Letter to the editor: Errors in crumb rubber literature review


Edmonds School District Superintendent Nick Brossoit and School Board President Diana White are continuing to insist that a literature review, commissioned by the Edmonds School District, and completed by Elizabeth Black of EMB Consulting LLC, proves that crumb rubber is safe. No public comments were allowed when Ms. Black presented her findings to the board, and the school board has not allowed the public comments relating to the report at school board meetings because “Ms. Black is not there to defend herself.”

I have a Ph.D. in Health Services Research. When scientists publish anything, be it an editorial or a research study, they put their reputations on the line. There is the expectation that it will be publicly discussed and critiqued by other scientists. This is how scientists communicate, learn from each other, generate hypotheses, and correct errors. Since the Edmonds School Board demonstrated hostility toward a civilized intellectual discourse in a controlled setting, those of us who know the scientific literature and who have read the report must publicly rebut Ms. Black’s report in other forums.

The Edmonds School Board members were provided a 19-page document detailing many of the biases, misrepresentations, and factual errors in the literature review before they voted to install crumb rubber on the fields at the Former Woodway High School. The Edmonds City Council was provided an updated document further rebutting this report.

Ms. Black repeatedly failed to demonstrate an understanding of the material being reviewed and even basic scientific concepts. For example, in her literature review, she claimed that while there are toxic chemicals in crumb rubber, an exposure pathway has not been demonstrated. In her testimony before the Edmonds City Council, she claimed the toxic chemicals were locked inside the rubber crumbs. She likened it to the way mercury was sealed in glass in old-fashioned thermometers.

However, laboratory studies demonstrate that toxic chemicals are constantly off-gassing from crumb rubber. It is easy to smell chemicals off-gassing from crumb rubber. I asked my 12-year-old daughter, “If you can smell something, is it getting inside your body?” She responded that you recognize smells when scent molecules attach to special receptors in the back of your nose. She told me she learned this from Ms. Frizzle on “The Magic School Bus.”

There are many serious problems with the literature review, but for this letter, I chose the one that could be easily be demonstrated with help from a 12-year-old child and Ms. Frizzle.

Christi Davis, Ph.D.

24 Replies to “Letter to the editor: Errors in crumb rubber literature review”

  1. I see lawsuits in the Edmonds School District’s future. It has been repeatedly proven that crumb rubber, for use in athletic fields, is NOT safe. It is unfortunate that ESD is turning a blind eye at the cost of children.


  2. I am still trying to understand how and why the school board (that work for us and in our best interest?) are able to act in this manner.
    Can’t wait to get my votes out!


  3. Your assertions repeatedly point towards me, so I would like to take this opportunity to respond. From day one, the Edmonds School Board has taken your complaints very seriously. In fact, we took the handful of articles, and websites from your opposition group and hired scientists (EMB Consulting) to view for credibility and authenticity of the authors. Scientific, and peer reviewed articles are given much more credibility than politically driven propaganda because, as you know, everything you see on the internet is not true.Verdant also issued a study to examine the use of crumb rubber and came to the same conclusion as the district.

    You have repeatedly reminded us of your PhD education, Christi, but the 19 page document statement you wrote in rebuttal to Ms. Black’s report does not constitute a fair and impartial view of the report, correct?

    When you attend the School Board Meetings to provide feedback, the directions are clear to every speaker that comments are not be personally directed towards someone. The Board has been patient, open and willing to listen to your groups repeated public comments for the past 6 months, however, the disruptive and condescending tone that you show at the meetings will not be tolerated.
    Diana White
    President Edmonds School Board


    1. I doubt most parents are aware that the School Board is RULED by a dictator that can state a condescending tone “will not be tolerated.” Possibly Ms. White should confer with the School District Attorneys and have them look at the State Open Public Meetings Act and also the United States Constitution as well as the legal definition of Disruptive as well as several US District 9 Court of Appeals rulings on Citizens freedom of speech at Public Meetings before she invites a Civil Rights lawsuit by throwing a person out for what she may believe is “disruptive” however is not what legally is disruptive.


    2. Ms. White, I have been nothing but civil during school board meetings, but it has been difficult. You chose to employ the tactic of repeatedly referring to the group that was opposed to the use of crumb rubber- a group which now numbers close to 1,000 locally- as a “small but vocal minority. Once you even used that tactic during an Edmonds City Council meeting…..while standing right next to a State Senator!

