We learn a little bit about what we might want to swim in and what not to breathe while (or while not) doing so …
https://www.theguardian.com/science/blog/2018/sep/13/could-cold-water-swimming-help-treat-depression
http://casereports.bmj.com/content/2018/bcr-2018-225007.abstract
https://edition.cnn.com/2018/09/17/health/placenta-pollution-babies-intl/index.html