Indoor monitoring of heavy metals and NO2 using active monitoring by moss and palmes diffusion tubes

Background; : Indoor pollution is a real threat to human health all over the world. Indoor pollution derives from indoor sources (e.g. smoking, gas stoves, coated furniture) as well as from outdoor sources (e.g. industries, vehicles). Long-term monitoring measurements in indoor environments are missing to a large extent due to a lack of simple to operate measuring devices. Mosses proved well as biomonitors in hundreds of studies. Nevertheless, indoor use has been extremely scarce. Therefore, this study aimed to determine indoor and outdoor pollution by active biomonitoring using moss as well as NO2 samplers to analyse outdoor and indoor levels of pollution. We exposed moss (Pleurozium schreberi) for 8 weeks indoors and outdoors in 20 households in the city of Girona, Spain. Al, Cr, Cu, Zn, Sn, Cd, Pb, Mo, and Sb were analysed by moss-samplers. Additionally, NO2 was measured with Palmes diffusion tubes.; Results; : Compared to the pre-exposure analysis, concentrations of almost all elements both on indoor and outdoor mosses increased. Except for Cd, all metals and NO2 had, on average, higher concentrations in outdoor mosses than at corresponding indoor sites. However, some 20% of the samples showed inverse patterns, thus, indicating both indoor and outdoor sources. Indoor/outdoor correlations of elements were not significant, but highest for markers of traffic-related pollution, such as Sn, Sb, and NO2. The wide range of indoor-outdoor ratios of NO2 exemplified the relevance of indoor sources such as smoking or gas cooking. Though mostly excluded in this study, a few sites had these sources present.; Conclusions; : The study at hand showed that moss exposed at indoor sites could be a promising tool for long-time biomonitoring. However, it had also identified some drawbacks that should be considered in future indoor studies. Increments of pollutants were sometimes really low compared to the initial concentration and therefore not detectable. This fact hampers the investigation of elements with low basic element levels as, e.g. Pt. Therefore, moss with real low basic levels is needed for active monitoring, especially for future studies in indoor monitoring. Cloned material could be a proper material for indoor monitoring yet never was tested for this purpose

Determination of trace elements in human milk by inductively coupled plasma sectorfield mass spectrometry (ICP-SFMS)

The potential of high resolution inductively coupled plasma sector field mass spectrometry (ICP-SFMS) was evaluated to quantify reliably various toxic and essential elements (Al, Sc, Ti, V, Cr, Mn, Fe, Ni, Co, Cu, As, Ag, Pt, Au, Pb) in human milk and infant formulae with respect to sensitivity, spectral and non-spectral interferences, blank levels, relative stability and accuracy. Some elements of potential interest such as Ti, V, Cr, Mn, Fe, Ni, Co and As are significantly interfered by polyatomic ions and cannot be determined under routine conditions without using high mass resolution, since interference levels vary significantly with the composition of the milk matrix. A microconcentric nebuliser in combination with a membrane desolvation unit was tested with respect to signal enhancement and reduction of interferences. In general, an increase of the signal intensities up to a factor of 5 was observed, whereas not all spectral interferences can be reduced to a negligible amount (only oxide containing ions to some extent). Moreover the use of the N(2) as the make-up gas did not improve the sensitivity but led to additional N-containing polyatomic interferences (e.g., for V, Cr and Mn). The use of a torch shielded by a Pt electrode did lead to the same signal intensities both for the conventional MCN100 and the MCN6000 with membrane desolvation. The investigation of In, Re, Ru, and Rh as internal standard showed that not all elements can be corrected for matrix suppression without using an additional correction factor derived from an approximate matrix composition. A series of milk samples was investigated using the optimised analytical set-up and compared to infant milk formulae. Trace element levels in instant milk formulae are significantly influenced by the quality of tap water used for preparation