World Trade Center dust induces nasal and neurological tissue injury while propagating reduced olfaction capabilities and increased anxiety behaviors

Objective: Previous in vitro and in vivo World Trade Center particulate matter (WTC_PM) exposure studies have provided evidence of exposure-driven oxidative/nitrative stress and inflammation on respiratory tract and aortic tissues. What remains to be fully understood are secondary organ impacts due to WTC_PM exposure. This study was designed to test if WTC particle-induced nasal and neurologic tissue injury may result in unforeseen functional and behavioral outcomes.Material and Methods: WTC_PM was intranasally administered in mice, evaluating genotypic, histopathologic, and olfaction latency endpoints.Results: WTC_PM exposure was found to incite neurologic injury and olfaction latency in intranasally (IN) exposed mice. Single high-dose and repeat low-dose nasal cavity insults from WTC_PM dust resulted in significant olfaction delays and enduring olfaction deficits. Anxiety-dependent behaviors also occurred in mice experiencing olfaction loss including significant body weight loss, increased incidence and time spent in hind stretch postures, as well as increased stationary time and decreased exploratory time. Additionally, WTC_PM exposure resulted in increased whole brain wet/dry ratios and wet whole brain to body mass ratios that were correlated with exposure and increased exposure dose (p<0.05).Discussion: The potential molecular drivers of WTC_PM-driven tissue injury and olfaction latency may be linked to oxidative/nitrative stress and inflammatory cascades in both upper respiratory nasal and brain tissues.Conclusion: Cumulatively, these data provide evidence of WTC_PM exposure in relation to tissue damage related to oxidative stress-driven inflammation identified in the nasal cavity, propagated to olfactory bulb tissues and, potentially, over extended periods, to other CNS tissues.

Electrospray ionization ion mobility spectrometer with new tristate ion gating for improved sensitivity for compounds with lower ion mobility

An electrospray is a dispersed nebula of charged droplets produced under the influence of a strong electric field. The charged droplets subsequently result in ions in the gas phase. Therefore, electrospray is a commonly used method for transferring liquids to the gas phase while ionizing its constituents at the same time. In this work, we investigate the performance of an electrospray ionization ion mobility spectrometer by varying the electric field strength in the desolvation region. In particular, we investigate a new tristate ion shutter with increased sensitivity for ions with higher molecular mass and lower ion mobility that are usually suppressed by classical Bradbury-Nielsen or Tyndall-Powell ion shutters when using short gating times as required for high resolving power. The electric field in the tristate ion shutter affects the optimal ratio of the electric field strengths in the drift and desolvation region. Furthermore, the solvent flow rate needs to be considered when setting the field strengths in the desolvation region. However, a higher electric field strength in the desolvation region affects the field at the emitter tip. For this reason, a smaller ratio of the drift field strength and the desolvation field strength is beneficial, especially since higher solvent flow rates require higher fields to initiate an electrospray. In this work, we use tetraoctylammonium bromide as an instrument standard and the fungicide metalaxyl, the herbicide isoproturon and the antibiotic cefuroxime as model compounds.

World Trade Center Dust induces airway inflammation while promoting aortic endothelial dysfunction

Respiratory ailments have plagued occupational and public health communities exposed to World Trade Center (WTC) dust since the September 11, 2001 attack on the Twin Towers in Lower Manhattan. We proposed that these ailments were proposed to be induced by inhalation exposure to WTC particulate matter (WTC_PM), that was released during the collapse of the buildings and its subsequent resuspension during cleanup. We investigated this hypothesis using both an in vitro and an in vivo mouse intranasal (IN) exposure models to identify the inflammatory potential of WTC_PM with specific emphasis on respiratory and endothelial tissue responses. The in vitro exposure studies found WTC_PM exposure to be positively correlated with cytotoxicity and increased NO₂^- production in both BEAS-2B pulmonary epithelial cells and THP-1 macrophage cells. The in vivo C57BL/6 mouse studies found significant increases in inflammatory markers including increases in polymorphonuclear neutrophil (PMN) influx into nasal and bronchoalveolar lavage fluids (NLF and BALF), as well as increased levels of total protein and cytokine/chemokines levels. Concurrently, NLF, BALF, and serum NO₂^- levels exhibited significant homeostatic temporal deviations as well as temporal myograohic aortic dysfunction in myography studies. Respiratory exposure to- and evidence -based retention of- WTC_PM may have contributed to chronic systemic effects in exposed mice that r resembled to observed effects in WTC_PM-exposed human populations. Collectively, these findings are reflective of WTC_PM exposure and its effect(s) on respiratory and aortic tissues, highlighting potential dysfunctional pathways that may precipitate inflammatory events, while simultaneously altering homeostatic balances. The tight interplay between these balances, when chronically altered, may contribute to- or result in- chronically diseased pathological states.

