The study of the decomposition of hair over time

[Rosemary]

I am taking a science research class and would like some help in the field of hair decompostion and how that could possibly be used in a forensics project. I was wondering if this has been done before, and if it is possible for a highschool student to do it. Also, is there any special equipment involved?

[Louise]

I am taking a science research class and would like some help in the field of hair decompostion and how that could possibly be used in a forensics project. I was wondering if this has been done before, and if it is possible for a highschool student to do it. Also, is there any special equipment involved?

Hi Kelly,
There is a lot of research on this topic and many different ways you could conduct and experiment. (For example, are you interested in hair in a hairbrush, hair that is buried, hair from a drain, etc? All will have different decomposition rates.) I suggest you try a simple internet search to obtain more information. I tried searching for "decomposition of hair and forensics" and got a ton of interesting hits.
I happen to use google as my default search engine. Different search engines search differently= give different results.

Two caveats on use of google, or any other search engine:

a. Small wording changes can have a big impact on the output. So experimentation is in order.
b. Beware of sites that are just trying to sell you something.

Also, a lot of scientific papers were returned by my search. You may not be able to access the full article (unless you are at a research university), but you should be able to access the abstract, which should give you a good idea of what the research/results were.

Once you've done some research and developed a question or hypothesis, feel free to post back here with more detailed questions.

Hope this helps,
Louise

[Rosemary]

I did some more research and found a paper on exactly what i want to do. He studied how hair still attached to cadavers decomposes. Does hair on a hairbrush decompose the same or differently than hair on a corpse? I cant find that on the internet. Im assuming it does, but i dont know how differently. Since I am just starting out in research, I will probably use hair off of a hair brush or one plucked from my head. If I wanted to study how it decomposes in water, air and underground, what special equipment do I need?

[Louise]

I did some more research and found a paper on exactly what i want to do. He studied how hair still attached to cadavers decomposes. Does hair on a hairbrush decompose the same or differently than hair on a corpse? I cant find that on the internet. Im assuming it does, but i dont know how differently. Since I am just starting out in research, I will probably use hair off of a hair brush or one plucked from my head. If I wanted to study how it decomposes in water, air and underground, what special equipment do I need?

Okay, so how does the guy in the paper do it? It sounds like you should use this as your procedure.


Louise

[geoffbruton]

Hi Rosemary,

This sounds like an excellent project! I agree with Louise - in order to determine if the decomposition of hair is comparable to that in the scientific literature (or at least the paper you mentioned), I would attempt to use the same method employed by the researcher(s). What did they do?

Also, I did notice that you discussed the use of hair from a hairbrush and one plucked from your head. I would suggest that you perform multiple tests in order to account for possible variability within each testing regime.

If you haven't had the opportunity to research it yet, try looking up "Forensic Taphonomy" in your library and online - in addition to searching for hair lifespan, growth phases and composition. All of this should help you understand the processes involved, and why there *might* be a difference in the study of loose versus plucked hairs.

Please post back with any more questions, if you have any, and be sure to let us know how your project is going.

Good luck!
Geoff.

[Rosemary]

I am in highschool and was wondering, for my project, if it is possible for me to obtain human head hair from a dead cadaver.

[Willz]

I am in highschool and was wondering, for my project, if it is possible for me to obtain human head hair from a dead cadaver.

Hi Rosemary!
This sounds like some really advanced stuff that you're doing! As you are a high school student, I'm not sure if you will be able to obtain cadaver hair at your age, but according to something I found online, it is possible to get cadaver hair: "Interestingly enough, from the FDA’s point of view, the sale of cadaver hair, if it is taking place, isn’t illegal. There are no medical warnings against it and no agency regulations currently forbid it. " However, like I mentioned before, I'm not sure if and where you can get it. Perhaps you should try asking the Anatomy teacher at your school, or a Biology teacher.
-Willz

[MelissaB]

You might not be able to get human cadaver hair, but you might be able to get dead dog or cat fur from a veterinarian's office and compare that with fur from living dogs or cats.

[Yingna]

I am in highschool and was wondering, for my project, if it is possible for me to obtain human head hair from a dead cadaver.

Hi Rosemary,

This topic sounds very interesting! If you're looking to get hair from a cadaver, I suggest trying to get in contact with the researchers who have conducted research with that kind of hair and see if there's any possibility that you could obtain any. Try contacting the researchers on the paper you have read.

Or, like Melissa wrote, substituting the hair with pet hair might also be good during the first stages.

[wildfirefox]

Here's some suggestions for you for your project:

Cadaver's hair can be obtained through the morgues from your local hospitals and police forensic labs. You have to contact the representatives to get the permission. Since it's for science, they're more than willing to cooperate with you. You can also try the local morticians. As they prep the bodies, some hair get tangled with the equipment, or the decomposing hair will fall off naturally due to weak cellular adhesion in the scalp.

