Roughly six in 10 people in Athens and Piraeus are exposed daily to levels of noise that could damage their health, according to figures presented yesterday at a conference on urban noise pollution. Some 60 percent of residents are regularly exposed to noise that measures 75 decibels, which is considerably higher than the recommended maximum level. The average person cannot sleep when subjected to 45 decibels of noise. At 120 decibels, the ear registers pain but hearing damage begins at about 85 decibels. The Piraeus Prefecture and the Technical Chamber of Greece found that the average level of noise next to busy roads in Athens and Piraeus is 81 decibels. Exposure to these levels of sound can have an effect on people's health, such as causing hearing problems or altering their mood due to a lack of sleep.