Comprehensive method for the analysis of multi-class organic micropollutants in indoor dust

Legacy and emerging contaminants in flamingos' chicks' blood from the Ebro Delta Natural Park

The Ebro Delta is a wetland of international importance for waterbird conservation but severally affected by intensive agriculture, toxic waste discharges from a past chloro-alkali industry and affluence of tourism. The discharge of contaminants associated to these activities pose waterbirds breeding in the Ebro Delta at risk. The aim of this study is to evaluate the exposure of 91 emerging and legacy micropollutants in flamingo chicks (Phoenicopterus roseus), an emblematic species of the area. Fifty chicks of 45-60 days were captured, biometric parameters measured and whole blood collected. Compounds analyzed included perfluoroalkyl substances (PFASs), pharmaceuticals, organophosphate esters (OPEs), in-use pesticides, polychlorinated biphenyls (PCBs), organochlorine pesticides (OCs), and polycyclic aromatic hydrocarbons (PAHs). The results indicate a multi-exposure of flamingo's chicks from a very young age. PFASs were the most ubiquitous compounds with ∑PFASs ranging from 9.34 to 576 ng/mL, being PFOA, PFOS and PFHxS detected in all samples. ∑PAHs ranged from 0.19 to 423 ng/mL, ∑PCBs from 0.5 to 15.6 ng/mL and ∑OCs from 1.35 to 37.8 ng/mL. Pharmaceuticals, OPEs and in-use pesticides were not detected. The flamingo's filtering behavior on mud and maternal ovo-transference are the more likely routes of exposure of organic micropollutants to flamingos' chicks. The reported levels of micropollutants were not associated with any alteration in the body condition of chicks. This is the first study to describe flamingos chicks' exposure to multiple contaminants, highlighting the importance of biomonitoring for wildlife conservation and biodiversity preservation.

Distribution and health risks of organic micropollutants from home dusts in Malaysia

Indoor dust is an important medium to evaluate human exposure to emerging organic contaminants. The principal aim of this study was to determine overall status of organic micropollutants (OMPs) of indoor dust in Kuala Lumpur, Malaysia and assess their corresponding health risks. One hundred thirty-three OMPs, ascribed to 13 chemical groups, were screened by Automated Identification and Quantification System with a GC-MS database. The concentrations of OMPs ranged between 460 and 4000 μg/g, with the median concentration of 719 μg/g. The dominant chemical groups were ascribed to n-alkanes (median: 274 μg/g), plasticizers (151 μg/g), sterols (120 μg/g), and pesticides (42.6 μg/g). Cholestrol was the most abundant compound (median: 115 μg/g). Different sources and usage patterns of OMPs in various houses were expected. Toxicity values of OMPs were obtained from existing databases or predicted by quantitative structure-activity relationship models. Cumulative hazard quotients for OMPs through ingestion route were lower than one for all the dust samples, demonstrating that there was no remarkable non-cancer risk. The cancer risks of these OMPs were greater than 10^-4, with cholestrol dominating 99.1% of the carcinogenic risks, which suggested that there was a significant cancer risk. This study might offer a benchmark to ensure the safety of chemical usages in future in Malaysia.

Multiresidue analytical method for high production volume chemicals in dust samples, occurrence and human exposure assessment

A multiresidue analytical method based on pressurised liquid extraction and gas-chromatography mass spectrometry was developed to determine 22 compounds belonging to different chemical families in indoor dust.: Seven organophosphate esters, six phthalate esters, three benzotriazoles, five benzothiazoles and four benzenesulfonamides were included in the present study, all of them belonging to the category of high production volume chemicals (HPVCs). Apparent recoveries ranged between 45% and 123% and method quantification limits ranged from 0.03 μg/g to 3.8 μg/g. The occurrence of the selected HPVCs was evaluated in indoor dust from different locations in the Tarragona (Catalonia, Spain) region. Two benzenesulfonamides, ortho-toluenesulfonamide and para-toluenesulfonamide, were detected in dust samples for the first time. Phthalate esters and organophosphate esters were the most abundant compounds found, and di-(2-ethylhexyl) phthalate (DEHP) was determined at the highest concentrations. With the data obtained, human exposure was assessed by calculating the estimated daily intakes (EDI) via ingestion and dermal contact. Non-carcinogenic and carcinogenic risk assessments found no risks in any of the scenarios tested, which included two age classes (children and adults) and two possible exposure scenarios (median and worst-case scenario), except for the evaluation of carcinogen risk due to ingestion of DEHP in the worst-case scenario.

