Monitoring the exposure of a patient to an environmental factor

A system for monitoring the exposure of a patient to at least one environmental factor, comprising:

• a receiver module for receiving a measurement signal representing a level of the environmental factor in a vicinity of the patient,
• a database for storing an environmental prescription for the patient, the environmental prescription specifying a maximum level of the environmental factor and a minimum duration for the level of the environmental factor to be smaller than the maximum level, wherein the maximum level and/or the minimum duration are specified individually for the patient;
• and
• an evaluation module configured to compare the level of the environmental factor with the maximum level on the basis of the measurement signal, to detect on the basis of the comparison a time interval in which the level of the environmental factor is substantially permanently below the maximum level and to compare a duration of the detected time interval with the minimum duration, wherein the evaluation module is configured to control at least one output unit to output information representative of the result of the comparison between the duration of the detected time interval and the minimum duration
• wherein the evaluation module is configured to control at least one output unit to output information representative of the result of the comparison between the duration of the detected time interval and the minimum duration.