Publications from UCDPER Members

Ozone-induced lung injury and sterile inflammation. Role of toll-like receptor 4.

Jeffrey D. Laskin, Ph.D. - Tue, 02/21/2012 - 15:00

Ozone-induced lung injury and sterile inflammation. Role of toll-like receptor 4.

Exp Mol Pathol. 2012 Jan 24;

Authors: Connor AJ, Laskin JD, Laskin DL

Abstract
Inhalation of toxic doses of ozone is associated with a sterile inflammatory response characterized by an accumulation of macrophages in the lower lung which are activated to release cytotoxic/proinflammatory mediators that contribute to tissue injury. Toll-like receptor 4 (TLR4) is a pattern recognition receptor present on macrophages that has been implicated in sterile inflammatory responses. In the present studies we used TLR4 mutant C3H/HeJ mice to analyze the role of TLR4 in ozone-induced lung injury, oxidative stress and inflammation. Acute exposure of control C3H/HeOuJ mice to ozone (0.8ppm for 3h) resulted in increases in bronchoalveolar lavage (BAL) lipocalin 24p3 and 4-hydroxynonenal modified protein, markers of oxidative stress and lipid peroxidation. This was correlated with increases in BAL protein, as well as numbers of alveolar macrophages. Levels of surfactant protein-D, a pulmonary collectin known to regulate macrophage inflammatory responses also increased in BAL following ozone inhalation. Ozone inhalation was associated with classical macrophage activation, as measured by increased NF-κB binding activity and expression of TNFα mRNA. The observation that these responses to ozone were not evident in TLR4 mutant C3H/HeJ mice demonstrates that functional TLR4 contributes to ozone-induced sterile inflammation and macrophage activation.

PMID: 22300504 [PubMed - as supplied by publisher]

Categories: Publications from UCDPER Members

New Jersey: a case study of the reduction in urban and suburban air pollution from the 1950s to 2010.

Paul J. Lioy, Ph.D. - Tue, 02/21/2012 - 15:00

New Jersey: a case study of the reduction in urban and suburban air pollution from the 1950s to 2010.

Environ Health Perspect. 2011 Oct;119(10):1351-5

Authors: Lioy PJ, Georgopoulos PG

Abstract
BACKGROUND: Air pollution has been a topic of intense concern and study for hundreds of years. During the second half of the 20th century, the United States implemented regulations and controls to reduce the levels of criteria air pollutants and achieve the National Ambient Air Quality Standards (NAAQS) for the protection of human health, while concurrently reducing the levels of toxic air pollutants.
OBJECTIVE: In this commentary we trace the changes in air pollution in New Jersey as a case study, demonstrating the impact of local, state, and federal strategies to control emissions of pollutants and pollutant precursors from the 1950s until today.
DISCUSSION: The original NAAQS (1970-1995) have been achieved, and significant progress has been made to achieve revised standards for ozone and particulate matter (PM) < 2.5 µm in aerodynamic diameter (PM2.5) in New Jersey, which in the past was considered a highly polluted industrial state.
CONCLUSIONS: Assuming no reversals on current regulations because of some major event or energy infrastructure disruption, outdoor air pollution reductions will continue to address health risks among specific segments of the general population affected by ozone/PM and pollution caused by neighborhood, local, and regional point and mobile sources.

PMID: 21622086 [PubMed - indexed for MEDLINE]

Categories: Publications from UCDPER Members

Size-dependent oxygen activation efficiency over Pd(n)/TiO2(110) for the CO oxidation reaction.

Fred S. Roberts, Ph.D. - Sat, 02/18/2012 - 03:00

Size-dependent oxygen activation efficiency over Pd(n)/TiO2(110) for the CO oxidation reaction.