Occurrence and exposure risk assessment of organic micropollutants in indoor dust from Malaysia

Indoor dust is an important source of human exposure to hazardous organic micropollutants (OMPs) because humans spend about 90 % of their time in the indoor environments. This study initially analyzed the concentrations and compositions of OMPs in the dust of different indoor environments from Kuala Lumpur, Malaysia. A total of 57 OMPs were detected and assigned to 7 chemical classes in this study. The total concentration of OMPs ranged from 5980 to 183,000 ng/g, with the median concentration of 46,400 ng/g. Personal care products, organophosphate esters, and pesticides were the dominant groups, with their median concentrations at 12,000, 10,000, and 5940 ng/g, respectively. The concentrations and compositions of influential OMPs varied in different microenvironments, suggesting different sources and usage patterns in the house. Then, the noncarcinogenic and carcinogenic risks of exposure to these substances for diverse age groups were assessed based on the median concentration. Cumulative noncarcinogenic risks of these OMPs via ingestion pathway were estimated to be negligible (1.41 × 10^-4 - 1.87 × 10^-3). The carcinogenic risks of these OMPs were higher than 10^-6 (1.63 × 10^-6 - 6.17 × 10^-6) and should be noted. Theobromine accounted for more than 89 % of the cumulative cancer risk, implying that the carcinogenic risk of theobromine needs further monitoring in the future. Toddler was the most affected group for cancer risk among all the age groups, regardless of the microenvironments. These findings from this study may provide a benchmark for future efforts to ensure the safety of indoor dust for the local residents.

Exhaustive characterization of (semi-)volatile organic contaminants in car dust using comprehensive two-dimensional gas chromatography ‒ Time-of-flight mass spectrometry

This work represents the first reported effort to build an extensive database of the organic volatile and semi-volatile contaminants present in car dust as a result of migration from materials used in auto-manufacturing. Untargeted analysis of car dust samples has been performed using comprehensive two-dimensional gas chromatography combined with time-of-fight mass spectrometry (GC×GC ‒ToF MS) after generic sample preparation. The enhanced separation power and structural confirmation capabilities provided by this technique have been used for the either positive or tentative identification of 245 GC-amenable compounds, a number of them being identified for the first time in this type of matrix. Information concerning 5 compounds remaining unidentified has also been provided. Results have been summarised in a searchable database containing chromatographic, mass spectral and normalised abundances calculated for the detected analytes in the ten investigated car dusts used to discuss the main findings of the study. Results are expected to serve other researcher to take decisions concerning priority analytes for further evaluation in this research field and for car manufacturers who might search for safer materials.

Accurate and ultrasensitive determination of 72 parent and halogenated polycyclic aromatic hydrocarbons in a variety of environmental samples via gas chromatography-triple quadrupole mass spectrometry

Polycyclic aromatic hydrocarbons (PAHs) and their halogenated derivatives (XPAHs) are ubiquitous in various environmental media. Analytical problems, however, make it difficult to accurately determine their concentrations. To develop a satisfactory analytical method suitable for a diversity of PAHs and XPAHs in multiple environmental samples, we evaluated three commercial analytical columns (DB-5MS, Select PAH, and Rxi-PAH) for better chromatographic separation and optimized the analytical conditions for gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS). Comparison of the abilities of the columns to separate peaks revealed that the Rxi-PAH was the best column for both PAH and XPAH analyses. Optimization of analytical conditions for GC-MS/MS resulted in sensitivities for PAHs and XPAHs that were 4.2-fold-2600-fold higher than the sensitivities of GC-high-resolution MS (GC-HRMS) (an example of a traditional analytical method). Although there were no statistically significant differences between the instrumental detection limits (IDLs) of PAHs and XPAHs measured by GC-HRMS, the IDLs of XPAHs were significantly lower than those of PAHs when measured by GC-MS/MS. This difference could be attributed to the unique ionization patterns of XPAHs in the GC-MS/MS analysis, which suppressed background noise and increased the analytical sensitivity. Analyses of PAHs and XPAHs in grilled chicken, vehicle exhaust, sea sediment, ambient air, and indoor dust via the analytical method optimized in this study revealed that the proposed method was sufficiently sensitive, comprehensive, and versatile for risk assessment purposes, and could eliminate interferences associated with the co-elution of target PAHs and XPAHs.

