Friday, April 10, 2015

About fluoride and Cancer

Claims about fluoride and cancer

This will be a long one. But the interesting stuff comes at "Dr John Yiamouyiannis". Skip to there to see some interesting data.

So, fluoride in tooth paste is apparently good against caries. But people I have been talking to, who refuse to use fluoridated tooth paste, claims that fluoride causes cancer. Again, I think these claims have no ground. I have asked them to show me epidemiological studies showing the relationship of fluoride and cancer (we have been using fluoride since 60's, so there should be a LOT of data).
The answers I keep receiving are as follows

  • The big companies does not want you to know the truth
    • My answer to this is: Well, yes I can agree to that to certain extent. Big companies does not want their product to have a bad reputation, but at the end, the truth will reach the consumers. See what happened with cigarettes, freons, carbon dioxide, eutrophication, acid rain etc.
I see some serious problems with the papers cited above. The amount of fluoride used in the tests is irrelevant for the topic. They use >50 mg/L (over 50 ppm) fluoride concentration to make their claims valid. That is a HUGE dosis!. If you want to make relevant studies, the dose must be in line with how the environment in your body is likely to be.
The concentration of fluoride in our body is around 0,01-0,03 ppm (ca 0,01-0,03 mg/L), although it can be higher in our bones. In the studies referred above, they use > 50 mg / L fluoride (ca 50 ppm), e.g. much higher concentrations to what is likely to be found in the human body.

Dr John Yiamouyiannis

I got also a link to a paper written by Dr John Yiamouyiannis, as a proof of correlation between fluridation of water and cancer.

Apparently, this guy is the guru of correlation between cancer and fluoride in drinking water. This means I will deviate from the topic "fluoride in tooth-paste" to the topic "fluoride in drinking water"

In this paper, they compared the mortality rate for cancer in the 10 largest fluoridated US cities to those of the 10 largest non-fluoridated US cities in the same time period. The idea was that other factors would be nullified as people in large cities have similar living habits. Thus, the differences in cancer deaths could be related to fluoride if any difference was found. Anyway, the authors found that there was a difference between the fluoridated and non-fluoridated cities, and they claimed that this difference was related to the fluoride in water that was added.

When I first read the paper I though "hmmm, interesting". But I did question the validity of their conclusions:

  • They found an increase in cancer death rate by 15 out of 100 000 persons in the population aged 45-64 years. Also, an increase by 35 out of 100 000 persons in the population ager 65 or more (65 +)
  • No significant increase was extracted from the data in the population 0-24 years and 25-44 years

When I saw these numbers and took a quick glance at the tables, I wondered: "15/100000 and 35/100000, is that REALLY a significant increase that can ONLY be related to fluoride in drinking water?

I decided to go deeper. I started to examine the tables and saw that the correlation coefficients they were using to confirm their claims were quite low (see tables 4 and 5, there raw data is there)

I used a simple regression analysis to start with. I took the average values of death rates of fluoridated cities vs  the average values of death rates of non-fluoridated cities. This is what I got:

Red squares: Average Cancer Death Rates (per 100000 inhabitans) in cities with fluoridated water, citizens 65+
Blue diamonds: Average Cancer Death Rates (per 100000 inhabitans) in cities without fluoridated water, citizens 65+

Just looking at the averages, you could say there is a very weak correlation between cancer occurrence and fluoridation, but VERY weak (correlation coefficient is 0,26). Almost no correlation was found for the non-fluoridated cities (corr coeff 0,005).

So, I decided to go deeper into the data and go through it city by city. Lets start with the fluoridated cities.

Fluoridated cities

The 10 studied cities were Philladelphia, Baltimore, Claveland, Washington, Milwauke, St Louis, San Francisco, Pittsburg, Buffalo

From the data, only three cities showed a correlation coefficient above 0,2! All other cities had corr coeff below this number. And, lets be sincere. Does a corr coeff below 0,4 really mean anything? With this said, let us take a closer look.

So Claveland, Baltimore and chicago all had a positive correlation, and correlations coefficients above 0,25.  So far, Yiamouyiannis claims might seem to be valid. But what about the rest of the cities?

