INTRODUCTION: Experimental studies indicate that some chemicals with UV blocking properties (known as UV filters) can act as endocrine disruptors. UV filters are used in sunscreens and other cosmetic- and personal care products, as well as in other consumer products such as food packaging, clothing and furniture textiles to protect the products against UV radiation. Here we present the urinary excretion of suspected endocrine active UV filters in Danish children and adolescents recruited from the general population.

METHODS: The content of benzophenone (BP), benzophenone-1 (BP-1), benzophenone-2 (BP-2), benzophenone-3 (BP-3), 5-chloro-2- hydroxybenzophenone (BP-7), 4-hydroxybenzophenone (4-HBP), 4-methyl-benzophenone (4-MBP), 3-(4- methylbenzylidene)-camphor (4-MBC) and 3-benzylidene camphor (3-BC) were monitored in 24h urine and two consecutive first morning samples from 129 healthy Danish children and adolescents (6-21 yrs). All 387 samples were collected during the autumn (Nov. 2007) and were analyzed by a new on-line TurboFlow-LC-MS/MS method developed for simultaneous biomonitoring of these nine UV filters in urine.

RESULTS: BP-3 and BP-1 were detected in more than 80% of the 24h samples and were significantly correlated (R(2)=0.815). BP, 4-HBP and BP-2 were found in 43, 15 and 5% of the samples, respectively. The median (range) concentrations of the UV-filters in 24-h urine were as follows: BP-3, 0.92 (LOD-115); BP-1, 0.54 (LOD-44.6); BP,<LOD (LOD-48.5); 4-HBP,<LOD (LOD-10.5); and BP-2,<LOD (LOD-8.43) ng/mL. In general BP-1 and BP-3 were higher in girls compared to boys and were also higher in the group of adolescent girls (16-21 yrs) compared to the younger age groups of girls. None of the other UV filters; BP-7, 4-MBP, 4-MBC or 3-BC were detected in urine. A highly significant correlation between first morning and 24h urine levels of BP-3, BP-1 and 4-HBP from the same day was observed.

CONCLUSION: Our project on UV filters analyzed by a new robust and sensitive LC-MS/MS method in Danish children and adolescents showed that almost all individuals were exposed to UV filters. Sun protection products have been claimed to be a major source of exposure to sunscreens. However since all children in the present study were exposed during autumn where sunscreens are not needed in Denmark our study also indicates that other sources and routes of exposure might be of relevance.