PLYMOUTH, England — Toxic metals might be as near as that drinking glass you sipped from earlier today, according to a recent study.
Researchers at the University of Plymouth have discovered an ever-widening source of toxic substances all around us. While past research looked at the dangers of playground paints, a new study focuses on what researchers say is an even greater environmental risk: the threat posed by those colorful, enameled drinking glasses.
“The presence of hazardous elements in both the paint and glaze of decorated glassware has obvious implications for both human health and the environment,” says Dr. Andrew Turner, associate professor in environmental sciences with the university and lead study author, in a university news release. “So it was a real surprise to find such high levels of lead and cadmium, both on the outside of the glassware and around the rim. There are genuine health risks posed through ingesting such levels of the substances over a prolonged period, so this is clearly an issue that the international glassware industry needs to take action on as a matter of urgency.”
Turner and his research team performed 197 tests on 72 new and second-hand drinking glasses, including tumblers, jars, and beer and wine glasses. Analyses were made with portable x-ray fluorescence (XRF) spectrometry. Of the products tested, 72 percent tested positive for lead. Lead was present in all colors, even in the decorative gold leaf of some glassware. Testing also showed 70 percent of the products contained cadmium, with the highest concentrations in red enamel.
Toxic metals were found on both surfaces and rims of the glassware. The U.S. Office of Environmental Health Hazard Assessment recommends a maximum of 200 parts per million (ppm) of lead on the outside decorated lip area of a drinking glass. The study found an astonishing range from 40 to 400,000 ppm, with an upper level 2,000 times the recommended maximum exposure.
With a recommended maximum of 800 ppm of cadmium for the outside rim, researchers recorded levels of cadmium ranging from 300 to 70,000 ppm, or as high as 88 times the recommended maximum amount.
Researchers say that recent environmental concerns have led to the use of organic inks instead of metallic pigments. Organic inks were used on many of the newer products tested and were found to be negative for lead and cadmium.
While the main focus of this study was glassware, the authors expressed concern about other sources of toxic metals that might come in contact with food during food preparation or serving. Other potential sources of lead and cadmium may lurk on the surfaces of jugs, wine or beer bottles, measuring cups and even the undersides of coasters or chopping boards.
“Given that safer alternatives are available to the industry, the overall results of this study are both surprising and concerning,” adds Dr. Turner. “Why are harmful or restricted elements still being employed so commonly to decorate contemporary glassware manufactured in China, the European Union and elsewhere? I believe consumers should be made aware of this, while retailers and the glass industry have the responsibility to eliminate toxic metals from decorated products.”
The full study was published in the March 2018 edition of the the journal Science of the Total Environment.