Pentachlorophenol is a human carcinogen, Group 1

In October 2016 18 scientists met at IARC for evaluation of pentachlorophenol (PCP) as a human carcinogen. The panel classified PCP as ‘carcinogenic to humans’ Group 1. PCP is a persistent organic pollutant under the Stockholm Convention. Chlorophenols, mostly PCP, have been used as wood preservatives. The use was banned in Sweden in 1978 with few exceptions. Wood impregnated with PCP may still entail a health hazard. In case-control studies we associated use of chlorophenols, as well as phenoxy herbicides, with increased risk for soft-tissue sarcoma (1979) and malignant lymphoma, both Hodgkin’s disease and non-Hodgkin lymphoma (1981). These results were the first studies in the world showing a carcinogenic potential of these agents, and further discussed in an article published in 1982.

Our results associated exposure to chlorophenols and the weed-killers phenoxy herbicides, with contaminating TCDD, with increased risk for soft-tissue sarcoma and malignant lymphoma. The results were soon questioned by industry and its allied experts including scientists with their own hidden agenda, even with funds from the Swedish Cancer Society aimed at preventing cancer, see


The lesson is that it took 37 years from the first publication showing PCP as a human carcinogen to establish causation, years that were lost for cancer prevention.

The Swedish Cancer Society, a controversial professor and Exponent

In a new article in NewsVoice, Mona Nilsson (scientific journalist) continues to review a controversial professor at KI and Harvard and his affiliations with industry. In spite of large funds from the Swedish Cancer Society to identify cancer risks and initiate prevention he has continued to greenwash cancer risks. This is a most remarkable story that can be read here, unfortunately only in Swedish. It is justified to ask what ethical, moral and not the least scientific principles are used (or not used at all) by the Swedish Cancer Society. After all the money comes from persons concerned about the increasing number of cancer cases and keen to know risk factors and reduce cancer risks.


Swedish cancer researcher paid by the Swedish Cancer Society has for long time worked for industry to deny cancer risks

In 2013 more than 61,000 new cancer cases were reported to the Swedish Cancer Register. This was all time high and may be compared with e.g. 1970 with 28,000 cases. The increase is remarkable even if age and population number is considered.

 The Swedish Cancer Society has for long time dominated as a sponsor of cancer research. Much has been achieved in microbiology and treatment. However, the Cancer Society has a less prominent history as to cancer prevention, especially regarding chemical risk factors such as pesticides, dioxins, and PCB.

In contrast, in a recent article in NewsVoice we are told that a Swedish cancer researcher with large funds from the Cancer Society, and even a personal employment to diminish cancer risks, for long time has worked for industry to deny cancer risks. In spite of this fact, known since more than a decade, the Cancer Society has continued to support that researcher with large funds achieved from donations from the public.

The article in NewsVoice is unfortunately in Swedish but starts with:

“The Cancer Society has during 2 decades paid in total more than 30 million Swedish krona (3,2 million Euro) to the controversial professor Hans-Olov Adami. Adami has been criticized more than 10 years ago for his close co-operation with the chemical industry. In spite of that fact the Cancer Society has continued to pay more than 20 million Swedish krona to Professor Adami. During the same time Adami has dismissed risks for cancer from Agent Orange, dioxin, formaldehyde, pesticides and mobile phones. During the same time period the number of persons that get cancer in Sweden has increased with 30 %.”

Increasing rate of brain tumours in Sweden

Radiofrequency fields emitted from mobile and cordless phones were in May 2011 evaluated to be ’possibly’ carcinogenic to humans, Group 2B, by IARC. This has had little effect on precaution. Instead incidence data on brain tumour from the Swedish Cancer Register have been used to dismiss the increased risk. In this study we show that these data are not reliable. Instead there is an increasing rate of brain tumours in Sweden. Using the Swedish National Inpatient we show in this study that the rate of brain tumours in Sweden increased since 2007. This increase was seen from 2008 in the Causes of Death Register. The increasing rates may be caused by use of mobile and cordless phones, see

‘Bad luck’ if one gets cancer – a publication not based on science rebutted by Collegium Ramazzini

The Collegium Ramazzini has published its 17th position statement entitled “Most Types of Cancer are Not Due to Bad Luck”.

The full text of the document and references may be downloaded here.

The Collegium Ramazzini strongly rejects the claim by Tomasetti and Vogelstein that 65% of cancers are due to “bad luck” and result from randomly acquired mutations of the genome (Tomasetti and Vogelstein 2015b). This claim is based on a skewed and highly selective reading of the literature. It examines only a fraction of cancers – 34% – in a single country – the United States (Wild et al. 2015). It ignores enormous differences in cancer incidence and mortality across countries (Wild et al. 2015) (Potter and Prentice 2015). It dismisses abundant clinical and epidemiological research that has discovered scores of environmental and occupational carcinogens to which millions of persons are exposed (Wild et al. 2015). It ignores the very great successes in cancer prevention that have been achieved by controlling exposures to known carcinogens (Ashford et al. 2015; Gotay et al. 2015; Potter and Prentice 2015; Song and Giovannucci 2015; Wild et al. 2015). 

The spurious claim of Tomasetti and Vogelstein poses grave danger to public health. It has the potential to undermine governmental programs for cancer prevention and also to discourage individuals from making wise decisions to change lifestyle, diet, and other factors that can reduce exposures to carcinogens. 

In rejecting the unsubstantiated claim by Tomasetti and Vogelstein, the Collegium Ramazzini is proud to join the International Agency for Research on Cancer (Wild et al. 2015) and distinguished scientists from around the world (Ashford et al. 2015; Gotay et al. 2015; Potter and Prentice 2015; Song and Giovannucci 2015). We fully endorse the IARC critique of the Tomasetti-Vogelstein report (Wild et al. 2015).

Finally, the Collegium Ramazzini notes that Tomasetti and Vogelstein failed to disclose potentially important financial conflicts of interest (Tomasetti and Vogelstein 2015b).