OMG! The correlations are still positive, but none of them have a correlation coefficient above 0,2!!! In other words, there is no correlation to talk about! But this is not all. The biggest surprise in this group was the city of Milwauke. As you can se below, the correlation is NEGATIVE, and the correlation coefficient is above 0,2 (if that means something)!

But this is not all. More surprises are to come in the non-fluoridated cities

Non-fluoridated cities

The non-fluoridated cities were Los Angeles, Boston, New Orleans, Seattle, Cincinnati, Atlanta, Kansas City, Columbia, Newark and Portland

I did the same type of correlation analysis and got a BIG surprise. Three of the non-fluoridated cities had a positive correlation between dead-rates and non-fluoridation of water (if you want to translate the results that way):

So, does this means that non-fluoridation is as dangerous as fluoridation of water? NO! This means that this study has not found any evidence for why the death rates are increasing! That is, Yiamouyiannis study does show nothing!

Just for the sake of consistency, here are the results of the other non-fluoridated cities:

In conclusion

To conclude. There is no evidence that fluoridation of water causes cancer given by studies. There is a much better paper by a japanese team. They have found a very weak correlation between fluoride and some types of cancer.

But as they say themselves: "Finally, we must conclude that the consistency of the fluoride-associations for cancers and temporal relationship are not yet adequately confirmed because of its sociological conditions. We would like to ask for the cooperation of researchers throughout the world to further assess fluoride as a genetic cause of cancers from the standpoint of epidemiology and also in animal experiments. so as to strengthen the power of five criteria and stop the application of fluoride for prevention of teeth caries if this indeed presents as a risk factor for cancer"

In other words, they are unsure of their results and more data is needed.

Therefore, the small amounts of fluoride you get from tooth paste does not pose a treat for you or your children, if administrated as intended!

Friday, April 3, 2015

About Fluoride in Tooth Paste

So this post will be about fluoride. The reason I choose to write about this is the fact that many people seem to have misunderstood the dangers about fluoride. Before I start, let me give some disclaimers so that you can understand my point of stand:

  • I come from Sweden. In Sweden, we do not fluoridate the water as it is done in the US. Therefore, I do mainly refer on the dangers of using fluoridating tooth paste. Not whether or not fluoridating your water supply implies a danger to your health, although this topic will also be addressed 
  • Again, I want to debunk the believe that fluoride in tooth past poses a health danger, as long as you don't eat the paste.

As many of us know, fluoride is a great tool to fight caries . This has been demonstrated time and time again. There is a bunch of scientific papers which discusses the benefits of fluoride agains tooth decay. Here is one of many.

As I said in the disclaimer, more than 1,5 mg/L fluoride in drinking water is not recommended (that is about 1,5 ppm fluoride) as this will lead to fluorosis. In some areas and countries, such as in Teneriffe, Iceland, some regions of India, China, the US etc, the NATURAL levels are way higher than those values and is not recommended to drink from that water.

Fluoride in Tooth Paste

Now, let us return to the main topic: fluoride in tooth paste. What happens in your mouth and why is fluoride effective against caries?

Emanel is mainly constituted by a mineral called hydroxylapatite Ca5(PO4)3(OH). When the pH of the mouth decreases, demineralization occurs. The chemical process can be described as shown below:


What fluoride does is that it replaces the hydroxyl ion with fluoride, forming fluorapatite Ca5(PO4)3F.  Fluorapatite withstands the acidic attack much better than hydroxyapatite, effectively delaying/inhibiting tooth decay.

Ca10(PO4)6(OH)2(s) + 2F-(aq) 
 Ca10(PO4)6(F)2(s) 2OH-

New studies have shone light to some new findings. It does also appear as if bacteria has a hard time creating colonies on fluorapatite. Less bacteria in your mouth will indirectly mean less acid is produced after a meal, and thus, less chances your teeth will be damaged by caries.

To conclude, fluoride is good for your teeth and there is very little evidence demonstrating the dangers of fluoride in small concentrations on your body (eg, what you get through tooth-brushing).  In next post, I will talk a bit about my conversations with people about fluoride and cancer. Peace & Love :)

Tuesday, March 17, 2015

Chemtrails, continuation

As I said last time, I would talk about this image, which is used as proof that we are being sprayed with God-knows-what (but they say it is Aluminum, Barium etc)...

So, what you see are a couple of "chemtrails" at 10:58 am. According to the people who believes in chemtrails, as time goes on, you can see "evidence" these are accumulating chemicals.

