Grantee Research Project Results
2007 Progress Report: Validation of Diesel Exhaust Biomarkers
EPA Grant Number: R832097Title: Validation of Diesel Exhaust Biomarkers
Investigators: Zhang, Junfeng , Lioy, Paul J. , Kipen, Howard , Zhang, Lin , Fiedler, Nancy , Ohman-Strickland, Pamela , Laumbach, Robert
Current Investigators: Zhang, Junfeng , Lioy, Paul J. , Stern, Alan , Kipen, Howard , Zhang, Lin , Fiedler, Nancy , Ohman-Strickland, Pamela , Laumbach, Robert
Institution: University of Medicine and Dentistry of New Jersey , New Jersey Department of Environmental Protection
Current Institution: Environmental and Occupational Health Sciences Institute , New Jersey Department of Environmental Protection , University of Medicine and Dentistry of New Jersey
EPA Project Officer: Aja, Hayley
Project Period: May 1, 2005 through April 30, 2008
Project Period Covered by this Report: May 1, 2007 through April 30,2008
Project Amount: $572,497
RFA: Application of Biomarkers to Environmental Health and Risk Assessment (2004) RFA Text | Recipients Lists
Research Category: Air Toxics , Air Quality and Air Toxics , Air
Objective:
The overall goal of this study is to examine whether urinary amino-PAHs can serve as biomarkers of diesel exhaust exposure, as amino-PAHs are metabolites of nitro-PAHs, a group of chemical compounds that are emitted specifically by diesel engines. The target amino-PAHs are 1-aminopyrene, 1-aminonaphthalene, 2- aminonaphthalene and 3-aminobenzanthrone. The study was carried out in 54 healthy and nonsmoking men and women during two one-hr controlled exposure sessions, to a diluted diesel exhaust and to clean air. Specifically, we are to: (1) optimize an amino-PAH analysis method to increase the sensitivities and recoveries and reduce the cost of sample analysis; (2) determine how long after DE exposure urinary amino-PAH concentrations reach maximum levels; (3) quantify inhalation exposure to the parent nitro-PAHs of each of the target biomarkers during the entire time window of urinary monitoring and minimize potential interferences from exposures that may occur before and after the controlled exposure session; (4) estimate the fraction of inhaled nitro-PAHs converted into amino-PAH metabolites and excreted in the urine; and (5) assess inter-individual biomarker variability, with respect to several physiological factors such as gender, age, and body mass index.
Progress Summary:
By the end of Year 3, 71 subjects have agreed to participate in the study and signed informed consent forms. Among them, however, 7 were excluded during the initial health screening; and 9 have dropped out of the study after the first exposure session due to subjects’ unwillingness or unavailability to continue their participation. In total, 55 subjects have completed two planned exposure sessions; but one subject provided insufficient urine volumes. Following the study protocol in which a pre-session urine void and all urine voids during the 24 hours following each session were collected, we obtained 763 urine samples. The majority of target compounds in 723 valid urine samples collected from 54 subjects were above method detection limits: 96 percent for 1-aminonaphthalene, 99 percent for 2-aminonaphthalene, 76 percent for 1-aminopyrene, and 90 percent for 3-aminobenzanthrone. Therefore, our methods had adequate sensitivity.
To date, we have analyzed one of the four target amino-PAHs, 1-amino-pyrene and reached the following conclusions. Time-weighted-average concentrations of urinary 1-aminopyrene were significantly greater following the DE exposure compared to the control (median 15.69 µg/mol creatinine vs. 2.46 µg/mol creatinine, p < 0.0001). Comparing DE to control exposures, we observed significant increases in 1-aminopyrine concentration from pre-exposure to either first post-exposure void or peak spot urine concentration following exposure (p = 0.027 and p = 0.0026, respectively). Large inter-individual variability, in both the concentration of urinary 1-aminopyrene and the time course of appearance in the urine following the standardized exposure to DE, suggests the need to explore subject variables that may affect conversion of inhaled 1-nitropyrene to urinary excretion of 1-aminopyrene.
Future Activities:
Perform analyses to examine relationships among four target amino-PAHs and inter-person variability, with a goal to examine the utility of these animo-PAHs as DE biomarkers.Journal Articles:
No journal articles submitted with this report: View all 4 publications for this projectSupplemental Keywords:
urinary metabolites, exposure, biomonitoring, air toxics, amino-PAHs, nitro-PAHs, 1-hydroxypyrene, Health, RFA, Air, Scientific Discipline, Health Risk Assessment, Risk Assessments, particulate matter, Environmental Chemistry, Environmental Monitoring, diesel exhaust, inner city, chemical characteristics, aerosol composition, airborne particulate matter, human exposure, ambient air monitoring, environmental risks, atmospheric particles, atmospheric aerosol particles, particulates, atmospheric particulate matter, biomarker, ambient air quality, air pollution, human health risk, PAHProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.