Human biomonitoring is a form of environmental public health surveillance. It is not to be confused with environmental biomonitoring (or ecomonitoring), which is the observation of living organisms implemented with the objective of monitoring quality of environments. Human biomonitoring enables us to monitor the presence of chemical pollutants in the body. Measurement of biomarkers has nevertheless some caveats: it does not directly tell us by which pathway a compound has penetrated the organism, and health risks associated with a certain level of impregnation are often unknown. A great number of biomonitoring studies have been conducted in France and in the world. The second national environment and health action plan (2009-2013) includes a national human biomonitoring program. It is composed of two parts: one perinatal-early childhood component which consists in the measurement of biomarkers in the ELFE cohort, recruited in 2011, and a national biomonitoring (environment, health nutrition) survey which will be implemented on a sample of 5000 persons (6-74), representative of the population living in metropolitan France. Regarding air quality, it is to be observed that human biomonitoring is ill-suited as an indicator of quality for a particular medium. Nevertheless, some studies make use of biomarkers which are relatively specific of air pollution exposure. They can be biomarkers of exposure, such as exhaled carbon monoxide, or biomarkers of effect, such as exhaled nitric oxide.