J Am Chem Soc. 2010 Sep 29;132(38):13097-9

Authors: Kaden WE, Kunkel WA, Kane MD, Roberts FS, Anderson SL

The dissociative binding efficiency of oxygen over Pd(n)/TiO(2)(110) (n = 4, 7, 10, 20) has been measured using temperature programmed reaction (TPR) mass spectrometry and X-ray photoemission spectroscopy (XPS) following exposure to O(2) with varying doses and dose temperatures. Experiments were carried out following two different O(2) exposures at 400 K (10 L and 50 L) and for 10 L of O(2) exposure at varying temperatures (T(surf) = 200, 300, and 400 K). During TPR taken after sequential O(2) and CO (5 L at 180 K) exposures, unreacted CO is found to desorb in three features at T(desorb) ≈ 150, 200, and 430 K, while CO(2) is observed to desorb between 170 and 450 K. We show that Pd(20) has exceptionally high efficiency for oxygen activation, compared to other cluster sizes. As a consequence, its activity becomes limited by competitive CO binding at low O(2) exposures, while other Pd(n) sizes are still limited by inefficient O(2) activation. This difference in mechanism can ultimately be related back to differences in electronic properties, thus making this question one that is interesting from the theoretical perspective. We also demonstrate a correlation between one of the two CO binding sites and CO(2) production, suggesting that only CO in that site is reactive.

PMID: 20809570 [PubMed]

Categories: Publications from UCDPER Members

Digital biology: an emerging and promising discipline.

Fred S. Roberts, Ph.D. - Sat, 02/18/2012 - 03:00

Digital biology: an emerging and promising discipline.

Trends Biotechnol. 2005 Mar;23(3):113-7

Authors: Morris RW, Bean CA, Farber GK, Gallahan D, Jakobsson E, Liu Y, Lyster PM, Peng GC, Roberts FS, Twery M, Whitmarsh J, Skinner K

This article examines the role of computation and quantitative methods in modern biomedical research to identify emerging scientific, technical, policy and organizational trends. It identifies common concerns and practices in the emerging community of computationally-oriented bio-scientists by reviewing a national symposium, Digital Biology: the Emerging Paradigm, held at the National Institutes of Health in Bethesda, Maryland, November 6th and 7th 2003. This meeting showed how biomedical computing promises scientific breakthroughs that will yield significant health benefits. Three key areas that define the emerging discipline of digital biology are: scientific data integration, multi-scale modeling and networked science. Each area faces unique technical challenges and information policy issues that must be addressed as the field matures. Here we summarize the emergent challenges and offer suggestions to academia, industry and government on how best to expand the role of computation in their scientific activities.

PMID: 15734552 [PubMed - indexed for MEDLINE]

Categories: Publications from UCDPER Members

Consensus functions and patterns in molecular sequences.

Fred S. Roberts, Ph.D. - Sat, 02/18/2012 - 03:00

Consensus functions and patterns in molecular sequences.

Bull Math Biol. 1993;55(4):695-713

Authors: Mirkin B, Roberts FS

In recent years, methods of consensus, developed for the solution of problems in the social sciences, have become widely used in molecular biology. We study a method of consensus originally due to Waterman et al. (Waterman, Galas and Arratis. 1984. Pattern recognition in several sequences: consensus and alignment. Bull. math. Biol. 46, 515-527) which is used to identify patterns or features in a molecular sequence where a pattern can vary in position within a given window. We show that some well-known consensus methods of the social sciences, the median and the mean, are special cases of this method for certain choices of the parameters used in it and give a precise account of the parameters for which these special cases arise. We also show that the specific parameters used in the method of Waterman et al. make their method equivalent to the media procedure which is widely used in the social sciences.

PMID: 8318927 [PubMed - indexed for MEDLINE]

Categories: Publications from UCDPER Members

Food protein-induced enterocolitis syndrome as a cause for infant hypotension.

Michael R. Greenberg, Ph.D. - Tue, 02/14/2012 - 03:00

Food protein-induced enterocolitis syndrome as a cause for infant hypotension.

West J Emerg Med. 2011 Nov;12(4):512-4

Authors: Coates RW, Weaver KR, Lloyd R, Ceccacci N, Greenberg MR

Abstract
Infants with food protein-induced enterocolitis syndrome (FPIES) may present to the emergency department (ED) with vomiting and hypotension. A previously healthy, 5-month-old male presented with vomiting and hypotension 2 to 3 hours after eating squash. The patient was resuscitated with intravenous fluids, antibiotics, and admitted for presumed sepsis. No source of infection was ever found and the patient was discharged. The patient returned 8 days later with the same symptoms after eating sweet potatoes; the diagnosis of FPIES was made during this admission. Two additional ED visits occurred requiring hydration after new food exposure. FPIES should be considered in infants presenting with gastrointestinal complaints and hypotension. A dietary history, including if a new food has been introduced in the last few hours, may help facilitate earlier recognition of the syndrome.

