PFAS
It is estimated that there are thousands of existing PFAS compounds, including transformation products formed during combustion or xenometabolism. Current food safety assessments by the European Food Safety Authority (EFSA) consider only four PFAS congeners and do not account for the relative potency (REP) of individual compounds.
ToxicoWatch’s biomonitoring research uses both chemical analysis (LC-MS/MS) and the PFAS CALUX® bioassay. Current EU regulation only addresses the sum of four PFAS compounds defined by the European Food Safety Authority (EFSA): PFOA, PFOS, PFHxS and PFNA (EFSA-4). This represents a limited selection of the toxic PFAS compounds now frequently detected in contaminated environments. The relative potency factor is included in the ToxicoWatch reports to provide a more accurate picture of the toxicity.
PFAS chemical LC-MS/MS analysis
Chemical PFAS analysis is limited, depending on the laboratory, with only 4–55 PFAS substances able to be measured. This means that fewer than 0.1% of total PFAS compounds can be quantified by chemical analysis. Chemical analysis (LC-MS/MS Liquid Chromatography Mass Spectrometry/Mass Spectrometry), performed by accredited labs for ToxicoWatch biomonitoring, contains a total of 24 PFAS compounds.
Bioassay PFAS CALUX analysis
The PFAS CALUX® uses human bone marrow cell lines (U2OS) incorporating the firefly luciferase gene under control of Thyroid Responsive Elements (TREs). It detects thyroid hormone-like inhibiting compounds based on the ability of PFAS to compete with thyroxine (T4) for transthyretin (TTR) binding sites. Increasing PFAS concentrations reduce TTR-bound T4. Disruption of T4-TTR binding is benchmarked against perfluorooctanoic acid (PFOA), with a reference value of one (1), analogous to TCDD in the TEQ calculations. Results of PFAS CALUX® are expressed as μg PFOA equivalent per gram product. The PFAS CALUX provides a more complete picture of the toxic pressure of PFAS than a simple summation of a few congener concentrations.
PFAS Assay FITC-T4 analysis
FITC-T4® is the acronym for Fluorescein IsoThioCyanate (FITC) and T4 refers to the thyroid hormone Thyroxine, which contains 4 iodine elements (T4). The PFAS bind to the thyroid transporter protein transthyretin (TTR), preventing the natural hormone thyroxine (T4) from binding to TTR. This free unbound hormone thyroxine (T4) is related to the amount of PFAS. Analysis results with the FITC-T4 are expressed in micrograms of PFOA equivalents per gram of product (µg PFOA eq./gr product). FITC-T4 is used to screen for perfluoroalkyl substances (PFAS), although other substances are also capable of disrupting thyroid function in humans.
PFAS and Waste incineration
ToxicoWatch (TW) data research (2015-2017) of the WtE incinerator REC emissions, showed that PFAS are part of the content of flue gas emissions of this waste incineration at the time of research. These TW findings are presented at the international Dioxin conference in Krakow Poland, 2018 (see Presentations).
It is a challenge for Waste-to-Energy (WtE)/waste incinerators to destruct PFAS completely by incineration of (household) waste. To deal with this challenge, much higher combustion temperatures are required than the current EU mandated 850°C (of 2 seconds resident time in the post-combustion-zone / PCZ), to achieve complete destruction of PFAS by waste incineration.
It is to be noted, that the de-novo synthesis in a waste incineration production process could, even at high combustion temperatures, play a key role in forming new fluorine substances/PFAS, likewise for dioxins and PAH. Due to the inevitable cooling down phase of every combustion process. Initially destructed – by incineration – persistent organic pollutant molecule structures, can be formed again into new (unkown) toxic substance structures of POPs.
Taken into account that newly formed (unknown) PFAS compounds (by de-novo synthesis) cannot be detected using current limited chemical analysis methods for PFAS. Therefore TW uses the bioassay PFAS CALUX to be able to detect as well unknown fluorinated substances with a PFAS-like effect of toxicity, which assesses the effects on hormonal thyroid function (T4).
Research and monitoring data of the incineration processes, during normal and Other-Than-Normal-Operating Conditions (OTNOC) of combustion processes, is needed to know whether PFAS is being emitted into the environment by flue gasses of waste incineration. Besides research and monitoring, an optimal use of adequate working filter systems are essential to help preventing PFAS being released by waste incineration emissions into the environment.
Very unfortunately, PFAS, is so prevalent in our daily lives nowadays. As a result of continuous and the large-scale industrial production worldwide of all kind of (single-use) consumer/medical/agriculture products, containing intentional produced PFAS. These man-made toxic fluorinated substances, ‘for-ever-chemicals‘ have been fabricated for almost a century. The production practices of fluorinated substances, which appear to be increasing by the year, causes a significant contribution to the tsunami of PFAS content in our daily (household) waste. Just think of plastic packaging material for foodstuffs with PFAS ink markings on it. This is only a very small part of the daily incinerated mountains of PFAS containing waste by (WtE) waste incinerators, which are inadequately equipped by construction to destroy PFAS completely, due to low combustion temperatures, and the possibility of de-novo synthesis.
If the toxic input of waste, containing PFAS and other POPs, continues to be incinerated by WtE/(co-) waste incinerators, the toxic output of POP containing emissions and incineration residues (bottom and fly ash), will remain a potential source of POP-contaminated air, soil and water, posing a serious threat to our health and the environment.
PFAS and Face masks - 2022
The aim of the ToxicoWatch (TW) Foundation is to raise public awareness about exposure to toxic chemicals in everyday life. Therefore, TW started in 2022 the initiative to set up a pilot study on face masks based on the questions:
- Is PFAS added to face masks?
- What are the risks for human health if PFAS is added to face masks?
This research focuses on PFAS and its many pathways into the human body via the skin, respiratory tract, mouth, lungs, eyes, nose, and the blood-brain barrier.
ToxicoWatch initially based this pilot study on three samples of single-use face mask samples (FFP2/medical). The facemask samples TW used were the same as the ones offered to public visitors for health protection at the entrance of nursing homes for the elderly, general practitioner practices and hospitals in 2021-2022.
The face masks for this study were purchased by TW team as customers at petrol stations and DIY stores, then prepared into small pieces of for analysis on PFAS. ToxicoWatch complemented this pilot research with a literature study on PFAS, toxic chemicals and textiles.
An increasing number of studies show a relationship between emerging diseases and PFAS.
From the precautionary principle point of view, highly persistent and toxic substance as PFAS in (medical) textiles – meant to protect our health – will be discussed in this report.
