Polycyclic Aromatic Hydrocarbons in the Indoor and Outdoor Air of Three Cities in the U.S.

The longitudinal NHEXAS-Maryland study measured metals, PAHs, and pesticides in several media to capture temporal variability. Questionnaires were concurrently administered to identify factors that influenced changes in contaminant levels over time. We constructed mixed-effects regression models for lead, phenanthrene, and chlorpyrifos (including metabolites) in indoor air, dust, dermal wipes, and biological fluids. Significant predictors represented time-varying activities as well as unchanging housing and demographic factors. There was little overlap among the models, with predictors generally reflecting the diverse characteristics of the target compounds. We estimated between-and within-person variance components to evaluate the reliability of the measurements. While only one measurement of lead in blood or chlopyrifos in dust was needed for a dependable estimate of an individual's average level, three to eight measurements were needed for most other compound/exposure medium combinations because of considerable temporal variability. Measurements in biological fluids and dust were generally more consistent than those in indoor air. The significant covariates in the full models preferentially reduced the between-person variance component. Since the regression models explained only 1-37% of the within-person variance, the questionnaires in this study provided only modest insight into the factors responsible for the temporal variability in the contaminant levels.

Section: Multiple Regression Analysismentioning

confidence: 71%

Section: Multiple Regression Analysismentioning

confidence: 99%

Determinants of temporal variability in NHEXAS-Maryland environmental concentrations, exposures, and biomarkers

Egeghy

Quackenboss

Catlin

et al. 2004

“…These samples were analyzed by gas chromatography/mass selective detection on a Hewlett Packard 6890/5973 for 37 individual PAHs and six chlordane species utilizing well-established methods (Offenberg and Baker, 1999;Naumova et al, 2002). The mass selective detector was operated in selective ion monitoring mode with an electron impact ionization energy of 70 eV.…”

Section: Quantitative Chemical Analysismentioning

confidence: 99%

Persistent organic pollutants in dusts that settled indoors in lower Manhattan after September 11, 2001

Offenberg

Eisenreich

Gigliotti

et al. 2004

The explosion and collapse of the World Trade Center (WTC) was a catastrophic event that produced an aerosol impacting many residents, workers, and commuters after September 11, 2001. In all, 12 bulk samples of the settled dust were collected at indoor locations surrounding the epicenter of the disaster, including one sample from a residence that had been cleansed and was once again occupied. Additionally, one sample was collected from just outside a fifth story window on the sill. These samples were analyzed for many components, including inorganic and organic constituents as well as morphology of the various particles. The results of the analyses for persistent organic pollutants on dusts that settled at indoor locations are described herein, including polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and select organo-chlorine pesticides. The S 86 -PCB concentrations, comprising less than one part per million by mass of the bulk in the two samples analyzed, indicated that PCBs were of limited significance in the dust that settled at indoor locations across lower Manhattan. Likewise, organo-chlorine pesticides, Hexachlorobenzene, Heptachlor, 4,4 0 -DDE, 2,4 0 -DDT, 4,4 0 -DDTand Mirex were found at even lower concentrations in the bulk samples. Conversely, S 37 -PAHs comprised up to 0.04% (o0.005-0.036%) by mass of the bulk indoor dust in the 11 WTC impacted bulk indoor samples. Analysis of one sample of indoor dusts collected from a vacuum cleaner of a rehabilitated home shows markedly lower PAH concentrations (o0.0005 mass%), as well as differing relative contributions for individual compounds. In addition to similar concentrations, comparison of PAH concentration patterns (i.e. chemical fingerprints) shows that dusts that settled indoors are chemically similar to previously measured WTC dusts found at outdoor locations and that these PAH analyses may be used in identifying dusts of WTC origin at indoor locations, along with ascertaining further needs for cleaning.

“…Accurate measurement of particulate organic PM 2.5 is also hampered by sampling artifacts (Turpin et al, 2000;Suburamanian et al, 2004), which have been extensively studied outdoors but largely ignored indoors. A few indoor organic PM species are relatively well studied (i.e., polycyclic aromatic hydrocarbons, PAHs; Dubowsky et al, 1999;Sakai et al, 2002;Naumova et al, 2002Naumova et al, , 2003. However, little is known about organic PM 2.5 concentrations, composition, behavior and sampling artifacts in residential indoor environments.…”

Section: Introductionmentioning

confidence: 99%

“…Air exchange rate, temperature and relative humidity were also measured in each home. PM 2.5 samples or subsets of samples were analyzed for mass (Meng et al, 2005a), functional groups , elements (Meng et al, 2005b), OC and EC, gas and particle phase PAHs (Naumova et al, 2002(Naumova et al, , 2003, and Chlordanes (Offenberg et al, 2004). Gas phase aldehydes (Liu et al, 2006) and volatile organic compounds were also measured.…”

Section: Introductionmentioning

confidence: 99%

Fine organic particulate matter dominates indoor-generated PM2.5 in RIOPA homes

Polidori

Turpin

Meng

et al. 2006

Self Cite

Residential indoor and outdoor fine particle (PM 2.5 ) organic (OC) and elemental carbon (EC) concentrations (48 h) were measured at 173 homes in Houston, TX, Los Angeles County, CA, and Elizabeth, NJ as part of the Relationship of Indoor, Outdoor and Personal Air (RIOPA) study. The adsorption of organic vapors on the quartz fiber sampling filter (a positive artifact) was substantial indoors and out, accounting for 36% and 37% of measured OC at the median indoor (8.2 mg C/m 3 ) and outdoor (5.0 mg C/m 3 ) OC concentrations, respectively. Uncorrected, adsorption artifacts would lead to substantial overestimation of particulate OC both indoors and outdoors. After artifact correction, the mean particulate organic matter (OM ¼ 1.4 OC) concentration indoors (9.8 mg/m 3 ) was twice the mean outdoor concentration (4.9 mg/m 3 ). The mean EC concentration was 1.1 mg/m 3 both indoors and outdoors. OM accounted for 29%, 30% and 29% of PM 2.5 mass outdoors and 48%, 55% and 61% of indoor PM 2.5 mass in Los Angeles Co., Elizabeth and Houston study homes, respectively. Indirect evidence provided by species mass balance results suggests that PM 2.5 nitrate (not measured) was largely lost during outdoor-to-indoor transport, as reported by Lunden et al. This results in dramatic changes with outdoor-to-indoor transport in the mass and composition of ambient-generated PM 2.5 at California homes. On average, 71% to 76% of indoor OM was emitted or formed indoors, calculated by (1) Random Component Superposition (RCS) model and (2) non-linear fit of OC and air exchange rate data to the mass balance model. Assuming that all particles penetrate indoors (P ¼ 1) and there is no particle loss indoors (k ¼ 0), a lower bound estimate of 41% of indoor OM was indoor-generated (mean). OM appears to be the predominant species in indoor-generated PM 2.5 , based on species mass balance results. Particulate OM emitted or formed indoors is substantial enough to alter the concentration, composition and behavior of indoor PM 2.5 . One interesting effect of increased indoor OM concentrations is a shift in the gas-particle partitioning of polycyclic aromatic hydrocarbons (PAHs) from the gas to the particle phase with outdoor-to-indoor transport.