PMID: 22224148 [PubMed - in process]

Categories: Publications from UCDPER Members

Exposure science and the exposome: an opportunity for coherence in the environmental health sciences.

Paul J. Lioy, Ph.D. - Tue, 02/07/2012 - 03:00

Exposure science and the exposome: an opportunity for coherence in the environmental health sciences.

Environ Health Perspect. 2011 Nov;119(11):A466-7

Authors: Lioy PJ, Rappaport SM

PMID: 22171373 [PubMed - in process]

Categories: Publications from UCDPER Members

Structural changes in the skin of hairless mice following exposure to sulfur mustard correlate with inflammation and DNA damage.

Jeffrey D. Laskin, Ph.D. - Sat, 02/04/2012 - 03:00

Structural changes in the skin of hairless mice following exposure to sulfur mustard correlate with inflammation and DNA damage.

Exp Mol Pathol. 2011 Oct;91(2):515-27

Authors: Joseph LB, Gerecke DR, Heck DE, Black AT, Sinko PJ, Cervelli JA, Casillas RP, Babin MC, Laskin DL, Laskin JD

Abstract
Sulfur mustard (SM, bis(2-chloroethyl)sulfide) is a bifunctional alkylating agent that causes dermal inflammation, edema and blistering. To investigate the pathogenesis of SM-induced injury, we used a vapor cup model which provides an occlusive environment in which SM is in constant contact with the skin. The dorsal skin of SKH-1 hairless mice was exposed to saturated SM vapor or air control. Histopathological changes, inflammatory markers and DNA damage were analyzed 1-14 days later. After 1 day, SM caused epidermal thinning, stratum corneum shedding, basal cell karyolysis, hemorrhage and macrophage and neutrophil accumulation in the dermis. Cleaved caspase-3 and phosphorylated histone 2A.X (phospho-H2A.X), markers of apoptosis and DNA damage, respectively, were increased whereas proliferating cell nuclear antigen (PCNA) was down-regulated after SM exposure. By 3 days, epithelial cell hypertrophy, edema, parakeratosis and loss of epidermal structures were noted. Enzymes generating pro-inflammatory mediators including myeloperoxidase and cyclooxygenase-2 were upregulated. After 7 days, keratin-10, a differentiation marker, was evident in the stratum corneum. This was associated with an underlying eschar, as neoepidermis began to migrate at the wound edges. Trichrome staining revealed increased collagen deposition in the dermis. PCNA expression in the epidermis was correlated with hyperplasia, hyperkeratosis, and parakeratosis. By 14 days, there was epidermal regeneration with extensive hyperplasia, and reduced expression of cleaved caspase-3, cyclooxygenase-2 and phospho-H2A.X. These findings are consistent with the pathophysiology of SM-induced skin injury in humans suggesting that the hairless mouse can be used to investigate the dermatoxicity of vesicants and the potential efficacy of countermeasures.

PMID: 21672537 [PubMed - indexed for MEDLINE]

Categories: Publications from UCDPER Members

Cardiopulmonary Resuscitation Prescription Program: A Pilot Randomized Comparator Trial.

Michael R. Greenberg, Ph.D. - Sun, 01/08/2012 - 03:00

Cardiopulmonary Resuscitation Prescription Program: A Pilot Randomized Comparator Trial.

J Emerg Med. 2011 Dec 15;

Authors: Greenberg MR, Barr GC, Rupp VA, Patel N, Weaver KR, Hamilton K, Reed JF

Abstract
BACKGROUND: The American Heart Association wants to increase the number of citizens who know how to perform cardiopulmonary resuscitation (CPR). It is unknown whether giving patients a prescription (Rx) to learn CPR is effective. We sought to determine if patients with, or at risk for, heart disease and their families were more likely to follow prescriptive advice to buy a CPR Anytime™ kit (American Heart Association, Dallas, TX) or to take a CPR class. METHODS: This was a prospective randomized pilot study of a convenience sample of 162 patients who presented to one of three recruiting sites: a suburban community emergency department (ED), an office-based primary care (IM), or cardiology (CD) setting. After consent was obtained, CPR-naïve participants aged>44 years were randomized to one of two study arms. One group received a Rx for a CPR Anytime™ self-learning kit, consisting of a CPR mannequin and a 22-minute DVD. The comparator group was prescribed a CPR class. RESULTS: At the IM office, 7/29 (24%), at the CD office 3/25 (12%), and at the ED 2/23 (9%) patients purchased the CPR kit. Across both investigational arms, 4 were lost to follow-up, yielding approximately 15% (12/77) who followed Rx advice to purchase the CPR kit and 0% (0/79) who took a CPR class. Cumulatively, a participant was significantly more likely to purchase a kit than to take a class (p=0.0004). CONCLUSION: Patients can be motivated to purchase CPR Anytime™ kits but not to take a CPR class from prescribed advice.

