SCERP Project A-05-1: Cytotoxicity Studies Relating to Long Term Exposure to Low Concentrations of Carbons Nanotube Aggregates in the Indoor Air: Implications for Asthma and Other Respiratory Health Effects in the Paso Del Norte Region

L. E. Murr, P.I. Department of Metallurgical and Materials Engineering

The University of Texas at El Paso, El Paso, TX 79968

K. M. Garza, Co-P.I. Department of Biological Sciences

The University of Texas at El Paso, El Paso, TX 79968

Presented By:

Priscilla Guerrero and Ariana Guerrero Department of Metallurgical and Materials Engineering

The University of Texas at El Paso, El Paso, TX 79968

(a) Schematic view of high-volume collector arrangement for a natural gas (range) burner. (b) Top view of natural gas cook top burner shown schematically in (a). G shows gas inlet reference.

Views of the high-volume PM collection from the natural gas burner in previous slide. (a) Overall view of the collection system. (b) Close up showing viewing window. (c) High-flow blue flame (HFBF) viewed through the window in (b).

(d) Thermal precipitator (TP) situated at the end (or top) of the collection line (removed from the high-volume collector) for PM collection for TEM analysis. IW is the input cooling water container for

the TP collector block.

Views of the high-volume PM collector arranged for heavy-duty diesel truck (DPM) collection.

(a) DPM (soot) emission at depressed throttle.

(b) Idle DPM collection. (c) and (d) show collection arrangement from emission stack.

TEM images of Low Flame soot (a and b). From natural gas burner collections from previous slides

FESEM images of diesel soot on filter.

Texas Piñon Pine wood soot collected by thermal precipitation in TEM grids. TEM images. Arrows in (b) show multiwall carbon nanotubes.

(a) On filter.

FESEM images of Texas Piñon Pine wood soot

(b) Creosote on filter fibers.

Examples of FESEM images of soot PM collected on the high-volume PM collector glass-fiber filters. All secondary electron (SE) images.

(c) Wood PM; Ir coated, 1 kV accelerating voltage.

(a) Oxygen deficient, yellow, natural gas flame soot PM; Ir coated, I kV accelerating voltage. (b) Diesel PM, uncoated, I kV accelerating voltage.

(d) Candle PM, Ir coated, 1 kV accelerating voltage.

Tire soot PM.

(a) TEM images of thermal precipitation-collected tire PM. (b) FESEM-STEM image of tire PM scraped from filter onto TEM grid.

(c) FESEM-SE image of (b).

TEM images of natural gas soot PM

(d), MWCNT aggregates collected above a kitchen stove during natural gas, by thermal precipitation.

(b) Soot collected by electrostatic precipitation,

(a) Black carbon (BC) placed on Tem grid sandwich.

(c) Commercial MWCNT aggregate material.

Comparative (48h) cytotoxicities (as relative cell viability) for surrogate carbonaceous PM (BC and MWCNT-R) as well as other nanoparticulate standards in cell culture assays at a concentration of 5 µg/mL.

(c) Human epithelial (A549) cells.(a) Murine macrophage (RAW 264.7) cells. (b) Human macrophage (THB-1) cells.

Direct filter contact cytotoxicity assays for human epithelial (A549) cell cultures (48h).

Comparative optical microscope views of human epithelial (A549) cells after direct filter contact assays in previous slide.

(a) Media only (control). (b) Media with blank filter contact.

(c) White candle PM exposure. (d) Wood PM exposure.

Comparative PAH content (%) and total PAH content for carbonaceous PM (underlined numbers in mg/g). The PAH key is as follows (from MW 128-278).

ConclusionConclusionIn this short report, we have illustrated a new In this short report, we have illustrated a new methodology for at least a qualitative assessment and methodology for at least a qualitative assessment and comparison of cytotoxic responses for a variety of comparison of cytotoxic responses for a variety of environmental soots, and soot-related environmental soots, and soot-related nanoparticles/aggregates. This involves direct filter nanoparticles/aggregates. This involves direct filter collections and cell contact. It is also apparent that while collections and cell contact. It is also apparent that while there are differences in the cytotoxic response of human there are differences in the cytotoxic response of human epithelial (lung function surrogate) cell (A549), detailed epithelial (lung function surrogate) cell (A549), detailed microstructural characterization shows that the “soots” microstructural characterization shows that the “soots” appear to be identical, same for variations in the primary appear to be identical, same for variations in the primary particle (spherule nanoparticle) size (or size distribution).particle (spherule nanoparticle) size (or size distribution).

AccomplishmentsAccomplishmentsPublicationsPublications (Published, Accepted (In Press), Submitted) (Published, Accepted (In Press), Submitted)

“ “Combustion-Generated Nanoparticles in the El Paso, TX, Combustion-Generated Nanoparticles in the El Paso, TX, USA/Juarez, Mexico Metroplex: Their Comparative Characterization USA/Juarez, Mexico Metroplex: Their Comparative Characterization and Potential for Adverse Health Effects”, L.E Murr, K.F. Soto, K.M. and Potential for Adverse Health Effects”, L.E Murr, K.F. Soto, K.M. Garza, P.A. Guerrero, F. Martinez, E.V. Esquivel, D.A. Ramirez, Y. Garza, P.A. Guerrero, F. Martinez, E.V. Esquivel, D.A. Ramirez, Y. Shi, J.J. Bang, J. Venzor, III, Shi, J.J. Bang, J. Venzor, III, International Journal of Environmental International Journal of Environmental Research and Public HealthResearch and Public Health (2006), Vol. 3(1), pp.48-66, (2006), Vol. 3(1), pp.48-66,

““Cytotoxic Response for Carbon Nanotubes and Aggregates and Cytotoxic Response for Carbon Nanotubes and Aggregates and Other Manufactured Nanoparticles: The Role of In Vitro Biological Other Manufactured Nanoparticles: The Role of In Vitro Biological Assays in Nanomaterials Evaluations”, K.F. Soto, K.M. Garza, L.E. Assays in Nanomaterials Evaluations”, K.F. Soto, K.M. Garza, L.E. Murr, Murr, Acta BiomaterialiaActa Biomaterialia, revised submission (2006); in press., revised submission (2006); in press.

““Carbon Nanotubes in Wood Soot”, L.E. Murr and P.A. Guerrero, Carbon Nanotubes in Wood Soot”, L.E. Murr and P.A. Guerrero, Atmospheric Science LettersAtmospheric Science Letters (2006), published on-line in Wiley (2006), published on-line in Wiley Interscience, in press.Interscience, in press.

Questions?Questions?

Priscilla Guerrero & Diana RamirezUndergraduate Research Assistants