‘A person suffers most from the suffering they fear’

What preceded this: On 17 January, we published ‘Unnecessarily Panicked About Nanograms’, a review written by Arno van ‘t Hoog about ‘Panic About Nothing’, the latest book by Simon Rozendaal. That review did not go unnoticed. Several critical responses followed, including an extensive commentary by ecotoxicologist Wim van Tilborg: ‘Are We Really Unnecessarily Panicked About Nanograms?’. Rozendaal now responds to Van Tilborg’s criticism.

It is gratifying that ecotoxicologist Wim van Tilborg has responded to Panic About Nothing. After all, it was written in part as a spanner in the toxicological works. And Van Tilborg is, here and there, quite right. Because the carbon-fluorine bond in PFAS is stable — they barely react with other substances — I argue that this is precisely why they are not particularly toxic. Van Tilborg points out that other effects may also play a role in toxicity. A fair point, with the caveat that he does not know whether that is actually the case.

That might emerge from studies. Van Tilborg asserts in this context that I hold ‘an entirely personal opinion’ on PFAS and that I cast doubt on ‘scientifically established findings’. In my book (vetted by chemists and toxicologists of repute) I draw on a range of experts. Environmental toxicologist Susan Goldhaber of the American Council on Science and Health follows all PFAS studies: ‘It is rather exceptional that there has been so much research into a single substance that has yielded so few negative results.’ Biochemist and emeritus professor of nutrition Martijn Katan wrote in the NRC about my book: ‘The evidence that these quantities of PFAS make people ill is extremely flimsy.’ Professor of toxicology Jan Tytgat of the University of Leuven told the AD that we worry too much about quantities that we can only measure thanks to what I term a ‘measurement revolution’. He is not aware of any convincing publication showing that people fall ill, let alone die, from PFAS.

Van Tilborg believes I misinterpret Paracelsus (to whom I dedicate my book). His adage runs: the dose alone makes the poison. This implies that any substance below a threshold is non-toxic. Naturally, that threshold differs for every substance, and I write as much repeatedly: DDT, for example, is more toxic than glyphosate. I do, however, conclude my book with advice — born above all from civic concern — to keep a cool head when faced with minuscule concentrations. In doing so, I draw a line at 1 ppm, anything smaller than 0.0001 per cent. Van Tilborg cites an interview in de Volkskrant, but could have read in my book how tentatively I put this forward. ‘I am not a toxicologist, not a doctor, not an epidemiologist, so I offer my advice with a great many caveats.’ And: ‘there are all manner of government bodies that are genuinely responsible for this.’

Setting aside the question of whether such a lower limit ought to be 1 ppm, 1 ppb, or somewhere in between, my hope is that government bodies, toxicologists, and the media will realise — partly through this book (now in its third printing) — that the fear of vanishingly small concentrations has more pathological consequences than those doses themselves. As the old adage has it: ‘A person suffers most from the suffering they dread but which never comes to pass.’