All posts by Aditi Babel


In class, we recently discussed the thalidomide incident and how it represented a pivotal shift in the way drugs were developed—particularly in providing an insight into the way drugs taken by a pregnant mother affect her baby. I was reminded of this while reading the news yesterday, as I came across this article discussing a case that could lead to the criminalization of alcohol consumption during pregnancy. (Gander, 2014)

Case: A six-year old girl suffered brain damage because of her mother’s alcohol consumption while carrying her—and it is now being argued that she is the victim of a crime / criminal offense committed by her mother.

This article deeply intrigued me, as I thought about all the implications that a law like this, if passed, could have. As we have (in our Medicines & Drugs unit) studied the effects that alcohol has on the body, I decided to investigate the chemistry of alcohol as it affects her mother and baby to answer the following question: to what extent does alcohol consumption by a mother negatively impact her baby?

I found that, once consumed, most substances are broken down in an intermediate step by enzymes (biological catalysts) to “metabolites”: other compounds that can be easily processed by the body. However, the alcohol we consume (ethanol– CH3CH2OH), is broken down by the body to the toxic and carcinogenic Ethanal (also called ‘Acetaldehyde’: CH3CHO). (Alcohol Metabolism: An Update, 2007)

The breakdown of Ethanol

Figure 1. The breakdown of Ethanol by the body.
(Alcohol Metabolism: An Update, 2007)

Note: ADH (Alcohol Degenerase) and ALDH (Aldehyde Degenerase) are the enzymes that catalyze the reactions.

As we can see from the above equation, in normal (non-pregnant) individuals the Ethanal is usually short-lived as it serves as an intermediate to when it is further broken down to Ethanoic Acid (also called ‘EthylAcetate’: CH3COOH), and then to carbon dioxide and water, after which it is eliminated from the body. (Alcohol Metabolism: An Update, 2007)

Ethanal itself is an aldehyde, and contains 2 carbons, a methyl group and its characteristic aldehyde functional group (C=O double bond).

Structure of Ethanal

Figure 2. Structure of Ethanal
(Environmental Chemistry: Lecture 21, n.d)

In pregnant women, this compound does pose a risk for their babies. A meta-analysis of 14 studies found that while 43% of pregnant alcoholics had high levels of acetaldehyde in their blood, 34% of them gave birth to a baby with ABRD (Alcohol Related Birth Defect). The researchers concluded that acetaldehyde “may play a major role in the cause of ARBD”. (Hard, Einarson, & Koren, 2001)

The precise mechanism as to how acetaldehyde impacts a fetus is not yet known, but alcohol in general has also been found to increase risk of foetal damage, and the risk of miscarriage. (Abuse and Mental Health Services Administration, n.d;  Bailey & Sokol, 2011) Other investigations have linked alcohol to damaging the DNA of a growing/ developing baby in the womb (however, these investigations have so far only been conducted on lab mice). (Medical Research Council, 2011) Already, a 50% increase has been seen in FAS cases (Fetal Alcohol Syndrome) in the past three years, and the Department of Health estimates that 1/100 babies are born with alcohol-related disorders. (Gander, 2014)

The adoptive mother of the six-year old has seen first-hand the consequences that alcohol consumption can have on children, and strongly believes that the legal system should step in and enforce some laws to prevent against further cases of FAS. “You can’t make it a criminal offense if you are still legally saying this a safe amount to drink, or you can drink. It needs to be clear from the start that you can’t [drink]”. (Gander, 2014)

Her argument is also supported by Dr. Raja Mukherjee, a consultant psychiatrist, who asserts that even minimal consumption by a woman during pregnancy puts her baby at risk for FAS, “If you want to guarantee safety and you want to guarantee no risk then no alcohol is the best way forward”. (Gander, 2014)

The implications of a law criminalizing the consumption of alcohol while pregnant will certainly serve to reduce the high numbers of babies suffering from ABRDs such as FAS. Babies suffering from FAS are usually hyperactive and delayed in their development– if exposed to high levels of alcohol while in the womb, they can display withdrawal symptoms such as extreme irritability, shaking, and diarrhea. Additionally, school aged children with FAS often experience learning and behavioral disabilities, and for this reason find themselves falling behind in school. They also are high at risk for having trouble with the law, developing mental health problems and themselves abusing alcohol and/ or drugs. (Canadian Paediatric Society, 2002) Considering this, as well as the previously conducted research demonstrating other harmful effects of alcohol consumption during pregnancy, it is apparent that alcohol is to a large extent extremely damaging to developing babies. A law criminalizing this act may not be the worst idea.


