Erratum to: Int Arch Occup Environ Health DOI 10.1007/s00420-009-0419-4

In Figure 1, in the above paper, there was an error in the caption text. The text should read as below:

Figure 1. Diurnal profiles of sleepiness and 6-sulfatoxymelatonin among nurses with different types of shift. Solid square KSS on a workday (solid line), open square KSS on a day off (solid line), solid triangle 6-sulfatoxy-melatonin on a workday (dashed line), open triangle 6-sulfatoxy-melatonin on a day off (dashed line)