Science Buddies: "Ask an Expert"

My science fair project is "how do chemicals from oil refineries affect the human body?",I am still trying to figure out how to test this.

Hi,

I'm sure you know you can't experiment on humans, but this is an interesting topic nonetheless! Many scientists that want to answer questions about the human body do so by using other organisms as model systems. There are many different model organisms such as worms (C. elegans), flies (Drosophila), sea urchins, mice etc. Scientists choose a model system to work on by considering their availability, ease of handling, the equipment the lab has for maintenance, the relevance of the system to the question they are answering, etc. The results they obtain from using these organisms are valuable because they hint at what occurs in humans (how closely model organisms mimic humans varies widely).

You can choose to test the effect of chemicals from oil refineries by using a model organism! Which one you choose will depend on the resources you have. You could google "model organisms" and then choose a few you would like to work with. You could talk to your mentor/professor to see if you can work in a lab that works on your model organism of choice.

Let us know what you decide!
Tanvi.

Hi,

Tanvi is steering you in the right direction by suggesting that you do some research into a model organism to test your hypothesis. But first you need to define what you mean when you say "chemicals from oil refineries". Refineries produce gasoline, kerosene, naphtha, propane, butane, diesel fuel, asphalt and more. All of these organic molecules are toxic to mammalian cells in various degrees. Which ones are you planning to test and why? What is your hypothesis?

As Tanvi said, the model you pick is partly determined by how you plan to do the experiment but also by what resources you have. Do you have access to a lab and someone to help you? Our lab does experiments with human lung cells grown in culture and these are a good model for respiratory diseases such as asthma and cancer. Organic chemical exposure has been clearly linked to cancer in people working in the chemical field and this can be shown using the human cell model.

Work with cultured human cells requires a lab with a certified biosafety level 2 tissue culture cabinet, CO2 incubator, and centrifuge and supplies like pipets, growth media, and sterile dishes. Learning to culture cells is not difficult, but it does require someone to teach you and supervise you.

Repost with more specific information on your hypothesis and we will be better able to help you.

Scibee

Thank you very much Tanvi and SciB, both of your feedbacks helped me a lot. It helped me see some options for testing my experiment. The 'model organism' experiment seems cool but I don't want to harm any life. Testing on model organism would surely give back good results but working with cultured human cells will work better for me.
I plan on using benzene (an additive in gasoline) and possibly other carcinogenic chemicals found in refineries and test the chemicals on human cells. Now I just need to
find a place that will help me test my experiment and I have to better understand the chemicals. Thank you guys once again, Both of your advice helped me find a path to a definite project. Is there anyway I can contact both you outside of science buddies.

Hello,

Sorry, the Scibuddy rules say we can only work with you through this platform. We will be happy to answer any questions, provide suggestions or send you links and references to speed your project on its way. Keep all your questions and comments in this thread so it's all together.

Benzene is already known to cause cancer, so what new experiments will you do? Do you live in an area where there is a refinery? If so, maybe you could get some soil, water or air samples from outside the refinery and compare them with similar samples taken from some place out in the country away from chemicals.

There are various different ways you can test environmental samples on cell models, so you would need to do some reading to see if there are any you could do. Try to think of things people are interested in but which have not been done before. That's what makes experimenting fun--you don't know how it is going to come out. Many important discoveries have been made totally by accident.

Keep thinking about your project and get back to us with your questions and ideas.

Best regards,

Scibee

Hello there,

Tanvi and Scibee are definitely steering you in the right direction! I would like to pitch in some of my advice as well. First of all, what kind of cultured human cells are you planning to use? One really cool idea is if you can try using cell lines that have been derived from many different types of organs to test whether these chemicals have effects on cells from specific organs only, or if they are toxic in general to all cell types. Cell lines are typically pretty expensive to purchase, but a majority of biology labs work with cultured cell lines--one thing you can do is try e-mailing different labs around the area in which you live and see if they would be willing to give you a small split of cells to try your experiments, and perhaps even give you some guidance. Of course, because you are planning on working with harmful chemicals, make sure you notify these labs of what chemicals you are planning on using and what experiments you are trying to do so they can assess whether the lab is certified to help you do these experiments. Second of all, what kind of observations do you expect to record during your experiments? In other words, what types of "effects" would you expect to see on your cells when you add the chemicals to them? Do you expect the cells to die when you treat them with the chemicals? If so, how do you think you will go about recording those observations? One typical thing biologists do to quantify cell death is to measure the percentage of cells within each sample that have died. Also, do you expect the chemicals to change the morphology of the cell? That would be really cool as well. Perhaps certain chemicals may not even cause cell death, but may instead make the cells divide even faster!

Although I understand that you would prefer to work on cultured human cells as opposed to model organisms, model organisms can actually tell you a lot more things than cultured cells alone. For example, what if those chemicals you used did cause a majority of the cell lines you've tested to die. Sure, that is really interesting in itself, but you are limiting yourself to only observing what would happen to cultured cells, and not looking at the overall effects these chemicals may have on an entire organism. For example, if you see in culture that one of your chemicals caused lung cells to die, wouldn't it be interesting to try and see whether exposing an actual organism to the chemical will result in lung damage? This will be a very interesting study that could provide implications for how these chemicals may affect human health. Although of course, if you prefer to not use any model organisms, that is totally up to you because this is your project after all, but I just wanted to give you something to think about!

Best of luck,
Connie

Hello Connie and SciB,

I have done more research on my project, I have also reconsidered using a Model Organism. I plan on using drosophila flies as my model organism because the ISEF rules don't allow me to use vertebrates. I have also heard that flies are a good substitute for vertebrates. I plan on testing benzene or toulene on drosophila flies. I picked flies because their life cycle is short and I could test this chemical on each stage of the flies life. Then I could use a dissecting microscopes to see the effect externally and internally. In addition I could see if it had any affect to the flies chromosomes. Although I've done research I still don't know how to compare it to a human's body, I'm also thinking of using a squid because they have some of the organs humans have. Any suggestions science buddies and what do you guys think about my experiment.

Hi,

I would stick with fruit flies. Scientists have been using them for genetics and other studies for over a hundred years. Their metabolism shares enough similarity with humans to make fly data relevant to humans. And as you say, their quick life cycle makes it easy to see effects in a short time.

Benzine and toluene are carcinogens, and i assume that is why you chose them, but they are also flammable and absorbable by inhalation and through the skin. I would not work with them unless you have access to a chemical fume hood, protective clothing, gloves and goggles and someone to supervise you. Here's the material safety data sheets (MSDS) for benzine and toluene: http://www.sciencelab.com/msds.php?msdsId=9927339 http://www.sciencelab.com/msds.php?msdsId=9927301

How did you plan to expose your flies to the chemical? What concentrations will you use? What will you look for as an effect of the chemical? Both benzine and toluene cause mutations in DNA, so you might see changes in wings, eyes or other parts in later generations of flies. The chemicals could also kill the flies or their eggs and larvae, so you will have to do some preliminary experiments to see how much of the chemical they can tolerate and for how long (dose response and toxicity over time).

This is a challenging experiment, but it should give you some very interesting results. If you have a camera attachment for your microscope, you can take lots of pictures to show the effects of a range of doses of the chemical on the eggs, larvae and adults.

If you have more questions, please repost to this same thread.

Regards,

Sybee