A preliminary naturalistic study of low-dose ketamine for depression and suicide ideation in the emergency department

Background

Rapid-onset antidepressants could have important clinical impact if their benefits extended to ED patients. We examined preliminary feasibility, tolerability and efficacy of single-dose IV ketamine in depressed ED patients with suicide ideation (SI).

Methods

Fourteen depressed ED patients with SI received a single IV bolus of ketamine (0.2 mg/kg) over 1–2 minutes. Patients were monitored for 4 hours, then re-contacted daily for 10 days. Treatment response and time to remission were evaluated using the Montgomery-Asberg Depression Rating Scale (MADRS) and Kaplan Meier survival analysis, respectively.

Results

Brief Psychiatric Rating Scale and Young Mania Rating Scale scores transiently increased in two subjects, consistent with ketamine's cognitive/behavioral effects in other populations. Mean MADRS scores fell significantly from 40.4 (SEM:1.8) at baseline to 11.5 (2.2) at 240 minutes. Median time to MADRS score ≤10 was 80 minutes (Interquartile Range: 0.67–24 hours). Suicide ideation scores (MADRS item 10) decreased significantly from 3.9 (SEM:0.4) at baseline to 0.6 (SEM:0.2) at 40 minutes post-administration, with improvements sustained over 10 days.

Conclusions

These data provide preliminary, open-label support for the feasibility and efficacy of ketamine as a rapid-onset antidepressant in the ED.

Man-Made Mineral Fibers (Mmmf): Human Exposures and Health Risk Assessment

MMMF are made by spraying or extruding molten glass, furnace slag, or mineral rock. Health concerns are based on the morphological and toxicological similarities between MMMF and asbestos, and the well-documented evidence that asbestos fibers can cause lung fibrosis (asbestosis), bronchial cancer, and mesothelioma in humans. Epidemiological evidence for human disease from inhalation exposures to fibrous glass is largely negative. Some positive associations have been reported for slag and rockwools. Most of the toxicological evidence for MMMF toxicity in laboratory animals is based on non-physiological exposures such as intratracheal instillation or intraperitoneal injection of fiber suspensions.

The risks for lung fibrosis, lung cancer, and mesothelioma for industrial exposures to most fibrous glass products are either low or negligible for a variety of reasons. First, most commercial fibrous glass products have mean fiber diameters of ∼ 7.5 μm, which results in mean aerodynamic diameters > 22 μm. Thus, most glass fibers, even if dispersed into the air, do not penetrate into the lung to any great extent. Second, the small fraction of smaller diameter fibers which do penetrate into the lungs are not persistent within the lungs for most fibrous glass products, due to mechanical breakage into shorter lengths and dissolution. Dissolution is most rapid for the smaller diameters (< 0.1 μm) capable of producing mesothelioma. The greater hazards for slag and rockwools, in comparison to conventional fibrous glass, appear to be related to their smaller diameters and greater durability within the lungs.

Self-assessment of competencies in dental education in Germany - a multicentred survey

INTRODUCTION

The aim was to assess the competencies of undergraduate dental students in Germany in the domains team competence, communicative competence, learning competence and scholarship.

MATERIALS AND METHODS

The survey was conducted at 11 dental schools that are equally distributed all over Germany. Competencies were assessed with the Freiburg Questionnaire to Assess Competencies in Medicine (FCM). A short version of the FCM was used in this study. This short form included the four domains: team competence (three items), communicative competence (eight items), learning competence (five items) and scholarship (four items). Students had to rate each item twice: first with regard to the respondent's current level of competence and second with regard to the level of competence that respondents think is required by their job. All items were rated on a five-point Likert scale (1 'very much' and 5 'not at all'). Responsible lecturers from all selected dental schools received another questionnaire to answer the questions whether the FCM domain corresponding learning objectives were taught at the respective dental school.

