Application of a novel reference material in an international round robin test on material emissions testing.

Emission testing of products is currently a rapidly increasing field of measurement activity. Labeling procedures for construction products are based on such emission test chamber measurements, and hence, measurement performance should be verified. One possible route is to conduct testing of one material in different laboratories within a round robin test (RRT), ideally using homogeneous reference materials, which can be used within interlaboratory studies or as part of the quality management system to ensure comparable results. The applicability of a lacquer system with nine added VOCs (hexanal, styrene, n-decane, limonene, 2-ethyl-1-hexanol, N-methyl-α-pyrrolidone, 2-ethylhexyl acrylate, dimethyl phthalate, and n-hexadecane) was evaluated in an international RRT with 55 participating laboratories. An intralaboratory quality check confirmed the homogeneity and reproducibility of the lacquer material for most of the compounds (RSD 5%-6%), which was confirmed in the RRT. However, emissions varied for the polar compound N-methyl-α-pyrrolidone and the higher boiling compounds 1,2-dimethyl phthalate, and n-hexadecane which could be traced back to analytical issues. In the RRT, the interlaboratory relative standard deviations (RSDs) ranged from 30% to 65% for all participants but for reference laboratories the range was between 20% and 45%.

USE OF COMMERCIAL RADON MONITORS FOR LOW LEVEL RADON MEASUREMENTS IN DYNAMICALLY OPERATED VOC EMISSION TEST CHAMBERS.

Compared to the intended EU reference level of 300 Bq m-3 for indoor radon concentrations, the contribution of building materials appears to be low. Considering the recommended limit of 100 Bq m-3 by WHO, their contribution is supposed to be relevant, especially at low air exchange rates. This study as part of a two-part research project investigated the suitability of direct low level 222Rn measurement under simulated indoor conditions with commercial radon monitors and dynamically operated emission test chambers. Active measuring devices based on ionisation or scintillation chambers with 1-σ uncertainties below 8.6% at 20 Bq m-3 were found to be best suitable for a practical test procedure for the determination of radon exhalation rates of building materials. For the measurement of such low concentrations, the knowledge of the accurate device background level is essential.

Determination of radon exhalation from construction materials using VOC emission test chambers.

The inhalation of (222) Rn (radon) decay products is one of the most important reasons for lung cancer after smoking. Stony building materials are an important source of indoor radon. This article describes the determination of the exhalation rate of stony construction materials by the use of commercially available measuring devices in combination with VOC emission test chambers. Five materials - two types of clay brick, clinker brick, light-weight concrete brick, and honeycomb brick - generally used for wall constructions were used for the experiments. Their contribution to real room concentrations was estimated by applying room model parameters given in ISO 16000-9, RP 112, and AgBB. This knowledge can be relevant, if for instance indoor radon concentration is limited by law. The test set-up used here is well suited for application in test laboratories dealing with VOC emission testing.

Inhalation exposure of children to fragrances present in scented toys.

UNLABELLED: When utilized in the perfuming of children's toys, fragrances capable of inducing contact allergy in human skin may also become bioavailable to children via the inhalation route. The aim of this study was to determine the area-specific emission rates of 24 fragrances from a plasticized PVC reference material that was meant to mimic a real plastic toy. This material was introduced into an emission chamber for 28 days at handling conditions or at worst-case conditions. As a result, fragrances can be separated into three categories according to their emission rates ranging from 0.0041 to 16.2 mg/m² × h, i.e., highly volatile, semivolatile, and low-volatile compounds. Compounds of the first and second categories were monitored with decreasing emission rates. Substances of the third category were detected with increasing emission rates over time. Further, higher temperatures led to higher emission rates. The emission concentration of fragrances from four real scented toys varied between 1.10 and 107 µg/m³ at day 1 in the test chamber. Therefore, short-term inhalation exposure to fragrances originating from toys was in the range of 0.53-2700 ng/kg BW/d for the children of age 1 and older. Long-term exposure to these fragrances was calculated in the range of 2.2-220 ng/kg BW/d. PRACTICAL IMPLICATIONS: Besides household products and cosmetics, fragrances can be found in toys for children. Some fragrances are known contact allergens in the skin, but there is a lack of information on their effects in the human respiratory tract. Here, we analyzed and categorized fragrances present in a plasticized PVC reference material according to their emission profiles and volatility. We also demonstrate that volatile fragrances are being emitted from real toys and thus may get inhaled under consumer conditions to different extents.

Molecular characterization of bovine CSN1S2*B and extensive distribution of zebu-specific milk protein alleles in European cattle.

