Intervention: Confronting the Real Risks of Genetic Engineering and Life on a Biotech Planet

  • Denise Caruso
Hybrid Vigor Institute: 2006. 272 pp. $17.95 0615135536 | ISBN: 0-615-13553-6
Warning sign: the number of genetically modified organisms released into the environment could increase rapidly. Credit: ALAMY

In Intervention, Denise Caruso challenges scientists to do a better job of evaluating the safety of genetically modified organisms (GMOs) and communicating unbiased findings to the public. Caruso, who founded the non-profit Hybrid Vigor Institute, examines with a healthy dose of scepticism the recent history of the regulatory policies affecting biotechnology in the United States. How, for example, can the Department of Agriculture simultaneously promote biotech research and agribusiness while also protecting the public and the environment from possible harm? In a broader context, how can the science of genetic engineering move forward and benefit society with sufficient oversight to prevent disasters? Caruso's answer is that we need to develop more transparent and democratic methods for incorporating scientific evidence in formal risk analysis and public policy.

One of the major strengths of the book is its accessibility to a general audience. Caruso, a former journalist, describes dry topics such as RNA interference and the US Coordinated Framework for Regulation of Biotechnology in terms that entertain the reader with wry humour and an appreciation for the absurd. In her view, molecular biology has “the whiff of the Holy Grail”, and if you question the experts who promote GMOs, “you'll generally get a scorching look of suspicion”. Sadly, many of the experts and industry representatives whom she targets are unlikely to read the book, although they should. I disagree with many of Caruso's conclusions, but I appreciate her thesis that the immense power of molecular biologists to redesign living organisms requires more scrutiny with each passing year. The release of certain transgenic crops, trees, fish, insects, viruses and bacteria into the environment could do much more harm than good. Malicious uses, such as designing transgenic organisms for bioterrorism, provide a worst-case scenario.

Despite her frustrations with scientific experts, Caruso is respectful of reports from the US National Academy of Sciences that deal with GMOs and risk assessment, especially the National Research Council's Understanding Risk. She notes that these reports offer constructive recommendations that have yet to be implemented, either in the United States or elsewhere. At the same time, she boldly challenges a fundamental tenet of the reports and all US regulatory policy, namely the notion that risk assessment should focus on the actual products or traits of GMOs case by case, rather than the engineering process used to obtain them. Mainstream scientists and regulatory agencies typically assume that the use of recombinant DNA is irrelevant to risk assessment because genetically modified products are carefully examined for unintended effects before deregulation. In other words, genetically modified products such as insect-resistant maize are “generally regarded as safe” unless proven otherwise. Likewise, the US Food and Drug Administration accepts the idea that expert opinion and a battery of lab tests are sufficient to prove that genetically modified food is “substantially equivalent” to its non-transgenic counterparts (which can also have genes that cause unwanted health effects).

Caruso develops a series of worst-case scenarios, some of which are rather far-fetched, to illustrate why the doctrine of “product, not process” may be wrong. She contends that the overconfident zeal of molecular biologists and strong economic pressures to rush genetically modified products into global markets have squelched legitimate scientific enquiry into the possible risks, including dangerous outcomes that could be inherent to any GMO. What if gene splicing causes novel interactions between native and introduced DNA in a given transgenic crop, resulting in subtle yet harmful effects on human health? Have government agencies and the biotech industry fully examined this possibility? No, she asserts, because “our appointed arbiters of risk” are not willing to discuss the limitations of their knowledge. Moreover, she makes a convincing argument for why it is exceedingly difficult to predict the long-term and large-scale effects on human health and the environment of intentionally produced genetically modified traits. Recognizing that all new technologies bring a mixture of risks and benefits, she then discusses the advantages of allowing ethicists, social scientists, environmental scientists and others to participate in discussions about risk analysis and public policy. Her point that risk assessments involve value judgements beyond the realm of pure science is well taken.

Countering the industry's spin on the bene-fits of biotech in both developed and developing countries, Caruso focuses on the dark side of genetically modified crops. Her book echoes many of the themes from Deborah Koons Garcia's The Future of Food, a documentary film that attacks all unsustainable and chemically intensive modern agriculture (http://www.thefutureoffood.com). Unfortunately, Caruso's reliance on websites, unofficial reports and news media for citations means that many of her findings should be checked for accuracy and context. For example, she describes reports that the cultivation of genetically modified crops has already harmed soil organisms, created superweeds, contributed to severe economic hardships, and made people and livestock sick by increasing their exposure to herbicides. Similar criticisms could be made of some non-transgenic crops. Indeed, certain transgenic crops offer greater health benefits than their conventionally produced counterparts. Regarding Terminator technology for producing non-viable seeds, she states that “critics fear that these plants would irreversibly spread their sterility to non-transgenic crops and across species to other plants by contamination”. However, these yet-to-be-released crops would not bear viable offspring and so could not spread their genes through reproduction.

Caruso's fears that transgenes could spread willy-nilly to the genomes of unrelated plants and animals — and even to humans — are overly paranoid because distantly related multicellular organisms are not capable of interbreeding. In a flight of hyperbole, she states: “Billions of transgenics have already been released into the marketplace and thus into our food, our water and the air that we breathe, breeding and exchanging their genetic material with each other and with us.” But perhaps today's hyperbole could be a prelude to the future, if GMOs are released indiscriminately around the world.

Reading Intervention made me more aware of the value of confronting uncertainty in the complicated process of assessing risks and bene-fits. This ambitious and engaging book does a good job of defending the layperson's frustrations and concerns about genetically modified organisms.