Science goes down the river

The US Environmental Protection Agency (EPA) and General Electric (GE) – described by Bloomberg.com as ‘the world’s second-biggest company by market value’ – recently reached agreement on plans to begin removing polychlorinated biphenyls (PCBs) from the Hudson River. Specifically, GE agreed to meet EPA demands to remove 10 per cent of the PCBs along a 40-mile stretch of the river in upstate New York. Negotiations are still underway regarding the clean-up of the other 90 per cent, and EPA will sue GE if it does not agree to a second phase of the removal process.

Environmentalists think this agreement is a travesty. As a Sierra Club officer put it: ‘It’s like an oncologist going in and only taking out 10 per cent of a tumor.’ Indeed, the ‘agreement’ is a travesty, but not for the reason cited by the Sierra Club.

EPA maintains that PCBs, particularly in Hudson River fish, pose a cancer hazard – but there is no evidence that such a risk exists. The stark truth is that there is no benefit to public health in mandating that traces of PCBs be removed from the river. There are, however, big costs – all of which will be borne by consumers.

Until 1977, PCBs were used in the manufacture of transformers, adhesives and capacitators, among other things. GE legally disposed of PCBs by releasing them into the river north of Albany. The PCBs are now embedded in the mud beneath the river and are not generally dispersed in the water.

The EPA’s assertion that PCBs in fish pose a human cancer risk is based solely on observations that high-dose, prolonged PCB exposure causes tumors in laboratory animals. A representative from the National Cancer Institute (NCI), which is staffed with the top cancer epidemiologists in the world, told me that they know of ‘no evidence’ that eating fish from the Hudson poses a human cancer risk.

So, a private company is being ordered by the government, under threat of large fines, to remove trace levels of PCBs, which they had deposited legally, when there is no evidence that this massive effort will in any way protect public health. EPA will require GE to spend at least $700million in this purposeless effort. Those costs are likely to be borne by GE stockholders, employees and consumers. Enormous costs, zero benefits.

How did this EPA order come about? Three reasons come to mind: First, for many years General Electric, armed with stacks of scientific literature showing that trace levels of PCBS in the Hudson posed no human health threat, fought the EPA mandate – but the company eventually gave up, perhaps under the pressure of public opinion, and elected to comply. Second, cancer experts at the NCI and at medical centres around the USA did little or nothing to protest this misdirection of cancer prevention efforts toward a phantom threat. Third, America’s fear of cancer is so intense that there is a prevailing view that we should do anything and everything to prevent the disease, even if there is no evidence that our efforts will be effective.

The strongly held (but inaccurate) belief that what causes cancer in very high doses in rodents must also be assumed to cause cancer in much smaller doses in humans prevails today as it has for almost 50 years. Indeed, we cling to animal cancer tests almost as we do to superstitions. As one cancer epidemiologist told me recently: ‘Of course rodent tests do not accurately predict human cancer risk, but most Americans perceive we have nothing else to protect ourselves from cancer. So, even if these tests are not useful in predicting our risks, we still embrace and respond to them – in the same way we know that walking under a ladder won’t bring us bad luck, but we take a few steps out of our way, just in case.’

The tragedy here is that that we do have alternatives to using animal data to prevent cancer: the science of epidemiology has clearly outlined factors that pose real cancer threats. And the more of our time and resources we squander on non-risks – like traces of PCBs in the Hudson – the less we have for tackling cancer.

Dr Elizabeth M Whelan is president of the American Council on Science and Health.