      Ms. White, you spoke on behalf of the whole board, when you denied a request made by Edmonds City Council Members, to meet and discuss the use of a non-toxic infill on the project they were a partners with you on. https://myedmondsnews.com/2015/07/edmonds-school-board-says-no-to-joint-meeting-with-city-council-on-crumb-rubber/

      It has was difficult not to be condescending when during a recent board meeting our school Superintendent, Nick Brossiot, equated “possible” carcinogens contained within the chairs we were sitting in, with the KNOWN toxins and carcinogens contained within the tire mixture; a mixture which is ground up tiny dust producing bits, which will become airborne and inhaled by athletes, and will also spread into the environment through wind and water.

      It was difficult not to be condescending knowing that the morning after the vote to use crumb rubber, Superintendent Brossoit sent an e-mail to Verdant Health in which he stated “I am wondering if at a minimum we might want to post signs at our fields across the district and/or include information to all sports and user groups as part of our fields use process that it is recommended that all field users wash hands and take showers following use of the fields and for parents of small children to be more mindful of what their kids might be eating, sampling, etc. Just as dirt is not a recommended diet, I suspect any of the infill materials were not designed to be ingested. Just as restaurants post signs in bathrooms about washing of hands, we may want to add this reminder to all fields, including those with natural grass.” (This is public record)

      Additionally, Superintendent Brossoit denied an offer by Verdant Health to consider additional funding for non-toxic infill. https://www.heraldnet.com/article/20150509/NEWS01/150509005

      I would like to make it clear- we simply asked you to use a non-toxic infill, so that ALL of us, the small minority still comfortable with the use of crumb rubber AND the majority of us that concerned with the health risks associated with crumb rubber, would be comfortable allowing our children to play on the fields. We asked you to use an infill that did not contain 12 known or probable carcinogens and 20 irritants, and a growing list of young athletes who suspect a connection between their cancer and years playing on crumb rubber turf.

      We asked you to use a non-toxic infill which would not pollute the area immediately surrounding the fields- a State protected Fish and Wildlife area which is frequented by many birds- some protected species (a fact ESD neglected to include on the SEPA report).

      We asked you to use a non-toxic infill that did not contain high levels of zinc, which is very toxic to aquatic life, and fire retardants, because as a petroleum product the field is flammable. Rain water falling on these fields, will pick up dust and chemicals and drain into the storm water system and empty directly into Puget Sound.

      We asked that you join other school districts and communities around the country, who have chosen to err on the side of caution and protect human and environmental health, by simply using a non-toxic infill. Sadly you did not, and now you have made plans to build or replace many more of these types of fields….once again with our tax dollars. https://myedmondsnews.com/2015/10/edmonds-school-board-approves-replacement-technology-and-capital-improvement-levy-special-election-set-for-next-february/


  4. Yes, Diana, you took SOME of the peer reviewed articles we provided the board and gave them to Ms. Black and asked her to provide “Turf Support,” not a “Literature Review.” Ms. Black’s invoices to the school district clearly list her job description as turf support. (It is also interesting to note which articles were left out. For example, the school district left out the study that links carbon black, which constitutes 30% of crumb rubber to lowered IQ in children.)

    As for the Gradient report. Gradient has worked for FieldTurf before. Their scientists have also defended BpA as well as the tobacco industry. I place an extremely high value on human health. When there are dueling scientists, I look at the original studies. I also assign much more credibility to scientists who lead the fight to protect children by removing lead from gasoline and paint than I do to scientists who defend the tobacco industry against claims that cigarette smoke is unhealthy.

    I’m sorry that I come across to you as condescending. I spend my days with children who are capable of rational thought and intelligent, informed arguments. I am used to being able to engage with others on this level and become frustrated and perhaps even condescending when I cannot do so.

    I also resent your characterization of me as disruptive. One time while deciding whether or not to use Nike Grind on the Edmonds Woodway High School field, a council member asked what was in Nike Grind. No one, including the contracted engineer knew, so I called up the information on my iPad and attempted to offer the council the information before they voted. I apologize deeply for attempting to interfere with the council’s decision to take an uninformed vote. I did not realize how upsetting such disruptive activities could be to you. I will refrain from such activities in the future.

    Christi Davis, Ph.D.


  5. For the record, I don’t have a Ph.D. – What I do have is a bit of common sense and more than 28 years of playing on turf fields. Now let me state, this doesn’t make me an expert on turf by any stretch…but I can count the number of players I know who have “died” because of crumb rubber from playing on turf – ZERO.

