Detection of Bromochloro Alkanes in Indoor Dust Using a Novel CP-Seeker Data Integration Tool.

Bromochloro alkanes (BCAs) have been manufactured for use as flame retardants for decades, and preliminary environmental risk screening suggests they are likely to behave similarly to polychlorinated alkanes (PCAs), subclasses of which are restricted as Stockholm Convention Persistent Organic Pollutants (POPs). BCAs have rarely been studied in the environment, although some evidence suggests they may migrate from treated-consumer materials into indoor dust, resulting in human exposure via inadvertent ingestion. In this study, BCA-C14 mixture standards were synthesized and used to validate an analytical method. This method relies on chloride-enhanced liquid chromatography-electrospray ionization-Orbitrap-high resolution mass spectrometry (LC-ESI-Orbitrap-HRMS) and a novel CP-Seeker integration software package for homologue detection and integration. Dust sample preparation via ultrasonic extraction, acidified silica cleanup, and fractionation on neutral silica cartridges was found to be suitable for BCAs, with absolute recovery of individual homologues averaging 66 to 78% and coefficients of variation ≤10% in replicated spiking experiments (n = 3). In addition, a total of 59 indoor dust samples from six countries, including Australia (n = 10), Belgium (n = 10), Colombia (n = 10), Japan (n = 10), Thailand (n = 10), and the United States of America (n = 9), were analyzed for BCAs. BCAs were detected in seven samples from the U.S.A., with carbon chain lengths of C8, C10, C12, C14, C16, C18, C24 to C28, C30 and C31 observed overall, though not detected in samples from any other countries. Bromine numbers of detected homologues in the indoor dust samples ranged Br1-4 as well as Br7, while chlorine numbers ranged Cl2-11. BCA-C18 was the most frequently detected, observed in each of the U.S.A. samples, while the most prevalent degrees of halogenation were homologues of Br2 and Cl4-5. Broad estimations of BCA concentrations in the dust samples indicated that levels may approach those of other flame retardants in at least some instances. These findings suggest that development of quantification strategies and further investigation of environmental occurrence and health implications are needed.

Polybrominated diphenyl ethers (PBDEs) in car and house dust from Thailand: Implication for human exposure.

This study examines concentrations of tri- to hexa-bromodiphenylethers (BDEs 17, 28, 47, 49, 66, 85, 99, 100, 153 and 154; Σ10PBDEs (polybrominated diphenyl ethers)) in car (n = 30) and house dust samples (n = 53) collected from different provinces in Thailand. The specific objectives of this study were: (i) to monitor levels of tri- to hexa-bromodiphenylethers (BDEs 17, 28, 47, 49, 66, 85, 99, 100, 153 and 154; Σ10PBDEs) in vehicle and residential dust sampled from various provinces in Thailand; (ii) to compare PBDE concentrations with those detected for domestic and automobile dust in studies from other countries and (iii) to estimate exposure of the Thai population to the target PBDEs via dust ingestion. Levels of Σ10PBDEs in vehicle and domestic dust were 0.68-38 and 0.59-260 ng g-1, respectively. BDEs 99 and 47 were the most abundant congeners in all automobile and residential dust samples. A t-test analysis indicated that Σ10PBDE concentrations in dust samples from dwellings exceeded significantly those from cars (p = 0.001). Furthermore, contents in dust of all PBDEs studied, except for BDE-28, were significantly higher in homes than in vehicles (p = 0.000-0.004). Principal Component Analysis (PCA) demonstrated no differences in PBDE congener patterns between Thai house and automobile dust, but revealed some subtle differences in the congener pattern between household dust samples in Thailand and those reported previously for the United Kingdom. Estimated environmental exposure of Thai adults and children for BDE-99 via dust ingestion were well within a chronic oral reference dose (RfD) for BDE-99 (100 ng/kg bw/day) proposed by the United States Environmental Protection Agency (US EPA).

Organophosphorus flame retardants (PFRs) and phthalates in floor and road dust from a manual e-waste dismantling facility and adjacent communities in Thailand.