RESULTS

A total of 317 undergraduate students from 11 dental schools in their last clinical year participated. The response rate varied between 48% and 92%. Cronbach's α for the FCM scales addressing the current level of competencies ranged from 0.70 to 0.89 and for the scales measuring the presumed level of competencies demanded by their job ranged from 0.72 to 0.82. The mean values of the scales for the assessment of the presumed level of competencies demanded by the job were significantly lower compared to the mean values of the scales for the current level of competencies (P < 0.001 in all analyses). We found large differences between the two levels - in terms of 'standardised response means' (SRM) - in the domains team competence (SRM 1.34), learning competence (SRM 1.27) and communicative competence (SRM 1.18). Overall, the learning objectives that correspond to the assessed domains of competencies were taught to 19.6% completely, to 55.4% partially and to 25% not at all at the participating dental schools.

CONCLUSION

The results of the present survey revealed that the participating students perceived deficiencies in all domains of competencies. These results indicate that the assessed domains are still barely integrated into dental medicine curricula in Germany and that further research in this field is needed.

[Validity and Reliability of the German Version of the HSS Expectation Questionnaire on Hip Joint Replacement]

Background: Total hip arthroplasty is one of the most successful operations in medicine. The clinical result after surgery and compliance during rehabilitation are influenced by the patient's expectations. There is a lack of a validated German instrument to record these expectations in a standardised manner. Patients: 193 patients from the Dresden Hip Register with osteoarthritis of the hip were surveyed with respect to their expectations before the operation. The study sample consists of 108 women and 85 men. The average age of the patients was 59.7 years, with a standard deviation of 12.2 years. Methods: The Hospital for Special Patient Expectations Survey was translated into German and culturally adapted. In addition, the RKI demographic core data set, the HADS-D, LOT-R and the SCL-(K-)9 were collected to validate the instrument. In the statistical analysis, four main factors could be distinguished. These were "everyday activities", "pain relief and improvement in function", "medication and social participation" and "gait improvement". Results: Patients were predominantly married. 20 % of the women were widowed. 20 % had received higher education. Almost half of the patients were retired, 30 % were employed, 15.1 % self-employed and 7.3 % were unemployed. For most of the items, patients expected major improvements up to normalisation of their health. There were many different answers to several items, such as the question on occupation. For sporting and sexual activities no high expectations were given. The average expectation of the whole sample shows major differences to individual expectations. Men showed higher expectations for medication, social participation and gait improvement than did women. There were lower expectations for everyday activities, medication and social participation and gait improvement for older patients. Summary: The German version of the HSS patients expectation survey was validated. The instrument is useful in the preoperative setting to give the surgeon a first impression on the patient's expectations.

Repeated measures of inflammation, blood pressure, and heart rate variability associated with traffic exposures in healthy adults

BACKGROUND

Previous human exposure studies of traffic-related air pollutants have demonstrated adverse health effects in human populations by comparing areas of high and low traffic, but few studies have utilized microenvironmental monitoring of pollutants at multiple traffic locations while looking at a vast array of health endpoints in the same population. We evaluated inflammatory markers, heart rate variability (HRV), blood pressure, exhaled nitric oxide, and lung function in healthy participants after exposures to varying mixtures of traffic pollutants.

METHODS

A repeated-measures, crossover study design was used in which 23 healthy, non-smoking adults had clinical cardiopulmonary and systemic inflammatory measurements taken prior to, immediately after, and 24 hours after intermittent walking for two hours in the summer months along three diverse roadways having unique emission characteristics. Measurements of PM2.5, PM10, black carbon (BC), elemental carbon (EC), and organic carbon (OC) were collected. Mixed effect models were used to assess changes in health effects associated with these specific pollutant classes.

RESULTS

Minimal associations were observed with lung function measurements and the pollutants measured. Small decreases in BP measurements and rMSSD, and increases in IL-1β and the low frequency to high frequency ratio measured in HRV, were observed with increasing concentrations of PM2.5 EC.

CONCLUSIONS

Small, acute changes in cardiovascular and inflammation-related effects of microenvironmental exposures to traffic-related air pollution were observed in a group of healthy young adults. The associations were most profound with the diesel-source EC.