[Research progress on analytical methods for the determination of hexachlorobutadiene]

Hexachlorobutadiene (HCBD) is one of persistent organic pollutants (POPs) listed in Annex A and Annex C of the Stockholm Convention in 2015 and 2017, respectively. Research on the sources, environmental occurrences, and biological effects of HCBD has a great significance in controlling this newly added POPs. Sensitive and credible methods for the determination of HCBD are preconditions and form the basis for related research work. In recent years, many researchers have included HCBD as one of the analytes in monitoring or methodological studies. Based on the results of these studies, this paper reviews the research progress on analytical methods for the determination of HCBD and focuses on sample pretreatment methods for the analysis of HCBD in various matrices such as air, water, soil, sewage sludge, and biological tissues. The advantages and disadvantages of the methods are also compared to provide reference for further research in this field.For air samples, HCBD was usually collected by passing air through sorbent cartridges. Materials such as Tenax-TA, Carbosieve, Carbopack, Carboxen 1000, or their mixtures were used as the sorbent. HCBD was thermally desorbed and re-concentrated in a trap and finally transferred for instrumental analysis. Limits of detection (LODs) for HCBD in these methods were at the ng/m3 scale. Compared to sampling using pumps, passive air samplers (PAS) such as polyurethane foam PAS (PUF-PAS) do not require external power supply and are more convenient for sampling POPs in air at a large scale. The LOD of the sorbent-impregnated PUF PAS (SIP-PAS) method was much lower (0.03 pg/m3) than that of the PUF-PAS method (20 pg/m3). However, the sampling volumes in the SIP-PAS and PUF-PAS methods (-6 m3) calculated from the log KOA value of HCBD have significant uncertainty, and this must be confirmed in the future.For water samples, HCl or copper sulfate was added to the sample immediately after sampling to prevent any biological activities. HCBD can be extracted from water using methods such as the purge and trap method, liquid-liquid extraction (LLE) method, and solid phase extraction (SPE) method. Among these methods, SPE enabled the simultaneous extraction, purification, and concentration of trace HCBD in a single step. Recoveries of HCBD on Strata-X and Envi-Carb SPE cartridges (63%-64%) were higher than those on Envi-disk, Oasis HLB, and Strata-C18 cartridges (31%-46%). Drying is another key step for obtaining high recoveries of HCBD. Disk SPE involving the combination of a high-vacuum pump and a low-humidity atmosphere is an effective way to eliminate the residual water. In addition, a micro SPE method using functionalized polysulfone membranes as sorbents and employing ultrasonic desorption was developed for extracting HCBD from drinking water. The recovery of HCBD reached 102%, with a relative standard deviation (RSD) of 3.5%.For solid samples such as dust, soil, sediment, sewage sludge, fly ash, and biota tissue, multiple pretreatment methods were used in combination, owing to the more complex matrix. Freeze or air drying, grinding, and sieving of samples were commonly carried out before the extraction. Soxhlet extraction is a typical extraction method for HCBD; however, it requires many organic reagents and is time consuming. The accelerated solvent extraction (ASE) method requires a small amount of organic reagent, and the extraction can be performed rapidly. It was recently applied for the extraction of HCBD from solid samples under 10.34 MPa and at 100 ℃. Purification could be achieved simultaneously by mixing florisil materials with samples in the ASE pool. Nevertheless, employing the ASE methods widely is difficult because of their high costs. Ultrasonic-assisted extraction (UAE) has the same extraction efficiency for HCBD, with much lower costs compared to ASE, and is therefore adopted by most researchers. The type of extraction solvent, solid-to-liquid ratio, ultrasonic temperature, and power affect the extraction efficiency. Ultrasonic extraction at 30 ℃ and 200 W using 30 mL dichloromethane as the extraction solvent resulted in acceptable recoveries (64.0%-69.4%) of HCBD in 2 g fly ash. After extraction, a clean-up step is necessary for the extracts of solid samples. Column chromatography is frequently used for purification. The combined use of several columns or a multilayer column filled with florisil, silica gel, acid silica gel, or alumina can improve the elimination efficiency of interfering substances.Instrumental analysis for HCBD is mainly performed with a gas chromatograph equipped with a mass spectrometer operating in selected ion monitoring mode. DB-5MS, HP-5MS, HP-1, ZB-5MS, and BP-5 can be used as the chromatographic columns. Qualification ions and quantification ions include m/z 225, 223, 260, 227, 190, and 188. GC-MS using an electron ionization (EI) source was more sensitive to HCBD than GC-MS using a positive chemical ionization source (PCI) and atmospheric pressure chemical ionization source (APCI). Gas chromatography-tandem mass spectrometry (GC-MS/MS), gas chromatography-high-resolution mass spectrometry (GC-HRMS), and high-resolution gas chromatography-high-resolution mass spectrometry (HRGC-HRMS) have recently been used for the separation and determination of HCBD and various other organic pollutants. Instrumental detection limits for HCBD in GC-MS/MS, GC-HRMS, and HRGC-HRMS were more than ten times lower than that in GC-MS, indicating the remarkable application potential of these high-performance instruments in HCBD analysis.

