Human Safety Thresholds for Endocrine Disrupting Chemicals May Be Inaccurate

10 April 2014 Bioscientifica Ltd

BPA containing plastic bottlesHuman and rat testes respond differently to endocrine disrupting chemicals such as BPA in two thirds of all cases, according to a recent review. As human safety levels are extrapolated from rodent data, the study could lead to a re-evaluation of the acceptable daily intake for many endocrine disruptors. The review is published in a special April issue of the journal Reproduction dedicated to endocrine disruptors.

Endocrine disruptors (EDs) are compounds that interfere with animal hormone (or endocrine) systems in various ways. Sometimes, this can lead to developmental problems, including those of the reproductive system. Over the past four decades, human sperm counts have been markedly decreasing and the rate of testicular cancer rates has risen. Meanwhile, the occurance of undescended testicles and abnormally developed male urethras are also thought to be increasing. Evidence suggests that these male reproductive disorders are at least partially due to the effects of endocrine disrupting chemicals which are becoming increasingly concentrated and prevalent in the environment and that these EDs act on the testis during fetal development.

Suspected EDs include pesticides, flame retardants and chemicals found in plastic goods such as bisphenol A (BPA) – one of a group called phthalates.. Currently, the human health risk from exposure to a given endocrine disruptor is normally assessed using a rodent model. The observed safety threshold is then reduced by a factor of 100 to calculate safety levels for humans.

In a recent review, researchers from the French Institute of Health and Medical Research (INSERM), Atomic Energy Commission (CEA) and University of Paris-Diderot compared the effects of six potential EDs on the function of rat, mouse and human fetal testis at comparable stages of their development. They simulated normal testicular development in each of these species using a novel in vitro culture system called FeTA. They found that the response to these six potential EDs was similar in humans and rodents for only one third of analyses. Human testes were more than 100 times more susceptible to some compounds, including BPA, compared to in rodents. For other compounds different effects were seen between species. More recent studies have confirmed the findings using a different experimental approach.

Sleeping Man and BabyProfessor René Habert, who led the study, said: “Our work suggests that for some compounds, human and rat cells show different susceptibilities. For others, there appear to be fundamental differences in the way these compounds act in humans and rodents. We think that these differences between species are even more pronounced for reproductive functions. This means we really have to question how relevant animal data is to assessing risk in humans.”

The FeTA system is an extremely reliable system for studying testicular cell development across species. It is more efficient than in vivo methods and also avoids problems of cross-contamination. “Our work highlights the fact that we need to test the effects of potential endocrine disrupting chemicals in both rat and human cells to be able to accurately predict the risk,” said Professor Habert. “The FeTA system is a great tool for comparing effects of endocrine disruptors on testis development in different species. However, the limitation is that we cannot use it to study long-term effects, as testis development can only be maintained for up to ten days, depending on the species.”

The next stage for the research is to assess the risk of BPA substitutes, including BPS and BPF, in both human and rodents. The group is also investigating how these compounds interact with rodent and human cells at the molecular level to understand how differences between species arise. “We need to develop specific tools to study chemical toxicity in human reproductive cells; this will allow us to accurately assess safety thresholds for different compounds, and re-evaluate the acceptible daily intake levels to protect human health for some of them” said Professor Habert.

USDA Set To Approve Next Generation of Genetically Engineered Pesticides

Dow: Destroying Our World
Center for Food Safety has launched a new national campaign focusing the food movement’s growing power on stopping the U.S. Department of Agriculture’s (USDA) approval of the next generation of genetically engineered (GE), pesticide-promoting crops: corn and soybeans engineered to be repeatedly doused in 2,4-D, a powerful herbicide that formed one half of Agent Orange. The campaign features a petition to the USDA and President Obama to reject Dow Chemical’s new GE crops, a campaign website and an animated video examining Dow Chemical’s sordid history.Why Dow Chemical? Dow Chemical has a long and troubling history of selling dangerous chemicals and poisons, and now they are targeting our food supply. We are launching this campaign to give people the chance to fight back, to speak with one voice and stop Dow Chemical’s “Agent Orange” crops.

2,4-D (2,4-dichlorophenoxyacetic acid), produced by Dow Chemical, was a component of Agent Orange, the toxic defoliant used in Vietnam. 2,4-D and other herbicides of its class have been independently associated with deadly immune system cancers, Parkinson’s disease, endocrine disruption, and reproductive problems.

Dow Chemical’s crops are the worst possible application of biotechnology. They offer zero consumer benefit while doubling down on the most devastating aspects of industrial agriculture. Instead of feeding the world, Dow Chemical’s new genetically engineered crops will poison it. Unless we stop them.

Check out our new animated video and campaign website, and join the campaign!

Center for Food Safety
660 Pennsylvania Ave, SE, #302
Washington DC 20003
phone (202) 547-9359 | fax (202) 547-9429
Contact Us: 
office@centerforfoodsafety.org

New Study Highlights Pesticide Application as Potential Source of Noroviruses in Fresh Food Supply Chains

Contaminated water used to dilute pesticides could be responsible for viruses entering the food chain, warn scientists

Human norovirus (hNoV), also known as the winter vomiting bug, is one of the most common stomach bugs in the world. The virus is highly contagious, causing vomiting and diarrhea, and the number of affected cases is growing. Currently there is no cure; sufferers have to let the virus run its course for a few days.

The consumption of fresh produce is frequently associated with outbreaks of hNoV but it remains difficult to identify where in the supply chain the virus first enters production.

A new study, published in the International Journal of Food Microbiology investigated whether contaminated water used to dilute pesticides could be a source of hNoV. Farmers use various water sources in the production of fresh fruits and vegetables, including well water and different types of surface water such as river water or lake water – sources which have been found to harbor hNoV.

