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Environmental Issues

The environmental concerns over PMF crops are similar to those surrounding genetically engineered crops that are currently being planted. For instance, will genes from a modified plant flow to a related plant? Will birds, animals or humans be harmed if they consume the plant?

However, there are several important differences. For one, many GM crops are modified to be resistant to specific herbicides and pesticides. Studies show that in some species of crops (such as spring canola and beet), there has been an impact of weeds and the insects that rely on these weeds for food and shelter. However, PMF crops are not currently being modified to be insecticide or herbicide resistant.

Another difference is that traits being inserted into PMF crops could be harmful to humans or animals if ingested. This potential for harm leads to a different set of environmental issues, with containment and confinement of crops becoming more important.

Some scientists caution that the movement of transgenes from modified plants to other sources is a virtual certainty. Therefore, any evaluation of risk should be based on the idea that gene escape, through natural means or human error, is very likely to occur.

Following are some specific concerns and ways risks may be mitigated.

Bird, animal and soil contamination
Environmentalists worry that there are several ways PMF crops could impact the environment:

  • Wild animals, birds and insects could be harmed by consuming PMF plants, depending on the compound being produced by the plant.
  • Carnivores, such as coyotes and foxes, will ingest PMF compounds when they eat birds and rodents which have consumed PMF crops.
  • Insects, invertebrates such as worms, and bacteria which live in soil could be impacted by ingesting compounds produced by PMF crops.
  • Chemical compounds could be released into soil when the PMF plants decompose. These compounds could also leach into ground or surface water systems.

These negative impacts to the environment could be mitigated by growing crops in greenhouses or other confined spaces.

Plant and crop contamination
There are several ways that PMF plants could escape into the environment and impact plants of the same or similar species:

  • Plants from PMF crops could persist in the environment through volunteer plants which grow in the subsequent season.
  • Genes from the modified plant could flow to the same or a related species through the spread of pollen.
  • Seeds from the modified plants could spread to other locations through a variety of means including birds, poorly cleaned farm equipment, spillage and human error.

There are ways to reduce the risk of gene and seed spread:

  • Reducing the risk of volunteerism and gene flow through containment and confinement practices. For instance, modified plants can be grown in greenhouses, buffer zones can be established around fields, and crops can be sown at different times so that modified and conventional plants do not flower at the same time.
  • Avoiding highly competitive plants for PMF platforms will reduce the risk of volunteerism.
  • Using non-food crops such as tobacco to reduce the risk of food and feed contamination.
  • Using crops with no known wild relatives in Canada, such as corn, soybean and flax, will reduce the risk of gene flow.
  • Modifying PMF plants to contain conditional genes which would allow the plant to grow or propagate only under certain conditions.

For more information on potential environmental impacts, please see:

In 2001, the Royal Society of Canada issued a report titled Recommendations for the Regulation of Food Biotechnology in Canada. To read the report, go to:
http://www.rsc.ca/index.php?page=expert_panels_food&lang_id=1&page_id=119

One of the largest studies on the environmental impacts of GM crops was carried out in the UK. For the results of these studies, see:
http://www.defra.gov.uk/environment/gm/fse/index.htm

In this article, the Environmental impacts of genetically modified crops: Ten years of field research and commercial cultivation, provides an overview of numerous studies that have looked at the impact of GM crops on the environment.
http://www.isb.vt.edu/news/2006/news06.dec.htm#dec0603

In this article, Gene flow from GE to conventional maize in real situations of coexistence, the authors argue that it is possible to reduce gene flow between modified and conventional maize crops through planting distance and by planting crops so that they flower at different times.
http://www.isb.vt.edu/news/2006/news06.dec.htm#dec0603