Grantee Research Project Results
2000 Progress Report: Health Effects of Concentrated Ambient Particles from the Central Valley of California
EPA Grant Number: R827995Title: Health Effects of Concentrated Ambient Particles from the Central Valley of California
Investigators: Pinkerton, Kent E.
Current Investigators: Pinkerton, Kent E. , Smith, Kevin R. , Sioutas, Constantinos
Institution: University of California - Davis
Current Institution: University of California - Davis , University of Southern California
EPA Project Officer: Chung, Serena
Project Period: February 1, 2000 through January 31, 2003 (Extended to July 31, 2003)
Project Period Covered by this Report: February 1, 2000 through January 31, 2001
Project Amount: $633,328
RFA: Airborne Particulate Matter Health Effects (1999) RFA Text | Recipients Lists
Research Category: Particulate Matter , Air , Human Health
Objective:
The overall objective of this project is to examine the mechanisms of particulate toxicity in the lungs of rats following short-term (3-day) exposure to concentrated ambient particles of the Fresno area during the fall and winter months?when particle size and composition in this region of California are dramatically different. We will examine the effects that these particles exert on epithelial cells of the airways, centriacinar regions, and alveoli. Because epithelial cells are the first cells in the respiratory tract to come into contact with inhaled particles, we hypothesize that damage to these cells can serve as a direct and highly sensitive measure of particle toxicity. We also hypothesize that epithelial-particle interactions initiate a cascade of events that underlie adverse effects associated with inhaled particles. In addition, we hypothesize that particle toxicity begins with DNA damage in epithelial cells, thus accentuating cytotoxic events that lead to cell death. In turn, cell death begins the process of cellular proliferation. Each of these events impacts negatively on the ability of the lungs to translocate and clear particles, thus leading to further irritation and injury. We will test each of these hypotheses by using novel approaches to examine epithelial cell structure and function throughout the airways and alveoli.Progress Summary:
Air drawn at the roof level of a three-story building in Fresno, CA, was used to concentrate ambient airborne particles to study particle effects in the rodent respiratory tract. This study is part of a series of toxicological studies done as part of the seasonal air-monitoring program for the EPA's Supersite in Fresno. Air at a rate of 250 liters/minute (L/min) is collected using a screened inlet and an aluminum tubing (7.6 centimeters [cm] in diameter) to draw air to the ground floor of the building. The particles in the air are concentrated using a portable ultrafine (<0.1 micrometer) and fine (0-2 micrometer) particle concentrator designed at the University of Southern California. These "California Particle Concentrators" are able to enrich and maintain particles in an airborne state up to 20 times the ambient concentration that is subsequently passed to four 20x43x18 cm chambers (working volume = 14.4 l) housing three rodents per cage. The housing is a standard polycarbonate cage fitted with an airtight top consisting of an acrylic and aluminum device designed to deliver aerosols and gases to the cage under controlled flow conditions. Using a unique delivery top that is sealed to the cage under a slightly negative pressure, the system can deliver ultrafine or fine aerosols with minimal loss. Testing of the system shows a uniform particle concentration in the cage that can be delivered at low flow rates. Each cage has independent flow control with the combined flow to the four chambers equal to the output of the concentrator. Particle size and distribution are rigorously maintained with this exposure delivery system. In preliminary results of studies done during the fall of 2000, exposure to concentrated ambient particles of Fresno, CA, was associated with a significant reduction in the viability of cells recovered from the lungs by bronchoalveolar lavage (BAL), as well as inducing a significant shift to greater numbers of neutrophils recovered by BAL.Future Activities:
Future activities include improving our understanding of concentrated ambient particulate matter (PM) effects on the respiratory tract within anatomically distinct regions from the trachea to the alveolus for better extrapolation of findings to humans. Causal relationships between specific PM components and biological responses will be evaluated, and outcomes of real-life ambient PM studies in Fresno will be compared with those of ongoing health studies at the University of California at Davis, using artificial preparations of carbonaceous and ammonium nitrate aerosols.Journal Articles:
No journal articles submitted with this report: View all 9 publications for this projectSupplemental Keywords:
PM2.5, PM10, particle size, composition., RFA, Health, Scientific Discipline, Air, Geographic Area, particulate matter, Toxicology, air toxics, Environmental Chemistry, Health Risk Assessment, State, Risk Assessments, Molecular Biology/Genetics, ambient air quality, particle size, airway epithelial cells, PM 2.5, DNA damage, cytotoxic events, chemical mixtures, lung inflammation, particulate exposure, Acute health effects, inhaled, PM, California (CA), respiratory, ultrafine particles, animal inhalation studyRelevant Websites:
http://www.envtox.ucdavis.edu/cehs/
http://agcenter.ucdavis.edu/agcenter/
Progress 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.