In 2015, 251 million tubes of toothpaste were sold in the United States.[1] A single tube holds roughly 170 grams of toothpaste, so approximately 43 kilotonnes of toothpaste get washed into the water systems annually.[2] Toothpaste contains silver nanoparticles, also known as nanosilver or AgNPs, among other compounds.[2]
Each tube of toothpaste contains approximately 91 mg of silver nanoparticles, with approximately 3.9 tonnes of silver nanoparticles entering the environment annually.[3] Silver nanoparticles are not entirely cleared from the water during the wastewater treatment process, possibly leading to detrimental environmental effects.[2]
:14
was invoked but never defined (see the help page).