When chemicals mix, trace amounts can kill

The Oconee Enterprise, February 16, 2017:
Dr. David Lewis

Although iodine is essential to good health, ingesting excessive amounts can be lethal. As the saying goes, dose makes the poison. Trace amounts in a normal diet can keep you healthy, but swallowing spoonfuls of pure iodine could send you to an early grave. And, while the proper antidote can completely neutralize it, other substances could make iodine even more deadly, even in trace amounts.

Synergism, in which certain chemicals amplify the effects of others, is something I first researched in 1969. Wineries in our area were having trouble fermenting peach concentrates made in Georgia. Concentrates imported from the State of Washington, by contrast, fermented normally. When my coworkers and I at the EPA lab in Athens, Georgia analyzed samples of the concentrates, we found traces of a fungicide called DCNA only in concentrates from Georgia. The concentrations, however, were extremely low—in the parts-per-billion range.

We found that trace amounts of DCNA alone did not harm yeasts used to make wines. But when we mixed them with low concentrations of ethanol, the mixture killed the yeasts. This explained why the peach concentrates stopped fermenting as soon as the process produced a little ethanol. This same effect occurs when people take acetaminophen while drinking alcohol. Combining the analgesic with ethanol in alcoholic beverages kills liver cells. Scientists at UC-Davis later applied our discovery to farming by demonstrating that mixing ethanol with DCNA is more effective than DCNA alone in controlling peach rot fungus. What hurt wineries ended up helping farmers, at least temporarily.

Dr. Lewis’ article posted in The Oconee Enterprise – Click to enlarge David Lewis

When I stopped by a local peach stand several years ago, I noticed white blotches on the peach skins and asked what it was. The owner explained: “Chemicals used for preventing rot aren’t as effective as they used to be. Growers can’t dilute them out as much and, when they dry, they turn white.” I suggested he tell his customers to peel the peaches and consider giving up drinking.

Predicting adverse health effects of a single, isolated chemical is pretty simple. But forecasting the effects it will have when mixed with numerous other chemicals is currently impossible. And, although scientists are aware that synergistic effects can cause even trace amounts of chemicals to trigger illness, even death, many tend to ignore it when defending government policies.

Last week, for example, Antonietta Gatti and her team of Italian and American scientists reported that human and animal vaccines contain a baffling array of non-biodegradable contaminants. Many of them are known to cause neurological damage and potentially trigger autoimmune diseases. Yet, the Vaccine Knowledge Project at the University of Oxford responded simply: “All vaccine ingredients are present in very small quantities, and there is no evidence that any of them cause any harm in these amounts.”

The opinions expressed are those of David Lewis, Research Director for the Focus for Health Foundation in Watchung, NJ (focusautism.wpengine.com/davidlewis), author of Science for Sale (Skyhorse Publishing, NY) and CEO of Saxon Road Church Inc. in Watkinsville, Georgia.

Join the Conversation

your thoughts matter


David Lewis, Ph.D.

Former U.S. EPA Research Microbiologist

David Lewis is an internationally recognized research microbiologist whose work on public health and environmental issues, as a senior-level Research Microbiologist in EPA’s Office of Research & Development and member of the Graduate Faculty of the University of Georgia, has been reported in numerous news articles and documentaries from TIME magazine and Reader’s Digest to National Geographic.

read more

Join the Conversation

Your email address will not be published. Required fields are marked *