Atlantic coasts of Brazil are covered by the sand with radioactivity which came back with the wave from the sea. The radioactivity was originated from the mountains rich in zirconites and monazites along the coast.

	Many people visit the beach with black sands , which are radioactive, for sea swimming and treatment of rheumatoid. The city has developed as a number one resort in Brazil with a population of 70,000.
Question to the couple in the photo: "How do you feel in the sand?" They said: "We feel very worm. We do not know the effect, but it is sure that it becomes warmer and warmer in the sand. We found something different from other places." The dosimeter indicated 5μSv/h.
	Black sand showed much higher value, i.e., 131μSv/h. Usually it is below 0.1μSv/h.