Bottles of beer, wine and spirits contain potentially harmful levels of toxic elements, such as lead and cadmium, in their enamelled decorations, a new study shows.
Researchers at the University of Plymouth analysed both the glass and enamelled decorations on a variety of clear and coloured bottles readily available in shops and supermarkets.
They showed that cadmium, lead and chromium were all present in the glass, but at concentrations where their environmental and health risks were deemed to be of low significance.
However, the enamels were of greater concern, with cadmium concentrations of up to 20,000 parts per million in the decorated regions on a range of spirits, beer and wine bottles, and lead concentrations up to 80,000ppm in the décor of various wine bottles.
The limit for lead in consumer paints is 90ppm.
The study also showed the elements had the potential to leach from enamelled glass fragments, and when subjected to a standard test that simulates rainfall in a landfill site, several fragments exceeded the US Model Toxins in Packaging Legislation and could be defined as “hazardous”.
Published in Environmental Science and Technology, the research was carried out by Associate Professor (Reader) in Aquatic Geochemistry and Pollution Science, Dr. Andrew Turner.
He has previously shown that the paint or enamel on a wide variety of items – including playground equipment, second hand toys and drinking glasses – can feature levels of toxic substances that are potentially harmful to human health.
Dr. Turner said: “It has always been a surprise to see such high levels of toxic elements in the products we use on a daily basis.
This is just another example of that, and further evidence of harmful elements being unnecessarily used where there are alternatives available.
The added potential for these substances to leach into other items during the waste and recycling process is an obvious and additional cause for concern.”
For the current research, bottles of beer, wine and spirits were purchased from local and national retail outlets between September 2017 and August 2018, with the sizes ranging from 50 ml to 750 ml.
They were either clear, frosted, green, ultraviolet-absorbing green (UVAG) or brown with several being enamelled over part of the exterior surface with images, patterns, logos, text and/or barcodes of a single colour or multiple colours.
Out of the glass from 89 bottles and fragments analysed using X-ray fluorescence (XRF) spectrometry, 76 were positive for low levels of lead and 55 positive for cadmium.
Chromium was detected in all green and UVAG bottles, but was only in 40% of brown glass and was never in clear glass.
Meanwhile, the enamels of 12 products out of 24 enamelled products tested were based wholly or partly on compounds of either or both lead and cadmium.
Dr. Turner added: “Governments across the world have clear legislation in place to restrict the use of harmful substances on everyday consumer products.
But when we contacted suppliers, many of them said the bottles they use are imported or manufactured in a different country than that producing the beverage.
This poses obvious challenges for the glass industry and for glass recycling and is perhaps something that needs to be factored in to future legislation covering this area.”
According to researchers from the University of Plymouth in the United Kingdom, enameled drinking glasses, including beer, wine and spirit bottles, may contain potentially harmful levels of lead and cadmium.
Researchers found lead and cadmium on the surface of the rims with more than 1000 times the concentration that is allowed.
For the study, the team carried out about 197 tests on 72 new and second-hand drinking glass products, including tumblers, beer and wine glasses, and jars.
They found lead present in 139 cases and cadmium in 134, both on the surface of the glasses and, in some cases, on the rims, with concentrations of lead sometimes even more than 1,000 times higher than the limit level.
The tests also showed that flakes of paint often chip on the glass due to regular use which indicates that these substances could be ingested over a prolonged period of time.
According to Andrew Turner, from University of Plymouth, “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.”
The study further revealed that more than 70 per cent of the products (52 out of 72) tested positive for lead, and the metal was found in all recorded colours, including the decorated gold leaf of some items, A similar number (51 out of 72) tested positive for cadmium, with the highest concentrations usually encountered in red enamel.
The lead concentrations ranged from about 40 to 400,000 parts per million (ppm), while quantities of cadmium ranged from about 300 to 70,000 parts per million (ppm), the researchers noted.
As per the United States Office of Environmental Health Hazard Assessment, the limit levels for the externally decorated lip area of drinking glass are 200 ppm and 800 ppm respectively.
Researchers point out that these hazardous materials have the potential to come in contact with the food or beverage and impact human health.
The study was published in the journal Science of the Total Environment and the researchers feel that these results were quite surprising as safer alternatives are available but no one seems to be using them.
More information: Andrew Turner, Heavy Metals in the Glass and Enamels of Consumer Container Bottles, Environmental Science & Technology (2019). DOI: 10.1021/acs.est.9b01726
Journal information: Environmental Science and Technology , Environmental Science & Technology
Provided by University of Plymouth