Geoffrey Kabat, a cancer epidemiologist at the Albert Einstein College of Medicine in the United States who has publicly criticised IARC, says the classifications do the public “a disservice."

"What the public wants to know is: What are the agents in our surroundings that are likely to have palpable effects on our health? Not theoretical exposures which might, under some far-fetched conditions, possibly have an effect,” said Kabat, who is also author of the book “Hyping Health Risks.”

The risks of public misapprehension were evident in some of the media reaction to IARC’s announcement on red and processed meats. The Huffington Post declared: “Meat is the new tobacco.” Britain’s Daily Mail said “health chiefs” had “put processed meat on same level as cigarettes.”

Such interpretations are misleading, in IARC’s view. Straif told Reuters that the blame for any confusion lies with industry, activist groups and the media.

“There are stakeholders on various sides that want to make it look ridiculous,” he said. “There are activist groups who want to say, ‘This is now an IARC carcinogen and we need to take all actions against it’. And then there is a third dimension – the media, who have their own interests in being sensational.”

Straif defended the decision to place processed meat in the same hazard category as plutonium, saying that “for both of these things there is clear evidence that these are human carcinogens.”

"NAIVE, IF NOT ANTI-SCIENTIFIC"

Some critics say the problems with IARC’s monographs begin well before they become headlines. Their concerns focus on the composition of the "expert working groups” that decide which of the five IARC categories a substance or activity should go in. These experts sometimes include people who have spent years publishing research on whether the substance or activity under scrutiny can cause cancer. They may be part of IARC working groups that review their own research or that of close colleagues.

Between 2012 and 2015, for example, IARC published or started 18 monographs involving 314 scientists. A Reuters analysis found that at least 61 of those scientists served on monograph working groups that considered their own scientific research. The analysis did not include the number of scientists on working groups that reviewed the research of close colleagues.

“What the public want to know is: What are the agents likely to have a palpable effect on health? Not theoretical exposures which might, under some far-fetched conditions, have an effect.” Geoffrey Kabat, cancer epidemiologist

In letters, commentaries and articles in scientific journals, Tarone of the International Epidemiology Institute and other scientists have questioned whether such people “are the best judges of the validity and methodological soundness of their own and allied work.”

IARC’s Straif said the agency’s working groups consist of “the world’s best experts” who critically review the scientific evidence and are not swayed by previous findings in their own work, or that of close colleagues. “IARC has a strong belief, for good reasons, that those who know the most about certain exposures are those who have worked on such exposures,” he said.

Straif said IARC’s rules ensure no “author or associated colleague” can directly evaluate a study they have published. And neutrality is assured, he said, because the discussions involve 20 to 30 people in an environment where “advocacy of any kind ... is not tolerated.”

Tarone regards IARC's assumption that all experts will be detached and independent as “naive, if not anti-scientific.” He told Reuters: “It's absurd to assert there are no issues of bias related to self-interest, reputation or careerism. It has nothing to do with bad motives, it’s just human nature.”

Tarone and other critics say IARC is inconsistent in its treatment of potential conflicts of interest and cite as an example a study of radiation of the sort emitted by mobile phones. In June 2011, IARC concluded such radiation is “possibly carcinogenic.” That ranking put mobile phone use in the same category as lead and chloroform.

Anders Ahlbom, a senior professor at the Karolinska Institute in Sweden, was originally invited to chair the working group on electromagnetic radio frequencies in May 2011. However, Ahlbom, who thinks there is little evidence to suggest mobile phones cause cancer, was asked to step down about a week before the meeting was due to begin after he told IARC he had been contacted by a journalist. The journalist had questioned him about being on the board of his brother’s consulting firm, which helps clients lobby on telecoms issues.

IARC decided that Ahlbom had a perceived conflict of interest. Ahlbom accepted this decision, although he said there was no conflict since he had no financial interest in his brother’s company. Ahlbom said his departure upset the balance of the IARC working group, which, he and five other scientists said, included researchers who already viewed mobile phones as likely to raise the risk of brain tumours.

