Compounds In House Dust Research Articles

Characterizing azobenzene disperse dyes and related compounds in house dust and their correlations with other organic contaminant classes

Azobenzene disperse dyes are the fastest-growing category of commercial dyestuffs and are implicated in the literature as potentially allergenic. In the indoor environment, these dyes may be shed from various textiles, including clothing and upholstery and accumulate in dust particles potentially leading to exposure in young children who have higher exposure to chemicals associated with dust due to their crawling and mouthing behaviors. Children may be more vulnerable to dye exposure due to their developing immune systems, and therefore, it is critical to characterize azobenzene disperse dyes in children's home environments. Here, we investigate azobenzene disperse dyes and related compounds in house dust samples (n = 124) that were previously analyzed for flame retardants, phthalates, pesticides and per- and polyfluoroalkyl substances (PFAS). High-resolution mass spectrometry was used to support both targeted and suspect screening of dyes in dust. Statistical analyses were conducted to determine if dye concentrations were related to demographic information. Detection frequencies for 12 target dyes ranged from 11% to 89%; of the dyes that were detected in at least 50% of the samples, geometric mean levels ranged from 32.4 to 360 ng/g. Suspect screening analysis identified eight additional high-abundance azobenzene compounds in dust. Some dyes were correlated to numerous flame retardants and several antimicrobials, and statistically higher levels of some dyes were observed in homes of non-Hispanic Black mothers than in homes of non-Hispanic white mothers. To our knowledge, this is the most comprehensive study of azobenzene disperse dyes in house dust to date. Future studies are needed to quantify additional dyes in dust and to examine exposure pathways of dyes in indoor environments where children are concerned.

Thermal desorption-based method for quantifying semi-volatile organic compounds in house dust: Method development and evaluation

As an important storage medium of semi-volatile organic compounds (SVOC) in indoor environments, house dust has been extensively used to assess the pollution level of indoor SVOC. SVOC in house dust are commonly quantified using solvent-extraction methods, which are however solvent-consuming, time-consuming and laborious. Thermal desorption (TD, solvent-free and easy-to-use) is a good alternative to solvent extractions, but its performance for analyzing house dust is still unverified. Therefore, we proposed a TD-based method for quantifying SVOC in house dust by incorporating the TD technique with GC-MS. Laboratory experiments (48 samples with high SVOC concentrations) and field-test experiments (12 samples with low SVOC concentrations) were performed to justify the proposed method by comparing its results to those of a traditional solvent-extraction method (Soxhlet extraction). For laboratory dusts, the accuracy (relative deviation < 20%) and repeatability (relative standard deviation < 13%) of the TD-based method were comparable to the solvent-extraction method. For field-test dusts, higher SVOC concentrations were typically obtained by the TD-based method, implying its superior performance. These results gave evident confidence in the performance of the TD-based method, which facilitated the simple, solvent-free and accurate quantification of SVOC in house dust.

Identification of Glucocorticoid Receptor Antagonistic Activities and Responsible Compounds in House Dust: Bioaccessibility Should Not Be Ignored.

More and more contaminants in dust have been found to be glucocorticoid receptor (GR) disrupting chemicals. However, little is known about the related potency and responsible toxicants, especially for the main bioaccessible ones in dust. An effect-directed analysis (EDA)-based workflow was developed, including solvent-based exhaustive extraction/tenax-assisted bioaccessible extraction (TBE), high-throughput bioassays, suspect and non-target analysis, as well as in silico candidate selection, for a more realistic identification of responsible contaminants in dust. None of the 39 dust samples from 23 cities in China exhibited GR agonistic activity, while GR antagonistic potencies were detected in 34.8% of samples, being significantly different from the high detection frequency of GR agonistic activities in other environmental media. The GR antagonistic potencies of the dust samples were all reduced after bioaccessible extraction. The mean bioaccessibility of GR antagonistic potency compared with the related exhaustive extracts was 36.8%, and the lowest value was 9%. By using in silico candidate selection, greater than 99% candidate chemical structures which were found by a non-target screening strategy were removed. Di-n-butyl phthalate (DnBP), diisobutyl phthalate (DiBP), and nicotine (NIC) were responsible for the activities of the exhaustive extracts of dust, contributing up to 91% potencies. DiBP and DnBP were also responsible for the bioaccessible activities, contributing up to 79% potencies. However, the contribution from NIC decreased significantly and can be ignored because of its low bioaccessibility. This study suggests that the improved workflow combining extraction, reporter gene bioassays, suspect and non-target analysis, as well as in silico candidate selection is useful for EDA analysis in dust samples. In addition, exhaustive extraction may overestimate the risk of contaminants, while bioaccessibility evaluation based on bioaccessible extraction is essential in both effect evaluation and toxicant identification.

