VFor three weeks, Professor Dieter Köhler was among the 112 renowned scientists, mostly pulmonologists, who doubted the hypothesis that particulate matter and nitrogen compounds in German cities were hazardous to health (WELT reported). The paper said that the signatories "currently do not see any scientific justification for the current limits for particulate matter and NOx". They therefore call for a reassessment of scientific studies by independent researchers.
Now the "Tageszeitung" (taz) reports under the headline "Pulmonary physician with dyscalculia" that the 70-year-old Kohler, who reproaches colleagues for systematic errors and one-sided interpretations, has miscalculated in his models. Literally it says in the long text that "Köhler, regardless of his poor understanding of epidemiology apparently has a lot of fundamental problems – with chemistry and especially mathematics. The mistakes made by Köhler are so serious that he partly proves the opposite of what he wanted to say. "To do this, one has to take a look at his calculations for comparing nitrogen oxide concentrations in cigarette smoke and diesel exhaust.
According to him, who lives on a busy street, breathes as much nitric oxide during a lifetime of 80 years as a heavy smoker does in six to 32 years. Köhler always claims that it is only about the dose of a few months of smoking. For this he has presented a detailed account in previous publications.
It was said in 2018 "German Medical Journal": "One can refute the study relatively simply by taking the amount of NO in cigarette smoke as a comparison," says Köhler in an interview with Deutsches Ärzteblatt. The lie at around 500 micrograms (ie 500 millionths) per cigarette. If you take a tidal volume for the calculation of the concentration when smoking a cigarette of ten liters, inhale 50 000 μg per cubic meter of air. That would be 1 million micrograms per pack per day, calculates Köhler. "
Due to these miscalculations a central statement of Köhler changes
In this example, the "taz" was alerted by an external reference to an obvious miscalculation: if a cigarette released 500 micrograms (μg) of NO2, the value for a pack of 20 cigarettes would not be one million micrograms, but only 10,000 micrograms – The result is thus falsified by a factor of 100. Köhler initially blamed the editors of the "Deutsches Ärzteblatt" on this "taz" request. However, the responsible editor referred to a manuscript from him, which he then confirmed.
According to "taz" also agree with the initial value, with Köhler reckons: The value of 500 micrograms per cigarette he mentioned does not apply to nitrogen dioxide (NO2), ie the gas, to which the limits apply and that for the driving bans in German cities responsible, but for nitrogen oxides in general (NOx). Köhler first mentions ten percent of NO2 as NOX in cigarette smoke – thus the result would be a total of a factor of 1000 wrong. In a later mail, he revised the information again and called without clear reference to a range of ten to 50 percent. However, the result of his calculation would even be reversed by a factor of 200 to 1000.
Due to these miscalculations a central statement of Köhler changes, so the "taz". He has compared a smoker and a non-smoker who inhales "permanent particulate matter or NOx in the limit range": "Smokers (one pack / day accepted) reach in less than two months, the fine dust dose that would otherwise inhale an 80-year-old nonsmoker in life , For NOx, the differences are similar, albeit a little lower. "
But according to "taz", this would not even be of the same order of magnitude: Instead of NOx, NO2 is meant here as well, Köhler has acknowledged – because only for this substance is there a limit, so that only a comparison is possible. Moreover, if Köhler's conversion error is taken into account, the amount of NO2 inhaled in the air for 80 years would not be what a smoker inhales in a few months, but 6.4 to 32 years, depending on the NO2 content of NOX.
Köhler does not see a big problem in these mistakes
Instead of demonstrating the harmlessness of the outside air in comparison to cigarette smoke, as Köhler intended with his comparison, this one shows the opposite with correct calculation. Köhler also made a simple calculation error in his deliberations on particulate matter pollution, according to the "taz": "The concentration of particulate matter in the main stream of cigarette smoke actually reaches 100-500 g / m3 and is thus up to one million times greater than the limit value ", Says the statement written by Köhler.
But a simple check shows that the daily limit value for particulate matter to which Köhler refers is 50 micrograms per cubic meter of air. Köhler's maximum value of 500 grams per cubic meter for cigarette smoke would be the equivalent of 500 million micrograms per cubic meter. If the figure quoted said that the concentration in cigarette smoke would not be a million times the threshold on the street – but ten million times.
Köhler confronted the "taz" with this miscalculation that surprised him: "Nobody has noticed that yet." According to him, cigarette smoke would be 10 to 50 micrograms instead of 100 to 500 micrograms per cubic meter. Then at least the mentioned factor of one million would be correct. But also the corrected number does not agree according to "taz": The fine dust value he calculated according to own data on the basis of the condensate content of the cigarettes (colloquially: tar). He said he had assumed 10 to 25 milligrams per cigarette. However, condensate has been subject to an EU-wide limit of 10 milligrams since 2004. "I did not know the specifications of the EU," he said.
Köhler himself does not see a big problem in these mistakes. The "magnitude" is still correct. His miscalculations and outdated information he explains: "I'm practically doing everything alone and do not even have a secretary as a retiree."