A recent study looked into life-threatening Acanthamoeba infections, and a few deaths, linked to the use of tap water with devices like neti pots. And, in ‘The Balanced Brain,’ Dr. Camilla Nord explores the neuroscience behind mental health, and how our brains deal with life’s challenges.Scientists Warn Against Nasal Rinsing With Unboiled Tap WaterResearchers at the Centers For Disease Control and Prevention published a study Wednesday that examined 10 cases of life-threatening Acanthamoeba infections that occurred after people cleaned their sinuses with neti pots, squeeze bottles, or other nasal rinsing devices. In most of these cases, which occurred in immunocompromised individuals over the span of a few decades, individuals had used tap water for nasal rinsing.Tap water, while generally safe to drink, is not sterile. Microorganisms and germs live in distribution systems and pipes that the water travels through, and Acanthamoeba amebae was the main link between the 10 cases, three of which resulted in death.Although contracting the Acanthamoeba pathogen is extremely rare, many people are unaware of the unsterile nature of tap water and use it for their sinuses, according to a survey study published last year. A third of participants incorrectly believed U.S. tap water is sterile, and almost two-thirds assumed it was safe to rinse your sinuses with it.The CDC and FDA recommend using distilled or sterile water for nasal rinsing. If you want to use tap water, they recommend boiling it for three to five minutes and allowing it to cool. While slightly more time consuming, it is an effective way to get sterile water.Rachel Feltman, host of “The Weirdest Thing I Learned This Week,” joins Ira to talk about this story and other news in science this week, including a new study that links microplastics in the human body to increased risk of heart disease and death, why the U.S. maternal mortality rate might be inflated, and why cicadas produce high-speed jets of urine.How Your Brain Constructs Your Mental HealthIf you’ve ever struggled with a mental health issue like anxiety or depression, or know someone who has, it’s pretty clear that what works for one person might not work for another. Antidepressants only work in about 50-60% of patients. Meditation or yoga may be a gamechanger for some people, but ineffective for others.Over the past few decades, neuroscientists have made huge advances in our understanding of the human brain. How can we use the latest neuroscience research to help improve our mental well-being? And what is the relationship between physical and mental health?To answer those questions and more, SciFri producer Shoshannah Buxbaum talks with Dr. Camilla Nord, director of the Mental Health Neuroscience Lab at the University of Cambridge and author of the new book The Balanced Brain: The Science of Mental Health.Read an excerpt of The Balanced Brain at sciencefriday.com.Transcripts for each segment will be available after the show airs on sciencefriday.com.  Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.