Grantee Research Project Results
2006 Progress Report: Validation of Diesel Exhaust Biomarkers
EPA Grant Number: R832097Title: Validation of Diesel Exhaust Biomarkers
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, 2006 through April 30, 2007
Project Amount: $572,497
RFA: Application of Biomarkers to Environmental Health and Risk Assessment (2004) RFA Text | Recipients Lists
Research Category: Air Quality and Air Toxics , Air Toxics , Air
Objective:
The overall goal of this study is to examine whether urinary amino-polycyclic aromatic hydrocarbons (PAHs) can serve as biomarkers of diesel exhaust (DE) 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 is being carried out in approximately 50 healthy and nonsmoking men and women during two 1-hour controlled exposures to diluted fresh DE and to clean air, respectively. The specific aims of the project include: (1) optimizing an amino-PAH analysis method to increase the sensitivities and recoveries and reduce the cost of sample analysis; (2) determining how long afterDE exposure urinary amino-PAH concentrations reach maximum levels; (3) quantifying inhalation exposure to the parent nitro-PAHs of each of the target biomarkers during the entire time window (24-hour) of urinary monitoring and minimizing potential interferences from exposures that may occur before and after the controlled exposure session; and (4) assessing inter-individual biomarker variability, with respect to several physiological factors such as sex, age, and body mass index.
Progress Summary:
During the first 2 years of this 3-year study, we have optimized all the laboratory analysis conditions and finalized standard operating procedures. The final methods have sensitivities, precisions, and recoveries, similar to or better than the published methods. The methods include a high-performance liquid chromatography (HPLC)/fluorescence technique for analyzing amino-PAHs in human urine samples and a gas chromatography (GC)/electron-capture detection (ECD) technique for analyzing nitro-PAHs in the air. We have characterized an atmosphere containing diluted DE (at a nominal PM10 concentration of 300 μg/m3) for nitro-PAHs, a group of compounds that are considered to be specifically emitted from diesel-powered engines. In this atmosphere, mean concentrations of nitronaphthalenes, 1-nitropyrene, and 3-nitrobenzanthrone were 0.73, 1.40, and 0.73 ng/m3, respectively.
By the end of Year 2, 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, 9 have dropped out of the study after the first exposure session due to subjects’ unwillingness or unavailability to continue their participation, 55 have completed two planned exposure sessions. In total, 768 urine samples were collected. By the end of Year 2, we had complete concentration data for 23 subjects who completed two exposure sessions. The majority of target compounds in 275 valid urine samples collected from these 23 subjects were above method detection limits: 95% for 1-aminonaphthalene, 93% for 2-aminonaphthalene, 75% for 1-aminopyrene, and 87% for 3-aminobenzanthrone. Therefore, our methods had adequate sensitivity. Preliminary data analyses from the 23 subjects showed that 1-hour exposure to diluted DE (at 300 μg/m3 PM10), on average, led to an increase in urinary concentration of all four amino-PAHs, including 1-aminonaphthalene, 2-aminonaphthalene, 1-aminopyrene and 3-aminobenzanthrone. Time-series plots of 1-aminopyrene concentrations showed that some subjects had peak concentrations within 3–5 hours while others showed peak concentration after 10 hours. More sophisticated statistical analyses are underway to address the specific aims described above.
Future Activities:
We will complete chemical analysis of all the urine samples collected from 55 subjects and will continue to conduct data analyses to examine whether urinary amino-PAHs can serve as biomarkers of exposure to diesel exhaust.
Journal Articles:
No journal articles submitted with this report: View all 4 publications for this projectSupplemental Keywords:
diesel exhaust exposure, biomonitoring, air toxics, amino-PAHs, 1-aminopyrene, nitro-PAHs, 1-hydroxypyrene,, RFA, Health, Scientific Discipline, Air, particulate matter, Environmental Chemistry, Health Risk Assessment, Risk Assessments, Environmental Monitoring, ambient air quality, atmospheric particulate matter, particulates, air toxics, atmospheric particles, chemical characteristics, ambient air monitoring, airborne particulate matter, environmental risks, inner city, air pollution, diesel exhaust, PAH, aerosol composition, atmospheric aerosol particles, human exposure, biomarkerProgress 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.