**4. Sample preparation and analytical methods selection for analyzing organic contaminants in biological samples collected non-invasively**

Through these studies two sample matrixes were chosen in order to evaluate the surrounding environmental contaminants on inhabitants, namely hair – in order to get a general overview about organic contaminants impact on humans exposed to them, and milk – throughout to could form an image regarding the infants' exposure from early age life. As regards animal exposure biomonitoring hair was chosen for mammalian animal subjects and feather in case of poultries biomonitoring studies. Therefore in our biomonitoring study we were able to collect high enough samples on an extended range of subjects (as species, age and geographical position) without causing any harm even when we talk about human biomonitoring or animal biomonitoring studies.
