Exposure assessment of organophosphorus and organobromine flame retardants via indoor dust from elementary schools and domestic houses.

To assess the exposure of flame retardants (FRs) for school-children, organophosphorus flame retardants and plasticizers (PFRs) and organobromine flame retardants (BFRs) were determined in the indoor dust samples collected from elementary schools and domestic houses in Japan in 2009 and 2010. PFRs were detected in all the dust samples analyzed and the highest concentration of total PFRs was thousand-fold higher than that of BFRs. Among the PFRs, tris(butoxyethyl)phosphate (TBOEP) showed the highest concentration with a median (med.) of 270,000 ng g(-1) dry weight (3700-5,500,000 ng g(-1) dry weight), followed by tris(methylphenyl)phosphate (TMPPs)>triphenyl phosphate (TPHP)=tris(1,3-dichloro-2-propyl)phosphate (TDCIPP)=tris(2-chloroisopropyl)phosphate (TCIPP)=tris(2chloroethyl)phosphate (TCEP)>ethylhexyl diphenyl phosphate (EHDPP). Significantly higher concentrations of TBOEP, tri-n-butyl phosphate (TNBP), TPHP, TMPPs, and total-PFRs were found in dust samples from elementary schools than from domestic houses. It might be due to that higher concentrations of TBOEP (as leveling agent) were detected from the floor polisher/wax products collected in those elementary schools. On the other hand, significantly higher concentrations of TCEP, TCIPPs, and total chloroalkyl-PFRs were found in domestic houses than in elementary schools. Exposure assessments of PFRs via indoor dust from elementary schools and domestic houses were conducted by calculating the hazard quotient (HQ). Among PFRs, HQs for TBOEP exceeded 1 (higher than reference dose: RfD) and its highest value was 1.9. To reduce the intake of TBOEP by school-children, it is recommended that the use of floor polisher/wax containing TBOEP be reduced in schools.

Mizouchi S ，Ichiba M ，Takigami H ，Kajiwara N ，Takamuku T ，Miyajima T ，Kodama H ，Someya T ，Ueno D ... -  《-》

Detection and intake assessment of organophosphate flame retardants in house dust in Japanese dwellings.

The demand for phosphorus flame retardants (PFRs) has recently increased as an alternative to polybrominated diphenyl ether (PBDE). PFRs have been detected in house dust, but little is known about the concentrations of PFRs in private homes and the effects on human health. We measured the levels of 10 PFRs in indoor floor dust and upper surface dust from 128 Japanese dwellings of families with children in elementary school. The median (min-max) concentrations (μg/g) of PFRs were as follows: tris(2-butoxyethyl) phosphate (TBOEP), 30.88 (<0.61-936.65); tris(2-chloro-iso-propyl) phosphate (TCIPP), 0.74 (<0.56-392.52); and triphenyl phosphate (TPHP), 0.87 (<0.80-23.35). These values exceeded 50% detection rates, and the rates are median over the LOD in floor dust. The concentrations (μg/g) of TBOEP 26.55 (<0.61-1933.24), TCIPP 2.23 (<0.56-621.23), TPHP 3.13 (<0.80-27.47), tris(2-chloroethyl) phosphate (TCEP) 1.17 (<0.65-92.22), and tributyl phosphate (TNBP) 0.74 (<0.36-60.64) exceeded 50% detection rates in the upper surface dust. A significant positive correlation (P<0.05) between the concentrations of TCIPP and TBOEP was shown in floor dust and upper surface dust (n=48). Estimated median and 95th percentile daily intake was calculated for toddlers and elementary school children and was compared with reference dose values (RfD) from the literature. For TBOEP, the estimated 95th percentile intake from floor dust was 14% of RfD for toddlers and 4% for school children. The estimated intake from upper surface dust was somewhat lower. Estimated median intake of TBOEP and median intake for the other PFRs were less than 1% of the RfD. TBOEP, TCIPP and TPHP were the main PFRs in the dust. The median levels of PFRs are well below the RfD values.

Tajima S ，Araki A ，Kawai T ，Tsuboi T ，Ait Bamai Y ，Yoshioka E ，Kanazawa A ，Cong S ，Kishi R ... -  《-》

Concentrations of brominated and phosphorous flame retardants in Finnish house dust and insights into children's exposure.