The B allele of the bovine alpha (S2)-casein gene (CSN1S2) was characterized at the molecular level and the distribution of zebu-specific milk protein alleles was determined in 26 cattle breeds originating from 3 continents. The CSN1S2*B allele is characterized by a C --> T transition affecting nucleotide 17 of exon 3, which leads to a change in the eighth amino acid of the mature protein, from Ser to Phe (i.e., TCC --> TTC). DNA-based methods were developed to identify carriers of CSN1S2*B and the other alleles (CSN1S2*A, C, and D) at the same locus. CSN1S2*B and other zebu-specific milk protein alleles and casein haplotypes are widely distributed in European cattle breeds, particularly those of southeastern origin. Alleles CSN1S2*B and CSN3*H are important in searching for zebu imprints in European cattle breeds. Diversity estimates at the milk protein loci were highest in the zebus followed by southeastern European taurines. Anatolian Black had the highest number of zebu alleles among European taurines. Common, group, and intergroup haplotypes occurred in the breeds and demonstrated relationships that concurred with developmental histories, genetic makeup, and, in particular, exposed the extent of zebu influence on southeastern European cattle.

Radiation hybrid mapping of all 10 characterized bovine Toll-like receptors.

Toll-like receptors (TLRs) are cell-surface signalling molecules that recognize a range of highly conserved pathogen molecules and instigate the appropriate immune response. Here, we report the mapping of all 10 characterized bovine TLR genes using a radiation hybrid panel. The genomic organization of the bovine TLRs is similar to that of humans and mice. TLR1, TLR6 and TLR10 map closely together on Bos taurus chromosome 6 (BTA6), while TLR7 and TLR8 map to the X chromosome. TLR2, TLR3, TLR4, TLR5 and TLR9 map to BTA17, BTA27, BTA8, BTA16 and BTA22 respectively. Our increased knowledge of the genomic organization of the bovine TLR genes may promote our understanding of their evolution and help in the identification of bovine genes underlying disease-resistance traits.

Genetic polymorphism of goat kappa-casein (CSN3) in different breeds and characterization at DNA level.

Data on genetic differences at CSN3 in goat breeds including a DNA based typing method and the mutations responsible for variation on protein and DNA level are presented here. Isoelectric focusing (IEF) in ultrathin polyacrylamide gels with carrier ampholytes was used to demonstrate CSN3 polymorphism in milk samples of Italian (Orobica n=88; Ionica n=68) and German goat breeds (Bunte Deutsche Edelziege n=244; Weisse Deutsche Edelziege n=134; Toggenburger n=25; Thüringer Waldziege n=70). A further CSN3 band was found presenting a more cathodic migration than CSN A. After chymosin action, the genetic polymorphism was also observed in the para-kappa-casein fraction. The new allele CSN3(B) was spread mainly in Orobica (37%), Bunte Deutsche Edelziege (11%) and Ionica (10%). CSN3(B) occurred in low frequency (<3%) in Thüringer Waldziege and in Weisse Deutsche Edelziege, and could not be demonstrated in milk samples of Toggenburger. The populations were in Hardy-Weinberg equilibrium at CSN3. The codominant genetic control of CSN3(B) was confirmed by genetic studies. Discrimination of CSN3 alleles A and B was also obtained by DNA SSCP analysis. Sequencing of CSN3(B) revealed four transitions at position 247, 309, 471, and 591 compared with CSN3(A). From these transitions, the following amino acid substitutions are deduced: 44 Gln --> Arg, 65 Val --> Ile, 119 Val --> Ile, and 159 Ser --> Pro. Among the four mutations, only the 44 Gln --> Arg can be revealed by milk protein IEF analysis while at DNA level three further genetic variants should exist in addition to CSN3(A) and CSN3(B).

The cattle interleukin-13 gene: genomic organization, chromosomal location, and evolution of the promoter.

Interleukin (IL)-13 plays a key role in the T-helper 2 type immune response. In domestic animal species no sequence information is available for the IL13 gene. Here, we report the isolation and sequencing of the cattle IL13 gene. Since a heterologous cDNA probe failed to hybridize to cattle genomic DNA the gene was identified by a positional sequencing approach. In human and mouse both cytokines are located within a region of about 30 kilobases (kb). Therefore the region upstream of the cattle IL4 gene has been sequenced by a shotgun approach. The cattle IL13 gene was found to be located about 20 kb upstream of IL4 in a head-to-tail orientation. The exon-intron structure and the promoter region is well conserved across species. The alignment of the IL13 sequences from different species allowed the identification of highly conserved amino acid positions and transcriptional elements. Two conserved amino acid positions (glu(31) and pro(94)) are most probably homologous to the interleukin-4 signalling residues. One of the potential binding sites for transcription factors is located at position -197 to -189 and is closely related to the P elements of the IL4 promoter. Nevertheless, the overall identity of the promoter sequences of IL13 and IL4 is low. Therefore we conclude that both cytokines use diverse regulatory elements. There is evidence that IL-13, but not IL-14, is the key mediator in allergic asthma. Furthermore IL-13 is involved in resistance to some infections. Therefore IL-13 is of interest for disease association studies in domestic animals.