Organophosphate Esters: Are These Flame Retardants and Plasticizers Affecting Children’s Health?

Purpose of Review: Organophosphate esters (OPEs) are applied to a variety of consumer products, primarily as flame retardants and plasticizers. OPEs can leach out of products over time and are consequently prevalent in the environment and frequently detected in human biomonitoring studies. Exposure during pregnancy is of particular concern as OPEs have recently been detected in placental tissues, suggesting they may be transferred to the developing infant. Also, studies have now shown that children typically experience higher exposure to several OPEs compared with adults, indicating they may be disproportionately impacted by these compounds. This review summarizes the current literature on reproductive and child health outcomes of OPE exposures and highlights areas for future research. Recent Findings: Experimental animal studies demonstrate potential for OPEs to adversely impact health, and a limited number of epidemiologic studies conducted in adult cohorts suggest that OPEs may interfere with the endocrine system. Neurodevelopment is perhaps the most well studied of children’s health endpoints, and several studies indicate that prenatal and early life OPE exposures impact both cognitive and behavioral development. Associations have also been reported with reproductive outcomes (e.g., fertilization and pregnancy loss) and with the timing of parturition and preterm birth. Cross-sectional studies also demonstrate associations between OPEs and respiratory health outcomes, allergic disease, and measures of adiposity. Summary: An expanding body of research demonstrates that OPEs are associated with adverse reproductive health and birth outcomes, asthma and allergic disease, early growth and adiposity, and neurodevelopment. Still, additional research is urgently needed to elucidate the full impact of OPEs on children’s health

Associations between blood BTEXS concentrations and hematologic parameters among adult residents of the U.S. Gulf States

Background Studies of workers exposed to benzene at average air concentrations below one part per million suggest that benzene, a known hematotoxin, causes hematopoietic damage even at low exposure levels. However, evidence of such effects outside of occupational settings and for other volatile organic compounds (VOCs) is limited. Objective To investigate associations between ambient exposures to five VOCs, including benzene, and hematologic parameters among adult residents of the U.S. Gulf Coast. Materials and methods Blood concentrations of selected VOCs were measured in a sample of adult participants in the Gulf Long-term Follow-up Study (GuLF STUDY) during 2012 and 2013. Complete blood counts with differentials were also performed on a subset of participants (n=406). We used these data together with detailed questionnaire data to estimate adjusted associations between blood BTEXS (benzene, toluene, ethylbenzene, o-xylene, m/p-xylene, and styrene) concentrations and hematologic parameters using generalized linear models. Results We observed inverse associations between blood benzene concentrations and hemoglobin concentration and mean corpuscular hemoglobin concentration, and a positive association with red cell distribution width among tobacco smoke-unexposed participants (n=146). Among tobacco smoke-exposed participants (n=247), we observed positive associations between blood VOC concentrations and several hematologic parameters, including increased white blood cell and platelet counts, suggestive of hematopoietic stimulation typically associated with tobacco smoke exposure. Most associations were stronger for benzene than for the other VOCs. Conclusions Our results suggest that ambient exposure to BTEXS, particularly benzene, may be associated with hematologic effects, including decreased hemoglobin concentration, mean corpuscular hemoglobin concentration, and increased red cell distribution width

Prenatal exposure to organophosphate esters and cognitive development in young children in the Pregnancy, Infection, and Nutrition Study

