In 2018, one of the bestselling blood pressure drugs, valsartan—sold as Diovan—was found to be contaminated by the “probably carcinogenic” nitrosamine known as N-nitrosodimethylamine (NDMA). It’s believed that approximately 20 million people worldwide were prescribed the drug tainted with this contaminant whose cancer risk has been shown to exceed that of many known potent carcinogens,…