PMID: 22178506 [PubMed - as supplied by publisher]

Categories: Publications from UCDPER Members

Risk-Based Decision Support Tools: Protecting Rail-Centered Transit Corridors from Cascading Effects.

Michael R. Greenberg, Ph.D. - Tue, 12/20/2011 - 03:00

Risk-Based Decision Support Tools: Protecting Rail-Centered Transit Corridors from Cascading Effects.

Risk Anal. 2011 May 12;

Authors: Greenberg MR, Lowrie K, Mayer H, Altiok T

We consider the value of decision support tools for passenger rail system managers. First, we call for models that follow events along main rail lines and then into the surrounding environment where they can cascade onto connected light rail, bus, auto, truck, and other transport modes. Second, we suggest that both probabilistic risk assessment (PRA-based) and agent-based models have a role to play at different scales of analysis and for different kinds of risks. Third, we argue that economic impact tools need more systematic evaluation. Fourth, we note that developers of decision support tools face a challenge of balancing their desire for theoretical elegance and the tendency to focus only on high consequence events against decisionmakers' mistrust of complex tools that they and their staff cannot manage and incorporate into their routine operations, as well as the high costs of developing, updating, and applying decision support tools to transport systems undergoing budget cuts and worker and service reductions.

PMID: 21564145 [PubMed - as supplied by publisher]

Categories: Publications from UCDPER Members

Ambient concentrations and personal exposure to polycyclic aromatic hydrocarbons (PAH) in an urban community with mixed sources of air pollution.

Paul J. Lioy, Ph.D. - Fri, 12/16/2011 - 03:00

Ambient concentrations and personal exposure to polycyclic aromatic hydrocarbons (PAH) in an urban community with mixed sources of air pollution.

J Expo Sci Environ Epidemiol. 2011 Sep;21(5):437-49

Authors: Zhu X, Fan ZT, Wu X, Jung KH, Ohman-Strickland P, Bonanno LJ, Lioy PJ

Abstract
Assessment of the health risks resulting from exposure to ambient polycyclic aromatic hydrocarbons (PAH) is limited by a lack of environmental exposure data among the general population. This study characterized personal exposure and ambient concentrations of PAH in the Village of Waterfront South (WFS), an urban community with many mixed sources of air toxics in Camden, New Jersey, and CopeWood/Davis Streets (CDS), an urban reference area located ∼1 mile east of WFS. A total of 54 and 53 participants were recruited from non-smoking households in WFS and CDS, respectively. In all, 24-h personal and ambient air samples were collected simultaneously in both areas on weekdays and weekends during summer and winter. The ambient PAH concentrations in WFS were either significantly higher than or comparable to those in CDS, indicating the significant impact of local sources on PAH pollution in WFS. Analysis of diagnostic ratios and correlation suggested that diesel truck traffic, municipal waste combustion and industrial combustion were the major sources in WFS. In such an area, ambient air pollution contributed significantly to personal PAH exposure, explaining 44-96% of variability in personal concentrations. This study provides valuable data for examining the impact of local ambient PAH pollution on personal exposure and therefore potential health risks associated with environmental PAH pollution.

PMID: 21364704 [PubMed - indexed for MEDLINE]

Categories: Publications from UCDPER Members

Potential for exposure to engineered nanoparticles from nanotechnology-based consumer spray products.

Paul J. Lioy, Ph.D. - Fri, 12/16/2011 - 03:00

Potential for exposure to engineered nanoparticles from nanotechnology-based consumer spray products.