Organophosphate esters (OPEs) are a class of chemicals commonly used as flame retardants and plasticizers. OPEs are applied to a wide variety of consumer products and have a propensity to leach from these products. Consequently, OPEs are ubiquitous contaminants in many human environments and human exposure is pervasive. Accumulating evidence suggests that OPEs are capable of interfering with childhood cognitive development through both neurologic- and endocrine-mediated mechanisms. However, observational evidence of cognitive effects is limited. We used data collected in the third phase of the Pregnancy, Infection, and Nutrition Study to investigate cognitive effects of prenatal exposure to OPEs. In a spot prenatal maternal urine sample, we measured the following OPE metabolites: diphenyl phosphate (DPHP), bis(1,3-dichloro-2-propyl phosphate) (BDCIPP), isopropyl-phenyl phenyl phosphate (ip-PPP), and 1-hydroxyl-2-propyl bis(1-chloro-2-propyl) phosphate (BCIPHIPP). We assessed children's language and multi-faceted and overall cognitive development between two and three years of age using the MacArthur-Bates Communicative Development Inventories (MB-CDI) and the Mullen Scales of Early Learning (MSEL). We used linear regression to estimate the change in children's scores on these developmental assessments per interquartile range (IQR) increase in log-transformed, specific-gravity-corrected prenatal OPE metabolite concentrations, adjusted for maternal age, education, income, race/ethnicity, BMI, and child's sex. A total of 149 children had both OPE metabolite measurements and MB-CDI scores, and 227 children had both OPE metabolite measurements and MSEL scores. We observed that higher concentrations of ip-PPP (ng/ml) were associated with lower scores on the MSEL Cognitive Composite Score (β = −2.61; 95% CI: −5.69, 0.46), and separately on two of the four MSEL Scales that comprise the Cognitive Composite, specifically the Fine Motor Scale (β = −3.08; 95% CI: −5.26, −0.91) and the Expressive Language Scale (β = −1.21; 95% CI: −2.91, 0.49). We similarly observed that prenatal ip-PPP concentrations were inversely associated with age-standardized scores on the MB-CDI Vocabulary assessment (β = −1.19; 95% CI: −2.53, 0.16). Other OPE metabolites were not strongly associated with performance on either assessment. Our results suggest that isopropylated triarylphosphate isomers, the presumed parent compounds of ip-PPP, may adversely impact cognitive development, including fine motor skills and early language abilities. Our study contributes to the growing body of observational evidence that suggests prenatal exposure to OPEs may adversely affect cognitive development

Prenatal exposure to organophosphate esters and behavioral development in young children in the Pregnancy, Infection, and Nutrition Study

Organophosphate esters (OPEs) are commonly used as plasticizers and flame retardants in consumer products, and exposure is relatively ubiquitous in most populations studied. This may be of concern as some OPEs may be neurotoxic, endocrine-disrupting, and interfere with behavioral development; however, observational evidence is limited. We used data from the Pregnancy, Infection, and Nutrition Study, a prospective birth cohort study, to investigate associations between maternal OPE metabolite concentrations during pregnancy and behavioral development in offspring. Women provided a urine sample during pregnancy that was analyzed for concentrations of OPE metabolites, including diphenyl phosphate (DPHP), bis(1,3-dichloro-2-propyl phosphate) (BDCIPP), isopropyl-phenyl phenyl phosphate (ip-PPP), and 1-hydroxyl-2-propyl bis(1-chloro-2-propyl) phosphate (BCIPHIPP). Offspring's behavioral development was assessed by the Behavioral Assessment System for Children (2nd Edition) (BASC-2) at approximately 36 months. Linear regression was used to estimate associations between tertiles in specific gravity-corrected OPE metabolite concentrations and children's scores on the BASC-2, adjusted for maternal age, maternal BMI, maternal race, maternal education, familial income, maternal depression, quality of the home environment, and sex. Higher BDCIPP concentrations were associated with higher scores on the Behavioral Symptoms Index (1st vs. 3rd tertile: β = 3.03; 95% CI = 0.40, 5.67) and Externalizing Problems (1st vs. 3rd tertile: β = 2.49; 95% CI: −0.12, 5.10) composites. Among BASC-2 scales, BDCIPP was most strongly associated with Withdrawal, Attention Problems, Depression, Hyperactivity, and Aggression. DPHP concentrations were also associated with higher scores on the Externalizing Problems and Behavioral Symptoms Index composites, but not as strongly as BDCIPP. Conversely, higher concentrations of ip-PPP were associated with fewer adverse behavioral symptoms, including an inverse association with the Internalizing Problems composite (1st vs. 3rd tertile: β = −3.74; 95% CI = −6.75, −0.74) and constituent scales. BCIPHIPP was not strongly associated with any measured behavioral outcomes. Our results suggest that greater maternal exposure to tris(1,3-dichloro-2-propyl phosphate) (TDCIPP, parent compound of BDCIPP) and, to a lesser degree, triphenyl phosphate (TPHP, parent compound of DPHP) during pregnancy is associated with adverse behavioral development in children. Our study contributes to the growing body of evidence pertaining to adverse developmental effects of prenatal OPE exposure and highlights the need for further research to characterize risks associated with this ubiquitous family of chemicals

Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment

This paper describes an analysis of the angular distribution of W->enu and W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and the missing transverse energy, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw > 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour, are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017 +/- 0.030, where the first uncertainties are statistical, and the second include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables, revised author list, matches European Journal of Physics C versio

Observation of a new chi_b state in radiative transitions to Upsilon(1S) and Upsilon(2S) at ATLAS

