Unsolicited Advice - Nalgene Bottle on Harness

[JayB]

Maybe. None of the data I've seen suggests that there's any risk from the levels of BPA that anyone using polycarbonate containers for food or water is likely to encounter in any realistic scenario.

 

": Toxicol Appl Pharmacol. 2007 Feb 1;218(3):280-8. Epub 2006 Dec 5.Click here to read Links

Analysis of the interaction of phytoestrogens and synthetic chemicals: an in vitro/in vivo comparison.

Charles GD, Gennings C, Tornesi B, Kan HL, Zacharewski TR, Bhaskar Gollapudi B, Carney EW.

 

Toxicology and Environmental Research and Consulting, The Dow Chemical Company, Midland, MI 48674, USA. charles_grantley@allergan.com

 

In the evaluation of chemical mixture toxicity, it is desirable to develop an evaluation paradigm which incorporates some critical attributes of real world exposures, particularly low dose levels, larger numbers of chemicals, and chemicals from synthetic and natural sources. This study evaluated the impact of low level exposure to a mixture of six synthetic chemicals (SC) under conditions of co-exposure to various levels of plant-derived phytoestrogen (PE) compounds. Estrogenic activity was evaluated using an in vitro human estrogen receptor (ER) transcriptional activation assay and an in vivo immature rat uterotrophic assay. Initially, dose-response curves were characterized for each of the six SCs (methoxyclor, o,p-DDT, octylphenol, bisphenol A, beta-hexachlorocyclohexane, 2,3-bis(4-hydroxyphenyl)-propionitrile) in each of the assays. The six SCs were then combined at equipotent ratios and tested at 5-6 dose levels spanning from very low, sub-threshold levels, to a dose in which every chemical in the mixture was at its individual estrogenic response threshold. The SC mixtures also were tested in the absence or presence of 5-6 different levels of PEs, for a total of 36 (in vitro) or 25 (in vivo) treatment groups. Both in vitro and in vivo, low concentrations of the SC mixture failed to increase estrogenic responses relative to those induced by PEs alone. However, significant increases in response occurred when each chemical in the SC mixture was near or above its individual response threshold. In vitro, interactions between high-doses of SCs and PEs were greater than additive, whereas mixtures of SCs in the absence of PEs interacted in a less than additive fashion. In vivo, the SC and PE mixture responses were consistent with additivity. These data illustrate a novel approach for incorporating key attributes of real world exposures in chemical mixture toxicity assessments, and suggest that chemical mixture toxicity is likely to be of concern only when the mixture components are near or above their individual response thresholds. However, these data suggest that extrapolation from in vitro assays to in vivo mixture effects should be approached with caution."

 

Toxicol Lett. 2007 Apr 25;170(2):165-76. Epub 2007 Mar 12.Click here to read Links

Estrogenic effects of mixtures of phyto- and synthetic chemicals on uterine growth of prepubertal rats.

van Meeuwen JA, van den Berg M, Sanderson JT, Verhoef A, Piersma AH.

 

Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands. J.A.vanMeeuwen@iras.uu.nl

 

Through the diet humans are exposed to many weak estrogenic phytochemicals (PCs) and synthetic chemicals (SCs), but most experimental studies used individual compounds rather than mixtures. Estrogenic effects were determined in the rat juvenile uterotrophic assay using a predefined phytochemical mixture (PCmix) containing coumestrol, genistein, naringenin, (+,-)catechin, (-,-)epicatechin and quercetin, and a predefined synthetic chemical mixture (SCmix) containing nonyl-, and octylphenol, beta-hexachlorocyclohexane, methoxychlor, bisphenol A and dibutylphthalate. The mixture composition was based on human dietary uptake and actual ratios in serum. 17beta-Estradiol and genistein were also tested individually. It was found that combinations of phytoestrogens and exogenous 17beta-estradiol act additive. In contrast SCmix, inactive by itself even at high dose levels relative to human exposure, caused no synergistic or antagonistic uterotrophic effect with E(2) and/or the PCmix. Based on ED(05) and ED(01) values of the PCmix the margin of exposure in regular human diet for a uterotrophic effect is estimated many orders of magnitude. However, food supplements with phytochemicals might bring individual exposure around ED(05) and ED(01) values of the PCmix. Based on the results of our study the contribution of SCs to total estrogenicity in human diet can probably be neglected."