This study was undertaken to investigate levels of organophosphorus flame retardants (PFRs) and phthalates in floor and road dust from a manual e-waste dismantling facility and nearby communities in Thailand. Concentrations of Σ10 PFRs and Σ6 phthalates in floor dust from the facility were approximately 36-1,700 and 86,000-790,000 ng g-1, whereas those from the communities were about 13-9,200 and 44,000-2,700,000 ng g-1, respectively. The highest content of Σ10 PFRs (9,200 ng g-1) and Σ6 phthalates (2,700,000 ng g-1) in indoor dust was both detected in the dust sampled from a house with no prevailing winds located 350 m northeast of the facility. Levels of Σ10 PFRs and Σ6 phthalates in road dust from the facility were around 1,100-2,100 and 40,000-670,000 ng g-1, while those from the residences were about 650-2,000 and 27,000-650,000 ng g-1, respectively. Concentrations of Σ10 PFRs (2,100 ng g-1) and Σ6 phthalates (670,000 ng g-1) in road dust were greatest in the dust collected from the facility. For the distributional pattern, TBEP (tris (2-butoxyethyl) phosphate) was the main PFR in residential dust, whereas TPP (triphenyl phosphate) was the major PFR in facility dust. TBEP was also found to be the most prominent PFR in all road dust samples. Furthermore, DEHP (di-2-ethylhexyl phthalate) was the most abundant phthalate congener in both floor and road dust samples. Under realistic high-end scenarios of environmental exposure to DEHP, Thai toddlers (25.29 µg kg-1 bw day-1) in the adjacent communities were exposed above the US EPA's (United States Environmental Protection Agency) reference dose (RfD) for this congener (20 µg kg-1 bw day-1). Our data reveal that the PFR and phthalate-containing products at the residences are a likely substantial source of PFRs and phthalates to the surrounding indoor environment, and humans can be exposed to PFRs and phthalates in their dwellings via the settled floor dust.

Polybrominated diphenyl ethers (PBDEs) in floor and road dust from a manual e-waste dismantling facility and adjacent communities in Thailand.

This study characterizes concentrations of polybrominated diphenyl ethers (PBDEs) in floor and road dust from a manual e-waste dismantling facility and adjacent communities in Thailand. Levels of Σ22 PBDEs in floor dust from the facility varied between 1,200 and 43,000 ng g-1, whereas those from adjacent communities were in the range 6.6-2,200 ng g-1. Concentrations of Σ22 PBDEs (43,000 ng g-1) were highest in floor dust collected from the facility. Levels of Σ22 PBDEs and all congeners studied, except for BDE-66, BDE-71, BDE-85, BDE-119, BDE-138, BDE-190 and BDE-191 in facility dust were significantly greater than those in residential dust (P = <0.001-0.017). Moreover, PBDE contents decreased with increasing distance from the facility, revealing that the facility may represent a principal source of PBDEs to the surrounding environment. Levels of Σ22 PBDEs in road dust from the facility varied from 27 to 21,000 ng g-1, while those from the adjacent residences were about 5.4-63 ng g-1. Concentrations of Σ22 PBDEs (21,000 ng g-1) were highest in road dust taken at the facility. The PBDE congener profile for floor dust from the facility was dominated by BDEs 28, 47 and 209, whereas domestic floor dust was predominated by BDEs 206 and 209. Under various scenarios of occupational and environmental exposure to BDE-99 and BDE-209, workers in the facility as well as adults and children in the adjacent communities were exposed below the United States Environmental Protection Agency (US EPA)'s reference doses (RfDs) for BDE-99 (100 ng/kg bw/day) and BDE-209 (7,000 ng/kg bw/day).

Di (2-ethylhexyl) phthalate effects on the growth, development, and reproduction of Moina macrocopa (Crustacea: Cladocera).

Di (2-ethylhexyl) phthalate (DEHP) is used as a plasticizer in plastics. The effects of DEHP on terrestrial vertebrates have been extensively reported but the effects of DEHP contamination on aquatic ecosystems have not been thoroughly studied. Since water bodies are one of the main mediums through which DEHP is released worldwide, the impacts of DEHP contamination should be manifested in water fleas. Therefore, maternal Moina macrocopa were exposed to 1, 10, 100, and 1000 µg/L concentrations of DEHP. Changes in growth and reproduction were evaluated. The findings demonstrated that DEHP exposure did not have a negative impact on growth or the ability to reproduce. An analysis of the ovary yolk body (YB) demonstrated that the average size and number of yolk bodies (YBs) produced by M. macrocopa exposed to 1000 µg/L DEHP were not significantly different to the average size and number of YBs produced in blank control and solvent control conditions. These outcomes support the cellular pathology data gathered by other researchers. Nevertheless, when M. macrocopa was exposed to 1000 µg/L DEHP for five days, a significant increase in YB numbers was observed with changes in YB morphology. The critical cellular pathology of YB showed morphological abnormalities, including rod-shaped YBs, and YB density was higher than in the blank and solvent controls. Even though these results suggest that antioxidative stress can be induced by DEHP exposure, growth, and reproduction were not significantly different among exposed water fleas compared to fleas in the blank and solvent controls. The result was attributed to the antioxidant response of the water flea. In conclusion, the present study enhances our understanding of previous findings from risk assessments of DEHP contamination in aquatic ecosystems.