(2007). Alcohol Metabolism: An Update. Alcohol Alert, 72. Retrieved February 23, 2014, from

Bailey, B. A., & Sokol, R. J. (2011). Prenatal Alcohol Exposure and Miscarriage, Stillbirth, Preterm Delivery, and Sudden Infant Death Syndrome . Alcohol Research & Health, 34(1), 86-91. Retrieved February 23, 2014, from the NIAAA Publications database.

Paediatric Society. (2002). Fetal alcohol syndrome: What you should know about drinking during pregnancy. Paediatrics & Child Health , 7(3), 177-178. Retrieved February 24, 2014, from the PMC database.

Environmental Chemistry: Lecture 21. (n.d.). NAU Courses. Retrieved February 23, 2014, from

Gander, K. (2014, April 23). Drinking alcohol while pregnant could become a crime after landmark test case . The Independent. Retrieved February 23, 2014, from

Hard, M. L., Einarson, T. R., & Koren, G. (2001). The Role of Acetaldehyde in Pregnancy Outcome After Prenatal Alcohol Exposure. Therapeutic drug monitoring, 23(4), 427-434. Retrieved February 23, 2014, from the PubMed database.

Research Council. (2011, July 6). Excess alcohol could damage our DNA. Medical Research Council News. Retrieved February 23, 2014, from

Abuse and Mental Health Services Administration. (n.d.). Effects of Alcohol on the Developing Embryo and Fetus. FASD Center for Excellence. Retrieved February 23, 2014, from

Can breathing kill you?

The October break gave me a lot of time to unwind, and was a nice break from the stressful and always dreaded “IB Year 2 Semester 1”. One of the ways I decided to spend my downtime was by blogging on a social media site called Tumblr, and it was then that I came across this post:

Post originally by

As we were studying Oxidation and Reduction in class, I had to investigate the idea further.

A quick Google search on the statement led me to a thread on The Student Room (UK) with others also discussing their fears: was breathing ultimately killing them?

A Clarifying Question by Ruthless Dutchman

A Bold Statement by Broken Social Gene

Some users showed their support and offered scientific explanations-

Explanation by Toquin, A Respected Member

It made sense… I had learned from Biology class that one of the reactants required for the process of cellular respiration is Oxygen which comes from the air that we breathe. Further research led me to a report linking Oxidative Stress (essentially a deficiency of anti-oxidants) to a string of diseases including Diabetes and Arteriosclerosis (Vendemiale et al., 1999). I realized then that this was not a debate to be taken lightly, and decided to investigate the following question for my blog post: to what extent does Oxygen harm the human body?

I turned to the experts for some insight.

It turns out, Oxidation is a natural occurrence when there is exposure to air. Cut an apple and leave it out, it will undergo Oxidation and slowly change color (to brown). Leave equipment made from Iron out unprotected, and it will rust. Breathe, and your cells will decay.

Oxygen in our body reacts with our cells, and as a result, these cells undergo oxidation. As oxidation is the loss of electrons, the affected cell is chemically altered and ultimately dies. It is then replaced by fresh, new cells. According to Jeffrey Blumberg, a professor of nutrition at Tufts University in Boston, this is nothing to worry about. Blumberg dismisses any fears about oxidation by saying that it is a “natural process” that occurs “during normal cellular functions” (Davis, n.d).

However, what we do have to worry about are those cells that are unintentionally damaged in the process- Blumberg asserts that although the metabolism of oxygen in the body is “efficient”, 1% – 2% of cells will suffer this damage in the process (Davis, n.d). This damage occurs by the breaking of covalent bonds between their molecules (SucceedMonavie, 2010). As two molecules split apart, the shared electron is released and both molecules become unstable and highly reactive as a result. These unstable and highly reactive molecules are known as ‘free radicals’, and are a type of Reactive Oxygen Species (Evans & Halliwell, 1999).