Comparison of supercritical fluid extraction and thermal desorption methods for analysing organic compounds in house-dust

<p>This study has been focused on the comparison of the application of Thermal Desorption (TD) and Supercritical Fluid Extraction (SFE) methods for the identification and quantification of organic chemicals in house dust samples. To investigate how the results obtained by SFE and TD of house dust compare to one another and whether the SFE has advantages over the TD method, an aliquot of a house dust sample has been subjected to desorption at successively increasing temperatures. The thermal desorption unit used cryo - focusing on capillary tubing and was connected to a GC-MS combination. A quantity of the same house dust sample was extracted, using a method consisting of a two-step SFE with CO2 and CO2 + 5% of methanol, and GC-MS analysis of the eluates. The comparison of the results showed that the SFE method was superior to the TD for analysing indoor dust samples because of the pre-separation and the absence of thermal degradation, particularly for compounds of low volatility. However, TD could be more appropriate for relatively volatile or lower molecular weight range compounds and thermally stable compounds.</p>

Enhanced Nontarget Screening Algorithm Reveals Highly Abundant Chlorinated Azo Dye Compounds in House Dust.

Humans spend 90% of their time indoors, but the majority of indoor pollutants remain unknown. In this study, a nontarget screening algorithm with reduced false discovery rates was developed to screen indoor pollutants using the Toxic Substances Control Act (TSCA) database. First, a putative lock mass algorithm was developed for post-acquisition calibration of Orbitrap mass spectra to sub-ppm mass accuracy. Then, a one-stop screening algorithm was developed by combining MS1 spectra, isotopic peaks, retention time prediction, and in silico MS2 spectra. A sufficient true positive rate (73%) and false discovery rate (5%) were achieved for the screening of halogenated compounds at a score cutoff of 0.28. Above this cutoff, 427 chemicals were detected from 24 house dust samples, including 39 chlorinated compounds. While some identified halogenated compounds (e.g., triclosan) are well known, 18 previously unrecognized chlorinated azo dyes were detected with high abundance as the largest class of chlorinated compounds. Two chlorinated azo dyes were confirmed with authentic standards, but the two most abundant chlorinated azo dyes were missed by the algorithm due to the limited breadth of the TSCA database. These compounds were annotated as chlorinated analogues of Disperse Blue 373 and Disperse Violet 93 using the DIPIC-Frag method. This study revealed the presence of highly abundant chlorinated azo dyes in house dusts, highlighting their potential health risks in the indoor environment.

Polycyclic Aromatic Compounds Identified in Thirdhand Smoke Contaminated House Dust

Thirdhand smoke (THS) is the residue of tobacco smoke that remains in house dust and on surfaces, and can be re-emitted into air and further react in the indoor environment to create additional compounds. THS-contaminated house dust poses a special risk to children due to their hand-to-mouth behaviors, as well as their vulnerable stage of development. Chemicals already characterized in THS-contaminated house dust include nicotine, tobacco-specific nitrosamines, and polycyclic aromatic hydrocarbons (PAHs). Here we report on the concentrations of a suite of non-traditionally measured polycyclic aromatic compounds (PACs), including oxygenated-PAHs and methyl-PAHs, which may be more toxic than parent PAHs. House dust samples were collected using the HVS3 cyclone vacuum from homes of smokers (n=30) and nonsmokers (n=9) in San Diego, CA, USA, and characterized for a variety of PACs by GCxGC/ToF-MS. Multiple PACs were elevated in dust samples from smokers’ as compared to nonsmokers’ homes. Of particular note was the detection of 1,2,naphthoquinone (1,2NQ), which was the most highly abundant oxy-PAH, and was elevated in smokers’ homes relative to nonsmokers’ (median 7822 ng/m2 vs. 4111 ng/m2), though this difference was not significant. 1,2NQ levels were significantly correlated with nicotine measured in the same samples (rho = 0.0374, p=0.027), suggesting that this compound may be associated with THS. 1,2 NQ is directly mutagenic and has not been reported before in house dust to our knowledge, though it has been reported in tobacco smoke, PM2.5 air pollution and diesel exhaust. Results indicate that measurement of traditional 16 EPA PAHs may underestimate toxic compounds in house dust, and that thirdhand smoke in house dust may be a source of elevated levels of certain toxic PACs. The compound 1,2 NQ and other PACs in house dust may pose a risk to children and policies should be strengthened to prevent THS exposure in homes.

