backtop


Print 18 comment(s) - last by xdrol.. on Jul 12 at 10:19 AM


  (Source: steadyhealth.com)
Bisphenol A is considered a toxic substance in some countries because of the hormone-like properties it possess

A new study shows that bisphenol A exposure could help cause a brain tumor called meningioma.

Bisphenol A (BPA) is an organic compound that is used to make epoxy resins, polycarbonate polymers and other plastics. It is considered a toxic substance in some countries because of the hormone-like properties it possess. Canada and the European Union have even banned it from being used in baby bottles.

Now, a new study from China has revealed that BPA could be a risk factor for meningioma brain tumors. They made this connection by studying 247 patients with meningioma and 258 patients with no cancer history. Each patient had their medical records and history collected for the sake of the study.

All patients were observed at the Union Hospital in Wuhan, China. The researchers would check the brain tumors with brain scans or biopsies while BPA levels were identified through urine samples.

All volunteers were placed into one of four groups, which were determined by the concentration of BPA levels in urine. The groups consisted of less than 0.53 ng/ml, 0.54-0.91 ng/ml, 0.92-1.69 ng/ml, and over 1.69 ng/ml. They determined whether increasing BPA levels in urine were linked to meningioma diagnosis.

According to the results, patients in the latter three groups with the higher BPA concentrations were 1.4 to 1.6 times more likely to be diagnosed with meningioma than those in the lowest BPA level group. The team also found that the association between the two remained consistent despite other factors like BMI, age and gender.

The study noted that this is the first time a link has been shown between BPA exposure and meningioma diagnosis.

Source: Environmental Health News



Comments     Threshold


This article is over a month old, voting and posting comments is disabled

Bad Science?
By petschska on 7/3/2012 12:10:31 PM , Rating: 2
The original paper is blocked by a paywall so I can't see the real details to vet this out. Does anyone else feel like this is questionable science?

First, this study shows a correlation, not a causation. What if all these people live next to a BPA and nuclear waste disposal facility. They also have meningioma. Just because their BPA levels are higher doesn't mean you can draw any conclusion about BPA. It's more likely it's the nuclear waste facility! BMI, age, and gender are great, but they are far from all the necessary variables that need to be examined to make a conclusion.

Secondly, this study was done performed on Chinese citizens, where environmental laws are not followed. Any number of carcinogens could have had this effect on these people.

I'm not trying to downplay BPA concerns. Chemicals need to be handled properly and safely. But I'd like to see good science backup our decisions when we restrict useful chemicals from our everyday products.




RE: Bad Science?
By ShaolinSoccer on 7/3/2012 2:21:07 PM , Rating: 2
Regardless, people shouldn't freeze or heat up water bottles. That plastic isn't rated for that type of exposure and could release chemicals into the water.


RE: Bad Science?
By geddarkstorm on 7/3/2012 2:26:27 PM , Rating: 2
From the tone, I don't think the study tries to make any claims about causation, just showing a correlation. Completely valid to do.

As from your other concerns,
quote:
All patients were observed at the Union Hospital in Wuhan, China
So the pool these patients come from is all from the same localized region, decreasing alternative effects as being factors in the correlation between rising BPA levels in urine and brain tumor incidence.

We've seen BPA do some nasty stuff in other studies, so this is definitely worth looking more into.


RE: Bad Science?
By xdrol on 7/12/2012 10:19:57 AM , Rating: 2
How is all subjects coming from the same region decrease the possible alternative effects?


RE: Bad Science?
By jtemplin on 7/5/2012 7:51:50 PM , Rating: 2
There is one major flaw with this work. EDIT: just saw the sourced page discusses what I was about to write about. keeping it brief.

The very crucial matter of the grouping of patients and associated statistical tests by a single urine test is quite flawed.

One snapshot of the amount of BPA onboard in these patients is almost completely useless in establishing BPA as a chronic factor or even a factor at all in these tumors. Evidence suggests that BPA is rapidly cleared from the body. If this is the case then to establish a biological relationship, the authors would have had to do a prospective/longitudinal design with frequent urine samples.

It is necessary to show that the meningioma patients were chronically exposed to higher BPA levels. They also need to show that the levels were high when the tumor was forming. Looks like their urine test is at time of diagnosis meaning they may have missed the important urine samples, potentially, by years.

An idea for longitudinal testing is that it be anchored around a meal like dinner. That way all patients will be in the same pharmacokinetic/dynamic state and differences in urine samples between subjects with identical BPA intake should be minimized. Given identical BPA intake, imagine someone being tested 5 hours after the BPA intake versus 1 hour. The 1 hour subject should look like they got way more BPA than the 5 hour.


"The Space Elevator will be built about 50 years after everyone stops laughing" -- Sir Arthur C. Clarke














botimage
Copyright 2014 DailyTech LLC. - RSS Feed | Advertise | About Us | Ethics | FAQ | Terms, Conditions & Privacy Information | Kristopher Kubicki