Molecule before Oxidation
Molecule before Oxidation – (SucceedMonavie, 2010)
Molecule breaks apart, releasing an electron
Molecule breaks apart, releasing an electron – (SucceedMonavie, 2010)
Molecules turn into unstable 'Free Radicals'
Molecules turn into unstable ‘Free Radicals’ – (SucceedMonavie, 2010)

Because of their unstable nature, ‘free radicals’ will attack healthy cells in an attempt to act as as an oxidizing agent to gain back an electron and achieve stability (SucceedMonavie, 2010). According to Blumberg, “these molecules will rob any molecule to quench that need [for an electron]”, and this makes the ‘free radicals’ potentially very dangerous (Davis, n.d). When attacked molecules are oxidized by a free-radical, the attacked molecules turn into free radicals themselves (SucceedMonavie, 2010). As 1 free-radical breaks apart a bond between 2 healthy cells to undergo reduction, 1 free-radical (if not stopped) is later responsible for the production of 2 radicals. This statistically works similar to bacteria growth, and results in a chain-reaction that produces a rapid and exponential increase in the number of ‘free radicals’ present in our body. Oxidative stress, defined as “a disturbance in the balance between the production of reactive oxygen species (free radicals) and anti-oxidant defenses” can be attributed to this chain reaction (Betteridge, 2000). It has been linked to various heart diseases and cancers, as well as to Alzheimer’s and Parkinson’s disease (Davis, n.d).

'Free Radicals' attack nearby healthy cells
‘Free Radicals’ attack nearby healthy cells   –   (SucceedMonavie, 2010)
1 'Free Radical' oxidizes 2 healthy cells
1 ‘Free Radical’ oxidizes 2 healthy cells – (SucceedMonavie, 2010)

Additionally, as the ‘free radicals’ attack healthy cells around them, they may not kill the healthy cells. This can potentially lead to devastating consequences for the body. According to Blumberg, “if free radicals simply killed a cell, it wouldn’t be so bad… the body could just regenerate another one”. He instead suggests that the problem lies with damage to the cell, as this damages the DNA which leads to the mutation of the affected cell, as well as abnormal growth and reproduction of that cell- “the seed of disease” (Davis, n.d).

So oxygen is harmful to the human body? Why don’t we just stop breathing?

I realized that the initial post had been right, to a certain extent. Although Oxygen does have the potential to do damage to our bodies, it is also vital to our survival- and it certainly does not “take 80 years to kill us”. We must also remember that only 1% – 2% of metabolized Oxygen actually turns into a ‘free radical’ (Davis, n.d). Valko et al. (2007) look to Reactive Oxygen Species as being “two faced”- though these can damage cell structures, proteins, and DNA, they can simultaneously strengthen the immune system. As this strengthened immune system can then combat a host of illnesses including Oxidative Stress, the actions of Reactive Oxygen Species “re-establish” and “maintain redox balance” or “redox homeostasis” (Valko et al., 2007). Interestingly enough, there are animals out there who do not need any oxygen whatsoever to survive (Danovaro et al., 2010). For us however, oxygen is required for cell respiration to occur- if you don’t breathe, you die.

So how can we take active measures to slow down the process of Oxidation and prevent the onset of Oxidative Stress?

The initial post on Tumblr was right to a certain extent; anti-oxidants do serve this purpose. Anti-oxidants are able to stop the dangerous chain reaction by donating one of their electrons to the unstable ‘free radical’, therefore stabilizing it. They are not oxidized in the process (this is one of their properties), so all potential harm is eliminated from the body (SucceedMonavie, 2010). It is for this reason that Oxidative Stress occurs only when there is an imbalance in the amount of ‘free radicals’ and levels of anti-oxidants present in the body; if the body is lacking in anti-oxidants or abundant in ‘free radicals’, then there will not be enough anti-oxidant to stop the chain reaction from occurring. Increasing intake of anti-oxidants will prevent the sickness from developing (Davis, n.d). Some common foods high in anti-oxidants are tomatoes, carrots, tea, and citrus fruits. Fun fact relating to China- Chinese oolong tea in particular, is 40 times richer in anti-oxidants than regular green tea (Rutherford, 2011). Blumberg urges, “Sure, you can live your whole life without getting epicatechin 3-gallate, a flavonoid found in huge quantities in green tea, but if having it in your diet promotes better health, why not try it?” (Davis, n.d)