“It appears that IARC handles conflicts of interest differently depending on who the person is and which ‘side’ he is assumed to represent,” Ahlbom told Reuters.

Straif said IARC “takes all conflicts of interest seriously, regardless of the individuals or organisations involved.” He said that Ahlbom’s exit from the working group did not leave it with an imbalance.

“It is difficult to perceive how a strong working group of 32 internationally renowned experts would suddenly not have a balance anymore because of one single expert who had a conflict,” he said.

SEEING RED

At the meetings of IARC working groups, invited observers who have “relevant scientific credentials” are allowed to attend; but they have to sign confidentiality agreements and cannot discuss the proceedings. Straif says this is to ensure the scientists can speak candidly, without fear of having their disagreements or discussions reported externally without their consent.

One observer, a specialist in food and animal science who attended the working group on red and processed meats in 2015, spoke to Reuters on condition of anonymity. The person alleged that the expert panel reviewing the scientific evidence appeared to aim for a specific result.

“I’m very happy with the way we do things. We really are at the head of the scientific community.” Kurt Straif, section head, International Agency for Research on Cancer

In its meat assessment, IARC went beyond its normal remit of assessing hazard, not risk. It gave specific warnings about the risk of eating red and processed meat products.

IARC said, for example, that for each 50 gram piece of processed meat eaten daily, the risk of a person developing colon cancer increases by 18 percent. The observer who spoke to Reuters said these data appeared “to come from nowhere, overnight.”

The observer said: “I expected that the science would be reviewed with a high level of rigour. But quite frankly, at the end of the 10 days, from a scientific standpoint I was really quite shocked.”

Straif said the numbers came from “a combined analysis” of the scientific papers under review, and were issued by IARC because there was sufficient evidence in human epidemiological studies for the working group experts to feel confident in them.

Straif told Reuters parts of the working group discussions may have been missed by some observers: “We really worked around the clock, up late into the night and all weekend, so I’m not sure if the observers were there at all times.”

In a subsequent email to Reuters, he said the risk estimates and corresponding scientific papers were part of the monograph discussions from “the very first working drafts and through all revisions.” He added: “It is very difficult to understand how any participant could have missed this discussion.”

While not disagreeing with IARC’s assessment of meat as a carcinogen, the WHO headquarters issued a series of tweets giving context. The WHO stressed that “the health risks of processed meat are vastly different of those cigarettes and asbestos” and that “meat provides a number of essential nutrients and, when consumed in moderation, has a place in a healthy diet.”

The controversy has raised questions at WHO headquarters about the organisation’s control over IARC. “There is talk here now of needing to rein IARC in,” said a Geneva-based WHO insider.

Charles Clift, a global public health specialist at the Centre on Global Health Security at Britain’s Chatham House, said the WHO should have taken more of a role in IARC's presentation of its conclusions on red and processed meat.

“The WHO should be there to give authoritative guidance,” Clift said, “not just endorse things that can be misinterpreted – either from IARC or anybody else.”

The WHO’s spokesman, Hartl, told Reuters that IARC was a “functionally independent” agency, and that when IARC flags up cancer hazards, the “WHO assesses or re-assesses the levels of risk associated with those hazards. Based on the risk assessment, WHO reaffirms existing or issues new guidance aimed at safeguarding public health.”

Straif of IARC said: “I’m very happy with the way we do things at the moment. We are really at the head of the scientific community.”