Metagenomic insights into isolable bacterial communities and antimicrobial resistance in airborne dust from pig farms.

This study aims to investigate bacterial communities and antimicrobial resistance (AMR) in airborne dust from pig farms. Airborne dust, pig feces and feed were collected from nine pig farms in Thailand. Airborne dust samples were collected from upwind and downwind (25 meters from pig house), and inside (in the middle of the pig house) of the selected pig house. Pig feces and feed samples were individually collected from the pen floor and feed trough from the same pig house where airborne dust was collected. A direct total bacteria count on each sampling plate was conducted and averaged. The ESKAPE pathogens together with Escherichia coli, Salmonella, and Streptococcus were examined. A total of 163 bacterial isolates were collected and tested for MICs. Pooled bacteria from the inside airborne dust samples were analyzed using Metagenomic Sequencing. The highest bacterial concentration (1.9-11.2 × 103 CFU/m3) was found inside pig houses. Staphylococcus (n = 37) and Enterococcus (n = 36) were most frequent bacterial species. Salmonella (n = 3) were exclusively isolated from feed and feces. Target bacteria showed a variety of resistance phenotypes, and the same bacterial species with the same resistance phenotype were found in airborne dust, feed and fecal from each farm. Metagenomic Sequencing analysis revealed 1,652 bacterial species across all pig farms, of which the predominant bacterial phylum was Bacillota. One hundred fifty-nine AMR genes of 12 different antibiotic classes were identified, with aminoglycoside resistance genes (24%) being the most prevalent. A total of 251 different plasmids were discovered, and the same plasmid was detected in multiple farms. In conclusion, the phenotypic and metagenomic results demonstrated that airborne dust from pig farms contained a diverse array of bacterial species and genes encoding resistance to a range of clinically important antimicrobial agents, indicating the significant role in the spread of AMR bacterial pathogens with potential hazards to human health. Policy measurements to address AMR in airborne dust from livestock farms are mandatory.

An international investigation of chlorinated paraffin concentrations and homologue distributions in indoor dust.

In this study, very short-, short-, medium-, and long-chain chlorinated paraffins (vSCCPs, SCCPs, MCCPs and LCCPs, respectively) were measured in 40 indoor dust samples from four countries including Japan (n = 10), Australia (n = 10), Colombia (n = 10) and Thailand (n = 10). Homologues of the chemical formula CxH(2x+2-y)Cly ranging C6-36 and Cl3-30 were analysed using liquid chromatography coupled to Orbitrap high resolution mass spectrometry (LC-Orbitrap-HRMS) and integrated using novel custom-built CP-Seeker software. CPs were detected in all dust samples with MCCPs the dominant homologue group in all countries. Overall median ∑SCCP, ∑MCCP and ∑LCCP (C18-20) concentrations determined in dust samples were 30 µg/g (range; 4.0-290 µg/g), 65 µg/g (range; 6.9-540 µg/g) and 8.6 µg/g (range; <1.0-230 µg/g), respectively. Of the quantified CP classes, overall concentrations were generally highest in the samples from Thailand and Colombia, followed by Australia and Japan. vSCCPs with C≤9 were detected in dust from each country with an overall frequency of 48%, while LCCPs (C21-36) were present in 100% of samples. Estimated daily intakes (EDIs) calculated for SCCPs and MCCPs relating to ingestion of contaminated indoor dust were considered not to represent health risks based on currently available toxicological data using the margin of exposure (MOE) approach. To the authors' knowledge, this study provides the first data on CPs in indoor dust from Japan, Colombia and Thailand, and is among the first reports of vSCCPs in indoor dust, globally. These findings indicate that further toxicological data and the availability of appropriate analytical standards are needed to evaluate the potential for negative health outcomes deriving from exposure to vSCCPs and LCCPs.

Analytical characteristics and determination of major novel brominated flame retardants (NBFRs) in indoor dust.