Brominated and phosphorous flame retardants (BFRs, PFRs) are added to household and consumer products to reduce their flammability. Some FRs are persistent in the environment and may have adverse health effects. As exposure indoors contributes significantly to total exposure, we wanted to estimate the exposure of children (3 years of age) through dust ingestion, inhalation, and dermal absorption. We measured 17 BFRs and 10 PFRs in indoor dust, predicted their respective concentrations in the indoor air and assessed children's exposure. Among the BFRs, decabromodiphenyl ether (BDE-209) had highest median level in the dust (411 ng/g) followed by decabromodiphenyl ethane (DBDPE, 119 ng/g) and bis-ethylhexyl tetrabromophthalate (BEH-TEBP, 106 ng/g). Among the PFRs, trisbutoxyethyl phosphate (TBOEP) had the highest concentration (11100 ng/g) followed by tris(2-chloroisopropyl) phosphate (TCIPP, 1870 ng/g) and triphenyl phosphate (TPHP, 773 ng/g). FR concentration in air predicted from dust concentrations were within the interquartile range of experimental data for 10/13 of BFRs and 4/8 of PFRs compared. Dust ingestion was the major route of exposure (75-99%) for higher molecular weight BFRs, TBOEP and phenyl based PFRs (73-77%). Inhalation was important for volatile BFRs like pentabromobenzene (PBB 71%) and pentabromotoluene (PBT 52%) and dermal exposure for volatile chlorinated PFRs (TCEP 84%, TCIPP 77%). Margins of Exposure (MoE) were calculated as the ratio of total exposure to oral Reference Dose (RfD). MoEs were lowest for TCEP (220), TBOEP (240) and TCIPP (830), and > 1000 for all other FRs. These MoEs imply no risk for Finnish children by the studied FRs.

Rantakokko P ，Kumar E ，Braber J ，Huang T ，Kiviranta H ，Cequier E ，Thomsen C ... -  《-》

Organophosphorus flame retardants (PFRs) and plasticizers in house and car dust and the influence of electronic equipment.

All nine PFRs studied were detected in house and car dust from the Netherlands with the exception of tris(butyl) phosphate (TNBP) and tris(isobutyl) phosphate (TIBP) in car dust. Tris(2-butoxyethyl) phosphate (TBOEP, median 22 μg g(-1)) was dominant in house dust collected around and on electronics followed by tris(2-chloroisopropyl) phosphate (TCIPP, median 1.3 μg g(-1)), tris(2-chloroethyl) phosphate (TCEP, median 1.3 μg g(-1)) and tris(phenyl) phosphate (TPHP, median 0.8 μg g(-1)). Levels of TPHP and tris(methylphenyl) phosphate (TMPP, also known as TCP) in house dust on electronics were significantly higher than in house dust collected around electronics, suggesting that electronic equipment has limited contribution to the PFR levels in house dust, with the exception of TPHP and TMPP. Car dust was dominated by tris(1,3-dichloroisopropyl) phosphate (TDCIPP) with the highest levels found in dust collected from the car seats (1100 μg g(-1)). The mean TDCIPP and TCIPP levels observed in car dust were significantly higher than the levels observed in dust collected around electronics. Significantly higher mean TMPP levels in dust taken from car seats were found compared to dust collected around the equipment (p<0.05). This is probably influenced by the use of TDCIPP, TCIPP in polyurethane foam (car seats) and the use of TMPP as plasticizer in car interiors. Worldwide four PFR patterns were observed in house dust. The PFR pattern in the Netherlands of TDCIPP, TMPP, TCEP, TCIPP and TPHP in house dust is comparable to the pattern found in six other countries, which may point to identical sources of these PFRs in the indoor environment. However, the PFR levels between the countries and within countries showed high variation.

Brandsma SH ，de Boer J ，van Velzen MJ ，Leonards PE ... -  《-》

Occurrence and human exposure to brominated and organophosphorus flame retardants via indoor dust in a Brazilian city.

Indoor dust is considered an important human exposure route to flame retardants (FRs), which has arised concern due the toxic properties of some of these substances. In this study, ten organophosphorus flame retardants (OPFRs), eight polybrominated diphenyl ethers (PBDEs) and four new brominated flame retardants (NBFRs) were determined in indoor dust from different places in Araraquara-SP (Brazil). The sampled places included houses, apartments, offices, primary schools and cars. The analysis of the sample extracts was performed by gas chromatography coupled to mass spectrometry and two ionization techniques were used (electron ionization - EI; electron capture negative ionization - ECNI). OPFRs were the most abundant compounds and tris(2-butoxyethyl) phosphate (TBOEP), tris(phenyl) phosphate (TPHP), tris(1,3-dichloroisopropyl) phosphate (TDCIPP) and tris(2-chloroisopropyl) phosphate (TCIPP) were present at the highest concentrations. Among the brominated FRs, the most ubiquitous compounds were BDE-209, bis(2-ethylhexyl) tetrabromophthalate (BEH-TEBP) and decabromodiphenyl ethane (DBDPE). Statistical analysis revealed that there were differences among dust typologies for TBOEP, TDCIPP, ethylhexyl diphenyl phosphate (EHDPHP), BDE-209, 2-ethylhexyl 2,3,4,5-tetrabromobenzoate (EH-TBB), BEH-TEBP and DBDPE, which were attributed to different construction materials in each particular environment and to the age of the buildings. The highest levels of brominated FRs were observed in offices, TBOEP was at high concentration in primary schools, and TDCIPP was at high concentration in cars. A preliminary risk assessment revealed that toddlers were exposed to TBOEP levels higher than the reference dose when considering the worst case scenario. The results obtained in this study showed for the first time that although Brazil does not regulate the use of FRs, these substances are present in indoor dust at levels similar to the observed in countries that have strict fire safety standards, and that humans are exposed to complex mixtures of these contaminants via indoor dust.

Cristale J ，Aragão Belé TG ，Lacorte S ，Rodrigues de Marchi MR ... -  《-》