We believe that blonde hair will be negatively affected by the presence of chlorine or salt water. Having swam most of our lives, we both have witnessed hair damage with other swimmers and discoloration. However we have not noticed any true signs of damage other than complaints, and we think that if this was put into an experiment it would definitely show a negative impact on blonde human hair. 

What is Hair?

Hair is a protein filament ( a long chain of proteins). It grows in a sac called the follicle of skin cells in the middle layer of skin. The surface of hair is mostly made up (65-95%) of fibrous protein (types of protein).  The structure of hair is a lot more complicated. The outer layer of the hair itself is called the Cuticle, it contains overlapping dead cells that protect the inner layers. The second layer is the Cortex. The cortex is the thickest part of the hair. This part contains the most pigment (the part that shows the hair colour). The next aspect of human hair is the Cortex Cells. The Cortex Cells are the cells that make up the cortex. The cells are tightly packed together and have Melanin granules inside of them. These cells are responsible for the hair’s shape/texture. The final part of the hair is the Medulla. This is the innermost layer of the hair. The exact function is unclear. 

What is the Genetic Makeup of Different types of Hair?

Brown/black hair and blonde/red hair do not have the same genetic makeup, because of how brown and black hair are usually caused by the presence of eumelanin which makes darker skin,eyes, and hair. Where as blonde and red hair is caused by the presence of pheomelanin which causes lighter hair, skin, and eyes. 

Why did We Choose to Use Blonde Hair in Our Experiment?

The reasons why we chose blonde hair over all the other hair colours are:

• Blonde hair is a known recessive gene with less pigment, because of this we thought that the way to go about this experiment would be to use a hair colour with less pigment. In our minds it would show the biggest effect from the chlorinated-salt water, especially if the water were to create a “green hue”.

• Blonde hair has a higher vitamin D production than any other hair colour (excluding red) this is because of adaptation. We want to see if the chlorinated-salt water would affect how the sunlight would react to the hair samples.  

What Shampoo do the Majority of Swimmers in Our Survey Use?

In our survey there was a variety of results on what type of shampoo the participants used. Though we concluded that Dove shampoo was the most generic and commonly used for not only athletes but people all around the globe.  

What is in Shampoos?

There are only a few components in most shampoos, including:

1. Sodium Lauryl (SLS) - derived from coconut/ palm oil
2. Sodium Laureth Sulfate (SLES) - derived from SLS (Creates a rich lather effect)
3. Cetyl - an alcohol that is in both shampoos and conditioners that helps retain moisture and improve texture
4. Stearyl Alcohols - other alcohols similar to Cetyl
5. Ceramides - natural lipids that are found in skin (in shampoos they are used to retain moisture).

All of these components work together to rid hair of oils, dirt, products, and environmental build-up, among other things. 

What Substances can Positively Impact Hair Health/ Colour?

From a dietary intake perspective, substances like lean proteins, foods high in omega-3s, eggs, whole grains, leafy greens, and fruits and vegetables high in vitamin-c have a positive impact on your hair. These food categories will not only help restore broken hair but can impact your body as a whole positively. 

Lean proteins: Lean proteins are things like chicken, beef, and fish provide a high amount of iron and protein. This is essential for everyday life because of its long chains of amino acids. It is beneficial for your teeth and nails as well because of its benefits for keratin supply. 

Foods high in omega-3: Examples of foods high in omega three include fatty fishes like salmon, mackerel, and herring. These foods have anti-inflammatory properties reducing oxidative stress. “Oxidative stress occurs when molecules called free radicals damage cells in your body.” says registered dietitian Michelle Dodd, RD, LD. “This damage can affect any part of your body, including hair follicles.” 

Eggs: Specifically egg yolks (not the whites) are high in Biotin. This B vitamin advances keratin abundances. One study done by the National Library of medicine shows us that there is a direct connection to biotin levels and hair loss, but other studies have yet to prove that biotin levels are directly connected to hair growth (This may be the case but biotin does affect hair loss).