Analysis of Bisphenol A, Alkylphenols, and Alkylphenol Ethoxylates in NIST SRM 2585 and Indoor House Dust by Gas Chromatography-Tandem Mass Spectrometry (GC/MS/MS).

Background: Ingestion of house dust has been demonstrated to be an important exposure pathway to several contaminants in young children. These compounds include bisphenol A (BPA), alkylphenols (APs), and alkylphenol ethoxylates (APEOs). Analysis of these compounds in house dust is challenging because of the complex composition of the sample matrix. Objective: The objective was to develop a simple and sensitive method to measure BPA, APs, and APEOs in indoor house dust. Methods: An integrated method that involved solvent extraction using sonication, sample cleanup by solid-phase extraction, derivatization by 2,2,2-trifluoro-N-methyl-N-(trimethylsilyl)acetamide, and analysis by GC coupled with tandem MS was developed for the simultaneous determination of BPA, APs, and APEOs in NIST Standard Reference Material (SRM) 2585 (Organic contaminants in house dust) and in settled house dust samples. Results: Target analytes included BPA, 4-tert-octylphenol (OP), OP monoethoxylate, OP diethoxylate, 4-n-nonylphenol (4nNP), 4nNP monoethoxylate (4nNP1EO), branched nonylphenol (NP), NP monoethoxylate, NP diethoxylate, NP triethoxylate, and NP tetraethoxylate. The method was sensitive, with method detection limits ranging from 0.05 to 5.1 μg/g, and average recoveries between 82 and 115%. All target analytes were detected in SRM 2585 and house dust except 4nNP and 4nNP1EO. Conclusions: The method is simple and fast, with high sensitivity and good reproducibility. It is applicable to the analysis of target analytes in similar matrixes, such as sediments, soil, and biosolids. Highlights: Values measured in SRM 2585 will be useful for future research in method development and method comparison.

Correction to Mutagenic Azo Dyes, Rather than Flame Retardants, are the Predominant Brominated Compounds in House Dust.

Correction to Mutagenic Azo Dyes, Rather than Flame Retardants, are the Predominant Brominated Compounds in House Dust.

Mutagenic Azo Dyes, Rather Than Flame Retardants, Are the Predominant Brominated Compounds in House Dust.

Characterization of toxicological profiles by use of traditional targeted strategies might underestimate the risk of environmental mixtures. Unbiased identification of prioritized compounds provides a promising strategy for meeting regulatory needs. In this study, untargeted screening of brominated compounds in house dust was conducted using a data-independent precursor isolation and characteristic fragment (DIPIC-Frag) approach, which used data-independent acquisition (DIA) and a chemometric strategy to detect peaks and align precursor ions. A total of 1008 brominated compound peaks were identified in 23 house dust samples. Precursor ions and formulas were identified for 738 (73%) of the brominated compounds. A correlation matrix was used to cluster brominated compounds; three large groups were found for the 140 high-abundance brominated compounds, and only 24 (17%) of these compounds were previously known flame retardants. The predominant class of unknown brominated compounds was predicted to consist of nitrogen-containing compounds. Following further validation by authentic standards, these compounds (56%) were determined to be novel brominated azo dyes. The mutagenicity of one major component was investigated, and mutagenicity was observed at environmentally relevant concentrations. Results of this study demonstrated the existence of numerous unknown brominated compounds in house dust, with mutagenic azo dyes unexpectedly being identified as the predominant compounds.

