Allergens in Paved Road Dust and Airborne Particles

Paved road dust present on the surface of streets in Southern California consists of a complex mixture of soil dust, deposited motor vehicle exhaust particles, tire dust, brake lining wear dust, plant fragments, and other biological materials. The research presented here shows that allergens from at least 20 different source materials are found in the paved road dust. These include pollens and pollen fragments, animal dander, and molds. When paved road dust is resuspended into the atmosphere by passing vehicle traffic, allergen concentrations in the air are increased above the levels that would prevail without the vehicle traffic. Using immunological assays that measure the proteins extracted from environmental samples that bind to IgE antibodies present in the blood serum of allergenic patients, it is possible to measure the allergen concentrations present in paved road dust and in airborne particle samples. Total protein contributions to monthly average airborne TSP and PM_(10) concentrations are found to be in the range from 1 to 5.8 μg m^(-3), potentially accounting for a significant fraction of the airborne particulate organic material that has not been identified to date by GC/MS techniques. Results show that up to 5−12% of the allergenicity of atmospheric total suspended particulate matter samples at Long Beach and Rubidoux, CA, is attributable to paved road dust emissions. In an industrial area of urban central Los Angeles where there is less proximity to vegetation and domestic activities, the paved road dust contribution to airborne allergen concentrations is lower, accounting for approximately 0.5% of the total allergenic activity of the atmospheric particle samples. In conclusion, paved road dust when entrained into the atmosphere by passing traffic is a source of allergen exposure for the general population and could be more important in areas with more abundant vegetation or with closer proximity of populations to major highways than is the case for the Southern California air monitoring sites studied here

Allergens in Paved Road Dust and Airborne Particles

Paved road dust present on the surface of streets in Southern California consists of a complex mixture of soil dust, deposited motor vehicle exhaust particles, tire dust, brake lining wear dust, plant fragments, and other biological materials. The research presented here shows that allergens from at least 20 different source materials are found in the paved road dust. These include pollens and pollen fragments, animal dander, and molds. When paved road dust is resuspended into the atmosphere by passing vehicle traffic, allergen concentrations in the air are increased above the levels that would prevail without the vehicle traffic. Using immunological assays that measure the proteins extracted from environmental samples that bind to IgE antibodies present in the blood serum of allergenic patients, it is possible to measure the allergen concentrations present in paved road dust and in airborne particle samples. Total protein contributions to monthly average airborne TSP and PM_(10) concentrations are found to be in the range from 1 to 5.8 μg m^(-3), potentially accounting for a significant fraction of the airborne particulate organic material that has not been identified to date by GC/MS techniques. Results show that up to 5−12% of the allergenicity of atmospheric total suspended particulate matter samples at Long Beach and Rubidoux, CA, is attributable to paved road dust emissions. In an industrial area of urban central Los Angeles where there is less proximity to vegetation and domestic activities, the paved road dust contribution to airborne allergen concentrations is lower, accounting for approximately 0.5% of the total allergenic activity of the atmospheric particle samples. In conclusion, paved road dust when entrained into the atmosphere by passing traffic is a source of allergen exposure for the general population and could be more important in areas with more abundant vegetation or with closer proximity of populations to major highways than is the case for the Southern California air monitoring sites studied here

Comparative effect of C3a and C5a on adhesion molecule expression on neutrophils and endothelial cells

Complement activation is known to enhance neutrophil binding to human umbilical vein endothelial cells (HUVECs). Recently, we have shown that recombinant human C5a upregulates P-selectin in HUVECs. Unstimulated human neutrophil binding is also increased on C5a stimulated HUVECs. We demonstrate in this report that C5a upregulates CD11b/CD18 in human neutrophils. Also shown is that synthetic C3a 57–77 and an analog 15 amino acid C3a peptide (C3a 15 ) neither upregulate CD11b/CD18 nor do the C3a peptides increase P-selectin, ICAM-1 or E-selectin in HUVECs. Thus C5a and not C3a is responsible for early (∼30 minutes) neutrophil adhesion to endothelial cells after complement activation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44514/1/10753_2005_Article_BF01487740.pd