So, let take this to a very basic level. That far up in the atmosphere, droplets of water are formed. Each droplet of water can create a NUCLEATION POINT. What is a nucleation point? Well, I should know. I am a chemist after all. It is something that we use very often in order to induce crystallization. Now, these droplets in the air acts the same way, allowing new droplets of water to grow on each one of these.

Here is a video exemplifying what I mean. At the beginning there is small crystal. As time goes by, the crystal serves as a nucleation point were new molecules can anchor, making the crystal to grow.

The video is courtesy of Curtis Sleve and shows crystal growth time lapse through microscope. Same thing is happening with the clouds, but as water droplets.

In other words, that image at the top serves as a beautiful example of nucleation and crystal growth. Although, this time it is not crystals that are growing, but clouds made of water droplets. Beautiful isn't it?

Well, next topic is why the levels of aluminum are high in some soils, such as in Hawaii....

Some words about Chemtrails etc...

Lately, I have been speaking with some people who believes that Chemtrails are actually chemicals that different governments or companies are paying for.

Before I continue, let me clarify some things.
  • I am against the belief that ALL aircraft, including commercial aircraft, are spraying chemicals in the air to control the weather or poison our lakes
  • I am aware that geo-engineering is for real. But geo-engineering is only being performed in smaller scale. Cloud seeding and such are old techniques that were used already in the Vietnam war. And yes, we can induce rain in very small geographical areas. 
  • The technique used for cloud seeding do need an airplane. The airplane has to be close to the cloud and release the "seeds" at the cloud's base or cloud's top.
  • My concern is that people spend so much time discussing Chemtrails, when all of these observations can be explained scientifically. And I will try to explain some of these physio-chemical phenomena here  
  • Airplains use combustion motors (turbines?) to fly. Combustion is a simple chemical equation: CxHy (g eller l) + zO2 (g) --> xCO2 (g) + (y/2)H2O (g) + energi.
    What that means is, you take gasoline or something with hydrocarbons, let it react with oxygen and you get carbon dioxide and water as products of combustion. So, Chemtrails are noting else than water condensation in the stratosphere
I will start talking about this video, which I was encouraged to see because it contained "facts" that proved Chemtrails are for real

When I watched this video, I did not start looking at it with the intention of not believing. I wanted to watch it, hear their facts and see how scientifically sound they were. Then, I wanted to compare their facts with scientifically proven facts.

Now. Let me debunk all of the "facts" given on the video, one by one.

First statements, minutes 0:58 to 36:56

The documentary presents their evidence about geo-engineering by attending a scientific conference. Again, geo-engineering is not a hidden fact, there are companies making a profit from it already and here is one of them.

Now, next 20-25 minutes or so, they focus in explaining WHAT is being sprayed. They interview people given testimony of elevated levels of alumina (Aluminum 3+ to be more accurate) and decreased levels of pH in the soil.

Let me take a pause here. I am a chemist. For me, this rang a bell. Does it ring a bell for you? So, they are saying that these chemtrails are metals (more exactly aluminum). That these metals are the ones contributing to elevated levels of Aluminum 3+ in soils, and also the cause for lowering the pH on the ground. Just wait...
  • Have you ever heard about ACID RAIN? Acid rain is a scientifically proven fact. For you who do not know about this, I will explain it in a minute.
    • Acid rain lowers the pH in soils and lakes
      • By lowering the pH in soils and lakes, metals starts to leak out from the earth crust. Remember that 7 % of the earth crust contains Alumina in different states.
      • This leakage of aluminum 3+ and other metals coordinates to other atoms that usually are taken by plants as nutrients, such as phophorous
        • By coordinating to phosphorous, plants cannot grow. That is why elevated levels of aluminum 3+ are undesired on soil
  •  Acid rain is caused by emissions of Sulfur Dioxide and Nitrogen Oxides from industry.
Here is a paper about this:

My point is. Why don't you people address the real cause for elevated levels of aluminum 3+ on soils? Focus on the real problem, not something without scientific back-up!

This will be my first post about this topic. Next post will be about this image, which is also the next topic of the documentary, and some facts about Hawaii and their elevated levels of aluminum...

This image is used as "evidence" of the spraying of chemicals. It has a very easy and scientifically exciting explanation.

