Recently it came out, that in some parts of Switzerland (where I live), there is Chlorothalonil & metabolites/breakdown-products of it in the drinking water. Yikes.
Problem is, chlorothalonil synthesis frequently result in contamination of it with small amounts of hexachlorobenzene (HCB), which is toxic. Worse, one of the metabolites/breakdown-products is 2,3,7,8-Tetrachlorodibenzodioxin, which is one of the most potent carcinogens known.
Now, according to official sources, the drinking water in my region, which exceeded the maximum permissible value by law (and those are not necessarely low, e.g. the nitrates permissible values is far too high), has been diluted with lake water from Lake Constance, and according to the official narrative, all is fine now. That's what the same official sources said before, too - until someone discovered that this wasn't the case. However, Syngenta, noble originater of the problem-causing fungicide(s), is moving in courts to successfully forbid obligatory measurements, because "it has not yet conclusively been proven that Chlorothalonil causes cancer". That's bullshit, but the scientific proof is indeed still owing, unfortunately, yet. Unfortunately, that little detail also means their court-work sabotage is successful. However, the correlation is clear, and I'm sure it will be proven in the not so distant future, sooner or later (but too late for the courts). Syngenta's behaviour equalling the reprehensible ethics of the tabacco industry.
Now, me being a distrustful person, I have bought a reverse-osmosis table-appliance, to be sure with my cooking and drinking water, just in case this is a lie. I have read that this filters the chemicals in question and more (or at least it should), and is also good for decalcification, which is an additional benefit.
However, assuming the reverse-osmosis-appliance itself is safe, not to mention it working as advertized, there remains the problem of showering and bathing water.
Is that even relevant for concentrations of Chlorothalonil breakdown products of <= 0.1 microgramms per liter, or is the main danger from oral consumption ?
For absorption by skin, can such concentrations be harmful ?
In January 2020, Syngenta Agro AG appealed to the Federal Administrative Court against the ban on chlorothalonil. The proceedings are still pending, but two interim rulings have already been issued in which Syngenta Agro AG's applications for precautionary measures have been approved. In the second interim ruling, the FSVO is required not to designate four metabolites of chlorothalonil, including R417888 and R471811, as toxicologically relevant for the time being (this would once again result in a high maximum level of 10 µg / l). According to a media release from the Federal Administrative Court of February 18, 2021, it will only be necessary to assess in the main decision which classification with regard to carcinogenicity (category 2 or 1B) is to be assumed and whether all metabolites are automatically considered relevant with a possible classification in category B1, and which maximum drinking water levels (10 µg / l or 0.1 µg / l) are applicable.
Due to the pending proceedings, Labor Veritas AG has decided to suspend the conformity assessment of water samples in accordance with the TBDV in connection with the chlorothalonil metabolites until the legal situation has been clarified. The following note therefore appears on our test reports: "Due to the currently unclear legal situation with regard to the applicable maximum values for the metabolites of chlorothalonil, the samples are no longer evaluated for conformity". In our Spotlight No. 34 from May 2020 , all metabolites of chlorothalonil are described as relevant due to the initial situation at the time. This statement should be treated with caution for the time being. This spotlight will not be updated for the time being, especially because the statements made in it could become valid again.