    If we are going to rally against some “bad” stuff, let’s rally around second hand smoke, or the sugar drinks many parents allow their kids to ingest, or Cheetos, or the countless other food products that kids consume.

    Crumb rubber is the least of our concerns…or certainly the least of my concerns.


    1. Mr. Schindler, not to doubt your experience however, a 5 minute Google serch will give a history of Artificial turf and “Crumb rubber” infill was developed in the early 2000’s. See several references. https://fivestarturfcommercial.com/a-short-history-of-artificial-turf-from-chemgrass-to-crumb-rubber-and-beyond/ or https://en.wikipedia.org/wiki/Crumb_rubber.

      So at most you played on it for possibly the past 5-7 years since it initially was limited in installation and at most if you were a professional football player possibly 10-12 years. You played on astro turf that is quite different.

      And like most other cancer-causing substances, the damage is found far down the road.

      However, whatever side of the argument on turf you are on, the bigger issue is the process by which the ESD and the City of Edmonds used to approve the project.

      Here are the facts that ESD and the City do not dispute.

      1. They used a Critical Areas waiver from 1993 fully 22 years ago for a different project. These waivers are specific to projects and anyone that is at all familiar with building permits can tell you no citizen could even come close to this same stunt. Further the City admits to only allowing 5 year old waivers.

      2. The ESD tried in 1999 to expand and change the use and the City explained in a letter that the property was Non-conforming and could not be done without a rezone. It was denied then. They have not rezoned the property and nothing has changed to allow them to be “conforming” Again, no individual could do this, but the city believes the law only applies to some.

      3. The zoning simply does not allow for lights, artificial turf, not backstops and high fencing. It is simple and straight forward unless as the city you turn your head and look away. Again, no individual would get away with this.

      So this is a simple issue of the ESD and the City believing the law only applies to the commoners while those elites are above it.

      Happy to meet and fully explain all of the above facts.


  6. Mike,
    I understand your confusion. While artificial turf has been around for over 50 years, crumb rubber only started to become a popular infill about 15 years ago. Scientists generally expect to see cancer develop 30 or more years after exposure to a toxic substance. We don’t expect to be seeing a lot of deaths right now. In fact, the possible increase in blood cancer in soccer goalies from crumb rubber exposure is extremely concerning because the cancer is occurring much sooner than expected. Typically, this would indicate a very potent carcinogen.

    As for your other points, I agree that children need to eat healthy diets and be kept away from cigarettes. I think all school children should have PE every day on grass fields. I also think that all the vending machines should either be removed from schools or be limited to selling water, organic milk, and organic fruits, vegetables, and nuts. These are what I consider healthy drinks and snacks. However I doubt that will ever happen because the ESD doesn’t want to give up the money it earns by selling 100 calorie packs of cookies and reduced fat Doritos to students. Perhaps you would like to pressure the school district on improving student nutrition and fitness. Many, many things affect health and we should work to improve them all. I would love to see more people advocating for our children!

    As a parent, I have a great deal of control over what my children eat and how much excersise they get, how much and what type of screen time they have, and so on. I also work to make sure their physical environment is as safe as possible. That became my issue when the school district decided to dump tire bits all over a field my children used to play on.

    I hope to see you standing up for kids,


  7. Ma’am, no confusion here. Our threat to health is not from crumb rubber. There are for more immediate threats that garner our attention than this issue…that tends to have scientific evidence supporting each position. And ma’am, you are welcome you to join me in my activities that involve the support of our youth.


  8. I believe someone should address the growing list of athletes , mainly soccer goalies, that have either passed away or are struggling with the same type (yes same) of cancer. Doctors need to come forward. Parents of these children need to come forward. The individuals on this list deserve better than all this. The sad thing I have witnessed as a concerned parent and citizen is watching the Edmonds School Board pass up on the opportunity to install a non toxic turf and yet choose to approve more toxic turf. This has to stop. A turf which contains known carcinogens is not necessary when there are other alternatives. The athletes deserve better than this. The environment deserves better than this. The people on that list deserve better than this. I wish they were here to speak on that.


  9. I’m hoping that considering all the scientific information regarding the glaring danger of this hazardous waste on all living things anywhere in our environment, that a thread does not show up in an investigation that might reveal a clear financial conflict of interest for the Edmonds School Board or the City of Edmonds or Verdant Health. I am still having a hard time wrapping my brain around Verdent Health being a part of this.

    I think it says everything regarding this product with Mr. Brossoit speaking of putting up what would clearly be warning signs at the fields in my opinion…….like kids unattended are going to run home, wash and shower. Like any parent would even take their kids on a field reading signs like this……As a parent, my red warning lights would come on for my childs safety. I would not use the field or have my child near it.

