The growing concern over vaccinations is understandable. Parents want what's best for their children, and the thought that they could be unwittingly injecting toxic chemicals into their infants and toddlers is legitimately terrifying. I realize that the choice to not vaccinate is usually made out of precaution and love. That being said, significant data supports the safety of vaccines. Not just government and medical industry studies, of which there are thousands, but ones from independent parties as well. Still, the ingredient list can be scary. And what's even scarier is when celebrities or Facebook videos circulate around the media making unfounded claims about what's in them. They use shock tactics. ANTIFREEZE! ETHER! BLACK TAR HEROIN! Okay maybe not that last one, but the claims get more and more exaggerated just as more and more contradictory studies are done in parallel. It was enough to make me want to look deeper. I am by no means a scientist. I am just a college junior in chemical engineering. I ate ramen noodles most nights this week. I'm not claiming I have any deep understanding of vaccines. But based on my passable knowledge of organic and biochemistry and trusty dusty google scholar, this is what I have found about the claims being made:

*For this article, I am not addressing allergic reactions to ingredients. The human body can be allergic to almost anything and it only follows that some people have adverse reactions to vaccines in this way.

Antifreeze

A number of celebrities, most notably Jenny McCarthy, have long been saying that antifreeze is in vaccines. For the most part, antifreeze is highly toxic to humans. The antifreeze used in most machinery and vehicles is composed of a chemical called ethylene glycol. The reason that people are worried about antifreeze in vaccines is that a similar molecule, a polyethylene glycol, also known as propylene glycol, is used in vaccines. It's also used in place of antifreeze when people need a less toxic version of it. Propylene glycol is used, for example, to keep water pipes from freezing in the winter. It still can have negative effects when you're exposed to it in an undiluted excess, as can almost any chemical under the planet (caffeine, for example, can cause an overdose in a teaspoon or less). That being said, it's toxic effects are minimal. Studies have been done on mice comparing the two molecules, and even in the most extreme conditions tested, propylene glycol caused only moderate reactions. Propylene glycol is used in toothpaste, skin creams, food products, and even a nasal spray. No negative long term effects have been recorded. Just because two molecules are similar does not equate them. A single placement of a single atom or even a pair of electrons can give molecules wildly different properties. It's kind like assuming that water (H2O) is dangerous because hydrogen peroxide (H2O2) is.

Formaldehyde

Formaldehyde is a preservative. Like everything in the entire world, too much of it is harmful. High concentrations of formaldehyde can cause cancer because it can affect the synthesis of DNA. We know that formaldehyde reacts with DNA because the human body produces it naturally and it is required for DNA and protein production. Naturally made formaldehyde is vital to our well-being. This doesn't mean that we want any extra, but it does show that formaldehyde in small amounts does not hurt us. For example, 0.2125 milligrams of formaldehyde are naturally in every 2.2 pounds of our bodies. That means I have 13.49 milligrams in me right now. On average, a 2-month-old baby will have around 1.1 mg in their bodies. The most they will receive total in vaccines is about 0.2 mg. That means there is five times more formaldehyde in an infant's body than the vaccines they will receive. It is also worth noting that studies have been done injecting animals with 600 times the amount of formaldehyde found in the combined vaccines, and no adverse effects took

Mercury

If any of the concerns towards vaccines are valid, it is this one. Mercury can have devastating effects on unborn and newborn children. Mercury poisoning has also been linked to autism. That being said, never in recorded scientific history has a link between autism and vaccines been shown by a credible study. Mercury can be found in vaccines through the compound thiomersal. Thiomersal is a preservative that prevents bacterial or fungal growth within the vaccine. Thiomersal breaks down in the body into two molecules, one of which is ethylmercury. This compound is often confused with methylmercury, the very toxic molecule found in seafood. Again, this is a case of assuming similar molecules behave the same way. Don't get me wrong; ethylmercury is still bad stuff. But it has properties that are significantly less harmful than methylmercury.

It boils down to something called a chemical half-life. A half-life of anything is the time required for its quantity to reduce to half its initial concentration. So if you have 10 molecules with a half-life of one day, after day one, there would be 5 molecules left. After day two, there would be 2.5 molecules left. After day three, there would be 1.25 left. You get the picture. The dangerous compound methylmercury has a very long half-life. Its half-life is around 50-70 days. That means that even a small amount can stay within the body for a long time. This is why, for example, eating lots of seafood even before a pregnancy can have a bad outcome. Ethylmercury has a much shorter half-life. It only takes about a week to 10 days to reduce by half. This means that it clears the body 5 to 10 times faster than methymercury. That's not a significant amount of time to do harm. This has been verified by independent studies not invested in any way in the vaccine industry.

Still, the vaccine industry heard the outcry against thiomersal. As of 2003, thiomersal was removed from all but the influenza vaccine and one rare version of the many options of tetanus shots. Also, advances in science allowed these be single dosage shots as opposed to a series, further limiting exposure to mercury. Still, if you don't want your child to have this, there are thiomersal-free options exist of every type of vaccine, although these required a series of shots and many be less effective. Since only two shots, only one commonly used, contain this compound (which, again, is not even considered dangerous), if you're still worried about autism and shots, ask for this specific version, or skip only these. The vast majority of vaccines don't contain mercury of any form.

Aluminum

In vaccines, aluminum boosts the immune system's response. Because of this, it is in most of them. Aluminum is everywhere. It's in everyone's diet. It's in everyone's body. It is in aspirin, antacids, deodorants, dairy, flour, honey, cereal, and more. It is in baby formula. It is in breastmilk.The average person consumes 7-9 mg daily.

In all the vaccines a child is recommended in the first year of their life, they receive around 4.225 mg. By this time, if their diet was exclusively breastmilk, they would already have consumed 7mg from that alone. Almost twice the amount they get from vaccines. If they were fed formula, they'd have consumed over 30 mg. There is absolutely no reason to believe that aluminum in vaccinations is causing harm. Everyone gets so much more from other places.

In conclusion, from the research I have done, there is nothing that I have found to lead me to believe that vaccines are hurting people. I looked at it with an open mind, wanting the know the truth and not just the opinions of others. I will be vaccinating any children I might have, and I hope for their sake that other parents do the same.