Environmental activism campaigns on climate change emphasise the scientific consensus that human activities contribute significantly to global warming. But almost all environmental activists are also strongly opposed to genetically modified food, at least partly on the basis that it poses long-term dangers to human health and the environment. This is despite the scientific consensus that currently approved GM food is safe for human consumption and poses no danger to the environment.
Many environmentalists also ignore strong scientific evidence in other areas, such as the health effects of radioactive fallout from the Chernobyl accident, presumably because the science doesn't align with green ideology.
Environmental activist groups strongly influence public opinion. A Pew Research Centre study in the US in 2014 in co-operation with the American Association for the Advancement of Science found that 88 per cent of scientists think humans are mostly responsible for climate change, and 89 per cent of scientists think it is safe to eat GM food. But 50 per cent of American adults disagree with scientists on climate change, and only 37 per cent think it is safe to eat GM food.
Activists opposed to GM food often claim there has been little scientific evaluation of the safety of GM food crops and that there is no scientific consensus on this issue. However, the truth is that GM foods are the most intensively tested foods ever introduced to the human food supply, and every significant international science body has reviewed the many independent studies on GM food and concluded that GM crops are as safe as conventional foods. Most recently a team of Italian scientists analysed 1,783 studies of the safety of genetically modifiedGM food (Alessandro Nicolia and others, Critical Reviews in Biotechnology, 2014). The team found no credible evidence showing that GM food poses any harm to humans or animals and little or no evidence that GM food crops have a negative impact on the environment. Neither is there any evidence that approved GM food introduces any unique allergens or toxins into our food supplies.
Environmental activists opposed to GM food also highlight gene flow from GM food crops into conventional crops in neighbouring fields. However, gene flow is not unique to GM technology: genes commonly flow from wild plants into non-GM crops. Scientists are studying ways to prevent or reduce gene flow from GM crops to conventional crops, but it is difficult to do the studies because of protests by activists against field trials.
Chernobyl accident
Scientists and environmental activists also disagree about the health effects of the Chernobyl nuclear accident in 1986. This accident caused the deaths within weeks of 30 workers and caused significant radiation injuries to more than 100 others. Large areas of Belarus, Russia and Ukraine were contaminated with radioactivity, and 355,000 people were evacuated from around the reactor.
Comprehensive scientific reviews of health consequences, under UN auspices, were conducted 20 years after the accident. More than 6,000 cases of thyroid cancer were recorded by 2005 in children and adolescents exposed to radiation at the time of the accident, but most cases have responded well to treatment. There is no evidence of increases in other cancers, mortality rates or rates of nonmalignant diseases that could be related to radiation exposure. These mainstream studies estimate that, theoretically, the Chernobyl radiation might cause, at most, an extra 9,000 cancer deaths in the three countries.
Many environmental activists disagree with these scientific conclusions. In 2006 Greenpeace published a report, The Chernobyl Catastrophe: Consequences on Human Health, which estimated that the accident caused 200,000 additional deaths in Belarus, Russia and Ukraine between 1990 and 2004. This report cited Russian investigations that, to my knowledge, were never published in mainstream, peer-reviewed scientific journals.
Public reporting by mainstream scientists is patchy and timid compared with the loud and confident campaigns run by environmental pressure groups, and media coverage of environmental debates tends to give equal weight to all voices. Scientists and the media need to perform much better, because the public deserves to be alerted each time environmentalists promote causes in the face of strong scientific evidence to the contrary.
William Reville is an emeritus professor of biochemistry at UCC http:// understandingscience.ucc.ie