Rather than focusing on human hair, you can also focus on animal hair. Remember, the cellular structure of fur and human hair is similar. Hair and fur are composed of dead cells.

[Louise]

Here's some suggestions for you for your project:

Cadaver's hair can be obtained through the morgues from your local hospitals and police forensic labs. You have to contact the representatives to get the permission. Since it's for science, they're more than willing to cooperate with you. You can also try the local morticians. As they prep the bodies, some hair get tangled with the equipment, or the decomposing hair will fall off naturally due to weak cellular adhesion in the scalp.

Rather than focusing on human hair, you can also focus on animal hair. Remember, the cellular structure of fur and human hair is similar. Hair and fur are composed of dead cells.

Just make sure you get this cleared by your teacher and the science fair board. I am also not sure what type of release the source of the hair might have to go through. The hair is not owned by the police or the mortician, but rather the relatives of the decreased person. They may not be interested in helping with your science fair. There are certainly ethical issues with using hair, and you need to make sure you deal with them appropriately. You might also need additional paperwork.

Louise

[geoffbruton]

Hi Rosemary,

Just something to add to that already said by others:

I wanted to ask why you wanted hair from a cadaver? What is it that makes you think there will be something different from hair that is much more easily obtained from the living? Were you able to find out any information concerning the stages that hair goes through in the living? Consider that, in a forensic context, hair may be recovered in any and all stages of its growth cycle.

With regards to the acquisition of cadaverous hair and samples from crime labs or Medical Examiners: The hair of the decedent would most likely never be released for use in a science fair project. It is either a) considered as evidence and would therefore be kept virtually indefinitely, or b) would be released along with the rest of the remains to the family of the deceased for burial or cremation.

The study of animal hair would perhaps be analogous to human hair (what have you found concerning differences or similarities?) - but I think you should stick to your original topic. But again, ask yourself why hair from a cadaver would be necessary for this project.

Please let us know what, specifically, you plan on studying, your experimental parameters and your hypothesis.

This sounds like a truly excellent project - and I, for one, can't wait to hear what you find!

Good luck,
Geoff.

[deleted-71588]

There was a period in the 1800's when jewelry was made out of human hair. The hair in this jewelry has NOT decomposed. Bows for violins and other stringed instruments are made from tail hair of horses that are a nearing a couple of hunderd years old.

If you want short lengths of human hair to experiment on, ask a barber shop / hair salon for their floor sweepings. Except for the root area, hair is dead.

[Rosemary]

For my experiment, i am planning on using a dead animal to study the stages of hair decomposition after death while still in the scalp. When the animal dies, i would like to pull a hair and look at the root. I could pull a new hair every couple of hours to see how the hair root has morphed. I need a way to measure or record the hair root. I could use appearance, but that seems kind of subjective. Mass may also work, but it would be very light weight. Do you have any ideas on how to measure the hair root at its different stages?

[Rosemary]

on a side note. i was wondering if i could somehow get Geoff Bruton's email. I cant find it online. thanks

[Louise]

on a side note. i was wondering if i could somehow get Geoff Bruton's email. I cant find it online. thanks

We aren't allowed to give you or emails or contact you directly. This is part of the terms of this site; all contact is through the forums for safety.

I'm concerned about your project as stated (monitoring the hair from an dead animal). You really need to clear this with your teacher and and talk to your parents about this.


Louise

[wildfirefox]

on a side note. i was wondering if i could somehow get Geoff Bruton's email. I cant find it online. thanks

Sorry Rosemary. There's no person contact one-on-one for project discussion. Forum's policy. It's a lot better for you to interact within the forum, since the experts can all share their info with you.

[geoffbruton]

For my experiment, i am planning on using a dead animal to study the stages of hair decomposition after death while still in the scalp. When the animal dies, i would like to pull a hair and look at the root. I could pull a new hair every couple of hours to see how the hair root has morphed. I need a way to measure or record the hair root. I could use appearance, but that seems kind of subjective. Mass may also work, but it would be very light weight. Do you have any ideas on how to measure the hair root at its different stages?

Hi Rosemary,

Okay, now I see why you were specifically wanting to look at hair (or fur) in relation to its source. This sounds very interesting, but I would echo the comments already posted by my learned colleagues in that I would question if the use of a deceased animal is a) absolutely necessary for your project, and b) if your teacher and the science fair board are okay with this subject. Please check with them before you take this any further. I honestly believe that there are suitable alternatives to carrying out this project which can then be applied to the specific question you are trying to answer. (By the way, what is your hypothesis?)