Anti-Oxidant on the scene
Anti-Oxidant on the scene   –  (SucceedMonavie, 2010)
Anti-Oxidant donates an electron
Anti-Oxidant donates an electron to the ‘Free Radical’ to stabilize it (SucceedMonavie, 2010)
Anti-Oxidant remains neutral, and 'Free Radical' is reduced / stabilized
Anti-Oxidant remains neutral, and ‘Free Radical’ is reduced / stabilized –  (SucceedMonavie, 2010)

Decreasing the risk of developing ‘free radicals’ in the body can also be a preventative measure. Although my blog post focused specifically on the action of Reactive Oxygen Species, there are other types of free radicals as well. One of these is the Reactive Nitrogen Species, taken into the body by breathing in Nitric Oxide (Valko et al., 2007). This is present in polluted air, something we are very much exposed to as residents of Shanghai. Blumberg asserts that the “toxins” present in the air of a city environment cause an “oxidative burden” on the body which is, with modernization and increased industry and technology, much higher than ever before. He also labels cigarette smoke as having “active free radical generators”, and recommends quitting smoking to “preserve health” (Davis, n.d). Minimizing exposure to pollution and second-hand smoke are also important steps that can taken to do this.

Other factors that can contribute to Oxidative Stress if exposed to in excess, are X-Rays, sunlight, strenuous exercise, and alcohol (Parnes, n.d). Although X-Rays are unavoidable for medical reasons, limiting consumption of alcohol and increasing consumption of anti-oxidants when participating in strenuous exercise or gaining excessive exposure to sunlight can reduce risk of developing Oxidative Stress.

So what? Who cares? (Implications)

Living in China, a country with huge amounts of pollution, increases our risk of developing Oxidative Stress. Additionally, as the sickness has been linked to a host of diseases, preventative measure should be taken in order to minimize the risk of developing those illnesses. Awareness of risk factors of the sickness can help us take these preventative measures.


DJ, B. (2000). What is Oxidative Stress?. Metabolism: Clinical And Experimental , 49, 3-8. Retrieved October 7, 2013, from the PubMed database.

Danavaro, R., Dell’Anno, A., Pusceddu, A., Gambi, C., Heiner, I., & Kristensen, R. (2010). The First Metazoa Living in Permanently Anoxic Conditions. BMC Biology, 8(30). Retrieved October 9, 2013, from

Davis, J. (n.d.). How Antioxidants Work: Preventing Free Radical Damage and Oxidation. WebMD. Retrieved October 7, 2013, from

Evans, F., & Halliwell, B. (1999). Free Radicals and Hearing: Cause, Consequence, and Criteria. Annals of the New York Academy of Sciences, 884, 19-40. Retrieved October 7, 2013, from the PubMed database.

Parnes, R. (n.d.). What is an Antioxidant?. Discovery Health. Retrieved October 7, 2013, from

Rutherford, D. (n.d.). Antioxidants and oxidative stress. NetDoctor. Retrieved October 6, 2013, from

SuceedMonavie. (2010, January 2). How antioxidants work. Youtube. Retrieved October 7, 2013, from

Suraru. (n.d.). Tumblr. Retrieved October 5, 2013, from

Valko, M., Leibfritz, D., Moncol, J., Cronin, M., Mazur, M., & Telser, J. (2007). Free Radicals and Antioxidants In Normal Physiological Functions and Human Disease. The International Journal of Biochemistry & Cell Biology, 39(1), 44-84. Retrieved October 7, 2013, from the PubMed database.

Vendemiale, G., Grattagliano, I., & Altomare, E. (1999). An Update on the Role of Free Radicals and Antioxidant Defense in Human Disease. International Journal of Clinical & Laboratory Research, 29(2), 49-55. Retrieved October 6, 2013, from the PubMed database.

The Alkaline Diet

After reading Nicholas’ post on the claim made by the company that produced water ionizers, I was reminded of a similar claim made by advocates of the ‘Alkaline Diet’. I decided to investigate whether these claims were accurate, or like the ones made by the water-ionizer company, scientifically wrong.

