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This study aimed to characterize the uptake of organophosphate esters (OPEs) by polyurethane foam (PUF) and sorbent-impregnated polyurethane foam (SIP) disk passive air samplers (PAS). Atmospheric OPE concentrations were monitored with high-volume active air samplers (HV-AAS) that were co-deployed with passive air samplers. Samples were analyzed for tris(2-chloroisopropyl) phosphate (TCIPP), tri(phenyl) phosphate (TPhP), tris(2-chloroethyl) phosphate (TCEP), and tris(2,3-dichloropropyl) phosphate (TDCIPP). The mean concentration of ∑OPEs in air was 2650 pg/m 3 for the HV-AAS. Sampling rates and the passive sampler medium (PSM)-air partition coefficient (K PSM-Air ) were calculated for individual OPEs. The average calculated sampling rates (R) for the four OPEs were 3.6 ± 1.2 and 4.2 ± 2.0 m 3 /day for the PUF and SIP disks, respectively, and within the range of the recommended default value of 4 ± 2 m 3 /day. Since most of the OPEs remained in the linear uptake phase during the study, COSMO-RS solvation theory and an oligomer-based model were used to estimate K PUF-Air for the OPEs. The estimated values of log K PUF-Air were 7.45 (TCIPP), 9.35 (TPhP), 8.44 (TCEP), and 9.67 (TDCIPP). Finally, four configurations of the PUF and SIP disks were tested by adjusting the distance of the gap opening between the upper and lower domes of the sampler housing: i.e. 2 cm, 1 cm, no gap and 1 cm overlap. The sampling rate did not differ significantly between these four configurations (p < 0.05)., (Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.)

Heterogeneous reactions between OH radicals and emerging flame retardant compounds coated on inert particles have been investigated. Organophosphate esters (OPEs) including triphenyl phosphate (TPhP), tris-2-ethylhexyl phosphate (TEHP), and tris-1,3-dichloro-2-propyl phosphate (TDCPP) were coated on (NH4)2SO4 particles and exposed to OH radicals in a photochemical flow tube at 298 K and (38.0 ± 2.0) % RH. The degradation of these particle-bound OPEs was observed as a result of OH exposure, as measured using a Time-of-Flight Aerosol Mass Spectrometer. The derived second-order rate constants for the heterogeneous loss of TPhP, TEHP, and TDCPP were (2.1 ± 0.19) × 10(-12), (2.7 ± 0.63) × 10(-12), and (9.2 ± 0.92) × 10(-13) cm(3) molecule(-1) s(-1), respectively, from which approximate atmospheric lifetimes are estimated to be 5.6 (5.2-6.0), 4.3 (3.5-5.6), and 13 (11-14) days. Additional coating of the OPE coated particles with an OH radical active species further increased the lifetimes of these OPEs. These results represent the first reported estimates of heterogeneous reaction rate constants for these species. The results demonstrate that particle bound OPEs are highly persistent in the atmosphere with regard to OH radical oxidation, consistent with the assumption that OPEs can undergo medium or long-range transport, as previously proposed on the basis of field measurements. Finally, these results indicate that future risk assessment and transport modeling of emerging priority chemicals with semi- to low-volatility must consider particle phase heterogeneous loss processes when evaluating environmental persistence.

Fifteen polybrominated diphenyl ethers (PBDEs) and eighteen non-PBDEs were measured in 116 dust samples collected from homes in Vancouver, Canada during 2007-2008 as part of the Chemicals Health and Pregnancy (CHirP) study. The highest concentrations of PBDEs in house dust were observed for BDE 209, with a median concentration of 1350 ng/g. This is about two times greater than the median concentration of the PentaBDE (represented by the most abundant compounds in this formulation, ΣBDE 47, 99 and 100). In the case of non-PBDE FRs, a detection frequency between 81% and 100% was observed for nine analytes including: HBCD, BTBPE, BEHTBP, EHTBB, HBB, PBTO, PBBe, ATE and DP. The high detection of new FRs in indoor environments reflects their ubiquitous presence in indoor environment due to regulation of the PBDEs. Exposure to FRs are estimated based on these data for adults and toddlers., (Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.)

