A 2004 paper in the journal Environmental Health Perspectives reported that this included 28 definite, 27 probable and 113 possible human occupational carcinogens. By contrast, the influential 1981 Doll/Peto paper, which for over two decades was the most commonly cited estimate of the contribution of occupation to cancer incidence, only considered cancer risks posed by a list of 16 substances or industries. The report notes the (now widely cited) “tables should be useful for regulatory or preventive purposes and for scientific purposes in research priority setting and in understanding carcinogenesis.

Siemiatycki J, Richardson L, Straif K and others. Listing occupational carcinogens. Environmental Health Perspectives, volume 112, number 15, pages 1447-1459, 2004.

Children fathered by men who have been exposed to polycyclic aromatic hydrocarbons (PAH) at work have a greatly increased chance of developing brain tumours, researchers have found. The researchers used occupational data to estimate parental PAH exposure during the five years before the children’s birth. The data came from population-based studies carried out in seven countries, and compared 1,218 cases of childhood brain tumour and 2,223 matched ‘control’ children without cancer. Paternal occupational PAH exposure increased the odds a child developing any type of brain tumour by 30 per cent, the researchers report in the American Journal of Epidemiology.

S Cordier, C Monfort, G Filippini and others. Parental Exposure to Polycyclic Aromatic Hydrocarbons and the Risk of Childhood Brain Tumors: The SEARCH International Childhood Brain Tumor Study, American Journal of Epidemiology, volume 159, number 12, pages 1109-1116, 2004.

First IBM made sure an analysis of its own workforce cancer records was ruled inadmissible in court, after researchers claimed they showed a clear cancer excess (Risks 125). Now a major academic publisher is refusing to publish the analysis and is facing an embarrassing contributors boycott as a result. IBM says the paper is flawed but denies putting pressure on the publishing group Elsevier to stop the paper’s publication. Dr Joe LaDou of the University of California at San Francisco, the guest editor of a special issue of Clinics in Occupational and Environmental Medicine on microelectronic industry health and safety, has joined other contributors in the protest which has seen them all withdraw their papers until the contentious article is reinstated.

The Observer, 20 June 2004. Risks 162.

Secondhand smoke causes cancer – and the evidence is so compelling the International Agency for Research on Cancer (IARC) says it ‘puts a final stop to all controversies fuelled at various degrees by the tobacco industry.’ IARC’s Monograph on tobacco smoke and involuntary smoking was prepared by a scientific working group of 29 experts from 12 countries, which reviewed all published evidence related to tobacco smoking and cancer, and which concluded both smoking and exposure to secondhand smoke should be classified as ‘Group 1’ carcinogens, definitely causing cancer in humans.

IARC Monographs on the evaluation of carcinogenic risks to humans, volume 83, Tobacco smoke and involuntary smoking, 2004. Risks 161.

Formaldehyde, a chemical to which an estimated 1 million European Union workers are exposed at work, definitely causes cancer in humans, officials say. The International Agency for Research on Cancer (IARC) has upped its assessment of the chemical to ‘Group 1’. Previous evaluations, based on the smaller number of studies available at that time, had concluded that formaldehyde was probably carcinogenic to humans, but new information from studies of persons exposed to formaldehyde has increased the overall weight of the evidence. Based on this new information, an expert working group has determined that there is now sufficient evidence that formaldehyde causes nasopharyngeal cancer in humans, a rare cancer in developed countries. The move follows protracted arguments between the chemical industry – which played down the link – and health advocates, who argued the commonly used industrial chemical should be subject to stringent controls.

IARC working group, 2-9 June 2004. IARC news release, 15 June 2004.