The Alkaline Diet is based on the theory that eating specific foods can affect maintenance of the body’s ideal pH balance, and improve health. (Collins & Chang, n.d) A website promoting holistic treatments gave the following reasoning for the diet:

The pH of the blood must always fall between 7.35 and 7.45  (slightly alkaline) to ensure an appropriate concentration of oxygen in the blood. A pH lower than 7.35 (Acidosis) may portray the beginnings of a disease / aging, while a pH higher than 7.45 (Alkalosis) would result in seizure, and a possible coma.

In order to keep the blood within this pH range, the website then explains, 75% of alkaline forming foods must be consumed; however, the American diet consists of 80% of acid forming foods.

The body creates a buffering system in order to counteract this abundance of acidic food in the diet; this buffering system runs on electrolytes, which are important for the metabolic functioning of body systems. Adequate electrolyte supply will pose no problem on the buffer system, however a shortage of these electrolytes will make it difficult for the body to maintain homeostasis (a state of equilibrium). A shortage of electrolytes usually occurs as a cause of excessive consumption of acid forming foods. (Frequency Rising, n.d)

At first, this claim made sense to me. After all, medical websites confirm that the blood’s pH must fall within a certain range. (Collins & Chang, n.d) Furthermore, there is evidence that shows that the concentration of Oxygen in the blood is affected by the blood’s pH, and as I have previously learnt in Biology class, it is true that the pH of blood must remain within a certain range to ensure health.  (RSC, n.d) Another medical website mentioned diseases such as Acidosis and Alkalosis, the former caused by a blood pH lower than what it should be, and another caused by a blood pH higher than it should be. (Dugdale & Zieve, n.d) Was the claim made by the holistic website accurate? Upon further examination and reflection, it was clear to me what the problem was: the holistic website was trying to convince people on the basis of a logical fallacy!* Our body deals with acidic food with a buffer system that does not work properly when you consume excessive acidic foods?


That makes no sense.

I soon realized that it was very easy to see the reason they would make this claim, as directly under the article, I saw this.

Water Ionizer Advertisement

This reminded me of Nicholas’ post, and confirmed my doubts: it was all just a marketing technique.

I decided to look at the biochemistry myself to determine the validity of the diet.

I found the concentration of Oxygen in the blood is controlled by a separate mechanism: oxygen flows around the body in blood by hemoglobin, a complex molecule with a central ion. (AUS-e-TUTE, n.d) The oxygenation of blood is an equilibrium reaction:

Hb4(aq) + 4O2(aq) <–> Hb4O8(aq)

A number of equilibrium reactions involving hemoglobin are responsible for the buffering of the blood: the net reaction being –

HbH+(aq) + O2(aq) <–> HbO2(aq) + H+(aq)

Metabolic reactions in the body release many acidic compounds, which lowers the blood’s pH by increasing the concentration of H+ ions present in the blood. This in turn, forces the equilibrium position to the left, resulting in acidosis. This decrease in oxygen supply causes fatigue and headaches. Acidosis is also the same condition you experience temporarily when you exercise without warming up, or when you engage in strenuous exercise when the available supply of oxygen cannot meet the demand for energy to complete the oxidation of glucose to carbon dioxide. (AUS-e-TUTE, n.d)

Thus, Acidosis really has nothing to do with what you eat.

Additionally, although electrolytes are important for the body, the only ion that affects the pH of the blood is the Phosphate Ion (PO42-), which is part of the Phosphate Buffer System. (Electrolytes, n.d) However, the primary buffer system for balance of the blood pH’s remains the Hydrogen Carbonate Buffer System.

Hydrogen Carbonate is produced in the body with water and CO2 (the end product of cellular metabolism) with the following reaction:

H2O + CO2 <–> H2CO3(aq)

The Hydrogen Carbonate is then involved in another (can be classified as a Bronsted-Lewry) reaction, which produces bicarbonate and the Hydronium ion:

H2CO3 + H2O <–> H3O+ + HCO3

If there is excess acid in the body (H3O+), the equilibrium shifts left.

H2CO3 + H2O <–  H3O+ + HCO3

Thus, the excess acid is neutralized by the base (HCO3)

The reverse takes place if there is excess base (OH) in the body: this reacts with the carbonic acid (H2CO3) and the equilibrium shifts right.