J Expo Sci Environ Epidemiol. 2011 Sep;21(5):515-28

Authors: Nazarenko Y, Han TW, Lioy PJ, Mainelis G

Abstract
The potential for human exposure to engineered nanoparticles due to the use of nanotechnology-based consumer sprays (categorized as such by the Nanotechnology Consumer Products Inventory) is examined along with analogous products, which are not specified as nanotechnology-based (regular products). Photon correlation spectroscopy was used to obtain particle size distributions in the initial liquid products. Transmission electron microscopy was used to determine particle size, shape, and agglomeration of the particles. Realistic application of the spray products near the human breathing zone characterized airborne particles that are released during use of the sprays. Aerosolization of sprays with standard nebulizers was used to determine their potential for inhalation exposure. Electron microscopy detected the presence of nanoparticles in some nanotechnology-based sprays as well as in several regular products, whereas the photon correlation spectroscopy indicated the presence of particles <100 nm in all investigated products. During the use of most nanotechnology-based and regular sprays, particles ranging from 13 nm to 20 μm were released, indicating that they could he inhaled and consequently deposited in all regions of the respiratory system. The results indicate that exposures to nanoparticles as well as micrometer-sized particles can be encountered owing to the use of nanotechnology-based sprays as well as regular spray products.

PMID: 21364702 [PubMed - indexed for MEDLINE]

Categories: Publications from UCDPER Members

Personal and ambient exposures to air toxics in Camden, New Jersey.

Paul J. Lioy, Ph.D. - Fri, 12/16/2011 - 03:00

Personal and ambient exposures to air toxics in Camden, New Jersey.

Res Rep Health Eff Inst. 2011 Aug;(160):3-127; discussion 129-51

Authors: Lioy PJ, Fan Z, Zhang J, Georgopoulos P, Wang SW, Ohman-Strickland P, Wu X, Zhu X, Harrington J, Tang X, Meng Q, Jung KH, Kwon J, Hernandez M, Bonnano L, Held J, Neal J,

