The Impact of Thalidomide On Society

Photo: Taken from

Origin of Thalidomide

Thalidomide was created by a family-owned pharmaceutical company, Chemie Grünenthal (Thalidomide Victims Association of Canada, 2017). Chemie Grünenthal was the first company to introduce Penicillin into the German market in the 1940s while in the 1960s, it introduced Thalidomide into the market.

Chemie Grünenthal first obtained a twenty-year patent for Thalidomide in 1954 and subsequently started clinical trials for the drug. Researchers at the company soon found out that the drug was rather effective in relieving morning sickness for pregnant mothers. Thalidomide was then marketed as Contergan® in the German market and was taken by many expectant mothers.

Beside West Germany where Thalidomide was first invented, Thalidomide was also distributed in the UK as Distaval, in Canada, and in the United States albeit without much success due to disapproval by the US Food and Drug Administration.

Impact of Thalidomide 

Thalidomide was promoted as a ‘wonder drug’ to treat a range of conditions including headaches, insomnia and depression. It was popular because it was atoxic and so it was impossible to overdose on it (Thalidomide Society, N.A.). But long-term ingestion of the drug will result in irreversible peripheral neuritis, which is damage to the peripheral nerves, causing numbness, weakness and pain in the hands and feet (Mayo Clinic, 2017). The main impairments caused by thalidomide affect the limbs and are usually bilateral – either both arms or both legs or all four limbs (Thalidomide Society, N.A.).

Due to the absence of a census, there has not been an accurate number of fatalities resulted by Thalidomide. But according to the Thalidomide Victims Association of Canada, there were between ten and twenty thousand students born disabled as a result of the drug Thalidomide. The drug was responsible for deformities in children born by expectant mothers who consume it during their third trimester.

Impact of Thalidomide in Singapore

According to FFDN, the Thalidomide Association of Sweden , there is a personal anecdote of a lady born in the 1960s with disabilities in Singapore. She believed her defects at birth were a result of the consumption of Thalidomide by her mother during pregnancy. In her words, ‘there was an outbreak of infants born with deformed or missing limbs’. She received treatment as an infant which includes several operations and many hours of therapy to straighten her limbs. Growing up, she learnt how to walk with the help of callipers and walking frame.

Henceforth, against this personal narrative, there may perhaps be other children born with defects in the same period in Singapore which may have been left out of official records. Thus, Thalidomide did affect Singaporeans in the 1960s, although it is hard to estimate its impact.


Chemistry Concept of Thalidomide

Researchers later realized that the problem lied in the fact that thalidomide was being provided as a mixture of two different isomeric forms.

Diagram 1: Two isomers of Thalidomide

Both isomeric forms have the same molecular formula and the same atom-to-atom connectivity. Both isomers differ in the arrangement of the three-dimensional space about one tetrahedral, sp3-hybridized carbon.  Hence, the two forms of thalidomide are known as stereoisomers.  Tetrahedral carbons with four different substituent groups are called stereocenters as  indicated in the diagram above


AE 6

Question 1. Mammoth Cave National Park in Kentucky is in close proximity to the coal-fired electric utility plants in the Ohio Valley. Noting this, this National Parks Conservation Association (NPCA) reported that this national park had the poorest visibility of any in the country.

  • What is the connection between coal-fired plants and poor visibility?
  • The NPCA reported ” the average rainfall in Mammoth Cave National Park is 10 times more acidic than natural.” From this information and that in your text, estimate the pH of rainfall in the park.


  1. Coal-fired plants releases sulfur dioxide. This results in sulfate particles to be present in the atmospheric air near the plant, and thus contributing to the poor visibility at the park.
  2. Generally, rainfall is of pH range of 5-6. Therefore, given that the average rainfall in Mammoth Cave National Park is 10 times more acidic than natural, its rainfall should be in the pH range of 4-5.

Question 2. Here are examples of  what an individual might do to reduce acid rain. For each, explain connection to producing acid rain.

  • Hang your laundry to dry it.
  • Walk, bike, or take public transportation to work.
  • Avoid running dishwashers and washing machines with small loads.
  • Add additional insulation on hot water heater and pipes.
  • Buy locally grown produce and locally produced food.


  1. Hanging your laundry to dry uses less energy as compared to using an electrical dryer to dry it.
  2. Walking, biking or taking public transport can reduce the amount of gasoline used.
  3. It uses less energy running dishwashers and washing machines only when they are fully loaded as opposed to running them in small loads.
  4. Adding additional insulation on hot water heaters and pipes can prevent heat loss and conserve energy. Therefore, electrical energy generated from the burning of coal in power plants can be conserved.
  5. Buying from locally grown produce and locally grown feed will greatly reduce the amount of gasoline used in transporting externally-grown produce. Therefore, less NO emission will be produced, contributing less to the acidity of the rain.

Question 3a. Give names and chemical formulas for five acids and five bases.