    ..of most impotance here, rather than using a non toxic infill, these people are concerned about covering their butts regarding liability?????…..putting up signs for warning

    Who are the people running this gig?…….and who might have a financial interest???……otherwise it is very hard to understand under the circumstances how this could possibly move forward

    historically, organized sports have always been put first and foremost before anything and now it is even more true than ever…….the biggest money machine now that I have ever seen…….its about billions and where does this start……in the playfields and how SOME people approach sports…….with the idea that it is more important than anything else no matter what

    washing your hands and showering after being on our fields……why would we need to if nothing to it…….is this the just in case part?


  10. Nobody wants to admit they made a mistake, this was a big one and it’s not OK. Anyone who has read all of the information provided should come down on the side of caution. This is bad stuff.


  11. No matter a persons politics, environmental concerns or other social issues they should be united in the games played with the process that enabled this to come about. Whether Mr. Walls lawsuit is successful or not, reasonable people can look at the evidence and say that short cuts were made by a collusion of the City Administration and the ESD. A solid process would have unified people around a reasonable solution instead of dividing people and causing not only distrust but also massive potential liability to both PUBLIC entities. The money was our money and the money being spent on legal fees and the long term legal battles is ludicrous.


    1. What is ludicrous too is the fact that this idea has been in the making for ten years with the ESD. Yet I as a citizen just became aware of this last May. No excuses for these kinds of errors. These were not simply mistakes but rather intentional actions. There was ample time for honest mistakes (?) to be corrected. There should have been more time devoted to thoughtful consideration of changing evidence and the growing list of deceased and ill soccer players. It came too close to home when I recognized the name of the mother of one well known soccer goalie. Someone needs to consider this growing list that is being compiled.


      1. To be clear I in no way wish to diminish the health concerns. They appear to be significant, just harder to directly link them. The hard, factual proof as to the process is not. While many things can affect a lawsuit, the facts are clear. There are many challenges that Edmonds will face and we need a ethical, transparent, accountable government to address them. It is critical that Lora Petso get re-elected. From the factual transcripts, she was the only Council member that is up for reelection that tried to ask the questions that needed to be asked.


        1. Thank you for clarification. I appreciate any clarity and honesty. Especially when there has been so much wrong doing in the process as you have mentioned. I think some doctors could help link things up too especially given the number of these cases and the similarities. It’s unbelievable really and haunting when you see the list I mentioned. No one can deny there is similarities with the patients. A good doctor always wants to eliminate what is causing the problem. Shouldn’t we all start somewhere at least close to the idea of stopping crumb rubber fields from being installed ?


  12. I would be a little cautious of the rubber . Its just too bad that here in the great usa we have to wait till bad things happen before anything is changed, not the case in europe they have to prove stuff is safe before they let them use it. Why Edmonds chose to go this route is beyond me you go to the store everything is organic you put up a building you get rewarded for being green well the only thing green about field turf is the color. Im sure you get enough of that rubber in your system it could do something bad , that should be reason enough not to use it


  13. To the Editor:
    I am surprised that a publicly elected body, charged with spending public dollars for the public good, would be ALLOWED to exclude public input, especially respectful, fact-based input. The fiduciary obligation of anyone in charge of public funds is to carefully spend those funds for the public benefit after considering all the information. Shutting out information before it can be heard makes a farce of this fiduciary obligation. Why is the fact that PhDs and toxicologists are alarmed at this stuff being so blithely disregarded?

    Where is the press on this? Where is the accountability? When is the next election?

    Signed, Diana Edensword Conway, descendant of several Mount Vernon WA families.


  14. For a Council that went out of its way to ban plastic bags, and has been pushing “green-ness” it is astounding that crumb rubber was installed at the High School and it was not addressed then. Plastic fields with recycled tire crumbs: but we are not allowed to have plastic bags because of the environmental impacts. Amazing. And plastic fields are part of the problem not just the “in fills”.


  15. Recent KOMO News coverage and national news concerning crumb rubber. Awareness and concern across the nation is growing and many are choosing to use safer alternatives to protect children’s health.

    Unfortunately, the Edmonds School District has decided to continue with it’s use of crumb rubber. The school board recently approved a $59 million dollar Technology and Capital Improvement Levy that will go before voters in February. It includes construction or replacement of 8 more fields in the district….currently they plan to continue using crumb rubber.






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