Abstract
Personal exposures and ambient concentrations of air toxics were characterized in a pollution "hot spot" and an urban reference site, both in Camden, New Jersey. The hot spot was the city's Waterfront South neighborhood; the reference site was a neighborhood, about 1 km to the east, around the intersection of Copewood and Davis streets. Using personal exposure measurements, residential ambient air measurements, statistical analyses, and exposure modeling, we examined the impact of local industrial and mobile pollution sources, particularly diesel trucks, on personal exposures and ambient concentrations in the two neighborhoods. Presented in the report are details of our study design, sample and data collection methods, data- and model-analysis approaches, and results and key findings of the study. In summary, 107 participants were recruited from nonsmoking households, including 54 from Waterfront South and 53 from the Copewood-Davis area. Personal air samples were collected for 24 hr and measured for 32 target compounds--11 volatile organic compounds (VOCs*), four aldehydes, 16 polycyclic aromatic hydrocarbons (PAHs), and particulate matter (PM) with an aerodynamic diameter < or = 2.5 microm (PM2.5). Simultaneously with the personal monitoring, ambient concentrations of the target compounds were measured at two fixed monitoring sites, one each in the Waterfront South and Copewood-Davis neighborhoods. To understand the potential impact of local sources of air toxics on personal exposures caused by temporal (weekdays versus weekend days) and seasonal (summer versus winter) variations in source intensities of the air toxics, four measurements were made of each subject, two in summer and two in winter. Within each season, one measurement was made on a weekday and the other on a weekend day. A baseline questionnaire and a time diary with an activity questionnaire were administered to each participant in order to obtain information that could be used to understand personal exposure to specific air toxics measured during each sampling period. Given the number of emission sources of air toxics in Waterfront South, a spatial variation study consisting of three saturation-sampling campaigns was conducted to characterize the spatial distribution of VOCs and aldehydes in the two neighborhoods. Passive samplers were used to collect VOC and aldehyde samples for 24- and 48-hr sampling periods simultaneously at 22 and 16 grid-based sampling sites in Waterfront South and Copewood-Davis, respectively. Results showed that measured ambient concentrations of some target pollutants (mean +/- standard deviation [SD]), such as PM2.5 (31.3 +/- 12.5 microg/m3), toluene (4.24 +/- 5.23 microg/m3), and benzo[a]pyrene (0.36 +/- 0.45 ng/m3), were significantly higher (P < 0.05) in Waterfront South than in Copewood-Davis, where the concentrations of PM2.5, toluene, and benzo[a]pyrene were 25.3 +/- 11.9 microg/m3, 2.46 +/- 3.19 microg/m3, and 0.21 +/- 0.26 ng/m3, respectively. High concentrations of specific air toxics, such as 60 microg/m3 for toluene and 159 microg/m3 for methyl tert-butyl ether (MTBE), were also found in areas close to local stationary sources in Waterfront South during the saturation-sampling campaigns. Greater spatial variation in benzene, toluene, ethylbenzene, and xylenes (known collectively as BTEX) as well as of MTBE was observed in Waterfront South than in Copewood-Davis during days with low wind speed. These observations indicated the significant impact of local emission sources of these pollutants and possibly of other pollutants emitted by individual source types on air pollution in Waterfront South. (Waterfront South is a known hot spot for these pollutants.) There were no significant differences between Waterfront South and Copewood-Davis in mean concentrations of benzene or MTBE, although some stationary sources of the two compounds have been reported in Waterfront South. Further, a good correlation (R > 0.6) was found between benzene and MTBE in both locations. These results suggest that automobile exhausts were the main contributors to benzene and MTBE air pollution in both neighborhoods. Formaldehyde and acetaldehyde concentrations were found to be high in both neighborhoods. Mean (+/- SD) concentrations of formaldehyde were 20.2 +/- 19.5 microg/m3 in Waterfront South and 24.8 +/- 20.8 microg/m3 in Copewood-Davis. A similar trend was observed for the two compounds during the saturation-sampling campaigns. The results indicate that mobile sources (i.e., diesel trucks) had a large impact on formaldehyde and acetaldehyde concentrations in both neighborhoods and that both are aldehyde hot spots. The study also showed that PM2.5, aldehydes, BTEX, and MTBE concentrations in both Waterfront South and Copewood-Davis were higher than ambient background concentrations in New Jersey and than national average concentrations, indicating that both neighborhoods are in fact hot spots for these pollutants. Higher concentrations were observed on weekdays than on weekend days for several compounds, including toluene, ethylbenzene, and xylenes (known collectively as TEX) as well as PAHs and PM2.5. These observations showed the impact on ambient air pollution of higher traffic volumes and more active industrial and commercial operations in the study areas on weekdays. Seasonal variations differed by species. Concentrations of TEX, for example, were found to be higher in winter than in summer in both locations, possibly because of higher emission rates from automobiles and reduced photochemical reactivity in winter. In contrast, concentrations of MTBE were found to be significantly higher in summer than in winter in both locations, possibly because of higher evaporation rates from gasoline in summer. Similarly, concentrations of heavier PAHs, such as benzo[a]pyrene, were found to be higher in winter in both locations, possibly because of higher emission rates from mobile sources, the use of home heating, and the reduced photochemical reactivity of benzo[a]pyrene in winter. In contrast, concentrations of lighter PAHs were found to be higher in summer in both locations, possibly because of volatilization of these compounds from various surfaces in summer. In addition, higher concentrations of formaldehyde were observed in summer than in winter, possibly because of significant contributions from photochemical reactions to formaldehyde air pollution in summer. Personal concentrations of toluene (25.4 +/- 13.5 microg/m3) and acrolein (1.78 +/- 3.7 microg/m3) in Waterfront South were found to be higher than those in the Copewood-Davis neighborhood (13.1 +/- 15.3 microg/m3 for toluene and 1.27 +/- 2.36 microg/m3 for acrolein). However, personal concentrations for most of the other compounds measured in Waterfront South were found to be similar to or lower than those than in Copewood-Davis. (For example, mean +/- SD concentrations were 4.58 +/- 17.3 microg/m3 for benzene, 4.06 +/- 5.32 microg/m3 for MTBE, 16.8 +/- 15.5 microg/m3 for formaldehyde, and 0.40 +/- 0.94 ng/m3 for benzo[a]pyrene in Waterfront South and 9.19 +/- 34.0 microg/m3 for benzene, 6.22 +/- 19.0 microg/m3 for MTBE, 16.0 +/- 16.7 microg/m3 for formaldehyde, and 0.42 +/- 1.08 ng/m3 for benzo[a]pyrene in Copewood-Davis.) This was probably because many of the target compounds had both outdoor and indoor sources. The higher personal concentrations of these compounds in Copewood-Davis might have resulted in part from higher exposure to environmental tobacco smoke (ETS) of subjects from Copewood-Davis. The Spearman correlation coefficient (R) was found to be high for pollutants with significant outdoor sources. The R's for MTBE and carbon tetrachloride, for example, were > 0.65 in both Waterfront South and Copewood-Davis. The R's were moderate or low (0.3-0.6) for compounds with both outdoor and indoor sources, such as BTEX and formaldehyde. A weaker association (R < 0.5) was found for compounds with significant indoor sources, such as BTEX, formaldehyde, PAHs, and PM2.5. The correlations between personal and ambient concentrations of MTBE and BTEX were found to be stronger in Waterfront South than in Copewood-Davis, reflecting the significant impact of local air pollution sources on personal exposure to these pollutants in Waterfront South. Emission-based ambient concentrations of benzene, toluene, and formaldehyde and contributions of ambient exposure to personal concentrations of these three compounds were modeled using atmospheric dispersion modeling and Individual Based Exposure Modeling (IBEM) software, respectively, which were coupled for analysis in the Modeling Environment for Total Risk (MENTOR) system. The compounds were associated with the three types of dominant sources in the two neighborhoods: industrial sources (toluene), exhaust from gasoline-powered motor vehicles (benzene), and exhaust from diesel-powered motor vehicles (formaldehyde). Subsequently, both the calculated and measured ambient concentrations of each of the three compounds were separately combined with the time diaries and activity questionnaires completed by the subjects as inputs to IBEM-MENTOR for estimating personal exposures from ambient sources. Modeled ambient concentrations of benzene and toluene were generally in agreement with the measured ambient concentrations within a factor of two, but the values were underestimated at the high-end percentiles. The major local (neighborhood) contributors to ambient benzene concentrations were from mobile sources in the study areas; both mobile and stationary (point and area) sources contributed to the ambient toluene concentrations. This finding can be used as guidance for developing better emission inventories to characterize, through modeling, the ambient concentrations of air toxics in the study areas. (ABSTRACT TRUNCATED)

