To view the article abstracts from this months research update follow this link: AUGUST 2018 RESEARCH UPDATE
Sticky Facts About PFAS
Many years ago, Lakhwinder Hundal, formerly of the Chicago biosolids team, was our featured speaker at Northwest Biosolids. His twin boys were still in diapers then. Now they are likely taller than he is. One topic he talked about at the conference were these new fluorinated organic compounds: PFOAs and PFAs. Lakhwinder predicted then that these compounds were the next big compound of concern on the horizon. He also said that, because they don’t degrade and are mobile in soils, they would be a major concern. I wish that he had been wrong.
This is the 4th library that I’ve done on this topic. I wish I could say that, just like the environmental concentrations of the long chain banned fluorinated compounds, this issue would slowly go away. No signs of that, however. The library starts with the first part of a two- part BioCycle article written by Ned Beecher. Ned at NEBRA has been the national lead on this topic for biosolids and other organics. The article provides a very clear overview of what we know and how to use this knowledge to work with regulators. In fact, this article is to PFOAs what an earlier article by Lakhwinder also in BioCycle, was to pharmaceuticals and personal care products. We know that the compounds that are currently the subject of advisories for drinking water have been banned and that, as a result, their environmental concentrations are decreasing. We know that the limited number of studies and samplings show generally low concentrations of these compounds in biosolids and other residuals. We know that drinking water is the primary concern. We don’t know much of anything on leaching of these compounds from biosolids-amended soils, how to properly test for them in a biosolids matrix and how to best address regulatory concerns. Ned gives suggestions. This is the one, easy to read, easy to digest article that you need on this subject.
The rest of the library provides important back up to this summary piece. Article #2 is a full- scale risk assessment of biosolids borne PFOS and PFOA and flame retardants. The authors have previously tested biosolids amended soil for potential earthworm exposure, crop uptake, leachate and runoff water concentrations of these compounds. Here they put together the data to evaluate the environmental risk via earthworm uptake, crop uptake and aquatic environments. In all cases, the risk quotient values were well below 1 -- the magic number that is used to identify potential for risk. This is a very good study to use to try to calm down people worried about these compounds in a biosolids matrix. What people who are so concerned about these compounds in biosolids seem to not get is that the compounds do not originate in the biosolids. The wastewater treatment process does not result in carbon bonding in complicated molecules with fluorine. By and large, these compounds show up in the biosolids because they are ubiquitous in our home environments.
Fess up. How many of you reading this have ever gotten take out for dinner? The next article in the library presents results from a survey of fast food packaging. The percent of different types of packaging that contained fluorine was tested to estimate concentrations of perfluorinated compounds in the packaging. It turns out that if you ever had a muffin or cookie from a store, there is about a 56% chance it was packaged with paper that contained perfluorinated compounds. Chances fall to 38% for those who got take out sandwiches and/or burgers. This is yet another reason to feel guilty about splurging on sweets. Paperboard containers, like those that hold French fries and onion rings, are more of a risk for excess carbs than for PFO, with only 20% have detectible fluorine. Finally, your latte cups showed no detection. So, order coffee and fries, but hold the hamburgers and cookies if you want your diet to minimize exposure to these compounds.
The next article gives you a map of Europe, with the different concentrations and likely sources of PFOS and PFOA in surface waters. The authors note that the primary source of PFOA is manufacturing, producing yet another compound that is hard to pronounce: ammonium perfluorooctanoate (APFO). About 2600 - 5050 tons of APFO were manufactured in Europe from 1950 - 2010. In contrast, much of the PFOS are from the breakdown of perfluorooctyl sulfonamidoethanols (POSF) in consumer products. Here are some of those compunds, in words that you can understand and even pronounce: carpets, clothing, paper and packaging. These consumer products are to blame for about 85% of losses of PFOS that show up in rivers from wastewater treatment plant effluent. The authors sampled over 200 points in Europe. They found that PFOA was concentrated in three river systems with emissions of PFOS more homogeneous. This correlates well with the previously identified sources. As manufacture of PFOA was phased out in Europe in 2007, industrial sources would be expected to become less prevalent over time. Emissions of PFOS fit a regression line equivalent to 27.4 ug per inhabitant per day. For PFOA for all samples were 82 ug per inhabitant per day. Samples from a WWTP in Germany showed emissions of 30 ug per inhabitant per day. In other words, for PFOA, as stated in the article introduction, the environmental sources are manufacturing, not homes.
The first 4 articles should provide information on concentrations of PFOA and PFOS in biosolids and the associated risks (low to none). You should now realize that sources are ubiquitous, from food packaging to carpet. Banning biosolids will not solve any problems associated with these compounds. The compounds that we have been so concerned about have been phased out, and we have seen environmental concentrations decreasing. One could hope that maybe the crisis over PFOA and PFOS will start to calm. Hope can be fleeting.
The last article in the library discusses the presence in world waters of the next generation of these compounds, the replacement for the longer chain PFOA and PFOS: perfluoroether carboxylic and sulfonic acids (PFECA and PFESA). The authors sampled water in China (n=106) the US (n=12), the UK (n=6), and found them. The next generation headache is approaching, while the pain associated with the first-generation headache is still pounding.
Remember those good old days when we used to worry about cadmium?