H2CO3 + OH <–  H2O + HCO3

This system thus operates under Le Chaletier’s principle, which states that “if a chemical system at equilibrium experiences a change in concentration, temperature, or total pressure, the equilibrium will shift in order to minimize that change ”. This reaction is the main mechanism used by our body to maintain homeostasis.

The Phosphate Buffer System plays a role in plasma and erythrocytes (components of blood)- (Tamarkin, n.d)

H2PO4- + H2O <–> H3O+ + HPO42-

Any excess acid reacts with monohydrogen phosphate to form dihydrogen phosphate –

H2PO4- + H2O <– H3O+ + HPO42-

Similarly, excess base is neutralized by dihydrogen phosphate –

H2PO4- + H2O –> H3O+ + HPO42-

So if this is all true, and the claim that eating alkaline foods can affect blood’s pH is not correct, then why do people continue to follow the Alkaline diet: and how can we explain their success stories?

The Alkaline Diet is “a diet of fresh fruits and vegetables, plenty of water, avoiding processed foods, coffee, and alcohol, which are all recommendations for a generally healthy diet anyway,” says Marjorie Nolan, who is an American Dietetic Association spokeswoman. (Collins & Chang, n.d) This is evident by an Alkaline Diet cheat sheet, which recommends eating cold-pressed olive oil instead of butter, frozen fruit instead of canned fruit, sparkling water instead of soda, honey instead of sugar, and so on. (Wilkinson, n.d) According to Nolan, any diet consisting of this meal plan is bound to prove successful, because it is “basically healthy”. She confirms however, that the body “regulates our pH between 7.35 and 7.45 no matter how we eat.” (Collins & Chang, n.d)

Alkaline Diet for Dummies: Cheat Sheet

Alkaline Diet for Dummies: Cheat Sheet

Alkaline Diet for Dummies: Cheat Sheet

So, what are the implications of this finding?

First, the negative implications: because the Alkaline diets promotes less consumption of dairy products and animal fats, followers of the diet if not careful, may develop calcium and protein deficiencies, according to John Asplin, an MD and kidney specialist. (Collins & Chang, n.d) A vegetarian myself, I was quick to disagree with this statement in my mind, however, he acknowledged that “vegetarians can be completely healthy in their diets, as long as they make sure to get adequate supplies of essential components to a diet.” Asplin also asserted that this could be seen as benefit also, because “many Americans over-consume protein”. (Collins & Chang, n.d) Another implication of this finding is that followers of the Alkaline Diet may not have a scientifically correct view of the functioning of their body, and this could lead to potential problems in the future. Followers of the diet may also waste money on expensive products (such as the water ionizer advertised on the holistic website) that do not affect our body in the way that the manufacturers claim.

What are the benefits? Because excess animal protein results in a higher risk of developing kidney stones, “eating a diet rich in vegetables, as with the alkaline diet” can lower this risk, according to Asplin. (Collins & Chang, n.d) It has also been suggested by research that an alkaline diet may slow bone loss and muscle waste, increase the growth hormone, and reduce the risk of certain chronic diseases (these are correlations however, and cannot be stated as a cause-effect relationship). (Schwalfenberg, 2011)

A negative correlation between the alkaline diet and incidence of cancer has also been shown, however the same results were obtained when the vegetarian diet was measured against cancer rates: additionally, as the study was correlational, there were many confounding variables that may have affected the results such exercise, alcohol consumption, smoking, genetics, etc. (Collins & Chang, n.d)

Nolan speaks of this finding, stating that “clinical studies have proved without a doubt that people who eat more fresh fruits and vegetables and hydrate properly do have lower rates of cancer and other diseases”, but that “it probably has nothing to do with blood pH”. (Collins & Chang, n.d)

The journey I took while examining this diet taught me to properly examine the agenda of the source making a claim before choosing to accept it: because the holistic website was advertising the water ionizer, they made claims that were scientifically inaccurate to make the product seem more appealing to customers. Web MD on the other hand, a medical website dedicated to providing people with factual information on clinical practices, provides evidence and information that supports the knowledge we have of the biochemistry of our body.

