Back in February, the Daily Mail published an article denouncing "The Great Asbestos Hysteria", and claiming that the health risks had been grossly exaggerated by "the BBC, profiteering lawyers, and gullible politicians".

The article was a response to a study raising concerns about the ongoing dangers of asbestos in UK schools. Those dangers were, the Daily Mail assured us, "all but non-existent". While many older school buildings still contained asbestos, almost all of it was "relatively harmless white asbestos, encapsulated in cement or other materials, from which it is virtually impossible to extract even a single dangerous fibre". The threat from such products was so "vanishingly small" that a study by the Health and Safety Executive (HSE) had concluded that the danger was "insignificant", with "arguably zero" risk of lung cancer.

Good news all round, then. No need for schools to worry about that crumbling asbestos roof. No need, we might think, for maintenance workers to wear protective clothing when renovating old school buildings. No need, it would seem, to employ specialist contractors to assess whether to leave asbestos undisturbed or get it removed. Those guys are, in any case, according to the Mail, a "commercial racket" with a "vested interest in exaggerating the dangers of products which are, in effect, harmless".

Last week, seven months after the article was published, the Daily Mail issued a carefully worded correction:

"...The HSE assessments related to specific levels of exposure to white asbestos fibres, not white asbestos products, and found a risk from higher levels. The article said that asbestos in UK schools is almost all white. According to the HSE the more harmful brown asbestos was also frequently used in schools..."

Not such good news. What many reading the Daily Mail article won't have known is that the author, Christopher Booker, has a long track record of downplaying the health risks of white asbestos. Though not a scientist himself, Booker has written at least 42 newspaper articles on this subject since 2002, making claims that run counter to the views of most experts, but are remarkably similar to those of the asbestos industry.

Several of the claims in the Daily Mail article – including that an HSE study once concluded the health risks of white asbestos cement were "insignificant" - have previously appeared in Booker's Sunday Telegraph column, prompting a series of direct rebuttals from the HSE. The available evidence, as assessed by – among others - the World Health Organisation, the UK and US governments, and the European Union, is that white asbestos poses a serious risk to human health that needs to be carefully managed.

If the experts are right about asbestos and Booker is wrong, then this matters for at least two reasons. Firstly, there's a danger that people may take unnecessary risks when handling the stuff, with potentially deadly consequences a couple of decades down the line. In 2008, a survey by the British Lung Foundation found widespread ignorance about the health risks, with under a third of tradespeople – the group most at risk of exposure – aware that it could cause cancer, and 28% "mistakenly assuming that some levels of asbestos are safe". Further misinformation surely won't help.

Secondly, for those affected by asbestos-related disease, ill-informed media reports belittling the health risks can be offensive and upsetting. I got the smallest glimpse of what that must be like when I saw that my blog had been linked to from a Facebook group set up by mesothelioma sufferers in response to Booker's Daily Mail article.

Several members of the group had decided to report the Mail to the Press Complaints Commission, for breaching section 1 of the PCC's ethical code: "The Press must take care not to publish inaccurate, misleading or distorted information". I've been following Booker's antics for a while – I researched his work in detail for my book Don't Get Fooled Again, and still write about him from time to time on my blog. So I decided to support the Facebook campaigners – and test out the PCC's claim to be "fast, free and fair" – by putting in a complaint of my own.

It wasn't difficult to produce evidence debunking the Mail's assertion that white asbestos was "relatively harmless". Back in 2002, the HSE had published a summary, with references, of the peer-reviewed research linking the material to mesothelioma and lung cancer. The newspaper's claim that an HSE study had found the dangers of white asbestos cement to be "insignificant" was also easy to disprove: Booker had made the self-same claim in the Sunday Telegraph back in 2008, and been rebutted in detail by the HSE.

Neither was it hard to show that the Mail had got it wrong in claiming that "it is virtually impossible to extract even a single dangerous fibre" from white asbestos cement. An HSE lab report from 2007 notes that "the claim that respirable airborne chrysotile fibres are not able to be released from asbestos cement products was refuted by the individual airborne fibres sampled during the breaking of the test sample with a hammer".

In theory, this should have been the end of the matter. According to the PCC's code, "a significant inaccuracy, misleading statement or distortion once recognised must be corrected, promptly and with due prominence". What happened instead, in my view, speaks volumes both about the character of the Daily Mail, and the credibility of the newspaper industry's self-regulatory body.

After a delay of several weeks, the PCC forwarded me a dismissive response from the Daily Mail's executive managing editor, Robin Esser. While acknowledging some minor errors, Esser insisted that the disputed HSE study did indeed back up Booker's views on asbestos. The fact that the HSE had put out a statement explicitly rebutting this merely proved that "those responsible for HSE press releases are similarly unable to grasp the significance of findings published by their own statisticians". For good measure, Esser accused me (falsely, just in case you're wondering) of being "allied to a well-organised and well-funded commercial lobby", who "stand to benefit financially" from the "anti-asbestos campaign".

Rather than take ownership of the process, assess the various bits of evidence and come to a judgement, the PCC instead asked me to go through this new set of claims and produce a further response. Here I began to see why so many people have given up on the PCC. If a newspaper digs in its heels and simply denies all the evidence that's been presented, there doesn't seem to be much that the PCC can do except bat the issue back to the complainant.

It was at this stage that I learned that the asbestos campaigner Michael Lees had also submitted a detailed complaint. Michael, who has been working to highlight the dangers of asbestos in schools since losing his wife Gina, a teacher, to mesothelioma, had been singled out by name – the third time that Booker had done this. Michael took particular exception to the dismissive terms in which the article had referred to his wife's death, adding to the offence of a previous piece in which Booker had dubbed the case "bizarre". He was also concerned that – aside from Booker's views on white asbestos – the article sidestepped the fact that many schools still contain large amounts of brown asbestos, whose dangers are beyond dispute.

More time-consuming exchanges followed, with long gaps in between, while we awaited a response from the Daily Mail. In the end we won, sort of. The newspaper agreed to make some amendments to the text of the article, publish a short correction, and write a private apology to Michael Lees over Booker's comments about his wife. But to get even this far has taken seven months, and a substantial time investment, while the Daily Mail seems to have been able to drag the process out with impunity. "Free", perhaps – but hardly "fast", or "fair".

Richard Wilson is the author of Don't Get Fooled Again – The Skeptic's Guide to Life. www.twitter.com/dontgetfooled