Health effects of World Trade Center (WTC) Dust: An unprecedented disaster's inadequate risk management

The World Trade Center (WTC) twin towers in New York City collapsed on 9/11/2001, converting much of the buildings' huge masses into dense dust clouds of particles that settled on the streets and within buildings throughout Lower Manhattan. About 80-90% of the settled WTC Dust, ranging in particle size from ∼2.5 μm upward, was a highly alkaline mixture of crushed concrete, gypsum, and synthetic vitreous fibers (SVFs) that was readily resuspendable by physical disturbance and low-velocity air currents. High concentrations of coarse and supercoarse WTC Dust were inhaled and deposited in the conductive airways in the head and lungs, and subsequently swallowed, causing both physical and chemical irritation to the respiratory and gastroesophageal epithelia. There were both acute and chronic adverse health effects in rescue/recovery workers; cleanup workers; residents; and office workers, especially in those lacking effective personal respiratory protective equipment. The numerous health effects in these people were not those associated with the monitored PM2.5 toxicants, which were present at low concentrations, that is, asbestos fibers, transition and heavy metals, polyaromatic hydrocarbons or PAHs, and dioxins. Attention was never directed at the very high concentrations of the larger-sized and highly alkaline WTC Dust particles that, in retrospect, contained the more likely causal toxicants. Unfortunately, the initial focus of the air quality monitoring and guidance on exposure prevention programs on low-concentration components was never revised. Public agencies need to be better prepared to provide reliable guidance to the public on more appropriate means of exposure assessment, risk assessment, and preventive measures.

Toxicological and epidemiological studies on effects of airborne fibers: coherence and public [corrected] health implications

Airborne fibers, when sufficiently biopersistent, can cause chronic pleural diseases, as well as excess pulmonary fibrosis and lung cancers. Mesothelioma and pleural plaques are caused by biopersistent fibers thinner than ∼0.1 μm and longer than ∼5 μm. Excess lung cancer and pulmonary fibrosis are caused by biopersistent fibers that are longer than ∼20 μm. While biopersistence varies with fiber type, all amphibole and erionite fibers are sufficiently biopersistent to cause pathogenic effects, while the greater in vivo solubility of chrysotile fibers makes them somewhat less causal for the lung diseases, and much less causal for the pleural diseases. Most synthetic vitreous fibers are more soluble in vivo than chrysotile, and pose little, if any, health pulmonary or pleural health risk, but some specialty SVFs were sufficiently biopersistent to cause pathogenic effects in animal studies. My conclusions are based on the following: 1) epidemiologic studies that specified the origin of the fibers by type, and especially those that identified their fiber length and diameter distributions; 2) laboratory-based toxicologic studies involving fiber size characterization and/or dissolution rates and long-term observation of biological responses; and 3) the largely coherent findings of the epidemiology and the toxicology. The strong dependence of effects on fiber diameter, length, and biopersistence makes reliable routine quantitative exposure and risk assessment impractical in some cases, since it would require transmission electronic microscopic examination, of representative membrane filter samples, for determining statistically sufficient numbers of fibers longer than 5 and 20 μm, and those thinner than 0.1 μm, based on the fiber types.

[Personality and comorbidity: are there "difficult patients" in hip arthroplasty?]

BACKGROUND

Concomitant disorders at the time of surgery in addition to psychological and socioeconomic patient characteristics may influence treatment outcomes in hip arthroplasty.

OBJECTIVES

To describe the impact of these factors on perioperative complications and postoperative results in terms of function, quality of life, and patient satisfaction.

MATERIALS AND METHODS

Review of relevant clinical studies, meta-analyses, and presentation of our own results.

RESULTS

Comorbidities in general, especially in combination, increase the perioperative risk profile. Socioeconomic factors (education, professional qualifications, social deprivation) in addition to psychological variables (depression, distressed personality) can have a major impact on postoperative functional outcomes and patient satisfaction.

CONCLUSIONS

It is of crucial importance to avoid inequalities in the provision of joint replacement for patients with hip osteoarthritis and co-existing risk factors. Preventive strategies should be implemented to reduce the negative impact of comorbidities on treatment outcome. Personalized communication and education may be helpful in avoiding unrealistic patient expectations before hip replacement.

Inhalation toxicology methods: the generation and characterization of exposure atmospheres and inhalational exposures

In this unit, the need for laboratory-based inhalation toxicology studies, the historical background on adverse health effects of airborne toxicants, and the benefits of advance planning for the building of analytic options into the study design to maximize the scientific gains to be derived from the investments in the study are outlined. The following methods are described: (1) the generation and characterization of exposure atmospheres for inhalation exposures in humans and laboratory animals; (2) the delivery and distribution into and within whole-body exposure chambers, head-only exposure chambers, face-masks, and mouthpieces or nasal catheters; (3) options for on-line functional assays during and between exposures; and (4) options for serial non-invasive assays of response. In doing so, a description beyond exposures to single agents and simple mixtures is presented, and included are methods for evaluating biological responses to complex environmental mixtures. It is also emphasized that great care should be taken in the design and execution of such studies so that the scientific returns can be maximized both initially, and in follow-up utilization of archived samples of the exposure atmospheres, excreta, and tissues collected for histology.

