A fact sheet issued by the campaign says that 31 deaths and more than 1500 serious illnesses "have been attributed to a genetically engineered amino acid called L-tryptophan." The Food and Drug Administration (FDA) failed to regulate the sale of the product because it was not labeled as "genetically engineered," the sheet charges.

Environmentalists fear genetic engineering will pollute native plant and animal species. Vegetarians and religious observers fear they may eat vegetables tainted with genes from animals.

But scientists, politicians and the FDA have a different perspective on the issue.

According to the San Francisco Chronicle, "Scientists overwhelmingly agree that there is nothing inherently risky about bio-engineered foods."

Scientists said requiring labels for genetically engineered foods would not only be irrelevant to nutrition and health but it also would stymie advancement in the field of genetics, according to the Chronicle.

If Cambridge passes Velluci's proposal, the city will not be alone. In August, Chicago's city council unanimously passed an ordinance 15-0 requiring the labeling of genetically altered food.

New York City drafted a similar bill in March.