PMID: 22097188 [PubMed - indexed for MEDLINE]

Categories: Publications from UCDPER Members

Characterization of spatial impact of particles emitted from a cement material production facility on outdoor particle deposition in the surrounding community.

Paul J. Lioy, Ph.D. - Fri, 12/16/2011 - 03:00

Characterization of spatial impact of particles emitted from a cement material production facility on outdoor particle deposition in the surrounding community.

J Air Waste Manag Assoc. 2011 Oct;61(10):1015-25

Authors: Yu CH, Fan Z, McCandlish E, Stern AH, Lioy PJ

Abstract
The objective of this study was to estimate the contribution of a facility that processes steel production slag into raw material for cement production to local outdoor particle deposition in Camden, NJ. A dry deposition sampler that can house four 37-mm quartz fiber filters was developed and used for the collection of atmospheric particle deposits. Two rounds of particle collection (3-4 weeks each) were conducted in 8-11 locations 200-800 m downwind of the facility. Background samples were concurrently collected in a remote area located -2 km upwind from the facility. In addition, duplicate surface wipe samples were collected side-by-side from each of the 13 locations within the same sampling area during the first deposition sampling period. One composite source material sample was also collected from a pile stored in the facility. Both the bulk of the source material and the < 38 microm fraction subsample were analyzed to obtain the elemental source profile. The particle deposition flux in the study area was higher (24-83 mg/m2 x day) than at the background sites (13-17 mg/m2day). The concentration of Ca, a major element in the cement source production material, was found to exponentially decrease with increasing downwind distance from the facility (P < 0.05). The ratio of Ca/Al, an indicator of Ca enrichment due to anthropogenic sources in a given sample, showed a similar trend. These observations suggest a significant contribution of the facility to the local particle deposition. The contribution of the facility to outdoor deposited particle mass was further estimated by three independent models using the measurements obtained from this study. The estimated contributions to particle deposition in the study area were 1.8-7.4% from the regression analysis of the Ca concentration in particle deposition samples against the distance from the facility, 0-11% from the U.S. Environmental Protection Agency (EPA) Chemical Mass Balance (CMB) source-receptor model, and 7.6-13% from the EPA Industrial Source Complex Short Term (ISCST3) dispersion model using the particle-size-adjusted permit-based emissions estimates.