The chi_b(nP) quarkonium states are produced in proton-proton collisions at the Large Hadron Collider (LHC) at sqrt(s) = 7 TeV and recorded by the ATLAS detector. Using a data sample corresponding to an integrated luminosity of 4.4 fb^-1, these states are reconstructed through their radiative decays to Upsilon(1S,2S) with Upsilon->mu+mu-. In addition to the mass peaks corresponding to the decay modes chi_b(1P,2P)->Upsilon(1S)gamma, a new structure centered at a mass of 10.530+/-0.005 (stat.)+/-0.009 (syst.) GeV is also observed, in both the Upsilon(1S)gamma and Upsilon(2S)gamma decay modes. This is interpreted as the chi_b(3P) system.Comment: 5 pages plus author list (18 pages total), 2 figures, 1 table, corrected author list, matches final version in Physical Review Letter

Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS

We present the results of a search for new, heavy particles that decay at a significant distance from their production point into a final state containing charged hadrons in association with a high-momentum muon. The search is conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS detector operating at the Large Hadron Collider. Production of such particles is expected in various scenarios of physics beyond the standard model. We observe no signal and place limits on the production cross-section of supersymmetric particles in an R-parity-violating scenario as a function of the neutralino lifetime. Limits are presented for different squark and neutralino masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final version to appear in Physics Letters

Measurement of the inclusive isolated prompt photon cross-section in pp collisions at sqrt(s)= 7 TeV using 35 pb-1 of ATLAS data

A measurement of the differential cross-section for the inclusive production of isolated prompt photons in pp collisions at a center-of-mass energy sqrt(s) = 7 TeV is presented. The measurement covers the pseudorapidity ranges |eta|<1.37 and 1.52<=|eta|<2.37 in the transverse energy range 45<=E_T<400GeV. The results are based on an integrated luminosity of 35 pb-1, collected with the ATLAS detector at the LHC. The yields of the signal photons are measured using a data-driven technique, based on the observed distribution of the hadronic energy in a narrow cone around the photon candidate and the photon selection criteria. The results are compared with next-to-leading order perturbative QCD calculations and found to be in good agreement over four orders of magnitude in cross-section.Comment: 7 pages plus author list (18 pages total), 2 figures, 4 tables, final version published in Physics Letters

Measurement of D*+/- meson production in jets from pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

This paper reports a measurement of D*+/- meson production in jets from proton-proton collisions at a center-of-mass energy of sqrt(s) = 7 TeV at the CERN Large Hadron Collider. The measurement is based on a data sample recorded with the ATLAS detector with an integrated luminosity of 0.30 pb^-1 for jets with transverse momentum between 25 and 70 GeV in the pseudorapidity range |eta| < 2.5. D*+/- mesons found in jets are fully reconstructed in the decay chain: D*+ -> D0pi+, D0 -> K-pi+, and its charge conjugate. The production rate is found to be N(D*+/-)/N(jet) = 0.025 +/- 0.001(stat.) +/- 0.004(syst.) for D*+/- mesons that carry a fraction z of the jet momentum in the range 0.3 < z < 1. Monte Carlo predictions fail to describe the data at small values of z, and this is most marked at low jet transverse momentum.Comment: 10 pages plus author list (22 pages total), 5 figures, 1 table, matches published version in Physical Review

Search for scalar top quark pair production in natural gauge mediated supersymmetry models with the ATLAS detector in pp collisions at sqrt(s) = 7 TeV

The results of a search for pair production of the lighter scalar partners of top quarks in 2.05 fb-1 of pp collisions at sqrt(s) =7 TeV using the ATLAS experiment at the LHC are reported. Scalar top quarks are searched for in events with two same flavour opposite-sign leptons (electrons or muons) with invariant mass consistent with the Z boson mass, large missing transverse momentum and jets in the final state. At least one of the jets is identified as originating from a b-quark. No excess over Standard Model expectations is found. The results are interpreted in the framework of R-parity conserving, gauge mediated Supersymmetry breaking `natural' scenarios, where the neutralino is the next-to-lightest supersymmetric particle. Scalar top quark masses up to 310 GeV are excluded for the lightest neutralino mass between 115 GeV and 230 GeV at 95% confidence level, reaching an exclusion of the scalar top quark mass of 330 GeV for the lightest neutralino mass of 190 GeV. Scalar top quark masses below 240 GeV are excluded for all values of the lightest neutralino mass above the Z boson mass.Comment: 7 pages plus author list (20 pages total), 4 figures, 1 table, matches published PLB versio