Hexachlorocyclopentadienyl-dibromocyclooctane (HCDBCO, CAS 51936-55-1) has been detected in residential indoor air and indoor dust in Ottawa, Canada. The positive identification of the chemical was based on the interpretation of the mass spectra of the chemical obtained under both electron impact and negative chemical ionization operation modes, as well as through the synthesis of this chemical. This is the first report on the presence of HCDBCO in the environment. Although the levels of HCDBCO in indoor dust, with a geometric mean of 2.7 ng g(-1) and a median of 2.0 ng g(-1) respectively, are generally low compared to those of polybrominated diphenyl ethers (PBDEs) and dechlorane plus, another recently detected flame retardant, high levels of HCDBCO were detected in several dust samples with a maximum level of 93,000 ng g(-1) which is 16 times higher than the maximum level of the structurally related dechlorane plus. On the other hand, levels of HCDBCO in indoor air, with a geometric mean of 70 pg m(-3) and a median of 92 pg m(-3), were higher than those of the major PBDE congeners. The maximum level of HCDBCO found in indoor air was 3000 pg m(-3). Structurally, HCDBCO belongs to a group of norbornane based halogenated flame retardants. The presence of HCDBCO in the indoor environment may raise awareness of the potential release of this and related flame retardants into the environment during the production and usage of products that contain them, and the potential implications of human exposure to these chemicals as people spend the majority of their time indoors in modern society.

Dechlorane plus (DP), a flame retardant recently identified in the air and sediment of the Great Lakes region, has been detected in residential indoor dust in the city of Ottawa, Canada using gas chromatography-mass spectrometry under negative chemical ionization mode. DP was detected in all dust samples with a concentration range of 2.3 to 182 ng g(-1), except for one dust sample (5683 ng g(-1)) which was much higher. The levels of DP in indoor dust were several times higher than those in the sediment of the Great Lakes. The presence of DP in indoor environments could have implications for potential human exposure to this chemical. The daily human intake of DP from dust was estimated using dust ingestion data from the U.S. Environmental Protection Agency. The large variation of the ratio of syn- and anti-DP isomers in the dust samples also suggests a complex degradation process of DP in the environment.

Passive air samplers consisting of polyurethane foam (PUF) disks housed in chambers were deployed at several sites along a approximately 75 km urban-rural gradient in Toronto and analyzed for polybrominated diphenyl ethers (PBDEs). Samplers were allowed to integrate gas-phase PBDEs over three consecutive seasons starting in the summer of 2000. PBDEs were fairly uniform along the transect with air concentrations in Toronto (10-30 pgm(-3)) about a factor of two greater than at rural sites. Lowest concentrations were observed during the winter and probably associated with reduced inputs from indoor sources of PBDEs and to a preference for PBDEs to partition to the particle-phase at colder temperatures. The composition of PBDEs in the air samples did not differ across the transect or for the different seasons.

The polybrominated diphenyl ethers (PBDEs) are widely used as flame retardants in plastics of soft furnishings, TV sets and computers, and insulation in the indoor environment. The penta-BDEs--now banned in most parts of Europe but still used in North America--are additive flame retardants that may be released to the indoor environment via volatilization or as dusts. In this study, to investigate general population PBDE exposure, air was sampled in 74 randomly selected homes in Ottawa, Canada and at seven outdoor sites during the winter of 2002--3, using polyurethane foam (PUF) disk passive air samplers. The passive sampling rate (2.5 m3 day(-1)) was determined through a pilot study employing active and passive samplers side-by-side at selected indoor locations. Indoor air concentrations of PBDEs were log-normally distributed with a geometric mean of 120 pg m(-3) and a median of 100 pg m(-3), approximately 50 times higher than the range of outdoor air concentrations (<0.1-4.4 pg m(-3)). The maximum daily human exposure via the inhalation pathway based on median PBDE levels found in this survey was estimated to be 1.9 ng day(-1) (female) and 2.0 ng day(-1) (male), representing 4.1% (f) and 4.4% (m) of overall daily intake.