Meteorological influences on respirable fragment release from Chinese elm pollen

Exposure to airborne pollen from certain plants can cause allergic disease, leading to acute respiratory symptoms. Whole pollen grains, 15&ndash;90 &mu; m-sized particles, provoke the upper respiratory symptoms of rhinitis (hay fever), while smaller pollen fragments capable of depositing in the lower respiratory tract have been proposed as the trigger for asthma. In order to understand factors leading to pollen release and fragmentation we have examined the rupture of Chinese elm pollen under controlled laboratory conditions and in the outdoor atmosphere. Within 30 minutes after immersion in water, 70% of fresh Chinese pollen ruptures, rapidly expelling cytoplasm. Chinese elm flowers, placed in a controlled atmosphere chamber, emitted pollen and pollen debris after a sequential treatment of 98% relative humidity followed by drying and a gentle disturbance. Immunologic assays of antigenic proteins specific to elm pollens revealed that fine particulate material (D p &lt; 2 &mu; m) collected from the chamber contained elm pollen antigens. In a temporal study of the outdoor urban atmosphere during the Chinese elm bloom season of 2004, peak concentrations of pollen and fine pollen fragments occurred at the beginning of the season when nocturnal relative humidity (RH) exceeded 90%. Following later periods of hot dry weather, pollen counts decreased to zero. The Chinese elm pollen fragments also decreased during the hot weather, but later displayed additional peaks following periods of more moderate RH and temperature, indicating that pollen counts underestimate total atmospheric pollen allergen concentrations. Pollen fragments thus increase the biogenic load in the atmosphere in a form that is no longer recognizable as pollen and, therefore, is not amenable to microscopic analysis. This raises the possibility of exposure of sensitive individuals to pollen allergens in the form of fine particles that can penetrate into the lower airways and pose potentially severe health risks.<br /

Cold-dependent activation of complement: Recognition, assessment, and mechanism

Cold-dependent activation of complement (CDAC) is a phenomenon characterized by low hemolytic complement activity in chilled serum. Complement component levels are normal when measured immunologically, and there is normal hemolytic activity in EDTA plasma or serum maintained at 37°C. Little attention has been paid to CDAC except in Japan, and current unfamiliarity with it, even by clinical immunologists, can lead to confusion and unnecessary laboratory tests. A 66-year-old patient with a complex medical history is described whose complement tests showed abnormalities characteristic of CDAC. Evidence for classical complement pathway activation in the cold was obtained by CH 50 measurements, by hemolytic C4 determinations, by C4a, C3a, and C4d generation, and by quantitating complexes. A good correlation was observed among these parameters. Cryoprecipitates were absent. CDAC activity has persisted for over 5 years and is greater at 13 than at 4°C. Activation is ablated by heating at 56°C and restored by the addition of C1 to the heated serum. Adsorption by streptococcal protein G-Sepharose and precipitation by 2.5% polyethylene glycol support the hypothesis that CDAC is caused by aggregated IgG. The CDAC factor(s) also induces complement activation in normal serum but has not interfered with Raji cell or C1q binding tests or with FACS analysis. More limited studies of a second individual experiencing CDAC yielded similar results.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44843/1/10875_2004_Article_BF00920794.pd

Particulate Air Pollution: Possible Relevance in Asthma

The relative importance of air pollution in the pathogenesis of bronchial asthma has been of interest for several decades. Numerous studies on the role of gaseous air pollution containing ozone, nitrogen dioxide, sulfur dioxide, and carbon monoxide have been published. Very little attention has been focused on the role of respirable particles in the causation of asthma. In this article we summarize some of our ongoing investigations into the sources and composition of airborne particles in the Los Angeles and Pasadena atmosphere, including the search for biologically active particles that may induce asthma attacks. It is found that the urban atmosphere contains not only combustion-derived particles from diesel engine exhaust and gasoline-powered motor vehicle exhaust, but also particles formed from biological starting materials including plant debris, cigarette smoke, wood smoke, and meat smoke as well as tire debris containing some natural rubber and paved road dust. Paved road dust is a very complex mixture of particles including garden soil, tire dust, plant fragments, redeposited atmospheric particles of all types, and pollen fragments presumably ground up by passing traffic. We have shown previously that latex allergen can be extracted from tire dust, from roadside dust, and from respirable air samples taken at Los Angeles and Long Beach. At present, work is underway to identify the larger range of allergens that may be contributed by the entrainment of paved road dust into the atmosphere. The possible importance of pollen fragments present in paved road dust in very small particle sizes is discussed as well as their potential relevance in asthma