Real-time selected ion flow tube mass spectrometry to assess short- and long-term variability in oral and nasal breath.

Breath-based non-invasive diagnostics have the potential to provide valuable information about a person's health status. However, they are not yet widely used in clinical practice due to multiple factors causing variability and the lack of standardized procedures. This study focuses on the comparison of oral and nasal breathing, and on the variability of volatile metabolites over the short and long term. Selected ion flow tube mass spectrometry (SIFT-MS) was used for online analysis of selected volatile metabolites in oral and nasal breath of 10 healthy individuals five times in one day (short-term) and six times spread over three weeks (long-term), resulting in nearly 100 breath samplings. Intra-class correlation coefficients (ICCs) were used to assess short- and long-term biological variability. Additionally, the composition of ambient air was analyzed at different samplings. The selected volatiles common in exhaled breath were propanol, 2,3-butanedione, acetaldehyde, acetone, ammonia, dimethyl sulfide, isoprene, pentane, and propanal. Additionally, environmental compounds benzene and styrene were analyzed as well. Volatile metabolite concentrations in ambient air were not correlated with those in exhaled breath and were significantly lower than in breath samples. All volatiles showed significant correlation between oral and nasal breath. Five were significantly higher in oral breath compared to nasal breath, while for acetone, propanal, dimethyl sulfide, and ammonia, concentrations were similar in both matrices. Variability depended on the volatile metabolite. Most physiologically relevant volatiles (acetone, isoprene, propanol, acetaldehyde) showed good to very good biological reproducibility (ICC > 0.61) mainly in oral breath and over a short-term period of one day. Both breathing routes showed relatively similar patterns; however, bigger differences were expected. Therefore, since sampling from the mouth is practically more easy, the latter might be preferred.

EPHECT I: European household survey on domestic use of consumer products and development of worst-case scenarios for daily use.

Consumer products are frequently and regularly used in the domestic environment. Realistic estimates for product use are required for exposure modelling and health risk assessment. This paper provides significant data that can be used as input for such modelling studies. A European survey was conducted, within the framework of the DG Sanco-funded EPHECT project, on the household use of 15 consumer products. These products are all-purpose cleaners, kitchen cleaners, floor cleaners, glass and window cleaners, bathroom cleaners, furniture and floor polish products, combustible air fresheners, spray air fresheners, electric air fresheners, passive air fresheners, coating products for leather and textiles, hair styling products, spray deodorants and perfumes. The analysis of the results from the household survey (1st phase) focused on identifying consumer behaviour patterns (selection criteria, frequency of use, quantities, period of use and ventilation conditions during product use). This can provide valuable input to modelling studies, as this information is not reported in the open literature. The above results were further analysed (2nd phase), to provide the basis for the development of 'most representative worst-case scenarios' regarding the use of the 15 products by home-based population groups (housekeepers and retired people), in four geographical regions in Europe. These scenarios will be used for the exposure and health risk assessment within the EPHECT project. To the best of our knowledge, it is the first time that daily worst-case scenarios are presented in the scientific published literature concerning the use of a wide range of 15 consumer products across Europe.

On organic emissions testing from indoor consumer products' use.

A wide range of consumer and personal care products may, during their use, release significant amounts of volatile organic compounds (VOC) into the air. The identification and quantification of the emissions from such sources is typically performed in emission test chambers. A major question is to what degree the obtained emissions are reproducible and directly applicable to real situations. The present work attempts partly to address this question by comparison of selected VOC emissions in specific consumer products tested in chambers of various dimensions. The measurements were performed in three test chambers of different volumes (0.26-20 m(3)). The analytic performance of the laboratories was rigorously assessed prior to chamber testing. The results show emission variation for major VOC (terpenes); however, it remains in general, within the same order of magnitude for all tests. This variability does not seem to correlate with the chamber volume. It rather depends on the overall testing conditions. The present work is undertaken in the frame of EPHECT European Project.

Laboratory and field validation of a combined NO2-SO2 Radiello passive sampler.