What has your background research uncovered as to what happens during decomposition, and specifically with regards to soft tissue and hair? What do you *expect* to happen to the root of the hair over time (that is, what do you predict will happen / that you will observe)? And would you expect these observations to be the same in decomposing tissue and hair versus plucked hair?

In an earlier post, I had asked you to look into the different growth stages of hair. What did you find and how can you apply this knowledge to the question at hand? If, for example, a head hair is plucked from the scalp, you may expect to see an intact root with cellular material attached to it. How does this differ (visually / microscopically / physically) from a head hair that naturally falls out? Why? What process has the hair / root undergone in order for this natural process to occur?

You had also previously mentioned that a researcher had done some work in virtually the same area that you were wanting to do your project. What was the initial purpose of the research and what were the observations and conclusions from the paper? If you can let us know more about the work that has already been done, we might be able to help you refine the experimental phase of your project.

You had also asked about how to measure the observations you make. Again, how did the researcher cover this in his/her work? I would suppose that as long as you make multiple examinations within each given time frame (to allow for variability), visual observations of what is occurring would be satisfactory. On the other hand, would you expect the hair and cellular material to dehydrate over time, depending upon the environmental conditions in which the decomposition occurred? If so, you may wish to consider the change in weight over time - but this may be extremely difficult to measure, depending upon what resources you have available.

on a side note. i was wondering if i could somehow get Geoff Bruton's email. I cant find it online. thanks

As others have already pointed out, I'm afraid that is against the rules of this forum. I would be more than happy to continue our discussion using this same thread - and that way, any others in the future who may wish to continue your research will have a head start! (Sorry for the awful pun!)

I will also discuss your project with some colleagues of mine who work in the Trace Evidence Section here at the lab. They work with hair - including hair from living and dead humans and animals - on a relatively frequent basis. If they have anything to add, I will certainly post it here.

Good luck with everything, and please let us know your thoughts.
Geoff.

[Rosemary]

For my project, i need to use a dead animal to see if i can determine a correlation between the dead hair root and the time of death. If i can perfect my procedure with animals, then someday i hope to use my information on humans.
In the research paper i found, the researcher found a direct correlation between dead human roots and time of death. However, her procedure is a little different than mine and she made her observations visually, which seems kind of subjective. Instead of plucking the hair and looking at it immediatly, she pluckd them all at once, then studied their decomposition over a period of time.
So basically for my project, id like to see how the study of root morphology can determine post mortem interval.

[deleted-71478]

Hi Rosemary,
One of the other experts on this forum happens to be one of my coworkers, Heather Mostman. She's working on a project right now where she's measuring different characteristics of hair on marine mammal pelts! I gave her a call because I think she's a perfect person to help you decide which root characteristics to measure with equipment you currently have available or how to find other equipment if you decide you need it. She should post here later today.

Good luck!
Alison

[Louise]

{snip}
In the research paper i found, the researcher found a direct correlation between dead human roots and time of death. However, her procedure is a little different than mine and she made her observations visually, which seems kind of subjective.
{snip}

What are you planning to do, if you aren't going to measure them visually? As long as you have very clear criteria, I don't think visual examination is necessilary subjective.

I'll say this one more time, and not mention it again. Where are you getting a dead animal? Where are you planning on storing a rotting animal? [And scientific questions are associated with this too- how controlled will this environment be?] How are you going to make sure this does not become a source of disease? Is this legal in your city or town? Does your school require specific permission for dealing with animals? Have your parents approved of this experiment, and do they understand what is involved?

I think you have an interesting research question, but I think you have not thought carefully about the reality of the project. Several people have asked you questions about this, and you haven't answered any of them. Better to address these questions now, rather than half way through the experiment.

Louise

[deleted-71536]

For my project, i need to use a dead animal to see if i can determine a correlation between the dead hair root and the time of death. If i can perfect my procedure with animals, then someday i hope to use my information on humans.

Hi Kelly,

I am the colleague that Alison mentioned. I read your thread with great interest! As part of my Ph.D. thesis, I have been examining hair characteristics of carnivores. One thing that I can tell you is that you would not necessarily need a whole dead animal to do this project. For my project, I obtained pelts (skin with the fur attached) from different animals. My pelt samples are just squares cut from a consistent location (e.g., the back, just below the shoulders). One way to get samples like this is to ask places like the Humane Society, which (unfortunately) have to put some animals to sleep or may perform necropsies (animal autopsies) on wild animals that have died. You may need to call around to your local organizations. Some veterinary clinics may be able to put you in touch with the right people.

There is a SAFETY CAUTION with this. If the animals died of natural causes, there may be pathogens (disease-causing organisms) still present. Make sure you always wear gloves when handling pelts.