A new method was developed and optimized for the detection of major "novel" brominated flame retardants (NBFRs), which included decabromodiphenyl ethane (DBDPE), 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), tetrabromobisphenol A-bis(2,3-dibromopropylether) (TBBPA-DBPE), 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB), bis(2-ethylhexyl)-3,4,5,6-tetrabromophthalate (TBPH) and hexachlorocyclopentadienyl-dibromocyclooctane (HCDBCO). Several solid phase sorbents were tested, and finally, a two-step cleanup procedure was established. The first step on activated silica was used to fractionate the dust extracts, while the second step on acidified silica (silica gel impregnated with sulphuric acid 44% w/w) and on Florisil(®), respectively, was essential for advanced cleanup. High recoveries for NBFRs (range, 75-94%) were achieved. Analysis was performed by gas chromatography coupled with mass spectrometry in electron capture negative ionization using a DB-5ms (15 m × 0.25 mm × 0.1 µm) capillary column. Quantification of DBDPE, BTBPE and TBBPA-DBPE was based on ion m/z 79, while characteristic ions were used for quantification of TBB (m/z 359), HCDBCO (m/z 310) and TBPH (m/z 384). The method provided good repeatability; within- and between-day precision were ≤14% for all NBFRs. Method limits of quantification ranged between 1 and 20 ng g(-1); dust and NBFRs were not detected in blanks. The method was further applied to indoor dust (n = 21) collected from e-waste facilities in Thailand. Except for HCDBCO, all NBFRs were detected in the e-waste dust with concentrations up to 44,000 and 22,600 ng g(-1) DBDPE and BTBPE, respectively. The dust profile was dominated by DBDPE (50%) > BTBPE (45%) > TBBPA-DBPE (3%) > TBPH (1.9%) > TBB (0.1%). Significant correlations (p < 0.05) were found between the concentrations of BTBPE and BDE 183 or BDE 197 on the one hand, between TBPH and BDE 47 or BDE 99, and between DBDPE and BDE 209, on the other hand. Concentrations of TBB were not positively correlated with TBPH, which suggests different emission sources.

The Development of a Rapid Health Impact Assessment Model for Songkhla Special Economic Zone (SEZ) Policy in Southern Thailand.

BACKGROUND: Rapid Health Impact Assessment (Rapid HIA) for Special Economic Zone (SEZ) has not been undertaken in Thailand. We aimed to develop a Rapid HIA model for policymaking by using Songkhla SEZ as a study model. METHODS: Four-stage of the research and development based on HIA process were used: 1) drafting the model using literature reviews and focus group discussions, 2) collecting additional information from 24 stakeholders, and conducting an in-depth interview with six informants, 3) verifying the model by drawing agreements on the model from 17 related agencies and experts, and 4) confirming the validity of the final model using seven experts. The study were conducted from Jan 2018 to Feb 2019. Content analysis and constant comparison were used to analyze the data. RESULTS: A four-step assessment model was obtained. They included public screening, scoping, assessing, and reviewing and influencing. Public screening is deduced from a meeting with organizations and related personnel. Public scoping is an outcome of literature reviewing and meeting with stakeholders and academics. The assessment step focuses on secondary data from related agencies and a participatory workshop with stakeholders and academics. Finally, a meeting with stakeholders and academics, including internet broadcasting, is the reviewing and influencing process. CONCLUSION: This Rapid HIA model was specifically developed for SEZ policy. Reviewing and influencing steps were combined, whereas the monitoring and evaluation step was removed for further operations. This model depends on the official appointment of the steering committee. HIA practitioners should be experienced academics from higher educational institutions.

Within-room and within-building temporal and spatial variations in concentrations of polybrominated diphenyl ethers (PBDEs) in indoor dust.