The occurrence and distribution of polycyclic aromatic hydrocarbons, bisphenol A and organophosphate flame retardants in indoor dust and soils from public open spaces: Implications for human exposure

Global concern exists regarding human exposure to organic pollutants derived from public open spaces and indoor dust. This study has evaluated the occurrence of 18 polycyclic aromatic hydrocarbons (PAHs), 11 organophosphorus flame retardants (OPFRs) and bisphenol A (BPA). To achieve this, a new simple, efficient and fast multi-residue analytical method based on a fully automated pressurised liquid extraction (PLE) and subsequent quantification by gas chromatography coupled to electron ionization-mass spectrometry (GC-EI-MS) in selected ion monitoring (SIM) mode was developed. The developed method was applied to indoor dust (12 sampling households) and soil derived from two public open spaces (POSs). Among all compounds studied, PAHs were the most ubiquitous contaminants detected in POS soils and indoor dust although some OPFRs and BPA were detected in lower concentrations. An assessment of the incremental lifetime cancer risk (ILCR) was done and indicated a high potential cancer risk from the POS sites and some of the indoor dust sampled sites. However, key variables, such as the actual exposure duration, frequency of contact and indoor cleaning protocols will significantly reduce the potential risk. Finally, the ingestion of soils and indoor dust contaminated with OPFRs and BPA was investigated and noted in almost all cases to be below the USEPA reference doses.

Organic pollutants in indoor dust from Ecuadorian Amazonia areas affected by oil extractivism

Fifty-five household dust samples collected within six settlements surrounding oil production complexes along the Ecuadorian Amazonia were analysed to evaluate the occurrence and distribution of polycyclic aromatic hydrocarbons (PAHs), phthalates, alkylphenols (APs), bisphenol A (BPA), nicotine, organophosphorus flame retardants (OPFRs), polychlorinated biphenyls (PCBs), legacy organochlorine pesticides (OCs) and organophosphorus pesticides. Studied areas are mainly affected by gas flares emissions and oil spilling coming from extractivist operations and pesticides used in agriculture. Median ΣPAHs values ranged from 739 to 1182 ng g^-1 and up to 52% of the PAH dust concentrations were associated to petrogenic activities from crude oil extraction, according to diagnostic ratios. ΣPAHs and toxic equivalents based on benzo[a]pyrene concentration (ΣTEQ_BaP, ng g^-1) suggested similar toxicities among the different areas. Individual lifetime cancer risk (ILCR_dust) was calculated for ingestion and dermal contact exposure routes and a non-acceptable total carcinogenic risk of up to 10^-4 (one case per ten thousand people) was found for newborns from 0 to 3 years-old in Pimampiro area. Plasticisers and OPFRs were present in dust at maximum median concentrations of 332,507 ng g^-1 (DEHP), 5,249 ng g^-1 (DBP), 1,885 ng g^-1 (BPA), 871 ng g^-1 (TBOEP) and 122 ng g^-1 (TEHP). Some dust samples from Ecuadorian houses had high maximum levels of legacy and modern pesticides such as chlorpyrifos (up to 44,176 ng g^-1), 4,4'-DDT (12,958 ng g^-1), malathion (34,748 ng g^-1) and α+β-endosulfan (10,660 ng g^-1) attributed to inappropriate use and storage of the pesticides. Finally, nicotine was seldom detected (36 ng g^-1). The sources and risks of these compounds are discussed based on the activities carried out in the study areas and attending to an additional non-cancer risk assessment which showed high hazard quotients (HQ) and hazard indexes (HI) for DEHP, DBP, 4,4'-DDT, malathion, chlorpyrifos, naphthalene and benzo[a]pyrene in newborns and children up to 16 years-old.