A double ‘relative risk’ (RRx2) test used by courts and government agencies to determine if a cancer is occupational ‘is useless’, top US scientists have said. The RRx2 system  requiring a condition to be twice as common in the affected group than in the general population is used by lawyers and state compensation agencies to set a cut off below which compensation will not be paid. But Richard Clapp and David Ozonoff, writing in 2004 in the American Journal of Law and Medicine, note: “To an epidemiologist using generally accepted methods of epidemiological analysis, however, a RR of 2.0 or more is not necessary in order to show that a causal link is ‘more likely than not’ present in the study population. In our experience as epidemiologists who participate in the legal process as experts, some attorneys maintain and some courts believe that a RR of 2.0 is needed before one can conclude from an epidemiological study that the outcome was ‘more likely than not’ due to the exposure. The arithmetic basis of this proposition would seem quite transparent, but like many things in the subtle and complex science, there are sound and accepted reasons why this argument is not valid. The reasons are both technical and ethical.” They note that the relative risks across a “usually hetrogenous” study group could mask much higher and genuine occupational risks in someone without few or none of other risk factors present in the group, leading to “a serious under-estimate of the effects of his or her exposure.” They add: “Without a specification of the underlying causation model, which in almost all cases is insufficiently known to allow an accurate calculation, or even any calculation, of the fraction of cases due to exposure, the doubling of the RR… is useless as a criterion for evidentiary admissibility.”

Clapp RW, Ozonoff D (2004). Environment and health: vital intersection or contested territory?  American Journal of Law and Medicine, volume 30(2-3), pages 189-215.

A solvent found in varnishes, paints, dyes and fuel additives and which is used in the semiconductor industry may raise the risk of cancer among women taking hormone treatments, say researchers. They found the chemical, ethylene glycol methyl ether (EGME), boosted the activity of hormones used in HRT and the contraceptive pill. This may increase the risk of breast or ovarian cancer for some women.

Susan C Nagel, Phillippa J Miranda, Edward K Lobenhofer, Cynthia A Afshari  and Donald Michelle S Jansen, P McDonnell. Short-chain fatty acids enhance nuclear receptor activity through mitogen-activated protein kinase activation and histone deacetylase inhibition, Proceedings of the National Academy of Sciences, volume 101, number 18, pages 7199-7204, 2004.

The European Commission is consulting workers and employers on reducing exposure to work substances that cause cancer and reduce fertility. It says it wants views on how to tackle gaps in existing legislation aimed at minimising exposure to substances that cause cancer and have other harmful effects. The consultation document asks four main questions: Should the current cancer directive be extended to cover reproductive hazards; should the number of substances covered by the Directive be increased; are the exposure limits in the existing Directive appropriate; and should measures be taken to make the procedures within the Directive simpler and more adaptable to scientific progress?

Risks 150.

A microelectronics trade group has said it is to sponsor a study on cancer risks in semiconductor manufacturing facilities. George Scalise, president of the Semiconductor Industry Association (SIA), said: ‘This industry has always looked for ways to improve the manufacturing processes that lower environmental impacts and improve the health and safety conditions for our employees.’ Critics have charged for years, however, that the chipmaking industry has stalled efforts to create good data on cancer and other risks in the plants. ‘It’s kind of a day late and a dollar short,’ said Ted Smith of the Silicon Valley Toxics Coalition. Smith said the study could be a good sign but that its credibility would depend on who actually performed the research and on whether there would be a third-party oversight panel to certify the findings.

CNET, 18 March 2004. Risks 149.

This Canadian criticism of the role of capitalism in creating environments conducive to cancer and then burying the costs along with the victims, concludes a different  approach is needed if cancer is to be prevented. “We can win the war against cancer. The best available research is necessary, but not sufficient, for our victory. Cancer research is designed and undertaken, and the results published and acted upon, in a deeply political context. The social, political and economic changes necessary to win the war against cancer will require more than research alone. It will also require collective action, the uniting of movements that have operated for the most part independently. The combined wisdom and skills of activists in the environmental, occupational health, women’s health and nutrition movements will be needed to successfully challenge the status quo and to insist that science, the state and corporations operate in the public interest. That is what is needed to stem the cancer tide that is sweeping across Canada and beyond.”

Lissa Donner and Robert Chernomas. The Cancer Epidemic as a Social Event, Canadian Centre for Policy Alternatives, March 2004. ISBN: 0-88627-357-9.