In the research paper i found, the researcher found a direct correlation between dead human roots and time of death. However, her procedure is a little different than mine and she made her observations visually, which seems kind of subjective. Instead of plucking the hair and looking at it immediatly, she pluckd them all at once, then studied their decomposition over a period of time.
So basically for my project, id like to see how the study of root morphology can determine post mortem interval.

When it comes to your procedure, take a look at what characteristics the researcher monitored. One characteristic that you can quantify (meaning, get numbers for) is the diameter of the hair root. This is not so subjective. A research assistant and I have been examining the length and diameter of hairs. The procedure is relatively simple. We use clear nail polish to ensure that the hair lies straight on a plastic sheet. Then we use calipers to measure the hair length. You could do the same for the root length. From there, we carefully cut a cross-section of the hair. Then we look at the cross-section under a compound light microscope, to which you should have access at school. Our microscope has an ocular micrometer, which is a tiny scale that you can see through the viewing lens. This scale allows us to measure and compare the diameter of the hairs.

Note that the hairs are not always perfectly round. They are often shaped like an ellipse. Because of that, we measure both the largest diameter and the smallest diameter of each hair.

You should be able to measure lengths and diameters of hair roots, using a similar procedure. Decomposition and dehydration would likely change these parameters, and then you would have objective numbers to report.

Good luck, and please write again if you need more help!

Cheers,
Heather

[Rosemary]

Both my parents and teacher say this project is okay to do. Actually, they are both more than willing to help me on it. I need to come up with a hypothesis. I figure that over time, the hair root will shrink in diameter and length, based on other research. I also think that I will find a direct correlation between the size of the root and the time of death. I am just not sure on how to phrase my hypothesis. Can you help me form one?

Also, thanks for all the help everyone. I really appreciate it.

[deleted-71536]

Both my parents and teacher say this project is okay to do. Actually, they are both more than willing to help me on it. I need to come up with a hypothesis. I figure that over time, the hair root will shrink in diameter and length, based on other research. I also think that I will find a direct correlation between the size of the root and the time of death. I am just not sure on how to phrase my hypothesis. Can you help me form one?

You are already there! A hypothesis is a prediction of what you expect to happen, based on your knowledge of previous research. From what you said, you have two predictions:
1) The hair root will shrink in diameter over time.
2) The hair root will decrease in length over time.
From these predictions, my understanding is that you hope to be able to estimate the time since the animal died, based on the changes in the hair root.

If your hypotheses are correct, your results will show a correlation between the size of the root (diameter and/or length) and the time of death. (What kind of correlation do you expect - positive or negative?)

Now it's time for you to think about how you can estimate time of death. How can you use your correlation? If you have a hair that has already undergone some decay, how do you predict the time that has passed? To what do you need to compare your hair?

Good luck, and feel free to post again with further questions!

Cheers,
Heather

[Rosemary]

when I pull the hairs, what time interval should I use? Should I pull them every hour, once a day, or once a week? Will I get results after a few days, or does it take longer for the root to change shape?

[deleted-71536]

when I pull the hairs, what time interval should I use? Should I pull them every hour, once a day, or once a week? Will I get results after a few days, or does it take longer for the root to change shape?

Hi Kelly,

My inclination is to say once a day, but it is not really based on knowledge. Do take a look at the research paper you found, and see how quickly the author reports seeing changes in the hair roots. That said, if you are unsure of the time frame in which the hair roots will change, you'll want to check the hairs at the same resolution at which you hope to predict time of death. If you want to predict time of death by how many days have passed, then you should pull hairs at least every day. If you want to predict time of death with greater resolution than that, you should pull hairs more often. I think that once a week is too long.

Keep up the good work!

Cheers,
Heather

[Rosemary]

I need to get a dead rat for my project. I know that they are killed often in labs for research which should make it easier to get. Do you know where I can get one? thanks

[deleted-71536]

I need to get a dead rat for my project. I know that they are killed often in labs for research which should make it easier to get. Do you know where I can get one? thanks

Hi Kelly,

I'm not sure exactly where you're located, but local universities would be a good place to start. Universities often have research labs that have to euthanize rats from research projects. I will check at my university and get back to you with more specific information.

Cheers,
Heather

[Rosemary]

For my experiment, are there any independent variables? Im not sure. I know that they are the things that you change in your experiment, so would it be the times at which I pull out the hairs? So therefore, the dependent variable would be the shape and size of the root?

[MelissaB]

Rosemary,

That's exactly right. 'Time since death' would be your independent variable, and the size and shape of the root would be your two dependent variables. If you need more information, there's a section on variables in our science fair guide (link is in upper left-hand corner of this page).