Thus, William Mundel, the vice chair of the department of General Internal Medicine at the Mayo Clinic in Rochester, advises against diets that “want you to buy only their product” (i.e.: the water ionizer), “focus on a narrow spectrum of foods” (i.e.: eliminate all animal fats), and “claim that science has kept something secret, or that someone has discovered something that nobody else knows about”. These are the types of diets that tend to be scientifically wrong. (Collins & Chang, n.d)

* The logical fallacy used is Circular Reasoning / Begging the Question.


Chemical Buffer Systems- Acid-Base Balance. (n.d.). Boundless. Retrieved May 22, 2013, from

Chemistry Tutorial : Oxygen Transport in Blood. (n.d.). AUS-e-TUTE For Astute Science Students. Retrieved May 22, 2013, from

Chemistry for Biologists: Transport of Oxygen in the Blood. (n.d.). Royal Society of Chemistry | Advancing the Chemical Sciences. Retrieved May 22, 2013, from

Collins, S., & Chang, L. (n.d.). Alkaline Diet: Pros, Cons, and Do They Really Affect Acid Levels in the Body?. WebMD. Retrieved May 22, 2013, from

Dugdale, D., & Zieve, D. (n.d.). Alkalosis – Symptoms, Diagnosis, Treatment of Alkalosis – NY Times Health Information . Health News – The New York Times. Retrieved May 22, 2013, from

Life Balances: Electrolytes. (n.d.). John Kitkoski’s Life Balances Program: Home Page. Retrieved May 22, 2013, from

Schwalfenberg, G. (2011, October 12). The Alkaline Diet: Is There Evidence That an Alkaline pH Diet Benefits Health?. National Center for Biotechnology Information. Retrieved May 22, 2013, from

Tamarkin, D. (n.d.). Buffers. STCC Faculty Webpages. Retrieved May 22, 2013, from

Wilkinson, J. (n.d.). Acid Alkaline Diet For Dummies – Cheat Sheet. For Dummies . Retrieved May 20, 2013, from

pH balance. (n.d.). Frequency Rising – Alternative Medicine and Holistic Health Products. Retrieved May 22, 2013, from

Indoor Air Pollution?

I have always had an obsession with scented candles: however, after moving into a wooden and carpeted house in Shanghai, my parents forbid me to use these candles because of the risks involved. I was upset, and I decided to do a little research on the benefits of using scented candles in order to convince them otherwise. When I found more negative than positive effects, I was shocked.

Candles contain Parrafin wax, which is derived from petroleum (alternatively, and more expensive, are candles made from plant oils such as palm, soybean, and beeswax).   According to Ruhullah Massoudi, PhD professor of chemistry at South Carolina State University, Parrafin when burned has been proven to release small amounts of cancer causing agents benzene and styrene, as well as toluene and hydrocarbon chemicals such as alkanes and alkenes. (Main)

Figure 1- Benzene is an organic chemical compound. Its molecule is composed of 6 carbon atoms joined in a ring, each attached to a single hydrogen atom. It is a resonance structure.
Figure 1- Benzene is an organic chemical compound. Its molecule is composed of 6 carbon atoms joined in a ring, each attached to a single hydrogen atom. It is a resonance structure.

Benzene (C6H6) is a colorless liquid with a pleasant odor, and a trace amount of this chemical is usually released whenever carbon-rich materials undergo an incomplete combustion. It is produced in forests fires and volcanoes, and is also a component of cigarette smoke. Benzene can irritate the nose and the throat, and may cause upset stomach/ vomiting. Benzene is also used as an inhalant: when inhaled, it can make you feel dizzy/ lightheaded, and can in extreme cases lead to convulsion and then death. These harmful effects can also be experienced without inhaling the chemical, as it has the ability to pass through the skin. . (Wikipedia) Prolonged exposure to benzene can cause interference with the production of bone marrow in the human body, thus resulting in aplastic anemia or certain types of leukemia. This is because pure benzene oxidizes in the body to produce benzene oxide, which is not readily excreted. Benzene oxide can interact with DNA to produce harmful mutations. The US Department of Health and Human Services (DHHS) classifies benzene as a hazardous substance and a human carcinogen. (Benzene Toxicology)

Figure 2- Styrene is an organic chemical compound. The structure consists of an ethane molecule, with the last hydrogen atom attached to the carbon replaced with a phenyl group. The molecule is also known as "vinyl benzene" and "phenyl ethane".
Figure 2- Styrene is an organic chemical compound. The structure consists of an ethane molecule, with the last hydrogen atom attached to the carbon replaced with a phenyl group. The molecule is also known as "vinyl benzene" and "phenyl ethane".

