International audience ; Several pesticides have been hypothesized to act as endocrine disrupting compounds, exhibiting hormonal activity and perturbing normal physiological functions. Among these, especially s-triazine-herbicides have received increased attention. Atrazine is, despite being banned in many countries, including the EU (2004), still the world's most widely used herbicide. Despite its discontinued use, considerable concentrations of atrazine and its degradation products, mainly desethylatrazine (DEA) and deisopropylatrazine (DIA), are still found in the environment, including drinking water sources. The aim of this investigation was to study concentrations of especially s-triazine-herbicides and major degradation products in drinking water, including spring water, tap water, and bottled water in Luxembourg. Spring water (2007/2008/2009, n=69/69/69), tap water (2008/2009, n=19/26), and bottled water (2007/2008/2009, n=5/13/7) were sampled at locations in Luxembourg and investigated for pesticides by HPLC-ESI-MS-MS. Atrazine was the predominant triazine, detectable in many spring water locations, tap and bottled water, ranging from 0-57(mean 9)ng/L, 0-44(mean 4)ng/L, and 0-4(mean 1)ng/L, respectively. DEA and DIA in spring water ranged from: 0-120(mean 19)ng/L and 0-27(mean 3)ng/L, with higher concentrations from agricultural areas and low molar ratios of DEA:atrazine<0.5 and high ratios of atrazine:nitrate suggesting point-source contaminations. DEA and DIA in tap water were 0-62(mean 14)ng/L and 0-6(mean<1)ng/L and in bottled water 0-11(mean 2)ng/L and 0-7(mean 2 ng/L). Simazine and other triazines were detected in traces (<5 ng/L). Thus, the conducted monitoring suggested the presence of low concentrations of s-triazines in raw and finished water, presumably partly due to non-agricultural contamination; with concentrations being below thresholds advocated by EU directive 98/83/EC.