In vitro and in vivo toxicity of urban and rural particulate matter from California

Particulate matter (PM) varies in chemical composition and mass concentration based on location, source, and particle size. This study sought to evaluate the in vitro and in vivo toxicity of coarse (PM_10-2.5) and fine (PM₂₅) PM samples collected at 5 diverse sites within California. Coarse and fine PM samples were collected simultaneously at 2 rural and 3 urban sites within California during the summer. A human pulmonary microvascular endothelial cell line (HPMEC-ST1.6R) was exposed to PM suspensions (50 μg/mL) and analyzed for reactive oxygen species (ROS) after 5 hours of treatment. In addition, FVB/N mice were exposed by oropharyngeal aspiration to 50 μg PM, and lavage fluid was collected 24 hrs post-exposure and analyzed for total protein and %PMNs. Correlations between trace metal concentrations, endotoxin, and biological endpoints were calculated, and the effect of particle size range, locale (urban vs. rural), and location was determined. Absolute principal factor analysis was used to identify pollution sources of PM from elemental tracers of those sources. Ambient PM elicited an ROS and pro-inflammatory-related response in the cell and mouse models, respectively. These responses were dependent on particle size, locale, and location. Trace elements associated with soil and traffic markers were most strongly linked to the adverse effects in vitro and in vivo. Particle size, location, source, and composition of PM collected at 5 locations in California affected the ROS response in human pulmonary endothelial cells and the inflammatory response in mice.

The effect of particle size, location and season on the toxicity of urban and rural particulate matter

Particulate matter (PM) varies in chemical composition and mass concentration based on a number of factors including location, season, source and particle size. The aim of this study was to evaluate the in vitro and in vivo toxicity of coarse and fine PM simultaneously collected at three rural and two urban sites within the metropolitan New York City (NYC) region during two seasons, and to assess how particle size and elemental composition affect toxicity. Human pulmonary microvascular endothelial (HPMEC-ST1.6R) and bronchial epithelial (BEAS-2B) cell lines were exposed to PM (50 μg/mL) and analyzed for reactive oxygen species (ROS). Mice (FVB/N) were exposed by oropharyngeal aspiration to 50 µg PM, and lavage fluid was analyzed for total protein and PMN influx. The ROS response was greater in the HPMEC-ST1.6R cell line compared to BEAS-2B cells, but the responses were significantly correlated (p < 0.01). The ROS response was affected by location, locale and the location:size interaction in both cell lines, and an additional association for size was observed from HPMEC-ST1.6R cells. Urban fine PM generated the highest ROS response. In the mouse model, inflammation was associated with particle size and by a season:size interaction, with coarse PM producing greater PMN inflammation. This study showed that the aerodynamic size, locale (i.e. urban versus rural), and site of PM samples affected the ROS response in pulmonary endothelial and epithelial cells and the inflammatory response in mice. Importantly, these responses were dependent upon the chemical composition of the PM samples.

Toxicological and epidemiological studies of cardiovascular effects of ambient air fine particulate matter (PM2.5) and its chemical components: coherence and public health implications

Recent investigations on PM2.5 constituents' effects in community residents have substantially enhanced our knowledge on the impacts of specific components, especially the HEI-sponsored National Particle Toxicity Component (NPACT) studies at NYU and UW-LRRI that addressed the impact of long-term PM2.5 exposure on cardiovascular disease (CVD) effects. NYU's mouse inhalation studies at five sites showed substantial variations in aortic plaque progression by geographic region that was coherent with the regional variation in annual IHD mortality in the ACS-II cohort, with both the human and mouse responses being primarily attributable to the coal combustion source category. The UW regressions of associations of CVD events and mortality in the WHI cohort, and of CIMT and CAC progression in the MESA cohort, indicated that [Formula: see text] had stronger associations with CVD-related human responses than OC, EC, or Si. The LRRI's mice had CVD-related biomarker responses to [Formula: see text]. NYU also identified components most closely associated with daily hospital admissions (OC, EC, Cu from traffic and Ni and V from residual oil). For daily mortality, they were from coal combustion ([Formula: see text], Se, and As). While the recent NPACT research on PM2.5 components that affect CVD has clearly filled some major knowledge gaps, and helped to define remaining uncertainties, much more knowledge is needed on the effects in other organ systems if we are to identify and characterize the most effective and efficient means for reducing the still considerable adverse health impacts of ambient air PM. More comprehensive speciation data are needed for better definition of human responses.

