What’s in the Water?: Examining Contamination by Poly- and Perfluoroalkyl Substances in Rainwater

May 1, 2020   /  

Student: Kyndalanne Pike
Majors: Chemistry, Mathematics
Advisors: Dr. Faust, Dr. Morrison

K PIkePoly- and perfluoroalkyl substances (PFAS) are emerging environmental contaminants of concern detected in waters around the world. These chemicals, used for food packaging and firefighting foams, have leeched into the environment, where they don’t degrade. This is of concern as PFAS have been linked to several serious health issues including cancer and neurogenerative diseases in children. This project focused on detecting PFAS in rainwater collected at seven sites during the summer of 2019. PFAS were detected in all of the samples collected. There were higher concentrations detected at some sites than others. This highlights the prevalence of these contaminants in our environment and the importance of local sources of PFAS.

Kyndalanne will be online to field comments on May 8:
Noon-2pm EDT (PST 9am-11am, Africa/Europe: early evening)

52 thoughts on “What’s in the Water?: Examining Contamination by Poly- and Perfluoroalkyl Substances in Rainwater”

  1. What do you think is the best way to get quick action based on your results? Since you found traces of PFAS in rain water and knowing the negative impacts, what might you suggest we do to try to mitigate or reduce these impacts?

    1. PFAS enters the environment through a lot of sources, some of which we can control by selecting PFAS free products. For example, did you know PFAS is in most popcorn bags? We can also support state level legislation of PFAS.

  2. Hi Kyndalanne,
    Excellent presentation and the work you are doing is really interesting! You mentioned that in your samples you saw a difference in concentration of PFAS based on the location. In what areas were the levels of PFAS the highest? In those locations were industrial areas or airports near the testing locations that could have contributed to the higher levels of PFAS? Also, will you continue to work on environmental chemistry while in graduate school?
    All the best and congratulations!
    P.S. What are aerosols?

    1. Hi John,
      I wasn’t able to see a very clear pattern in the contamination levels at the sites. This may be due to the fact that I didn’t track wind direction. You are very right that we would expect industrial locations and airports to have higher levels and this did appear to be roughly true.
      As for grad school, I will probably be applying chemistry and mathematics to understanding human health.

  3. Hi Kyndalanne,

    Awesome work! A few questions:

    Can you talk about the methods you used to detect the PFAS in the samples? Did you have to concentrate before detecting?

    Did you look for all the PFAS shown on slide 2, or just PFOS and PFOA? Did you see any interesting trends in the distribution of the compounds over the different sites? I’m also curious if you compared your results to the levels of PFAS that have been measured in surface water– I imagine some PFAS are more likely to end up in rainwater than others?

    Great work and congratulations!

    – Bailey

    1. Hello Bailey,

      The rainwater was concentrated (from parts per trillion to parts per billion) and then detected by liquid chromatography tandem mass spectrometry.
      I looked at 15 different PFAS (most of which are on the PFAS slide). Different sites definitely showed different contamination, but there were also marked similarities. For example, the same compound was the most concentrated at all sites. I did not do a direct comparison to surface water, but the concentration of some species would be expected to be much lower (such as PFOA and PFOS) as they are not very volatile while other species may be more concentrated. Overall, I would expect the concentrations in rain to be lower than in surface water.

  4. I’m glad that you and other researchers are looking into this important issue. As you say, PFAS have properties that can be really useful for certain applications.

    Would you say that “chemistry” is part of the problem? Part of the solution? Or both?

    1. Both- when chemistry is practiced without regard for the lifetime and impact of the molecules it is part of the problem, but chemistry can also be part of the solution by tracking and identifying points of contamination and creating technology to clean water.

  5. Great work KAP. Really cool!

    I had a question about what controls were put in place to make sure that the trace levels of PFAS observed in rain water were not inadvertently caused by contamination from your collection vessel?

    Furthermore, were studies conducted on measuring the concentration of PFAS over time in the collection vessel?

    Really excited to see where you go and what you do next? You have a great future in front of you! Hope that you are well!


    1. Hi Chris,
      Blanks were collected in the samplers at each site. Time was considered in the modeling.
      Thanks! Off to UW-Madison next year.

      1. Awesome about headed to Madison. I have heard it is a great campus! Do you have anyone in particular you are planning on studying with! We should stay in touch!


  6. I have learned a lot from you this year, Kyndalanne! What do you wish more chemists knew about statistical testing?

    1. Thanks for giving me so much guidance! I would say check the conditions of models ALWAYS, because if you don’t meet the conditions you can draw invalid conclusions, and no one want that.