Within-house and within-room spatial temporal variability in PBDE contamination of indoor dust may influence substantially the reliability of human exposure assessments based on single point samples, but have hitherto been little studied. This paper reports concentrations of PBDEs 17, 28, 47, 49, 66, 85, 99, 100, 153, and 154 in indoor dust samples (n=112) from two houses in Birmingham, UK. To evaluate within-house spatial variability, four separate rooms were sampled in house 1 and two separate rooms sampled in house 2. Up to four different 1 m² areas in the same room were sampled to evaluate within-room spatial variability, and for all studied areas, samples were taken for eight consecutive months to evaluate temporal and seasonal variability. Concentrations of ΣPBDEs in individual samples from house 1 varied between 21 and 280 ng g⁻¹; while the range of concentrations in house 2 was 20-1000 ng g⁻¹. This indicates that where and when a sample is taken in a house can influence substantially the contamination detected. In one room, concentrations of PBDEs in an area located close to putative PBDE sources exceeded substantially those in an area 2m away, with marked differences also observed between two areas in another room. Substantial within-room spatial differences in PBDE concentrations were not discernible in the other rooms studied. Concentrations of PBDEs in the majority of rooms within the same houses were not markedly different between rooms. Nevertheless, large differences were observed between PBDE concentrations detected in two rooms in the same house in both houses studied. In one instance, this is hypothesised to be attributable to the presence of a carpet in one room and bare wooden floor in another, but firm conclusions cannot be drawn. Within-room temporal (month-to-month) variability was substantial (relative standard deviations for ΣPBDEs=15-200%). In some rooms, the introduction and removal of putative sources like a TV and a bed, appeared to exert a discernible influence on PBDE concentrations. PBDE concentrations in spring and summer were not markedly different from those observed in autumn and winter. Possible dilution of PBDE concentrations in dust at higher dust loadings (g dust per m² floor surface) was investigated in a small number of rooms, but no firm evidence of such dilution was evident.

Brominated flame retardants (BFRs) in air and dust from electronic waste storage facilities in Thailand.

This study reports concentrations of brominated flame retardants in dust samples (n=25) and in indoor (n=5) and outdoor air (n=10) (using PUF disk passive air samplers) from 5 electronic and electrical waste (e-waste) storage facilities in Thailand. Concentrations of Sigma(10)PBDEs (BDEs 17, 28, 47, 49, 66, 85, 99, 100, 153 and 154) in outdoor air in the vicinity of e-waste storage facilities ranged from 8 to 150 pg m(-3). Indoor air concentrations ranged from 46 to 350 pg m(-3), with highest concentrations found in a personal computer and printer waste storage room at an e-waste storage facility. These are lower than reported previously for electronic waste treatment facilities in China, Sweden, and the US. Concentrations of Sigma(21)PBDEs (Sigma(10)PBDEs+BDEs 181, 183, 184, 191, 196, 197, 203, 206, 207, 208 and 209), decabromodiphenylethane (DBDPE), decabromobiphenyl (BB-209) in dust were 320-290,000, 43-8700 and <20-2300 ng g(-1) respectively, with the highest concentrations of Sigma(21)PBDEs, BDE-209 and DBDPE in a room used to house discarded TVs, stereos and radios. PBDE concentrations in dust were slightly higher but within the range of those detected in workshop floor dust from an e-waste recycling centre in China. The highest concentration of BB-209 was detected in a room storing discarded personal computers and printers. Consistent with recent reports of elevated ratios of BDE-208:BDE-209 and BDE-183:BDE-209 in household electronics from South China, percentage ratios of BDE-208:BDE-209 (0.64-2.9%) and of BDE-208:BDE-183 (2.8-933%) in dust samples exceeded substantially those present in commercial deca-BDE and octa-BDE formulations. This suggests direct migration of BDE-208 and other nonabrominated BDEs from e-waste to the environment. Under realistic high-end scenarios of occupational exposure to BDE-99, workers in the facilities were exposed above a recently-published Health Based Limit Value for this congener. Reassuringly, estimated exposures to BDE-209 were below the USEPA's reference dose for this congener.

Mercury contamination and potential impacts from municipal waste incinerator on Samui Island, Thailand.

In recent years, mercury (Hg) pollution generated by municipal waste incinerators (MWIs) has become the subject of serious public concern. On Samui Island, Thailand, a large-scale municipal waste incinerator has been in operation for over 7 years with a capacity of 140 tons/day for meeting the growing demand for municipal waste disposal. This research assessed Hg contamination in environmental matrices adjacent to the waste incinerating plant. Total Hg concentrations were determined in municipal solid waste, soil and sediment within a distance of 100 m to 5 km from the incinerator operation in both wet and dry seasons. Hg analyses conducted in municipal solid waste showed low levels of Hg ranging between 0.15-0.56 mg/kg. The low level was due to the type of waste incinerator. Waste such as electrical appliances, motors and spare parts, rubber tires and hospital wastes are not allowed to feed into the plant. As a result, low Hg levels were also found in fly and bottom ashes (0.1-0.4 mg/kg and