At the point of European colonial arrival, an estimated 100 million people live on Turtle Island, with many of these communities concentrated into densely-populated areas. This population density is likely sustainable because communicable disease is kept to extremely low levels on the continent. Dunbar-Ortiz (2014) writes: "the practice of herbal medicine and even surgery and dentistry, and most importantly both hygienic and ritual bathing, kept disease at bay. Settler observers in all parts of the Americas marveled at the frequent bathing in winter in cold climates... Above all, the majority of the Indigenous people of the Americas had healthy, mostly vegetarian diets based on the staple of corn and supplemented by wild fish, fowl, and four-legged animals. People lived long and well with abundant ceremonial and recreational periods." Among many other medical inventions, the Indigenous people of Turtle Island create syringes, herbal pain relief, sunscreen, baby bottles, and mouthwash.