Styrene (C6H5CH=CH2) is a colorless oily liquid with a sweet smell. It is also known as vinyl benzene and phenyl ethane. Like benzene, styrene is usually oxidized in humans by cytochrome P450 (a group of enzymes) to form styrene oxide, which is considered to be mutagenic, and possibly carcinogenic. According to the U.S Environmental Protection Agency, styrene is “a suspected toxin to the gastrointestinal tract, kidney, and respiratory system, among others.” Chronic exposure to styrene leads to tiredness and lethargy, headaches, memory deficits, and vertigo. (Wikipedia)

Synthetic fragrances are also present in scented candles: these, like Parrafin wax, are derived from petroleum and contain phthalate esters.  These are added to the candle to help the smell linger: however, they are not much healthier than the contaminants released by car exhausts. According to the Environmental Protection Agency, can interfere with a body’s hormone system, making the person more susceptible to diabetes, certain cancers, obesity, and thyroid disease. Phthalates can also build up as household dust and linger for long periods of time. They can be ingested by inhaling or through the skin. (Tierny 2011)

A candle enclosed in glass, after 7 days.

Lastly, the most harmful and abundant emission from scented candles is soot. Soot is the product of an incomplete combustion of organic fuels, usually petrochemical based. This is also what makes the flame of a candle glow. As Parrafin wax burns, the surrounding air is constantly filled with particulate matter (soot) with the potential to cause sever damage to the lungs:  “Their size, less than 1  µm, allows deep penetration of the respiratory system and alveolar deposition. The insoluble, carbonaceous core structure with high surface area allows adsorption of extractable volatile, and semi-volatile organic compounds.” (Krause 1999) “Soot can also accumulate on furniture, carpeting and walls, and linger for long periods of time. (Main)

When studies suggest that the negative effects of candle soot may be equivalent to those of factory emissions, are we right to complain about the air pollution outside our homes when the quality of air inside our homes is within our control, and yet we still manage to contaminate it? (Main)

While the negative information I found on the topic overwhelmed me, I also researched possible solutions to overcoming indoor pollution. The most common suggestion I found was to stop using scented candles altogether, and instead set out some baking soda or a bowl of white vinegar in a room to get rid of an odd smell. Good quality essential oils can also be used (as long as they are not burned).

If one wishes to occasionally use a scented candle, beeswax candles are recommended. In a Paraffin candle, the flame does not get hot enough to completely burn oil and thus results in an incomplete combustion and release of toxic chemicals. Beeswax candles however, burn at a lower temperature and therefore do not have that problem. They smell sweet without chemical fragrances, and beeswax is believed to contain negative ions that improve indoor air quality. (Main)

Side note: Candles made from palm oil (vegetable wax) should be avoided as the palm oil comes from pal tree plantations, for which rainforests are sacrificed. Wicks should be checked as many candlewicks contain lead: when burned, inhaling the fumes has been proven to be harmful to human health. According to Jerome O. Nriagu, Ph.D., a professor of environmental chemistry at the University of Michigan in Ann Arbor, candle-makers use metal-core wicks because “cotton wicks are often limp and fall over into the wax, extinguishing the flame.” (Downey)

From what I gathered by reading between the lines of various articles on the issue, it is not likely that occasional exposure to fumes from scented candles will severely harm us, but prolonged/ daily exposure should be avoided.

Reference List:

–> (Main)

Main, E. (n.d.). Study: Candle chemicals pollute indoor air. Retrieved from,0

–> (Wikipedia)

Wikipedia. In Benzene. Retrieved from

–> (Wikipedia)

Styrene. In Styrene. Wikipedia. Retrieved from

–> (Krause 1999)

Krause, D. (1999). Us scented candles study. Retrieved from

–> (Downey)

Downey, C. (n.d.). Toxins in burning candles, candle wicks, and incense. Retrieved from

–> (Benzene Toxicology)

Benzene: Toxicology. (n.d.). Retrieved from

–> (Tierney 2011)

Tierney, J. (2011, March 15). Scented candles can cause ‘indoor air pollution’. Retrieved from