Last data update: May 13, 2024. (Total: 46773 publications since 2009)
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Query Trace: Porter EN[original query] |
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Variability of urinary concentrations of polycyclic aromatic hydrocarbon metabolite in general population and comparison of spot, first-morning, and 24-h void sampling: erratum
Li Z , Romanoff LC , Lewin MD , Porter EN , Trinidad DA , Needham LL , Patterson DG Jr , Sjodin A . J Expo Sci Environ Epidemiol 2013 23 (1) 109-10 Tables 2 and and33 contained transcription errors that gave rise to minor errors in the calculated sample-size results. The corrected tables are reproduced below in their entirety and the values presented correctly. The author regrets the error. |
Characterization of PM2.5-bound polycyclic aromatic hydrocarbons in Atlanta - Seasonal variations at urban, suburban, and rural ambient air monitoring sites
Li Z , Porter EN , Sjodin A , Needham LL , Lee S , Russell AG , Mulholland JA . Atmos Environ (1994) 2009 43 (27) 4187-93 Twenty-eight polycyclic aromatic hydrocarbons (PAH) and methylated PAHs (Me-PAH) were measured in daily PM2.5 samples collected at an urban site, a suburban site, and a rural site in and near Atlanta during 2004 (5 samples/month/site). The suburban site, located near a major highway, had higher PM2.5-bound PAH concentrations than did the urban site, and the rural site had the lowest PAH levels. Monthly variations are described for concentrations of total PAHs ([summation sign]PAHs) and individual PAHs. PAH concentrations were much higher in cold months than in warm months, with average monthly [summation sign]PAH concentrations at the urban and suburban-highway monitoring sites ranging from 2.12 to 6.85 ng m-3 during January-February and November-December 2004, compared to 0.38-0.98 ng m-3 during May-September 2004. [summation sign]PAH concentrations were found to be well correlated with PM2.5 and organic carbon (OC) within seasons, and the fractions of PAHs in PM2.5 and OC were higher in winter than in summer. Methyl phenanthrenes were present at higher levels than their un-substituted homologue (phenanthrene), suggesting a petrogenic (unburned petroleum products) input. Retene, a proposed tracer for biomass burning, peaked in March, the month with the highest acreage and frequency of prescribed burning and unplanned fires, and in December, during the high residential wood-burning season, indicating that retene might be a good marker for burning of all biomass materials. In contrast, potassium peaked only in December, indicating that it might be a more specific tracer for wood-burning. |
Variability of urinary concentrations of polycyclic aromatic hydrocarbon metabolite in general population and comparison of spot, first-morning, and 24-h void sampling
Li Z , Romanoff LC , Lewin MD , Porter EN , Trinidad DA , Needham LL , Patterson DG Jr , Sjodin A . J Expo Sci Environ Epidemiol 2009 20 (6) 526-35 Urinary mono-hydroxy polycyclic aromatic hydrocarbons (OH-PAHs) are commonly used in biomonitoring to assess exposure to polycyclic aromatic hydrocarbons (PAHs). Similar to other biologically non-persistent chemicals, OH-PAHs have relatively short biological half-lives (4.4-35 h). Little information is available on their variability in urinary concentrations over time in non-occupationally exposed subjects. This study was designed to (i) examine the variability of nine urinary OH-PAH metabolite concentrations over time and (ii) calculate sample size requirements for future epidemiological studies on the basis of spot urine, first-morning void, and 24-h void sampling. Individual urine samples (n=427) were collected during 1 week from 8 non-occupationally exposed adults. We recorded the time and volume of each urine excretion, dietary details, and driving activities of the participants. Within subjects, the coefficients of variation (CVs) for the wet-weight concentration of OH-PAHs in all samples ranged from 45% to 297%; creatinine adjustment reduced the CV to 19-288% (P<0.001; paired t-test). The simulated 24-h void concentrations were the least variable measure, with CVs ranging from 13% to 182% for the 9 OH-PAHs. Within-day variability contributed on average 84%, and between-day variability accounted for 16% of the total variance of 1-hydroxypyrene (1-PYR). Intraclass correlation coefficients of 1-PYR levels were 0.55 for spot urine samples, 0.60 for first-morning voids, and 0.76 for 24-h voids, indicating a high degree of correlation between urine measurements collected from the same subject over time. Sample size calculations were performed to estimate the number of subjects required for detecting differences in the geometric mean at a statistical power of 80% for spot urine, first-morning, and 24-h void sampling. These data will aid in the design of future studies of PAHs and possibly other biologically non-persistent chemicals and in the interpretation of their analytical results.Journal of Exposure Science and Environmental Epidemiology advance online publication, 26 August 2009; doi:10.1038/jes.2009.41. |
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