Whole grains: Whole grain has a substance called selenium which helps maintain your thyroid glands healthy. “Thyroid disease can cause your hair to become brittle and fall out,” says Michelle Dodd. But people who have absent thyroid issues can still intake foods with selenium to prompt hair growth. 

Leafy greens: Leafy greens such as spinach, lettuce, kale, etc. have high amounts of vitamin-A. “This fat-soluble vitamin helps make sebum, the oily substance that moisturizes your scalp and keeps hair healthy,” shares Michelle Dodd. “A vitamin A deficiency can cause a dry, scaly scalp and poor hair growth.”

Though all of these foods can impact your hair positively it doesn't have a huge impact on hair that is exposed to chemicals. 

Can the Age of the Hair Impact its Ability to Withstand Colour Damage?

Hair colour changes with age. This is because of how your hair follicles (the sac in which your hair grows) produce less melanin. Which means that the pigment in your hair appears duller or gray. White hair has no melanin. Some other factors come into play too, including: 

• Genetic Factors - family history with hair colours
• Grooming HabitsIs there any Other Chemical that Can Be Used as a Substitute for Chlorinated/ Salt water pools? - chemical products
• Lifestyle Factors - stress, food habits, smoking

As well as other factors.   In conclusion the age of hair does impact its ability to withstand colour damage because of how there is less melanin in the hair follicles.  

How does Bleaching your Hair Affect its Health?

Bleaching overall is negative for your hair’s health. The bleach penetrates into the follicles and strips them of your natural colour. This changes the structural integrity of your hair. It becomes weak and the strands break easily. The bleach also strips the melanin from your hair. There are two main types of chemicals in bleach that do this, ammonia and hydrogen peroxide. Many people think the risk is small, however bleaching your hair more than once is terrible for its health.  

Is there any Other Chemical that Can Be Used as a Substitute for Chlorinated/ Salt water pools?

There are many different options to not using chlorinated - salt water as a disinfectant for pools. This includes:

• Ozone Pools - This method uses ozone gas, that is put into the pool water. The gas kills all bacteria, viruses, etc. The ozone gas then turns into oxygen. Ozone pools are a very environmentally friendly choice.
• UV Pool Systems - This system harnesses Ultraviolet Light to disrupt the D.N.A of the pathogens (bacteria, etc)  in the pool. This stops them from multiplying. However UV pool systems do not eliminate all pathogens.

There are many other options. But these two are the main ones being used today. 

How does Your Hair type Affect the Impact of the Chemicals on It?

Blonde hair, along with greying hair are more prone to getting damage from UVB radiation (the sun’s rays). Coily hair, especially type 4C are can shrink and break from nearly all chemicals. Hair types 1A, 1B, and 1C are also susceptible to certain types of chemicals. 

What Shampoo Products are Already Available to Prevent Hair Damage from Pool Chemicals?

Already there are so many different shampoo brands available to prevent hair damage from pool chemicals. However between the two of us, we’ve noticed none of them seem to work. Here is a list of the top names:

1. SoCozy Kids Swim 3-in-1
2. Ultra Swim Chlorine Removal
3. Paul Mitchell Shampoo Three
4. Malibu C Wellness Kit
5. Fairy tales Swim Shampoo

All of these products promise soft, silky, healthy hair after usage. 

What is in Chlorine Clarifying Shampoo?

Chlorine clarifying shampoos contain agents like EDTA or citric acid to break down and remove chlorine buildup, along with substances to cleanse the hair. They also typically include moisturizing and nourishing ingredients such as plant oils, aloe, and fruit extracts to counteract dryness from chlorine damage.

Manipulated: The type of hair, shampoo type. Controlled: Water sample, type of hair in individual container. Responding: How the hair reacts to different types of shampoo.