Multi-analyte method for the analysis of various organohalogen compounds in house dust

In the present study, a novel analytical approach for the simultaneous determination of 27 brominated flame retardants (BFRs), namely polybrominated diphenyl ethers (PBDEs), isomers of hexabromocyclododecane (HBCD), tetrabromobisphenol A (TBBPA) and several novel BFRs (NBFRs), together with 18 perfluoroalkyl substances (PFASs) in indoor dust was developed and validated. To achieve integrated isolation of analytes from the sample and their fractionation, a miniaturized method based on matrix solid phase dispersion (MSPD) was employed. Principally, after mixing the dust (<0.1g) with the Florisil®, the mixture was applied on the top of a sorbent (Florisil®) placed in glass column and then analytes were eluted using solvents with different polarities. For the identification/quantification of target compounds largely differing in polarity, complementary techniques represented by gas and liquid chromatography coupled to tandem mass spectrometry (GC–MS/MS and LC–MS/MS) were used. The results of validation experiments, which were performed on the SRM 2585 material (for PBDEs, HBCDs and TBBPA), were in accordance with the certified/reference values. For other analytes (NBFRs and PFASs), the analysis of an artificially contaminated blank dust sample was realized. The method recoveries for all target compounds ranged from 81 to 122% with relative standard deviations lower than 21%. The quantification limits were in the range of 1–25ngg−1 for BFRs and 0.25–1ngg−1 for PFASs. Finally, 18 samples (6 households×3 sampling sites) were analyzed. The high variability between concentrations of PFASs and BFRs in the dust samples from various households as well as collecting sites in a respective house was observed. The total amounts of PFASs and BFRs were in the range of 1.58–236ngg−1 (median 10.6ngg−1) and 39.2–2320ngg−1 (median 325ngg−1), respectively. It was clearly shown that dust from the indoor environment might be a significant source of human exposure to various organohalogen pollutants.

The Occurrence of Bisphenol A, Phthalates, Parabens and Other Environmental Phenolic Compounds in House Dust: A Review

Dust from indoor environments can contain significant amounts environmental contaminants and is an important source of human exposure to several toxicants. In this article, studies on the occurrence of several emerging environmental contaminants, namely bisphenol A (BPA), tetrabromobisphenol A (TBBPA), phthalates, parabens, and other environmental phenolic compounds in indoor dust from various countries, were reviewed. Issues associated with sampling of dust and the uncertainties introduced in the analytical procedures were also summarized. Finally, exposure to environmental phenolic compounds through dust ingestion was evaluated, and the contribution of indoor dust to the total daily exposure of toxicants was estimated. Overall, the reported concentrations of target chemicals in dust were found, in decreasing order, as phthalates (overall mean: 949 ± 669 µg/g, range: 0.9-10,900 µg/g) >>> nonylphenol (8.9 ± 6.8 µg/g, 2.6-29.2 µg/g) > BPA (3.6 ± 4.5 µg/g, 0.35-16.6 µg/g) > Σparabens (1.53 ± 0.52 µg/g, 0.03-125 µg/g) > pentachlorophenol (1.39 ± 2.31 µg/g, 0.050- 5.76 µg/g) > triclosan (0.65 ± 0.23 µg/g, 0.38-0.93 µg/g) > TBBPA (0.18 ± 0.14 µg/g, 0.049-0.505 µg/g). Despite the elevated levels of the target phenolic compounds reported in indoor dust, exposure of humans through dust ingestion was minor. Nevertheless, dust can be a significant source of exposure to phenolic compounds for infants and toddlers. Elevated levels of phenolic compounds were found in dust collected from certain microenvironments such as offices and laboratories.

