In 2018, Mary Kosuth, a microplastics researcher and graduate of the University of Minnesota School of Public Health, conducted a study of anthropogenic debris – aka, man-made inorganic particles such as plastics and microplastics – in tap water, beer, and sea salt. She examined 159 samples of globally sourced tap water, 12 brands of Laurentian Great Lakes beer, and 12 brands of commercial sea salt.

Utilizing a dye that stains organic substances, Kosuth was able to filter out and examine the inorganic particles present in her test samples. She discovered that 81% of the tap water samples contained microplastics, with the highest average concentration sourced from waters in the United States, and the lowest average concentration sourced from water in the European Union.

Of the twelve brands of beer samples, every single brand tested positive for the presence of microplastics, and further study found that the results could not be solely blamed on the use of microplastic-contamined tap water. This indicates that the beer brewing process itself may be a factor in their contamination.

Like the beer samples, all twelve brands of sea salt tested positive for the presence of microplastics.

The study concludes with a general concern at the presence of microplastic contamination in tap water, because although both beer and salt intake can be modified or reduced, water is a daily necessity that is involved in all sources of hydration.

To read the complete study, please visit