 

 

I'm not an expert in the field by any means, the biology of estrogen receptors is complex, the affinity of estrogen mimetics for estrogen receptors and their effect on the genes that ER's upregulate or downregulate is even more so, etc, etc, etc...but at the end of the day we're talking about a mode of action consistent with that of a natural hormone here.

 

I think you may live in Canada, where perhaps there's a requirement that the scientific validity of a particular claim may have to be established before anyone can be held liable, but that's certainly not the case here in the US. Consequently, I can pretty much guarantee that it's the fear of liability - irrespective of scientific merit - that's driving the behavior of manufacturers and retailers in this case.

 

 

[KaskadskyjKozak]

Consequently, I can pretty much guarantee that it's the fear of liability - irrespective of scientific merit - that's driving the behavior of manufacturers and retailers in this case.

 

 

Exactly. Fear of lawsuit and the vulture trial lawyers.

[JayB]

Most studies that claim polycarbonate is totally harmless have been criticized for ignoring or misrepresenting data the arrives at the opposite conclusion.

 

If you are interested, a great statistic is the following: ( iread this on Wikipedia a month ago)

 

Of 131 studies of the health effects of bispehenol A, 110 studies funded and conducted by government and academia found some level of or potential adverse effect

 

21 studies funded and conducted by the plastics industry found no adverse effects

 

JayB and Kk, you guys want to argue that the industry knows what they're doing and the special interest groups in government and academia are pumping our dangerous, biased data?

 

I generally think that when it comes to arguments concerning contentious biological phenomena that have caught the public eye, it's generally safe to argue against whatever position that you personally take.

 

Other than that, I'm basing my conclusions on what I know about the biology of nuclear receptors like the estogen receptor, retinoid receptors, etc, dose responses, toxic thresholds, the way animal studies are conducted...etc...on the fact that it's been used in a gazillion applications for decades without incident, and that the mode of action is to mimic a natural hormone. I also think it's highly amusing that this has become even a blip on the health-radar in a nation full of sedentary fatasses who are far more likely to consume themselves to death in some fashion or another than they are to sustain the slightest perturbation in their health on account of traces of estrogen mimetics - whether they're synthetic or natural.

 

I think it's important to note biases, and eliminate them where possible in such studies. If there's a big disparity between the results obtained in one set of circumstances versus another, that's usually a problem. I also think that it's important to determine whether the experimental systems, etc that are being compared in meta-analyses are close enough to result in an apples to apples comparison. If the conflict persists, the best way to sort things out is to have independent facilities conduct the same experiments and see if the results are consistently reproducible. If there's data out there that conclusively prove that BPA exposure resulting from food and beverage containers constitutes a real threat to human health, I'll gladly revise my stance.

 

 

[hafilax]

When MEC pulled all polycarbonate bottles I did a lot of reading and came across ourstolenfuture.org which is focussed on plastic safety. The alarmist URL threw me off but their analysis seemed sound. Initially they said the jury was out on whether or not polycarbonate was bad. They've since changed their tune as new studies come out. There is little doubt in my mind that there is a long term hazard associated with using polycarbonates over the long term especially if they are dishwashed/agressively-cleaned and once they become aged and cloudy.

 

This page has links to the latest studies they are supporting:

http://www.ourstolenfuture.org/NEWSCIENCE/oncompounds/bisphenola/bpauses.htm

[JayB]

I wasn't nearly as impressed with the site, which I found vaguely reminiscent of the tone and content one finds at vaccine-autism sites, but to each his own, I suppose.