PMID: 22070034 [PubMed - indexed for MEDLINE]

Categories: Publications from UCDPER Members

Exacerbation of Acetaminophen Hepatotoxicity by the Anthelmentic Drug Fenbendazole.

Jeffrey D. Laskin, Ph.D. - Tue, 12/13/2011 - 03:00

Exacerbation of Acetaminophen Hepatotoxicity by the Anthelmentic Drug Fenbendazole.

Toxicol Sci. 2011 Nov 1;

Authors: Gardner CR, Mishin V, Laskin JD, Laskin DL

Abstract
Fenbendazole is a broad spectrum anthelminthic drug widely used to prevent or treat nematode infections in laboratory rodent colonies. Potential interactions between fenbendazole and hepatotoxicants such as acetaminophen are unknown, and this was investigated. Mice were fed a control diet or a diet containing fenbendazole (8-12 mg/kg/day) for 7 days prior to treatment with acetaminophen (300 mg/kg) or phosphate buffered saline. In mice fed a control diet, acetaminophen administration resulted in centrilobular hepatic necrosis and increases in serum transaminases which were evident within 12 h. Acetaminophen-induced hepatotoxicity was markedly increased in mice fed the fenbendazole containing diet, as measured histologically and by significant increases in serum transaminase levels. Moreover in mice fed the fenbendazole-containing diet, but not the control diet, 63% mortality was observed within 24 h of acetaminophen administration. Fenbendazole by itself had no effect on liver histology or serum transaminases. To determine if exaggerated hepatotoxicity was due to alterations in acetaminophen metabolism, we analyzed sera for the presence of free acetaminophen and acetaminophen-glucuronide. We found that there were no differences in acetaminophen turnover. We also measured cytochrome P450 (cyp) 2e1, cyp3a and cyp1a2 activity. Whereas, fenbendazole had no effect on the activity of cyp2e1 or cyp3a, cyp1a2 was suppressed. A prolonged suppression of hepatic glutathione (GSH) was also observed in acetaminophen-treated mice fed the fenbendazole-containing diet when compared to the control diet. These data demonstrate that fenbendazole exacerbates the hepatotoxicity of acetaminophen, an effect that is related to persistent GSH depletion. These findings are novel and suggest a potential drug-drug interaction that should be considered in experimental protocols evaluating mechanisms of hepatotoxicity in rodent colonies treated with fenbendazole.

PMID: 22048645 [PubMed - as supplied by publisher]

Categories: Publications from UCDPER Members

Exposure science and the exposome: an opportunity for coherence in the environmental health sciences.

Paul J. Lioy, Ph.D. - Thu, 11/10/2011 - 03:00

Exposure science and the exposome: an opportunity for coherence in the environmental health sciences.

Environ Health Perspect. 2011 Nov 1;119(11):a466-7

Authors: Lioy PJ, Rappaport SM

PMID: 22063759 [PubMed - in process]

Categories: Publications from UCDPER Members

Exposure science for terrorist attacks and theaters of military conflict: minimizing contact with toxicants.

Paul J. Lioy, Ph.D. - Tue, 11/08/2011 - 15:00

Exposure science for terrorist attacks and theaters of military conflict: minimizing contact with toxicants.

Mil Med. 2011 Jul;176(7 Suppl):71-6

Authors: Lioy PJ

Abstract
The strategies for protecting our deployed U.S. Forces are outlined in National Research Council documents published in 1999-2000. This article summarizes experiences and information gathered and interpreted regarding population and rescue workers' exposures in the aftermath of the 2001 World Trade Center attacks, with the aim to provide insights on issues related to military deployment to locations with hazardous agents. Issues covered include phases of exposure, materials of concern, detection equipment, and personal protection equipment. The focus is on human exposure issues, which are primarily associated with strategies 1 through 3 of the National Research Council's report entitled "Protecting Those Who Serve: Strategies to Protect the Health of Deployed U.S. Forces". Contact and duration of contact with hazardous substances are critical areas of concern, which require prevention and intervention procedures and protocols to reduce the incidence of acute and long-term health outcomes.

PMID: 21916334 [PubMed - indexed for MEDLINE]

Categories: Publications from UCDPER Members