A semi-quantitative approach for analysing low-volatile organic compounds in house dust using an SFE method: Significant common features and particular differences of the extracts

A number of samples have been collected from various indoor environments located in a semi-rural area in north-western Italy, for extraction with supercritical carbon dioxide (CO2) and analysis of low volatility organic compounds on house dust. The investigation was based on a survey analysis approach aiming at the identification of the organic content of indoor dust. The quantification of the content of the compounds was obtained with a semi-quantitative method, incorporating three pre-defined concentration ranges. The classes of compounds, mostly detected in the indoor dust samples analyzed, were fatty acids and some of their esters, n-alkanes, phthalates and alcohols. Other less frequently found classes were other esters, phenols, aliphatic aldehydes and ketons. The compounds that were identified in all or in most of the house dust samples appeared predominantly in high concentration ranges while compounds detected scarcely were measured mainly in low concentrations. The experimental study verified that the most important emission sources for the organic compounds detected in the indoor environment were a wide variety of plastic materials and human activities (e.g., cooking). Particular features of some extracts were attributed to specific actions that took place in the house prior or during sampling, and/or to the materials used in the house construction or heating methods. Among the compounds identified as prominent in the house dust samples were the phthalates, of major interest with regard to their impact on human health.

Dioxin-related compounds in house dust from New York State: Occurrence, in vitro toxic evaluation and implications for indoor exposure

This study analysed sulphuric-acid-treated extracts of house dust from New York State with DR-CALUX assay and HRGC-HRMS to elucidate the total dioxin-like (DL) activities, the occurrence of various dioxin-related compounds (DRCs), including PBDD/Fs, and their toxic contribution. The DL activities were 30–8000, median 210 pg CALUX-TEQ/g. PCDD/Fs, PBDD/Fs and DL-PCBs were detected with a large variation in concentrations (0.12–80, 0.33–150, 0.46–35, medians 1.7, 2.1 and 5.6 ng/g, respectively) and profiles, indicating the existence of multiple contamination sources in homes. PCDD/Fs, PBDD/Fs and DL-PCBs with known potency theoretically contributed <1%–130%, <1%–21% and <1%–6.8%, respectively, of the measured CALUX-TEQs. These results and those from DR-CALUX assays with fractionated dust extracts indicated that a substantial portion of the CALUX-TEQs could be caused by unknown dust contaminants. Considering that the DRC intake from indoor dust ingestion can be significant, identification of unknown DL contaminants in indoor dust is necessary.

Determination of synthetic musk compounds in indoor house dust by gas chromatography–ion trap mass spectrometry

A new method for the simultaneous determination of 11 synthetic musks and one fragrance compound in house dust was developed. The nitro musks included musk ketone (MK, 4-tert-butyl-3,5-dinitro-2,6-dimethylacetophenone), musk xylene (MX, 1-tert-butyl-3,5-dimethyl-2,4,6-trinitrobenzene), musk ambrette (1-tert-butyl-2-methoxy-4-methyl-3,5-dinitrobenzene) and musk moskene (1,1,3,3,5-pentamethyl-4,6-dinitroindane). The polycyclic musk compounds were 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-(γ)-2-benzopyran (HHCB), 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene (AHTN), 4-acetyl-1,1-dimethyl-6-tert-butylindane, 6-acetyl-1,1,2,3,3,5-hexamethylindane, 5-acetyl-1,1,2,6-tetramethyl-3-isopropylindane, 6,7-dihydro-1,1,2,3,3-pentamethyl-4(5H)-indanon. The one macrocyclic musk was 1,4-dioxacycloheptadecane-5,17-dione. The bicyclic hydrocarbon fragrance compound (1,2,3,4,5,6,7,8-octahydro-2,3,8,8-tetramethylnaphthalen-2yl)ethan-1-one (OTNE) and HHCB-lactone (4,6,6,7,8,8-hexamethyl-1H,3H,4H,6H,7H, 8H-indeno[5,6-c]pyran-1-one), a degradation product of HHCB, were also analysed. NIST SRM 2781 (domestic sludge) and SRM 2585 (organic contaminants in house dust) were analysed for these target compounds. The method was applied for the analysis of 49 paired samples collected using two vacuum sampling methods: a sample of fresh or "active" dust (FD) collected using a Pullman-Holt vacuum sampler, and a household dust (HD) sample taken from the participants' vacuum cleaners. Method detection limits and recoveries ranged from 12 to 48ng/g and 54 to 117%, respectively. AHTN, HHCB, OTNE and HHCB-lactone were detected in all samples, with median concentrations of 552, 676, 252 and 453ng/g for FD samples, respectively; and 405, 992, 212 and 492ng/g for HD samples, respectively. MX and MK were detected with high frequencies but with much lower concentrations. The two sampling methods produced comparable results for the target analytes. Widely scattered concentration levels were observed for target analytes from this set of 49 house dust samples, suggesting a wide variability in Canadian household exposure to synthetic musks.

