Public Lab Research note

Tampon Testing for Wastewater

by mcairns | July 23, 2015 15:24 23 Jul 15:24 | #12093 | #12093

As part of the Thermal Fishing Bob Workshop on Northeastern's campus, we worked to test the utility of tampons in detecting wastewater pollution. We had a bunch of awesome people collaborate on this!

My work has long been focused on how individuals and communities can better understand, manage, and construct infrastructure for water, sanitation, and wastewater treatment. In this case, myself and Sara Wylie were really interested in testing tampons' ability to detect optical brighteners, which are a component of wastewater but NOT present in the materials used to make tampons. Thus, if a tampon collects water with optical brighteners, you have a good clue that wastewater was present in that waterway. The way that you test for optical brighteners is with a regular old UV flashlight--and the test is simple. If the tampon glows, there are brighteners; if the tampon doesn't glow, there aren't. This has every chance to be a cheap, accessible, and easy way to test for wastewater pollution in waterways. Notably, this technique is best used when the water is moving/has an outlet and where researchers can detect areas where sewage misconnections and/or effluent may enter the waterway.

Dave Mark Chandler and David Nicholas Lerner pioneered and tested this technique, and their results are available in their academic paper entitled "[A low cost method to detect polluted surface water outfalls and misconnected drainage]." In Water and Environment Journal. Their study showed that the method did detect pollution (2015:202).

So, we wanted to see what we could do with this idea. We workshopped the method at Northeastern by using products known to have optical brighteners (such as Tide Laundry Detergent) and those that are purported to not have these ingredients (such as Mrs. Meyer's Clean Day Dishwashing Liquid).


We found that tampons indeed did not fluoresce on their own (not placed in water). We found that tampons did not fluoresce when dipped in water that contained detergents without optical brighteners.


And we found that tampons did fluoresce when dipped in water that contained optical brighteners. So, we found that tampons were a good way to detect brighteners.


We also wanted to get an idea of whether or not we could use tampons to collect water samples that we could then use in conjunction with Public Lab's spectrometers so that we would be able to understand what kind of chemicals are indeed in the wastewater if brighteners are present. This we only were able to do partially, but we did get to build some spectrometers and test some water samples. i think this will work eventually, but we need a clean, clear way to get a water sample from the tampon and then look at it through the spectrometer. This could be as easy as squeezing the water into a test tube, but we're still working on it.


Next steps for us are to test this in an actual river (Charles/Mystic) and to make the tampon testing mesh in some way with the thermal fishing bob. Also, it couldn't hurt, for sure, to make the tampons a bit more visually appealing. I'm thinking of cutting them into little octopus shapes, or something aquatic.


This is great. Using absorbent materials to concentrate aquatic contaminants for analysis has a good, long history and the next step -- extracting sample from that absorbent material without altering the composition of the sample -- is the challenge. I'm glad to see work being conducted on this, as it could be applicable to a range of contaminants, from optical brighteners to aquatic oil sheens to pesticides... Good stuff!

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This is one of the first things that was done with UV fluorescence with the Public Lab Spectrometer -- showing brighteners in free & clear laundry detergent -- so don't assume that they're truly free of brighteners!


The spectrum image is reversed, but you can see the graph here:

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What kind of tampons did you use in this experiment? I was just looking up tampon materials, and it looks like different brands use cotton, rayon, or a blend of cotton and synthetics. Relevant info:

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I wonder if just plain cotton balls would work just as well?

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Hi All, Tampons shouldn't contain brighteners--we tested several different types, from the "all natural and organic" types, to plain old Tampax, to fancy "pearl" and pocket ones, and none had brighteners, irrespective of material type. Cotton balls probably do have brighteners, as they are present in most fabrics/cottons to make them appear whiter.
Thing is, tampons are cheap and ubiquitous, and frankly have a handy string to tie them to things to dip them in the water--they work well, so I don't think cotton balls would be an improvement, anyway. Also, as far as what detergents have brighteners--certainly do the testing, it is pretty fascinating, and labeling as "natural" or "free" doesn't necessarily mean that they're free of brighteners.
Still trying to find a time to field test this technique...

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The cotton balls that I have do not have brighteners. I checked with my UV laser. I was wondering if they have the same absorption characteristics. Somehow I believe that a cotton ball will be cheaper than a tampon but perhaps not as absorbent. String is real cheap also. :-)

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