A combined NO2-SO2 Radiello radial-type diffusive sampler was validated under controlled laboratory conditions and compared with NO2-SO2 results of 3 other type of samplers in a field comparison at two locations Ghent-Mariakerke and Borgerhout in Flanders. Laboratory exposures at different temperatures (-5, 10 and 30 degrees C) and relative humidities (0, 50 and 80% RH) in combination with varying concentration levels and exposure times were carried out, with a focus on extreme conditions. Concentration level and exposure time were changed together following suppliers linear working range of samplers and assuring absolute amounts of compounds on the sampler corresponding to those of environmental levels. The average uptake rate for NO2 for 24 hour exposures at 10 degrees C and 50% RH and tested concentration levels (+/-73, 146 and 293 ppb NO2) was 0.076 +/- 0.011 ng ppb(-1) min(-1). Uptake rates during all experiments were lower than the uptake rate given in the instruction manual of the sampler. A significant effect of temperature and relative humidity on NO2 uptake rate was observed. The temperature effect from 10 to 30 degrees C corresponds to the temperature effect given by the supplier of the samplers. High relative humidity (70 to 80%) caused a strong non-reproducible decrease of uptake rate for NO2 at 24 hour experiments but this effect was not observed at longer exposures except for the tests at -5 degrees C. At the tested temperature below zero in combination with high relative humidity the sampler showed anomalous behaviour for NO2. The possible effect of concentration level and exposure time for NO2 needs further research. The average uptake rate for SO2 calculated from all exposures is 0.478 +/- 0.075 ng of sulfate ion each ppb min of SO2 and accords to suppliers uptake rate. No clear effects of temperature, relative humidity or concentration level/exposure time on the uptake rate for SO2 were found, partly due to the large scatter of results. Although NO2 accuracy of Radiello samplers was better during field campaigns than during laboratory validation, IVL and OGAWA samplers gave better results for NO2. In the field, IVL samplers showed best agreement with the continuous analyzers for both NO2 and SO2.

European sampling intercomparisons for aromatic and chlorinated hydrocarbons in workplace air.

Thirty-eight laboratories of the EU Member States, representing government, manufacturers of personal samplers, industrial and university laboratories have participated in a quality assurance scheme which allows to evaluate errors associated with both the sampling and analytical step of personal sampling methods. State-of-the-art bias, within and between laboratory coefficients of variation for pumped and diffusive methods currently applied are discussed. The data enable verification of compliance of the method-laboratory combinations with EN 482 and quantification of errors, in specific related to the sampling step. The merits of the project regarding improved procedures and results are discussed in detail.

Sampling intercomparisons for aldehydes in simulated workplace air.

Thirty one laboratories of various EU Member States have participated in two interlaboratory comparisons in order to assess errors of personal sampling methods associated with both the sampling and the analytical steps. In contrast to conventional quality control schemes, this project particularly focuses attention on the sampling and identification step; it is executed by means of sampling exercises and has included discussions on potential sources of error. In a sampling exercise, participants come to a central facility and perform measurements on synthetic workplace air in a laboratory installation. Concentration levels of formaldehyde, acrolein, glutaraldehyde and acetaldehyde between 0.1 and 2 times the limit value for workplace air were prepared at various humidity levels and with acetone, occasionally, as interferent. Sampling times varied from 1-4 h. The related analytical work is performed at the analyst's own laboratory. The intention is for each participant to determine the observed value of the delivered standard atmosphere using the sampling method of his own choice. Trueness (bias), precision and relative overall uncertainty of each method-laboratory combination is calculated and verified towards compliance with EN 482, which outlines minimum performance criteria. The first challenge involved the precise gas phase generation of the selected analytes in high air flows (up to 300 1 min-1) and calculating the true value only by direct reference to primary standards. This was accomplished by modifying the capillary dosage injection technique so that reactive compounds, like low molecular mass aldehydes, could be dosed with the same accuracy and precision as unreactive solvents. A permeation tube with high emission rate was developed for formaldehyde. Up to ten different sampling techniques were evaluated. The measurement methods used by the majority of the participants were based on pumped sampling on silica cartridges (or tubes) and glass fiber filters, coated with 2,4-dinitrophenylhydrazine. It was observed that for formaldehyde, and in some cases for acetaldehyde and glutaraldehyde, the majority of the method-laboratory combinations complied with an overall uncertainty of 30%. The results for acrolein, however, indicated a systematic negative bias, often larger than minus 50% of the true value, caused by the decomposition of the acrolein DNPH derivative in the presence of excess acid and excess DNPH.