(NaturalNews) A new generation of genetically modified (GM) crops, engineered to produce pharmaceutical or industrial products and ingredients, poses an even more serious threat to health and the environment than older GM crops, the Union of Concerned Scientists has warned.Presenting at the conference of the American Association for the Advancement of Science in Boston, the group warned that the primary risk comes from the possibility of genetic contamination, in which the modified genes from a GM plant spread via normal cross-pollination to the same or closely related species of domestic or wild plants. This would lead to pharmaceutical and industrial chemicals potentially entering the food supply of humans and wildlife.Most commercial genetic engineering to date has focused on making food crops more resistant to herbicides or pests. Even this degree of modification has raised concerns about cross-pollination and contamination of non-modified varieties, and the health impacts this could have on humans and wildlife.According to plant geneticist Paul Gepts of the University of California-Davis, it is essentially impossible to keep modified genes from spreading."Gene flow is really a regular occurrence among plants," Gepts said. "So if you put a gene out there, it's going to escape. It's going to go to other varieties of the same crop or to its wild relatives. It's clear that zero contamination is impossible at present."In fact, a number of cases of contamination of non-GM crops with modified genes have been well-documented, leading in many cases to major economic losses as crops intended for food involuntarily found themselves in the same category as crops not approved for human consumption. And while no cases of human health problems from this contamination have ever been proven, the risk is expected to increase as large-scale cultivation of second-generation GM crops begins.Largely a U.S. phenomenon, wide-scale planting of GM crops has mostly been rejected in Europe. Ironically, however, studies show that the European public feels less strongly negative about crops engineered for medical benefits - the very plants that are most dangerous."With the products we are talking about, there's the potential for [consequences] to be much more serious than what we have seen so far," said Robert Wisner of Iowa State University.So-called "pharma" crops, or crops modified to produce pharmaceutical chemicals and ingredients, are becoming an increasingly popular area of research, and the biotechnology industry has been promoting their supposed benefits over conventional drug production methods. According to advocates of the technology, drug-producing plants could be grown cheaply in poorer countries, and edible drugs would eliminate the expensive need for refrigeration and a supply of sterile needles.The U.S. Department of Agriculture has already allowed outdoor test trials of these crops in 35 states. This means that genetic contamination may already have occurred, and would certainly worsen if large-scale commercial farming begins.Among the chemicals produced by pharma crops are disease treatments, anticoagulants, artificial blood, hormones, enzymes and antibodies intended to target tooth decay or cancer. Another popular area of research is "edible vaccines," or plants engineered to deliver a vaccine when eaten.A related area of research is into plants that produce industrial or research chemicals, such as substances used to manufacture plastics, detergents, paper and personal care products. Other chemicals engineered into plants include laboratory diagnostic chemicals and enzymes used in biofuel manufacture.The Union of Concerned scientists has warned that many of the chemicals produced in these plants are toxic or otherwise bioactive."What would be the impact societally, economically, if for example, cornflakes were contaminated by some sort of drug or chemical?" asked Karen Perry Stillerman, senior food and environment program analyst with the Union of Concerned Scientists. "I think it's really hard to say, because there is a variety of different drugs and chemicals that might be manufactured in plants this way. Our perception is that some of them might be toxic, but all of them would certainly cause tremendous economic upheaval."It is for this reason that both the Grocery Manufacturers Association and the Food Products Association have expressed concerns about the possibility of pharma and industrial genetic contamination of the food supply.The USDA is currently revising its GM crop guidelines, with new rules expected by the end of the year. In response to this ongoing process, the Union of Concerned Scientists has urged the USDA to ban all outdoor cultivation of GM pharma and industrial crops, if the species modified is also one used for food production.This ban would not go as far as the measures some people say are needed. According to Gepts, outdoor cultivation poses the greatest contamination risk, because pollen and seeds can be carried to other locations by wind, birds and other animals, and even from falling on farm machinery. He says that growing crops in greenhouses or underground, or using non-food crops such as tobacco, would eliminate much of this contamination.It would still be possible, however, for pollen or seeds to be carried out of a greenhouse on someone's clothing. And the Union of Concerned Scientists acknowledges that while cultivating non-food pharma crops outdoors would reduce the risk of food contamination, it might still place wildlife at risk."If these crops are grown out of doors, grazing wildlife, pollinators, herbivorous insects, and soil microbes will be exposed to pharma/industrial compounds that may have adverse effects," the organization writes on its Web site. "The crops could also outcross with wild and weedy relatives, perpetuating the pharma/industrial transgenes in nearby ecosystems."