Tuesday, October 14, 2014

LDA and its pesky bi-product

Who would have though that LDA can, instead of acting as a base in the presence of acidic protons, be oxidized to give some impurities which will make you pull your hear until you lose it or it turns grey?

Well, I would not but it did. It turns that a very very very small amount of this LDA actually can give you impurities (ca 0.28 area % in my case) due to oxidation of the base.
To give you a more specific example, if you have an ester, and you use LDA to pick a proton in another part of your target molecule, do not get puzzled if you get things like

Side reaction of esters and LDA

Of course, most of the LDA will act as a base and the desired product will be the major product you will obtain. But when looking at impurities is important, it is easy to overlook at this one.

So, what is actually happening. According to Férézou and Chevalley (Tetrahedron 68 (2012) 5882-5889), LDA can be oxidized by interaction with aldehydes and ketones (they have used benzophenone and benzaldehyde, among others, as oxidazers). A plausible mechanism is presented below:

First, the oxidative agent coordinates with Lithium, reducing the alcohol and oxidizing LDA, you get an imine
Another LDA molecule acts as base, attacking one of the nitrogens next to the imine carbon. An enamine is created. 
Through resonance, the enamine carbon acts as nucleophile, attacking the electrophilic carbonyl carbon. This would yield the bi-product. This mechanism is not confirmed but is fully possible.
As you can imagine, changing the reaction conditions could make this bi-product the mayor product. But that is a totally different story.

Tuesday, October 7, 2014

Back again, 2 years after last post

Well, I am back here to post some stuff about chemistry. I have a new job (Ok, been here for over 1 year now) at Cambrex as Process/Synthetic chemist and I love it.

Well, what has happened now is that we have been having a problem with a quench. We are using Dess-Martin Periodinane (DMP) for an oxidation and Sodium Thiosulfate for quenching DMP and its bi-products (IBA and possibly IBX).

We found a big problem in the process. Some of the batches that were produced contained elementary sulfur and first we though it could be alleviated by decreasing the amount of thiosulfate used for the quench. It did not work too well.

Second, we found a paper (DOI: 10.1021/op700227p) were they described a similar problem, and the recommendation was to add the quench solution to basified reaction mixture. We used Sodium bicarbonate to basify our solution and then started the addition of Sodium Thiosulfate. Sometimes it did work, sometimes it did not.

Further work demonstrated that the pH first increased upon addition of Sodium thiosulfate, but started to decrease over time. Experiment showed that longer quenching times increased the amount of sulfur formed in the reaction.

That is when I found this very useful paper (for me at this moment it is very useful at least). It is written by Takei et al,, DOI 10.1246/bcsj.49.70.

In this paper they make a series of experiments in acidic media, in which they observe and measure the disproportionation of thiosulfate and other sulfur containing species, at high temperatures (>70 °C). Although their reaction conditions do not match the ones in the oxidation I am performing, an interesting detail can be found in page 73. First some background.

Sodium thiosulfate is used to typically reduce idodine and bromine. In the reaction I am interesting to quench, I am using Sodium Thiosulfate to reduce Dess-Martin Periodinane (DMP) and its related bi-products (IBA and possibly IBX). 

If the reduction of DMP follows the same electronic pattern as the reduction of iodine (and is quite likely), Sodium Thiosulfate should oxidize to tetrathionate. Now, check page 73 in the publication from the 70's.Tetrahionate can disproportionate to sulfur, sulfate and acid. This would explain why, I am obtaining sulfur even though I am using alkaline solvents. 

This assumptions seems very likely, as when I measure the pH of my quenching, the pH first increases to 9-10, but then starts to decrease to 8 over time, and more sulfur is formed.

3SO4O62- + 2H2O --> 7S + 5SO42- + 4H+

Well, hope if someone encounters this problem this can be of help. If I am mistaking me hugely, please correct me.


/ Alejandro

Sunday, November 25, 2012

Back again

Well, been away for quite a while (more than 1 month since last post), but it has been very busy time. I just got my second child and just starting to get back to my normal groove (with some deviations). Hopefully I will be able to keep writing about more chemistry soon. Going to have a presentation on total synthesis, going to post it here when I am done.

My little Vincent Thiago

And he looks a bit angry here