  7. Kyndalanne,
    What an important and interesting topic! Since you are measuring PFAS compounds at such low concentrations, what kind of techniques did you use to avoid PFAS contamination in the lab equipment you used? Also, if you could have more sampling sites, where would you choose to collect rainwater from? I am interested in hearing more about your results. Congratulations! 🙂

    1. Hello Eva,
      Contamination was a HUGE issue I ended up building a drying manifold from scratch due to this (big thanks to Dr. Faust) and replumbing my solid phase extraction manifold (thanks to Dr. E). The biggest thing I learned was not to use any glassware as all the glassware in our lab was contaminated.
      I would love to have a couple sites near known PFAS point sources such as landfills and airports.
      Thanks Eva!

  8. Congrats, and what a project! I admire your work ethic and am grateful for your friendship.

  9. Great presentation! Which of the PFAS did you find had highest concentration in your samples?

  10. Kyndalanne, I have several friends who live in a town that was plagued with PFOA contamination in its drinking water. The source was traced to a wire manufacturer’s abandoned site:
    Their experience made me aware of how useful it is to routinely monitored PFAs in groundwater around any such sites. The health, economic, and psychosocial consequences of not monitoring can be enormous.
    So congratulations on all of your hard, important work!

  11. Kyndalanne,
    Congratulations on finishing. What impact would you expect from the rain on water tables? Is PFAS filtered as it moves through the earth? How often is the form of PFAS altered by environmental conditions?

    1. Rainwater can be a significant source of PFAS, but in areas where there are other sources such as a landfill, rain’s contribution is probably negligible.
      PFAS do “stick” to soil, but it is dependent on the PFAS molecule, so some will be filtered out while other will make it to the groundwater. It also depends on the type of soil.
      Perfluoroalkyl substances don’t break down. Polyfluoroalkyl substances break into perfluoroalkyl substances under the correct conditions. So there is very little alteration (only from polyfluoroalkyl substances to perfluoroalkyl).

  12. Excellent work, Kyndalanne! It was a pleasure to get to know you these past few years. I have a couple questions:

    -How readily does environmental PFAS diffuse throughout the environment versus remain relatively local to its source?
    -You say PFAS doesn’t degrade. But, over time, does PFAS tend to accumulate in certain places and remove itself slowly from the water supply?

    1. Hi Dr. Fox,

      It is environmental diffusion is compound dependent: PFOA and PFOS appear to stay fairly local while some other PFAS travel much further.
      It is hypothesized that eventually essentially all PFAS will either make their way to the oceans or end up deep in the soil, but this process will take hundreds of years.

  13. Congratulations and thank you for sharing your research.

    As you mention these classes of compounds are found widely around the world. Is it understood what impact structural differences of the PFOA/PFAS have on how widely they spread and on their partitioning in the environment (air vs. water for example)?

    Enjoy your summer and best wishes as you start graduate school!

    1. PFOA partitions into the air more easily than PFOS, which does impact its ability to spread. This is complicated by the degradation of a common, very volatile, polyfluoroalkyl compound into PFOA, so it is difficult to determine whether the PFOA was from degradation or spread a certain distance on its own.

  14. Did you run the analysis at The College of Wooster? That’s great that you have access to an HPLC-MS. Would the acidity of the rainwater have any affect on your measurements? Did you measure the pH or other properties of the rainwater you collected?

    Congratulations on your senior year accomplishments and I hope you continue with science research.

    1. Yes, we ran the whole analysis at Wooster! I did not measure the pH of the rainwater, but as the samples were completely extracted and reconstituted in a new (known pH) solution, the pH of the rainwater shouldn’t have affected the results.

  15. Wow! Interesting research that caused me to think 🤔 and want to know more. Does your analysis reflect total concentrations of the compound? Any reason to believe that there is a dissolved fraction? Does rain basically wash the compounds out of the air? How do the compounds become airborne and are they in an aerosol or particulate form? How “local” are the sources? Any possibility of long-range transport that may be associated with combustion sources? I am sure that you have thought of these questions I and may be addressing them in your graduate studies. Good luck 👍 in your future research and God bless your path.