Insuffisance respiratoire aiguë révélant un carcinome bronchiolo-alvéolaire

A novel, highly selective method for the determination of nicotine, N-nitrosamines and tobacco-specific nitrosamines (TSNAs) in indoor dust samples is presented in this study. Samples were extracted by in-cell clean-up pressurized liquid extraction (PLE) that allows high extraction efficiency with moderate consumption of organic solvents. The extracts were analyzed by comprehensive gas chromatography and detected with a nitrogen chemiluminiscence detector (GC × GC-NCD) that provided enhanced selectivity and sensitivity for organic nitrogen containing compounds. Method validation showed good linearity, repeatability and reproducibility (%RSD < 8%). Recovery was higher than 80% for most target compounds and limits of detection lower than 16 ng g−1. The method was used for the determination of the nitrosamine target compounds in house dust samples from both smoking and non-smoking households. All the analytes were found in the samples, nicotine being the most abundant compound in smokers’ dust and one of the most abundant in non-smokers’ dust. To our knowledge this is the first time that volatile N-nitrosamines and TSNAs have been determined in indoor dust samples. The results demonstrate the presence of these highly carcinogenic compounds in house dust, with inherent human exposure through inhalation and/or involuntary ingestion of house dust.

Optimization of variables on the supercritical fluid extraction of high-boiling organic compounds in house-dust

Epidemiological and clinical studies in the recent years have shown that the importance of the indoor air quality to human health should not be underestimated. The assessment of indoor quality requires efficient and reliable methods producing useful information particularly on that related to indoor dust. A significant task in designing mitigation or prevention measures is to identify firstly the classes of compounds that are present in house dust and secondly obtain their contribution in the samples particularly that of low-volatile or non-volatile organic compounds, for which sparse data is available. Extraction of house dust can be used as a screening method for high boiling organic compounds in the indoor environment. Most published work so far, on organic compounds of low volatility and on particulate organic matter has been focused on a few classes of compounds of known toxicity. However, the absence of knowledge on other possibly present classes of compounds could be crucial in determining the extent of exposure. To override this lack of knowledge, the present study introduces a new method based on supercritical fluid extraction (SFE) to detect the classes of the low-volatile or non-volatile organic compounds that are present in the house-dust samples. The application of the particular method of SFE with CO2 can help to extract and analyze a broad range of low volatile organic compounds in dust of indoor environments, which can lead effectively to a more complete characterization. The particular extraction/analytical method for organics in house dust has been set up consisting of a two step supercritical fluid extraction (SFE) with CO2 and CO2+5% of methanol, collection of the extracts on ODS trap, elution of the extracted compounds with methanol and n-hexane and GC/MS analysis of the eluates.

Determination of nicotine and N-nitrosamines in house dust by pressurized liquid extraction and comprehensive gas chromatography—Nitrogen chemiluminiscence detection

A novel, highly selective method for the determination of nicotine, N-nitrosamines and tobacco-specific nitrosamines (TSNAs) in indoor dust samples is presented in this study. Samples were extracted by in-cell clean-up pressurized liquid extraction (PLE) that allows high extraction efficiency with moderate consumption of organic solvents. The extracts were analyzed by comprehensive gas chromatography and detected with a nitrogen chemiluminiscence detector (GC×GC-NCD) that provided enhanced selectivity and sensitivity for organic nitrogen containing compounds. Method validation showed good linearity, repeatability and reproducibility (%RSD<8%). Recovery was higher than 80% for most target compounds and limits of detection lower than 16 ng g(-1). The method was used for the determination of the nitrosamine target compounds in house dust samples from both smoking and non-smoking households. All the analytes were found in the samples, nicotine being the most abundant compound in smokers' dust and one of the most abundant in non-smokers' dust. To our knowledge this is the first time that volatile N-nitrosamines and TSNAs have been determined in indoor dust samples. The results demonstrate the presence of these highly carcinogenic compounds in house dust, with inherent human exposure through inhalation and/or involuntary ingestion of house dust.

