Each centimetre of hair analysed provides information on exposure to environmental pollutants over a period of one month. By default, the analyses proposed by EXPOZOM are based on the study of a 3-centimetre long hair strand (proximal segment, closest to the scalp) and cover a period of one quarter (90 days).
In theory, it is possible to analyse the whole length of a hair strand, but it is recommended to limit the analysis to a length of 6 cm, i.e. over a period of 6 months. The analysis can be done on a length of up to 6 centimetres, i.e. 6 months. Beyond 6 centimetres the interpretation of the results becomes more difficult due to the natural alteration of the hair and the possible degradation of its structure by hair and cosmetic treatments.
On request, the analysis can be carried out on several consecutive 1 cm segments, thus enabling a monthly histogram of exposure to be established.
It is important to know that a ½ centimetre long segment is not accessible during hair sampling and corresponds to a period of 15 days prior to the sampling date.
As hair is not biologically active, the substances incorporated in the hair structure are not degraded by biological processes and have a very good stability over time, which allows them to be analysed long after they have been collected.