    1. Yes, my analysis reflects total concentrations of the compound. Rain does essentially wash compounds out of the air, if fact studies have shown that most PFAS washes out in the first few mm of rain. PFAS can enter the air as an aerosol, be attached to particulate, enter directly through emission (maybe from a smokestack), or they can volatilize. I don’t actually know what the point sources are, so I don’t have a distance for “local”. There definitely is a chance that PFAS are being released from combustion sources, Chemical & Engineering news just released an article on this: https://cen.acs.org/environment/persistent-pollutants/Incincerators-spread-break-down-PFAS/98/web/2020/04

  16. Kyndalanne, I attended the Justice Dialogue you organized and learned so much from it! It’s great to see the completion of the project. Congratulations!!

  17. Congratulations Kyndalanne! I really like your project and presentation. I think your work is really important in helping to improve environmental health and living conditions. I hope you are able to continue your research in the future! Thanks for being my table partner in Inorganic!

  18. Great presenation!

    Two questions:

    Do you think the PFAS would bioaccumulate in food crops? Has anyone looked at this?

    (Insiders Question:)
    What compounds would you look for if you had an LC/Q-ToF mass spectrometer?

    1. 1. Yes! See below:
      (1) Ghisi, R.; Vamerali, T.; Manzetti, S. Accumulation of Perfluorinated Alkyl Substances (PFAS) in Agricultural Plants: A Review. Environmental Research 2019, 169, 326–341.
      (2) Lan, Z.; Zhou, M.; Yao, Y.; Sun, H. Plant Uptake and Translocation of Perfluoroalkyl Acids in a Wheat–Soil System. Environ. Sci. Pollut. Res. 2018, 25, 30907–30916.
      2. I would definitely start with the EPA’s list, but there are some areas of particular interest such as perfluoralkyl ethers because these have been used to replace PFOA and PFOS.

  19. Congratulations, Kyndalanne, and we wish you the best with your graduate work in Madison!

  20. Congratulations, Kyndalanne!
    From ARCH roommates to Wooster grads (ok, one grad and one rising senior), I’m so glad to have witnessed some of your IS process (casually running through Severance with big containers amongst other things) and your growth throughout these past 3 years! I now wonder about PFAS in the Babcock flood…

    Excited to see your next adventures at UW!

  21. Hi Kyndalanne,

    Congratulations on completing an interesting IS project!

    I have a few questions. First, how do PFAS actually make their way into rainwater? Is this process largely driven by PFAS volatility, or can you get PFAS in rainwater via aerosolization of groundwater? Secondly, what was the overarching goal of your statistical modeling? Were you trying to relate the PFAS concentrations with environmental parameters at your collection sites? (Sorry if I missed this in your presentation…)

    I hope you have a relaxing summer, and best wishes as you begin grad school!

    1. Hello Kimberly,

      I believe both mechanisms are at work and there are debates about which one is the more prevalent (though PFAS do appear to form aerosols very well). My modeling focused on determining whether there were differences in PFAS concentration between locations.

  22. Congratulations on persevering through all the challenges on such important work!

  23. I too would be interested in knowing which PFAS were most common in the samples you analyzed.
    Congratulations on your work and enjoy UW. I worked in Madison for several years before retiring and enjoyed Wisconsin.

  24. Since these compounds are being found in rainwater, how much work has been done on determining their atmospheric residency and is there a geographical pattern of “sources” and “sinks”? How do these molecules compare in size to to typical cloud condensation nuclei? Lastly, I’m curious that since plants transpire what plant physiology may be impacted by their presence. Thanks & good luck after Wooster

    1. Work has been done tracing PFAS in the atmosphere, but their residency is highly dependent on the species and whether or not the PFAS is on an aerosol. I am unaware of any geographical pattern of sources and sinks, though there has been al lot work done in recent years identifying sources: https://www.ewg.org/interactive-maps/pfas_contamination/. If I understand what cloud condensation nuclei are (and this is not my area), they are aerosols and therefore larger than PFAS molecules. PFAS are found in plants and it has been suggested that volatile PFAS are able to enter plants via transpiration, while nonvolatile PFAS generally enter through the roots.

  25. Thanks for sharing your research with us, Kyndalanne! I have two questions:
    – Is there a known final ‘sink’ for PFAS compounds?
    – Do you know of any ways that we as consumers can educate ourselves on what products are safer and PFAS-free?

    1. Slow mixing of the ocean layers is hypothesized as the eventual ‘sink’ for PFAS along with, possibly, deep sediment burial. Both of these will take hundreds of years.
      Some products advertise as ‘PFAS free’, but otherwise there is little way of knowing (that I know of) due to the lack of regulation on PFAS. Let me know if you find a way!

      1. Thanks Kyndalanne! Congratulations on an awesome project and best of luck at UW!

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