monsanto's Roundup
Nitrate
Dioxin in Pesticides
General comments on the toxicity of agricultural chemicals
Pesticides are toxic by design and meant to kill weeds, insects, rodents and other pest organisms; they do so by impairing the nervous and immune system function. Many pesticides and their byproducts (which include PCBs) are highly
toxic, persistent and bioaccumulative in humans. Because our nervous system shares basic physiology with other living things, pesticides also harm the human nervous and immune systems [see Rachel's #660]. Of the 140 pesticides officially
known to be neurotoxicants, only 12 (8.5%) have been tested for potential impacts on children's development.[10] A study of Mexican children exposed to pesticides found impaired memory, creativity and motor skills compared to an unexposed population. The pesticide exposed children had trouble drawing
an ordinary stick figure of a human, something the unexposed children could readily do.[11]
[10] Ted Schettler and others, IN HARM'S WAY: TOXIC THREATS TO
CHILD DEVELOPMENT (Cambridge, Mass.: Greater Boston Physicians
for Social Responsibility [GBPSR], May 2000).
[11] Elizabeth A. Guillette and others, "An Anthropological
Approach to the Evaluation of Preschool Children Exposed to
Pesticides in Mexico," ENVIRONMENTAL HEALTH PERSPECTIVES (June
1998) Vol. 106, No. 6, pgs. 347- 353.
Reference: RACHEL'S ENVIRONMENT & HEALTH NEWS #821. http://www.rachel.org. July 7, 2005
"Agricultural chemical formulations have been proven to be harmful to humans."
[Reference: Crinnion W.J: Environmental Medicine, Part 1 'The Human Burden of Environmental Toxins and their Common Health Effects'. Alt. Medical Review 5:52-63, January 2000). As cited by Dr Alison Bleaney in her submission on the review of the Tasmanian aerial spraying code of practice, May 2005].
"Chemicals can be harmful either as a single agent or in combinations and often at lower concentrations than recommended as being safe."
[Reference: Pollak J: 'A Short Review of the Problems Posed by Xenobiotics in chemical mixtures and the role of mixed function oxidases'. International Journal of Environmental Health Research 8. 157-163,1998]. As cited by Dr Alison Bleaney in her submission on the review of the Tasmanian aerial spraying code of practice, May 2005].
Specific information about the toxicity of individual agricultural chemicals
In 2002 and again in 2003, Univ. California Berkeley endocrinologist Tyrone Hayes published results documenting hermaphroditism in frogs caused by exposure to extremely low levels (0.1 ppb) of atrazine. (Reference: Hayes, TB. 2004. There is no denying this: defusing the confusion about atrazine. BioScience 54:1138-1149).
0.1 ppb (parts per billion) is the Australian Drinking Water Guideline level. That is, the level at which action should be taken to prevent further repeated contamination of drinking water in Australia. These 'guidelines' have no legal standing and are generally not implemented in Tasmania.
The Human Health Level for Atrazine in Australia, however, is 40 parts per billion. In a Financial Review article authored by Julie Macken (May 7-8, 2005) US expert Professor (Integrative Biology) Tyrone Hayes made this comment: “Australia is allowing 400 times the amount of water contamination (with atrazine) that we found in castrated amphibians and fish [ie 0.1ppb] — there is no way I’d be drinking the water”..
“..a chemical interaction between atrazine and nitrite and between simazine and nitrite results in the formation of N-nitrosoatrazine and N-nitrososimazine. These nitrosamines have not been adequately tested for carcinogenicity, but structure-activity considerations raise a concern that they may have carcinogenic potential.”
Note: Nitrite is a common contaminant of fresh water in Australia as a result of runoff from commercial fertiliser applications and grazing activities.
Source: US Agency for Toxic Substances and Disease Registry.
http://www.atsdr.cdc.gov/interactionprofiles/IP-10/ip10-c1.pdf
In the 1980s Dioxin was identified as a contaminant in many pesticides.
Dioxin is a Class One carcinogen
High nitrate content in food and drinking water can be converted to nitrosamines that are carcinogens. Nitrates can impair the ability of the blood to carry oxygen, and may pose a risk of methemoglobinemia. FAO (2000)
'Monsanto's Roundup Linked to Pregnancy & Reproductive Problems & Endocrine Disruption'
June 3, 2005
Conclusion
Our studies show that glyphosate acts as a disruptor of mammalian cytochrome P450 aromatase activity from concentrations 100 times lower than the recommended use in agriculture; this is noticeable on human placental cells after only 18 hr, and it can also affect aromatase gene expression. It also partially disrupts the ubiquitous reductase activity but at higher concentrations. Its effects are allowed and amplified by at least 0.02% of the adjuvants present in Roundup, known to facilitate cell penetration, and this should be carefully taken into account in pesticide evaluation. The dilution of glyphosate in Roundup formulation may multiply its endocrine effect. Roundup may be thus considered as a potential endocrine disruptor. Moreover, at higher doses still below the classical agricultural dilutions, its toxicity on placental cells could induce some reproduction problems.
More at:
http://www.organicconsumers.org/monsanto/pregnancy060305.cfm