Is your weed killer carcinogenic? The latest dispute to blow up around IARC concerns glyphosate, an ingredient in one of the world’s most widely-used weed killers, Roundup, made by Monsanto. In March 2015, an IARC monograph concluded that glyphosate is “probably carcinogenic.” Yet seven months later the European Food Safety Authority (EFSA), an independent agency funded by the EU, published a different assessment, saying glyphosate is “unlikely to pose a carcinogenic hazard to humans.” The EFSA study drew on work by the German Federal Institute for Risk Assessment, which had concluded there was “no validated or significant relationship” between exposure to glyphosate and an increased risk of cancer. Some campaign groups have suggested EFSA was unduly influenced by studies backed by Roundup’s manufacturer, Monsanto. An EFSA spokesman said its assessment considered hundreds of scientific studies, both independent and industry-sponsored. “The status of a study – e.g. independent or industry-sponsored – is irrelevant to the assessment if the study is designed, carried out and reported well,” he said in an emailed response. He said EFSA had published detailed information about every study used in its glyphosate assessment, including regulatory studies submitted by companies. The WHO – IARC's parent organisation – and the United States Environmental Protection Agency (EPA), which first assessed glyphosate in 1986 and has reviewed it several times since then, had also previously concluded that glyphosate “has low toxicity for humans.” The differences might seem modest, but they have potentially huge implications for farmers, the food industry and consumers because IARC’s ruling may affect whether the European Union continues to authorise glyphosate for use in Europe. EU officials are now faced with conflicting scientific advice. Without the herbicide, say some campaigners, food production may suffer. A public war of words between EFSA and IARC has ensued. It began with a letter last November from 96 scientists who wrote to a senior EU official urging him to ignore what they said was a “flawed” EFSA assessment of glyphosate and to prefer IARC’s judgment instead. The letter was led by the American scientist Chris Portier, who has worked part-time since 2013 with the Environmental Defense Fund (EDF), a U.S. non-governmental campaign group. The EDF describes its mission as preserving “the natural systems on which all life depends.” A spokeswoman said it neither supports or opposes pesticides, but is "strongly in favour of scientific research to assess how chemicals impact human and environmental health." On IARC’s website Portier was listed in 2013 as affiliated to the EDF as a “Senior Collaborating Scientist.” “We produce a scientific opinion, but we cannot take into account whether it will be liked or not.” Bernhard Url, executive director of the European Food Safety Authority In 2014, Portier chaired an IARC meeting at which the agency’s priorities for the coming year were outlined. They included an evaluation of glyphosate. The following year, Portier served as an “invited specialist” to the working group which decided that glyphosate was probably carcinogenic. Critics say Portier’s EDF connections represent a conflict of interest and argue IARC should not have allowed him to be involved in the glyphosate evaluation. IARC said his involvement presented no problem, since he took part only as an invited specialist, who does not draft any text or participate in the evaluation. Asked by Reuters whether he had a conflict of interest, Portier said: “I agree that this has the appearance of being a conflict of interest. However, in my opinion, for this to be a real conflict of interest, I would have to be working for the EDF on pesticide related issues and/or specifically on glyphosate related issues. I am not.” He said IARC’s decision to include him as an invited specialist was “proper and reasonable.” EFSA defended its finding on glyphosate and hit back. In a speech to the European parliament in December 2015, EFSA executive director Bernhard Url described the letter from 96 scientists as “Facebook science.” He said it was taking an approach where “you have a scientific assessment, you put it on Facebook and you count how many people like it.” Url said that was not how EFSA operated: “For us, this is no way forward. We produce a scientific opinion, we stand for it, but we cannot take into account whether it will be liked or not.” Url also published an 18-page response to the letter from the 96 scientists, explaining how EFSA took a different approach to IARC. In it he invited IARC to a meeting to discuss their evidence and methodologies. IARC declined, demanding instead that EFSA issue a correction to its letter, which it alleged contained “factual errors.” Kurt Straif, the head of IARC’s monographs assessing whether substances cause cancer, said his agency had turned down the invitation because EFSA had failed “to correct false statements,” and because “we don’t see a basis for a discussion within closed doors.” An EFSA spokesman said it was “regrettable that the meeting is not going to take place,” and said EFSA “restates its commitment to co-operate with IARC and any other scientific organisation involved in the assessment of pesticides.”

Additional reporting by Himanshu Ojha

————— Doctoring Who By Kate Kelland Photo editing: Simon Newman Graphics: Matthew Weber Design: Catherine Tai Edited by Richard Woods