Per- and polyfluorinated compounds in house dust and indoor air from northern Norway – A pilot study

Polyfluorinated compounds (PFCs) are an extremely versatile class of compounds and are used in a variety of consumer applications and products. Recent studies have suggested that PFCs in indoor air and dust could act as sources of human exposure and outdoor air contamination. This study presents method development and analysis of a wide range of PFCs in dust and air using active sampling techniques with commercially available sampling equipment (forensic nozzles with filter housings for dust collection and polyurethane foam (PUF)-XAD2-PUF sandwich-tubes for air sampling) using both liquid and gas chromatography mass spectrometry. The developed method was validated and tested for applicability to analyze dust and air samples at both low and high concentrations (0.5ng and 25ng per analyte per air sample, respectively). Samples from private households and an office building were analyzed to explore differences in distribution patterns and concentrations. Perfluorooctane sulfonate, perfluorodecane sulfonate, perfluoroheptanoate, perfluorooctanoate and perfluorononanoate were observed in all samples of dust from private households, in the range from 1 to 80.1ngg−1. Fluorotelomer alcohols (FTOHs) were the predominant PFCs in indoor air samples with ∑FTOHs ranging between 4.7 and 17.9ngm−3. The concentrations found in the present study are generally lower than those previously reported. This variation may be due to differences associated with geographical locations and lifestyles. However, use of different sampling techniques and strategies among studies can introduce large variations in PFC concentration found, making direct comparisons challenging.

Health ranking of ingested semi-volatile organic compounds in house dust: an application to France

People spend most of their time indoors. Dust settled in the home may be contaminated by semi-volatile organic compounds (SVOCs). Exposure to these compounds is of great concern, in particular for infants. Their number is large so arose the question of which ones should be selected for dust ingestion exposure assessment. This work proposes a health ranking of SVOCs ingested through settled dust. This ranking is based on the toxicity and contamination of SVOCs in dust. Data on compounds and contamination was retrieved from a bibliographic review. Where possible, toxicity data was retrieved from databases, otherwise it was calculated from raw data. One hundred and fifty-six SVOCs were selected, 66 of which were prioritized. Forty-two could not be prioritized because contamination data was below the limit of detection, and 48 could not be prioritized because there was no contamination or toxicity data. The top-ranked compounds were phthalates, pesticides, short-chain chlorinated paraffins, PBDEs, PFCs, organotins, PCBs, and PAHs. As most of these have reprotoxic and neurotoxic properties, an integrated multi-pollutants approach to exposure is required and simultaneous measurement methods should be developed. The large number of compounds identified in settled dust in recent years should be considered for the assessment of exposure to dust ingestion. This work provides a health ranking of SVOCs ingested through settled dust. Most of the top-ranked compounds have reprotoxic and neurotoxic properties, and particular attention should, therefore, be paid to them in future studies.

Perfluorinated Compounds in House Dust from Ohio and North Carolina, USA

The perfluoroalkyl acids (PFAAs), including perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), have come under increasing scrutiny due to their persistence, global distribution, and toxicity. Given that their human exposure routes remain poorly characterized, the potential role of house dust needs to be more completely evaluated. In this study, new methods for the analysis of 10 PFAAs and three fluorinated telomer alcohols (FTOHs) were developed for dust samples collected from homes (n = 102) and day care centers (n = 10) in Ohio and North Carolina in 2000-2001. FTOHs were measured by GC/ MS and PFAAs were analyzed by LC-MS/MS. PFOS and PFOA were the most prominent compounds detected, occurring in over 95% of the samples at median concentrations of 201 and 142 ng/g of dust, respectively. Maximal concentrations of PFOS were 12 100 ng/g (95th percentile, 2240 ng/g), PFOA 1960 ng/g (95th percentile, 1200 ng/g), and perfluorohexanesulfonate (PFHS) 35 700 ng/g (95th percentile, 2300 ng/g). The 8:2 FTOH, which is volatile and can degrade to PFOA, had a maximum concentration of 1660 ng/g dust (95th percentile, 669 ng/g). These results indicate that perfluorinated compounds are present in house dust at levels that may represent an important pathway for human exposure.