The people of Flint, Michigan aren't the only ones exposed to dangerous doses of lead dissolved in their drinks. Some of us, however, can't blame municipal plumbing. Instead, it's our choice of drinking vessels at fault – an easier problem to deal with, but only if you know about it first.
Dr Andrew Turner of the University of Plymouth, UK tested a range of glass products used for storing liquids, both new and second hand. These included tumblers, beer glasses, wine glasses, and jars. More than 70 percent of the 72 products tested contained lead. Almost as many had cadmium.
The presence of heavy metals within the range of sensitive detection devices isn't necessarily dangerous, but Turner found some rims with lead concentrations more than a thousand times the safe limits.
Lead oxide makes glass easier to melt and manipulate, and makes it more beautiful, but it's now discouraged for food storage. Turner's findings have more to do with lead enamel, flecks of which came off in simulations created to match the use and cleaning that should be realistically expected.
Lead is a neurotoxin, with exposure in childhood being strongly associated with reduced intelligence and impulse control. Exposure to lead from petrol has been blamed for the rise in crime rates that occurred across the developed world between the 1960s and early 1990s and is only now fading away. It would be fading much faster if regulators were more rigorous about cutting down on sources of exposure.
Turner has previously shown paints in children's playgrounds to be an under-recognized source of lead. However, he thinks glassware could be an even bigger problem. "The presence of hazardous elements in both the paint and glaze of decorated glassware has obvious implications for both human health and the environment. 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,” he said in a statement.
The US Office of Environmental Health and Hazard Assessment considers concentrations of lead above 200 parts per million (ppm) in the lip area to be unsafe, while cadmium is safe up to 800 ppm. In Science of The Total Environment Turner reports findings as high as 400,000 ppm for lead – meaning the glass' rim was 40 percent lead, while the highest cadmium concentration was a terrifying 70,000 ppm. Weak acids, such as vinegar or Coca-cola, easily stripped the metals, releasing them for consumption.
Lead drinking vessels have been proposed as one possible explanation for the Roman Empire's decline, but they had limited alternatives and a lack of scientific knowledge. Neither excuse applies to us. It's enough to drive you to drink.