NASA Scientific and Technical Aerospace Reports

20040070705 NASA Ames Research Center, Moffett Field, CA, USA
Environment Partitioning and Reactivity of Polybrominated Diphenylethers
Hua, Inez; Iraci, Laura T.; Jafvert, Chad; Bezares-Cruz, Juan; March 1, 2004; 1 pp.; In English; American and Canadian
Geophysical Union Meeting, 17-21 May 2004, Montreal, Canada
Contract(s)/Grant(s): RTOP 622-67-21-10; No Copyright; Avail: Other Sources; Abstract Only
Polybrominated diphenyl ethers (PBDEs) are an important class of flame retardants. Annual global demand for these
compounds was over 67,000 metric tons in 2001. PBDEs have recently been extensively investigated as environmental
contaminants because they have been detected in air, sediment, and tissue samples from urban and remote areas. Important
issues include quantifying PBDE partitioning in various environmental compartments, and elucidating transformation
pathways. The partitioning of PBDE congeners to aerosols was estimated for 16 sites in the USA, Canada, and Mexico. The
aerosol particles were PM2.5, the total suspended particle (TSP) concentration varied between 3.0 - 55.4 micro g/cubic meter,
and the organic fraction ranged from 11 - 41%; these data are published values for each site. It is estimated that the largest
fraction of each PBDE associated with the aerosol particles occurs in Mexico City, and the smallest fraction in Colorado
Plateau. Although the organic fraction in Mexico City is about 60% of that observed in the Colorado Plateau, the TSP is larger
by a factor of about 18.5, and it is the difference in TSP that strongly influences the fraction of particle-bound PBDE in this
case. PBDE partitioning to PM2.5 particles also varies seasonally because of temperature variations. For the less brominated
congeners the percentage that is particle-bound is relatively low, regardless of air temperature. In contrast, the heavier
congeners exhibit a significant temperature dependence: as the temperature decreases (fall, winter) the percentage of PBDE
that is particle-bound increases. The partitioning calculations complement experimental data indicating that
decabromodiphenyl ether (DBDE) dissolved in hexane transforms very rapidly when irradiated with solar light. DBDE is the
most highly brominated PBDE congener (10 bromine atoms) and occurs in the commercial formulation which is subject to
the largest global demand.
Author
Bromine; Congeners; Contaminants; Diphenyl Compounds; Ethers; Reactivity; Global Air Pollution
20040070706 NASA Ames Research Center, Moffett Field, CA, USA
Brown Cloud Pollution and Smog Ozone Transport 6,000 km to the Tropical Atlantic: Mechanism and Sensing
Chatfield, Robert B.; Thompson, Anne M.; Guan, Hong; Witte, Jacquelyn C.; Hudson, Robert D.; [2004]; 1 pp.; In English;
Quadrennial Ozone Symposium 2004, 1-8 Jun. 2004, Kos, Greece; No Copyright; Avail: Other Sources; Abstract Only
We have found repeated illustrations in the maps of Total Tropospheric Ozone (TTO) of apparent transport of ozone from
the Indian Ocean to the Equatorial Atlantic Ocean. Most interesting are examples that coincide with the INDOEX observations
of late northern winter. Three soundings with the SHADOZ (Southern Hemisphere Additional Ozonesondes) network help
confirm and quantify degree of influence of pollution, lightning, and stratospheric sources, suggesting that perhaps 40% of
increased Atlantic ozone could be Asian pollution during periods of maximum identified in the TTO maps. This analysis also
indicates a mechanism for such extended transport. We outline recurrent periods of apparent ozone transport from Indian to
Atlantic Ocean regions outside the late-winter period. Clearly brown-cloud aerosol affects tropospheric ozone, both limiting
its chemical production and also potentially obscuring its detection by the TOMS instrument. Introductory statistical studies
will be presented, evaluating the role of tropopause meteorology, aerosol, and other factors in the modifying the relationship
between true tropospheric ozone measured by SHADOZ and the TTO product, with suggestions for extending the product.
Author
Ozone; Pollution Transport; Smog; Air Pollution; Gas Transport
20040070986 Health Effects Inst., Boston, MA, USA
Peroxides and Macrophages in the Toxicity of Fine Particulate Matter in Rats
Laksin, D. L.; Morio, L.; Hooper, K.; Li, T. H.; Buckley, B.; Dec. 2003; In English
Report No.(s): PB2004-103505; No Copyright; Avail: National Technical Information Service (NTIS)
This study was conducted to determine: (1) whether tissue injury induced by aerosols is medicated by cytotoxic hydrogen
peroxide carried into the lower lung by fine particles and (2) whether exposure of rats to fine particulate matter (PM) leads
to accumulation of activated macrophages in the lung.
NTIS
Exposure; Hydrogen Peroxide; Injuries; Lungs; Toxins and Antitoxins
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