Although condoms are often available on-site, Dr. Tierno said the protest’s evolution to private tents, from sleeping out in the open, had raised the risk of sexually transmitted diseases. The site’s pounding drum circles, he added, could lead to hearing damage. He compared conditions at Zuccotti Park to those in a hajj — the pilgrimage to Mecca, in which whole groups of people have come down with respiratory infections in a short time — and those experienced by the flower children of the 1960s, when, he said, communal living situations created problems with sanitation and sexually transmitted diseases.