Science in Society Archive

MAFF Reveals New Scientific Findings Confirming Fears Over Health Hazards of GMOs

The following warnings come from a letter from N. Tomlinson of UK MAFF's Joint Food Safety and Standards Group dated 4 December 1998 to the US FDA, commenting on its draft document, "Guidance for Industry: Use of Antibiotic Resistance Marker Genes in Transgenic Plants".

  • Exposure of farm workers and food processors to transgenic DNA in dust and pollen
  • Transfer of antibiotic resistant marker genes to gut microorganisms
  • Transfer of antibiotic marker genes to environmental organisms
  • Transfer of transgenic DNA into mammalian cells
  • Ampicillin resistance marker gene may compromise treatment for meningitis

The letter from MAFF cites new findings from the University of Leeds showing "the relative difficulty with which plant DNA is degraded during processing"(p.4). It mentions other new research showing that bacteria in the mouth can take up foreign DNA and express the gene(s); and transformable bacteria are also present in the respiratory tract.

MAFF warns that "there is a case to be concerned about the problem of gene transfer to environmental organisms" and that bacteria that have taken up the antibiotic resistance genes "could also act as a gene pool that may interact with human pathogens." (p.4).

"The widespread use of transgenics carrying antibiotic resistance marker genes will involve a massive amplification of these genes in the biosphere. Whether or not these genes are expressed, amplification on the scale that will occur when transgenic crops are planted in large fields means that arguments about the rarity of possible transfer events will become less significant." (p.5).

MAFF cites recent publications showing that transgenic DNA may gain access into mammalian cells by being carried in pathogenic bacteria that invade cells. The ampicillin-resistance marker gene encodes a beta-lactamase which inactivates penicillin and other penicillin-like antibiotics. This gene is highly mutable, and hence capable of extending its spectrum of resistence to many other similar antibiotics. "Human respiratory flora contains notable potential pathogens including Neisseria meningitidis and Streptococcus pneumoniae. These bacteria do not currently exhibit high-level, beta-lactamase mediated resistance to penicillins." (p.5)

Dr. Mae-Wan Ho , a scientists who has been warning of these possibilities of horizontal gene transfer to unrelated species for several years, says,"It is irresponsible for the Government to continue with the massive farm-scale field trials in view of the evidence its own scientists are taking into account." She points out that transgenic pollen can travel for miles. Not only farm workers and food processors, but the general public will also be exposed to transgenic DNA, while bees will certainly take it up and contaminate the honey.

There is no provision to monitor for horizontal gene transfer or impacts on health in the current farm-scale trials.

The current farm-scale field trials involve herbicide-tolerant transgenic maize and canola. The transgenic maize carries a 'disrupted' ampicilllin-resistance gene, which is not expressed. However, given the mutability of that gene, it may become re-activated in bacteria.

Article first published 1999

Got something to say about this page? Comment

Comment on this article

Comments may be published. All comments are moderated. Name and email details are required.

Email address:
Your comments:
Anti spam question:
How many legs on a spider?