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Real Science

Genetically modified foods

Michael Rosenthal

(9/2016) The United States House of Representatives approved a compromise bill in July, already approved by The Senate, that would create a national standard for labeling genetically modified foods (GMOs); it was signed by President Obama on July 29. The legislation requires companies to label GMO with either text on the packaging or a barcode that can be read by a cell phone. Several states had enacted legislation requiring GMO foods be labeled as such, and other states were considering doing so. Some praised the labeling requirement, while others wanted legislation that states the GMO status explicitly in all cases.

Genetically Modified Foods are foods produced from organisms that have had changes introduced into their DNA via genetic engineering to modify the foods. The commercial sale of GMOs began in 1994 with a delayed-ripening tomato to give it a longer shelf life. Food modifications have been introduced to increase pathogen and herbicide resistance. As well as the advantages, there are ongoing public concerns relating to food safety, environmental impact, and intellectual property rights with GMOs. By 1910 some 29 countries had planted commercialized biotech crops and 31 more counties approved the import of such crops. In 1911 the United States led the world production of such foods with approval of 25 crops. By 2015 92% of corn, 94% of soybeans, and 94% of cotton produced in the United States were genetically modified strains. The creation of golden rice in 2000 was designed to increase its nutrient value. In 2015 a strain of salmon became the first "animal" raised with genetic modification, enabling it to be grown year-round instead of just during spring and summer. The most widely planted GMOs are designed to tolerate herbicides.

There is a general scientific consensus that currently available food derived from GM crops poses no greater risks to human health than conventional food, but that each GM food needs to be tested on a case-by-case basis. Not surprisingly, many members of the public do not have that level of confidence. Confidence in and regulation of GMOs varies widely from country-to-country. The U.S. Food and Drug Administration determined that GMOs are "Generally Recognized as Safe." Regulation in the United States is shared by the FDA, the Department of Agriculture (USDA), and the Environmental Protection Agency (EPA).

Now letís take a look at some of the subjects from previous REAL SCIENCE articles that have been updated. Just last month the topic was chlorofluorocarbons (CFCs). Now, the use of hydrofluorocarbons (HFCs) has become an issue. HFCs are similar in chemical structure to CFCs, but they contain no chlorine. They are used in air conditioners, refrigerators, and aerosols; they contribute strongly to global warming. They have come into extensive use since the phasing out of CFCs through the 1987 Montreal Protocol, to protect the ozone layer. HFC use has increased 258 percent since 1990. A major international effort has resulted in dozens of countries working to agree on major reduction of HFC use to protect us from global warming and to reduce danger from global temperature rise.

Fortunately, there are alternatives to HFCs. Propane can be used as a home coolant and ammonia as an industrial coolant with greatly reduced climate impacts. Cost is an issue in the proposed transition, especially for developing counties. The richer countries (United States, Canada, Japan, and the European Union) will need to continue to assist the poorer countries through the Montreal Protocol.

There have been many new developments evolving from the Flint, Michigan drinking water lead contamination. State prosecutors filed criminal charges against six more government workers, accusing them of criminal negligence in concealing urgent information about the lead that was leaching into the cityís drinking water and doing nothing to stop it from happening, totaling nine as the number of public employees so charged. The Michigan attorney general also hinted that higher level officials may yet be charged. Tests show that unfiltered tap water is still not safe to drink, and officials are trying to monitor thousands of Flint children exposed to the lead contaminated water.

The State of Michigan is picking up the tab for distributing bottled water and filters since the federal emergency aid came to an end in August, and the feds had warned the state that this was the last extension, and that Michigan will be required to take up the permanent responsibility for suppling safe drinking water. Medical services by the federal government will continue, and the federal role in monitoring the water quality will continue indefinitely.

To make things even worse in Flint, a new study indicates that two outbreaks of Legionnairesí Disease are linked to the water crisis. Legionnairesí Disease is a deadly pneumonia caused by inhaling a bacterium that lurks in the organic matter lining drinking water pipes. Corrosion in the pipes stimulates the bacteria effectiveness; hence, the outbreak in Flintís corroded pipes. Homes supplied with Flint River water recorded concentrations of the Legionella bacteria seven times higher than the baseline. No bacteria were found in the buildings using Detroit water.

The Flint crisis has stimulated more water supply studies across the nation. It has been found from a study of 36,000 samples in a Harvard University study that more than 6 million Americans have drinking water that has an unsafe level of polyfluoroalkyl and perfluoroalkyl (PFAS) substances, which are chemicals long used in industrial and commercial products. Long term exposures have been linked to increased risks of kidney cancer, thyroid problems, high cholesterol, and hormone disruption. These chemicals come from and are found in or near industrial sites, military bases, and civilian airports. PFAS substances are not regulated by the federal government, but appear on the EPA unregulated contaminant list. No new contaminants have been added to the regulated contaminant list in two decades! There is a growing clamor that PFAS chemicals be added to the regulated contaminant list. Health advisories have been issued by the EPA urging utilities around the country to follow more stringent guidelines than previously recommend by the EPA.

Finally, a new study indicates that partial replacement of lead pipes with copper pipes in drinking water systems may make things worse. Partial replacement leads to electrochemical reactions that release the lead ions into the water. Full line replacement with copper was much more effective says the study, but some lead may remain due to lead deposits in old galvanized iron plumbing and faucet aerators.

Michael is former chemistry professor at Mount. St. Marys

Read other articles by Michael Rosenthal