 

Unfortunately for me, the case has been conclusively settled in the court of public opinion at this point, so it looks like I'll have to start hoarding polycarbonate food containers.

 

On second thought, I guess that I shouldn't be so fatalistic, since we've witnessed the resurrection of the silicone breast implant...

 

 

[Choada_Boy]

BPA decreases the anogenital distance.

[sobo]

...Unfortunately for me, the case has been conclusively settled in the court of public opinion at this point, so it looks like I'll have to start hoarding polycarbonate food containers...

You could prolly go the CC.com Spring Picnic and pick yerself up a buttload of them thar dangerous wadder boddles at the Gear Swap...

[rob]

So, I get it on the nalgenes.

 

But is it acceptable to clip a kleen kanteen to my harness?

[KaskadskyjKozak]

On second thought, I guess that I shouldn't be so fatalistic, since we've witnessed the resurrection of the silicone breast implant...

 

 

Another example of hysteria, CYA, and trial lawyer-induced bloodletting.

[KaskadskyjKozak]

So, I get it on the nalgenes.

 

But is it acceptable to clip a kleen kanteen to my harness?

 

Only if you are wearing gaiters and shorts over polypro.

[el jefe]

"unsolicited advice" -- probably a better name for this website than "cascadeclimbers"

[KaskadskyjKozak]

"unsolicited advice" -- probably a better name for this website than "cascadeclimbers"

 

look at the new site logo - the "dot" is very symbolic

[sobo]

as in a "black hole" of despair?

[KaskadskyjKozak]

as in a "black hole" of despair?

 

as in it sucks you in, and nothing can escape, not even light.

[sobo]

as in a "black hole" of despair?

 

as in it sucks you in, and nothing can escape, not even light.

cascadeclimbers.com... the event horizon of the intertubez

[lizard_brain]

Please do not clip your Nalgene bottle to your harness using the the little plastic lid retainer. The lid retainer is meant to keep you from losing the lid - it is not meant to support the weight of a full water bottle. You will eventually lose your water bottle, which could cause you to become thirsty...and the water bottle might kill someone as it rockets down the cliff.

 

Really not trying to sound like a jerk - its a simple mistake that a lot of people just might not think about, but it is a simple mistake that could kill or seriously injure someone.

 

Is this not the most uptight post evar?

[ivan]

Please do not clip your Nalgene bottle to your harness using the the little plastic lid retainer. The lid retainer is meant to keep you from losing the lid - it is not meant to support the weight of a full water bottle. You will eventually lose your water bottle, which could cause you to become thirsty...and the water bottle might kill someone as it rockets down the cliff.

 

Really not trying to sound like a jerk - its a simple mistake that a lot of people just might not think about, but it is a simple mistake that could kill or seriously injure someone.

 

Is this not the most uptight post evar?

i can't accept it as such until you have at least 3 other candidates - do your homework motherfucker!

[snoboy]

Uptight or not - he does seem to have a point.

[billcoe]

 

Is this not the most uptight post evar?

i can't accept it as such until you have at least 3 other candidates - do your homework motherfucker!

 

Opps, we have a new leader on the leader board, congrats Ivan! OK -2 candidates have now appeared for most uptight post evAr! Do we have a 3rd? Wheres RainDawg? Can I get an AMEN BROTHER!

 

AMEN BROTHER!

 

Dohhh! I should know better than to listen to some old Otis Redding at 160 Db and drink wine......

[robotsweat]

Plus, these Al bottles are turning into the new "coffee mug on a carabiner" ID badge for the coolest of the cool eco-hipsters and college freshman.

 

What the fuck is the issue with that? I agree its sort of funny to see people walking around with a mug but it makes SENSE to not be using single use containers.

 

 

 

[ScottP]

Danger...Danger young Will Robinson!