Nasal lavages as a tool for monitoring exposure to organic pollutants

Exposure to air and dust pollutants can cause several adverse effects on human health. This study proposes the use of nasal lavages as a non-invasive sampling technique to determine in a direct way pollutant intake through inhalation. We evaluate the occurrence of compounds widely used in domestic products and construction materials (organophosphorus flame retardants (OPFR), phthalates, alkylphenols and bisphenol A), applied for pest control in cities (pesticides) and emitted through car exhausts (polycyclic aromatic hydrocarbons, PAHs) or smoking (nicotine). Contaminants were liquid-liquid extracted from nasal lavages and analysed using gas chromatography coupled to tandem mass spectrometry (GC-MS/MS). All 29 individuals inhabiting in Barcelona city had phthalates and bisphenol A at concentrations up to 31,300 ng mL^-1 for diethylhexyl phthalate (DEHP) and 118 ng mL^-1 for BPA. Individual PAHs, OPFR and alkylphenols had median values below their MQLs except for 2-ethylhexyldiphenyl phosphate (EHDPhP) with a median of 1.47 ng mL^-1. Nicotine was detected at the highest concentrations in all active smokers (median 2.16 ng mL^-1). Contrarily, pesticides were sporadically detected. Nasal lavages revealed to be an appropriate indicator likely to reflect exposure to dust and air contaminants.

Assessment of gas chromatography time-of-flight mass spectrometry for the screening of semi-volatile compounds in indoor dust

Indoor dust contains a complex mixture of anthropogenic and synthetic compounds closely related to dermal and respiratory diseases. Target methods have been developed for the quantification of distinct groups of substances in dust samples; however, the comprehensive characterization of the different species existing in this matrix remains a challenging issue. Herein, we assess the performance of gas chromatography (GC) time-of-flight mass spectrometry (TOF-MS), using electron ionization (EI), for the screening of compounds present in indoor dust. Samples are processed by pressurized-liquid extraction (PLE) before GC-EI-TOF-MS analysis. The study proposes a data mining workflow for the non-target identification of species contained in dust extracts, aided by preliminary comparison with nominal resolution EI-MS spectra in the NIST17 library. The possibilities, and the limitations, of the above approach are discussed and the identities of >75 compounds are confirmed by comparison with authentic standards in dust from indoor environments. Some species, such as indigo, phthalic anhydride, 2,4-toluene di-isocyanate, phthalimide, certain UV absorbers and octyl isothiazolinone, identified in this research, have not been previously considered in target methods dealing with dust analysis. The study also evaluates two different algorithms for the suspected-target screening of dust extracts using a customized library of accurate EI-MS spectra. Finally, a semi-quantitative estimation of the range of concentrations for a group of 44 pollutants in a set of 27 dust samples is provided.

Differential occurrence, profiles and uptake of dust contaminants in the Barcelona urban area

Dust is a complex but increasingly used matrix to assess human exposure to organic contaminants both in indoor and outdoor environments. Knowledge concerning the effects of organic pollution towards health outcome is crucial. This study is aimed to determine the presence of legacy compounds (DDTs and polychlorinated biphenyls, PCBs), compounds used in recent times (organophosphorous flame retardants, organophosphorous pesticides, BPA, phthalates and alkylphenols) and compounds originated from combustion processes (polycyclic aromatic hydrocarbons, PAHs) as well as nicotine in indoor environments along the metropolitan area of Barcelona. Monitored sites include public areas with high turnout (high schools, museums samples) and libraries and private spaces (houses and cars). Almost all compounds (57 over the 59 targeted) were found in each dust sample and libraries and schools were the most contaminated, with concentrations of ∑phthalates and ∑OPFRs up to 15 and 10 mg g^-1, respectively. One-way ANOVA tests, Tukey contrasts and principal component analysis (PCA) revealed that sampling place influenced the observed contamination profiles and public and private environments were clearly differentiated. Finally, based on the concentrations detected, a deterministic calculation was performed to estimate the total daily intakes of each compound via dust. This information was used to evaluate the human exposure for toddlers, teenagers and adult workers. Consistently, the highest concentrations coming from plasticisers and flame retardants gave the major exposure rates. As expected, toddlers were the most affected group followed by museum and library workers, although the levels were below the reference doses.

A simple analytical method for the simultaneous determination of multiple organic pollutants in sediment samples

Due to the extensive application of synthetic organic chemicals, the resulting environmental contamination with such chemicals is of great concern. Herein, we describe the development of a simple analytical method to determine several groups of organic compounds in sediment samples. Samples were soxhlet-extracted with dichloromethane, separated, and cleaned-up by passage through a combined column of neutral alumina/silica gel, then identified and determined by GC—MS analysis. Four sediment samples were analyzed to validate the efficiency, and acceptable recoveries and good repeatability were obtained.

•

Combined chromatographic columns of silica gel and alumina have been used for separation and clean-up.

•

Five groups of organic compounds have been simultaneously analyzed.

•

Acceptable recoveries with good reproducibility have been achieved.