Five acids:

  1. Nitric acid, HNO3
  2. Hydrochloric acid, HCl
  3. Sulfuric acid, H2SO4
  4. Phosphoric acid, H3PO4
  5. Carbonic acid, H2CO3

Five Bases:

  1. Sodium hydroxide, NaOH
  2. Potassium hydroxide, KOH
  3. Ammonium hydroxide, Nh4OH
  4. Magnesium hydroxide, Mg(OH)2
  5. Calcium hydroxide, Ca(OH)2

Question 3b. Name three observable properties generally associated with acids and bases.


Properties of Acid:

  1. Taste sour
  2. Turn litmus paper red
  3. Release carbon dioxide from a carbonate.

Properties of Base:

  1. Taste bitter
  2. Turn litmus paper blue
  3. Slippery feel in water

Question 4. The concerns of acid rain vary across the globe. Many countries in North America and Europe have websites dealing with acid rain. Either search to locate one (”Canada, acid rain”) or use these links to websites in Canada, the UK, or Europe. What are the issues in Singapore? Does the acid deposition originate outside or inside the Singapore’s borders?

  • /

Answer: One issue that Singapore is facing is the impact of biomass burning  on rainwater acidity and composition. Large scale forest fires in Indonesia, to clear land and make way for new harvest, are being set from August to October every year. This process releases large amount of gaseous and particulate pollutants into the atmosphere, and adversely affected the air quality in Southeast Asia region. A study done in 1997 revealed that major inorganic and organic ions (SO42-, NO3 and NH4+) were detected in the collected rain samples, and the acidity of this rain were between the pH values of  3.79 to 6.20. The decrease in pH of precipitation in response to the increased concentration of acids is marginal, due to the neutralisation of acidity by NH3 and CaCO3.


Question 1. When Styrofoam packing peanuts are immersed in acetone (the primary component in some nail-polish removers), they dissolve. If the acetone is allowed to evaporate, a solid remains. The solid still consists of Styrofoam, but now it is solid and much denser. Explain. 

Hint: Remember that Styrofoam is made with foaming agents.

Answer: When acetone dissolves the polymer (polystyrene), gas trapped in the foaming agent is allowed to escape and the polymer collapses on itself. Given that density = mass/volume, when the gas is removed from the polymer, volume decreases and density increases. Hence, the polymer becomes more dense.

Question 2. Consider Spectra, Allied- Signal Corporation’s HDPE fiber, used as liners for surgical gloves. Although the Spectra liner has a very high resistance to being cut, the polymer allows a surgeon to maintain a delicate sense of touch. The interesting thing is that Spectra is linear HDPE, which is usually associated with being rigid and not very flexible. 

  • Suggest a reason why branched LDPE cannot be used in this application.
  • Offer a molecular level reason for why linear HDPE is successful in this application.


  1. Branched LDPE cannot be used in this application as it does not have required strength to act as liners of surgical gloves.
  2. Linear HDPE is successful in this application as a thin liner of it allows sufficient flexibility while providing the required strength for surgical gloves.

Question 3. When you try to stretch a piece of plastic bag, the length of the piece of plastic being pulled increases dramatically and the thickness decreases. Does the same thing happen when you pull on a piece of paper? Why or why not? Explain on a molecular level.

Answer: When a piece of plastic is stretched, the strip narrows and “necks down”. The molecules become aligned parallel to each other and in the direction of the pull. This alteration of the 3D structure is irreversible, and if the pulling continues, the plastic breaks. When the same pulling force is applied to a piece of paper, the paper tears instead of stretching. This is because paper is made up of cellulose molecules which form cross-linkers and are held more rigid in place. As such, the molecules are not able to be aligned parallel to each other to be stretched.

Question 4. A Teflon ear bone, a Fallopian tube, or heart valve? A Gore-Tex implant for the face or to repair a hernia? Some polymers are bio-compatible and now used to replace or repair body parts.

  • List four properties that would be desirable for polymers used within the human body.
  • Other polymers may be used outside your body, but in close contact with it. For example, no surgeon is needed for you to use your contact lenses- you insert, remove, clean and restore them yourself. From which polymers are contact lenses made? What properties are desirable in these materials? Either a call to an optometrist or a search on the Web may provide some answers.
  • What is the difference in the material used in ”hard” and ”soft”contact lenses? How do the differences in properties affect the ease of wearing of contact lenses? 


  1. The benefits for polymers used within the body should far outweigh any risks. Two main properties of the polymers are being stable over time of the intended use and being non-toxic to the body. The polymers used in the body should also not be able to react with the bodily fluids or dissolve in them, and the ease of implantation should be considered.
  2. There are several different types of contact lenses on the market and each uses a different type of polymer. Polymathy methacrylate (PMMA), one of the earliest polymers used for rigid gas permeable lenses, is structurally similar to Lucite and plexiglas. Silicone-acrylate materials now are more commonly used under trade names such as Kolfocon. Newer rigid gas permeable (RGP) polymers contain fluorine: flour-silocone-acrylate polymers and flour-silicones.
  3. Hard contact lenses are typically made of PMMA, a rigid non-gas permeable plastic. The soft contact lenses that replaced them are made of silicone, which is flexible and allows oxygen to reach the eye. Due to such properties, the soft lenses tend to be more comfortable.