To test this theory, eight different pesticides were analyzed in the study; each was diluted with hNoV contaminated water. The researchers tested whether traces of the virus were present in the samples after the two elements were combined. Results showed that the infectivity of the norovirus was unaffected when added to the pesticide samples. In other words: pesticides did not counteract the effects of the contaminated water.

The authors conclude that the application of pesticides on fresh produce may not only be a chemical hazard, but may in fact also be a microbiological risk factor; both having consequences on public health.

Pesticide Use Ramping Up As GMO Crop Technology Backfires

October 1, 2012, Chicago Tribune/Reuters
http://www.chicagotribune.com/business/sns-rt-us-usa-study-pesticides…

U.S. farmers are using more hazardous pesticides to fight weeds and insects due largely to heavy adoption of genetically modified crop technologies that are sparking a rise of “superweeds” and hard-to-kill insects, according to a newly released study.

Genetically engineered crops have led to an increase in overall pesticide use, by 404 million pounds from the time they were introduced in 1996 through 2011, according to the report by Charles Benbrook, a research professor at the Center for Sustaining Agriculture and Natural Resources at Washington State University. Of that total, herbicide use increased over the 16-year period by 527 million pounds while insecticide use decreased by 123 million pounds.

Herbicide-tolerant crops were the first genetically modified crops introduced to world, rolled out by Monsanto Co. in 1996, first in “Roundup Ready” soybeans and then in corn, cotton and other crops. Roundup Ready crops are engineered through transgenic modification to tolerate dousings of Monsanto’s Roundup herbicide.

In recent years, more than two dozen weed species have become resistant to Roundup’s chief ingredient glyphosate, causing farmers to use increasing amounts both of glyphosate and other weed killing chemicals to try to control the so-called “superweeds. Resistant weeds have become a major problem for many farmers reliant on GE crops, and are now driving up the volume of herbicide needed each year by about 25 percent,” Benbrook said.

It looks like we have unintended consequences as well as framers are replacing farm equipment tires at a much shorter frequency than before. The solution appears to be kevlar lined tires instead of planting crops that don’t destroy tires.

Note: For deeply revealing reports from reliable major media sources on the environmental and health risks posed by GMO foods, click here.

Ban Pesticide Responsible For Wiping Out Honey Bees.

Since 2006, U.S. honey bee populations have been in precipitous decline, with some estimates suggesting losses as high as 30% per year.1 While that’s terrible, the problem is far greater than just the loss of a species. Without bees, a big piece of our food supply is in serious danger. Pollination by honey bees is key in cultivating the crops that produce a full one-third of our food.

Scientists have been scrambling to understand the crisis — termed Colony Collapse Disorder — but have yet to find a single, definitive cause. There are likely multiple interacting causes, and mounting evidence suggests that one widely used class of pesticides may be a critical factor.

One such chemical, called clothianidin, is produced by the German corporation Bayer CropScience. It is used as a treatment on crop seeds, including corn and canola, and works by expressing itself in the plants’ pollen and nectar. Not coincidentally, these are honey bees’ favorite sources of food.

Shockingly, no major independent study has verified the safety of this pesticide. While clothianidin has been used on corn — the largest crop in the U.S. — since 2003, it was officially approved by the Environmental Protection Agency last year on the basis of a single study, conducted by Bayer. However, recently leaked documents show that the study was actually debunked by the agency’s own scientists, so the pesticide was effectively approved with no scientific backing.2

It is outrageous that the E.P.A. is putting a vital species, the livelihoods of farmers and beekeepers, and our very food supply at risk just so Bayer can peddle its pesticide. Click here to automatically sign the petition asking the E.P.A. to immediately issue a ban on clothianidin.

When clothianidin first came to market, there was little or no scientific review of its effect on the environment. The E.P.A. allowed “conditional registration” in 2003 but requested additional study to establish the safety of the chemical. Bayer, the producer of the chemical, conducted one such study, and without public notice, the E.P.A. granted unconditional use in early 2010.

But E.P.A. documents3 leaked at the end of last year expose a more sordid story. Agency scientists who reviewed Bayer’s study determined that the evidence was by no means sound, and even downgraded the study to a level at which it should not have been allowed as the basis for an unconditional approval of the pesticide.

Additional independent studies have shown that neonicotinoid pesticides like clothianidin are highly toxic to honey bees, providing compelling evidence that they should be immediately taken off the market until the E.P.A. can conduct a full and valid scientific review.

This appears to be a case of the E.P.A. catering to the needs of a large chemical corporation at the expense of a lynchpin species in our ecosystem. France, Italy, Slovenia, and Germany — the home of Bayer — have already banned clothianidin.

The stakes are simply too high to continue the use of this chemical in the absence of any scientifically verified evidence that it is safe to use. Click here to automatically sign the petition telling the E.P.A. to immediately prohibit the use of clothianidin and conduct a full scientific review to determine its impact on honey bee and other non-target populations.

Thank you for speaking out to protect the honey bees and our food supply.

Adam Klaus, Campaign Manager
CREDO Action

1 secure.wikimedia.org/wikipedia/en/wiki/Colony_collapse_disorder
2 www.grist.org/article/food-2010-12-10-leaked-documents-show-epa-allowed-bee-toxic-pesticide-
3 www.panna.org/sites/default/files/Memo_Nov2010_Clothianidin.pdf

Superfoods cover image

Play The Is It Healthy Game!

Read Nutrition News

Making Healthy Choices Easier Than You Think

You have Successfully Subscribed!