1. Take 60 strands of pure hair (A) and separate it into 8 petri dishes. 15 strands in each dish. 
2. Take 60 strands of chemically changed (bleached) hair (B) and separate into 8 petri dishes. 15 strands in each dish.
3. Add 40 millimeters of chlorinated-salt water in each petri dish
4. Dish 1A will not be touched
5. Dish 1B will not be touched
6. Dish 2A will be washed with Dove Volume and Fullness hair (2mL) once a week.
7. Dish 2B will be washed with Dove Volume and Fullness hair (2mL) once a week. 
8. Dish 3A will be washed  with tri hub (2mL) once a week.
9. Dish 3B will be washed with tri hub (2mL) once a week.
10. Dish 4A will be rinsed with shower water once a week.
11. Dish 4B will be rinsed with shower water once a week. 

Repeat the same procedure for the second time.

Test #1	Week 1	Week 2	Week 3	Week 4
Sample 1A temperature and observations	Temp=17.9 C

Seems to create “air bubbles” when touched in any way. Under the microscope there are no visible changes yet. | Temp=16.6 C

The texture is more ruff and has no moisture. | Temp= 18 C

Strands appear thinner under a microscope.

| Temp= 18.1 C

No visible changes from last observation. | | Sample 2A temperature and observations | Temp=17.3 C

Also have “air bubbles”. The texture of the hair is brittle and ruff. No visible changes under microscope.  | Temp=16.6 C

Has “air bubbles” and is also with ruff texture. | Temp= 17.8 C

No moisture and colour is darker. | Temp= 18 C

No visible changes from last observation. | | Sample 3A temperature and observations | Temp=16.9 C

No visible changes under microscope or texture wise.  | Temp=16.4 C

Hair is a darker shade of blonde. | Temp= 17.4 C

No visible changes from last observation.

| Temp= 17.5 C

No visible changes from last observation. | | Sample 4A temperature and observations | Temp=17 C

The texture is also ruff and has split ends.  | Temp=17 C

No visible changes from last observation. | Temp= 17.7 C

No visible changes from last observation. | Temp= 18 C

No visible changes from last observation. | | Sample 1B temperature and observations | Temp=17.4 C

No visible changes under microscope or texture wise.  | Temp=17.1 C

Has “air bubbles” and its colour has shifted slightly to a lighter blonde/white. | Temp= 18.1 C

No visible changes from last observation. | Temp= 17.9 C

Colour has changed to even lighter blonde. | | Sample 2B temperature and observations | Temp=17.6 C

Have split ends. | Temp=15.4 C

No visible changes since last observation. | Temp= 17.7 C

No visible changes from last observation. | Temp= 18.1 C

No visible changes from last observation. | | Sample 3B temperature and observations | Temp=17.6 C

No visible changes under microscope. | Temp=15.6 C

No visible changes since last observation. | Temp= 18 C

No visible changes from last observation. | Temp= 18.3 C

No visible changes from last observation. | | Sample 4B temperature and observations | Temp=16.3 C

The texture is ruff. | Temp=17.3 C

The texture is ruff. | Temp= 17.5 C

No visible changes from last observation. | Temp= 17.8 C

No visible changes from last observation. |

Test #2	Week 1	Week 2	Week 3	Week 4
Sample 1A2 temperature and observations	Temp=15.9 C

Have “air bubbles” and faint blue hue. | Temp=14.5 C

The color is more white than blonde. | Temp= 17.6 C

No visible changes from last observation. | Temp= 17.4 C

No visible changes from last observation. | | Sample 2A2 temperature and observations | Temp=16.3 C

Have “air bubbles”. | Temp=16.2 C

Has “air bubbles” still. | Temp= 17.5 C

No visible changes from last observation. | Temp= 17.2 C

No visible changes from last observation. | | Sample 3A2 temperature and observations | Temp=15.8 C

Split ends. | Temp=14.7 C

Split ends. | Temp= 16.9 C

No visible changes from last observation. | Temp= 17.1 C

Hair appears “dirty”. | | Sample 4A2 temperature and observations | Temp=17.5 C

No visible changes under microscope or texture wise. | Temp=16.4 C

No visible changes under microscope or texture wise.

| Temp= 17.5 C

The hair is now thinner. | Temp= 16.9 C

No visible changes from last observation. | | Sample 1B2 temperature and observations | Temp=12.9 C

No visible changes under microscope or texture wise. | Temp=17.2 C

Has “air bubbles”. | Temp= 16.8 C

No visible changes from last observation. | Temp= 17 C

No visible changes from last observation. | | Sample 2B2 temperature and observations | Temp=17.5 C

Texture appears ruff and “dry” (no moisture). | Temp=17.1 C

Colour has changed to look darker/dirty. | Temp= 17.6 C

Has “air bubbles”. | Temp= 17.3 C

No visible changes from last observation. | | Sample 3B2 temperature and observations | Temp= 17 C

Split ends. | Temp=14.5 C

Split ends still. | Temp= 15 C

No visible changes from last observation. | Temp= 14.9 

No visible changes from last observation. | | Sample 4B2 temperature and observations | Temp=17.7 C

Has “air bubbles” in both water and hair.  | Temp=17.4 C

The texture is ruff.  | Temp= 18.2 C

No visible changes from last observation. | Temp= 17.8 C

No visible changes from last observation. |

Samples 1A/ 1A2 and 1B/1B2 all seem to have one thing in common: the colour has changed to be a lighter shade of blonde, almost white. Samples 2A/ 2A2 and 2B/ 2B2 showed signs of the hair colour becoming darker. Almost dirty looking. Sample 3A/ 3A2 and 3B/ 3B2 seem to all have a green hue. Samples 4A/ 4A2 and 4B/ 4B2 have all lost the most moisture and also seem to have a stronger green hue along with dirt. In all of the samples we also noticed that the hair was slowly becoming more ruff and losing all moisture from the beginning as well.  

The common denominator between all samples is that the texture, and colour of hair strands has changed to become more dirty or ragged looking. Over time the hair strands have lost their source of melanin, this is proved because of their loss of colour. The chlorinated-salt water has seemed to quicken this process comparing to what natural hair would react to without the exposure. To summarize all that has been said the chlorinated-salt water has had a negative impact on the hair strands proving our hypothesis to be correct.

This information is very important for swimmers all over the world that train in chlorinated-salt water pools. This experiment also shows that the chlorine clarifying shampoo is not as helpful as promised, which means that people can make better choices with buying their shampoo products now . Learning of the damages that the water can do to your hair can also help people make a better decisions about whether or not they want to go into a chlorinated-salt water pool as well. 

1. We only replaced the chlorinated salt water once in the four week period. Chlorine evaporates over time\, meaning that the hair could have had a more noticeable affect/difference if we had replaced the water more frequently . If we were to re do this project we would have changed the water.

2. We would have expanded the survey to more than ten people. We feel it would have aided our choice of shampoo better.

3. We attempted to find out the amount of chlorine that is added to the MNP pools\, because that is were we got the water from. However we never received their response.

Sources: 

Understanding Hair Color Genetics and its Role in Inherited Traits

What is the Difference Between Eumelanin and Pheomelanin - Pediaa.Com

Chemistry of Wellness: Hair and Hair Care | Department of Chemistry

What Hair Colors Are Dominant and Recessive? - Necole Bitchie

Which hair colors are dominant and recessive?

The Science Behind Blonde Hair | ShunSalon

Vitamin D and Hair Growth: What Dermatologists Want You to Know | Dr Raechele Derm

Best Foods for Hair Growth: What to Eat, Drink & Avoid

Your guide to aging and hair | UCLA Health

Bleaching Hair Bad for Your Health: Unraveling the Impact on Overall Wellness - Restore Hair Guide

5 Healthier Alternatives to Chlorine for Swimming Pools - Olympian Water Testing, LLC

Ingredients to help hair thrive - Karla Pope 

8 Foods to help grow heather, longer hair - Cleveland Clinic

Serum biotin levels in women complaining about hair loss - The National Library of Medicine

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