An x-ray setup to investigate the atomic order of confined liquids in slit geometry

A setup has been designed to investigate thin films of confined liquids with the use of X-ray scattering methods. The confinement is realized between the flat culets of a pair of diamonds by positioning and orienting the lower diamond with nanometer and micro radian accuracy. We routinely achieve gaps between 5 and 50 nm at culet diameters of 200 μm. With this setup and a micro focused X-ray beam we have investigated the in-plane and the out-off-plane atomic order of benzene with atomic resolution.

National Particle Component Toxicity (NPACT) Initiative: integrated epidemiologic and toxicologic studies of the health effects of particulate matter components

Particulate matter (PM*), an ambient air criteria pollutant, is a complex mixture of chemical components; particle sizes range from nanometer-sized molecular clusters to dust particles that are too large to be aspirated into the lungs. Although particle composition is believed to affect health risks from PM exposure, our current health-based air quality standards for PM are limited to (1) the mass concentrations of PM2.5 (particles 2.5 microm or smaller in aerodynamic diameter), which are largely attributable to combustion products; and (2) PM10 (10 microm or smaller), which includes larger-sized mechanically generated dusts. Both of these particle size fractions are regulated under the National Ambient Air Quality Standards (NAAQS) and both have been associated with excess mortality and morbidity. We conducted four studies as part of HEI's integrated National Particle Component Toxicity (NPACT) Initiative research program. Since 1999, the Chemical Speciation Network (CSN), managed by the U.S. Environmental Protection Agency (U.S; EPA), has routinely gathered air monitoring data every third or sixth day for the concentrations of numerous components of PM2.5. Data from the CSN enabled us to conduct a limited time-series epidemiologic study of short-term morbidity and mortality (Ito study); and a study of the associations between long-term average pollutant concentrations and annual mortality (Thurston study). Both have illuminated the roles of PM2.5 chemical components and source-related mixtures as potentially causal agents. We also conducted a series of 6-month subchronic inhalation exposure studies (6 hours/day, 5 days/week) of PM2.5 concentrated (nominally) 10 x from ambient air (CAPs) with apolipoprotein E-deficient (ApoE(-/-)) mice (a mouse model of atherosclerosis) (Chen study). The CAPs studies were conducted in five different U.S. airsheds; we measured the daily mass concentrations of PM2.5, black carbon (BC), and 16 elemental components in order to identify their sources and their roles in eliciting both short- and long-term health-related responses. In addition, from the same five air-sheds we collected samples of coarse (PM10-2.5), fine (PM2.5-0.2), and ultrafine (PM0.2) particles. Aliquots of these samples were administered to cells in vitro and to mouse lungs in vivo (by aspiration) in order to determine their comparative acute effects (Gordon Study). The results of these four complementary studies, and the overall integrative analyses, provide a basis for guiding future research and for helping to determine more targeted emission controls for the PM components most hazardous to acute and chronic health. Application of the knowledge gained in this work may therefore contribute to an optimization of the public health benefits of future PM emission controls. The design of each NPACT study conducted at NYU was guided by our scientific hypotheses, which were based on our reviews of the background literature and our experience in conducting studies of associations between ambient PM and health-related responses. These hypotheses guided the development and conduct of the four studies. Hypothesis 1. Coarse, fine, and ultrafine PM are each capable of producing acute health effects of public health concern, but the effects may differ according to particle size and composition. (Applies to all studies.) Hypothesis 2. Long-term PM2.5 exposures are closely associated with chronic health effects. (Applies to studies 1 and 4.) Hypothesis 3. The source-apportionment techniques that we have developed and refined in recent years provide a useful basis for identifying major categories of sources of PM in ambient air and specific chemical components that have the greatest impacts on a variety of acute and chronic health effects. (Applies to all studies.) Hypothesis 4. The health effects due to ambient PM exposures can best be seen in sensitive subgroups within overall human populations and in animal models of such populations. (Applies to studies 1, 3, and 4.) Overall, the studies have demonstrated that the toxicity of PM is driven by a complex interaction of particle size range, geographic location, source category, and season. These findings suggest that the components of PM--associated with certain categories of sources--are responsible for the observed adverse health effects. Most importantly, the responsible components and source categories vary with the health-related endpoints being assessed. Across all studies, fossil-fuel combustion source categories were most consistently associated with both short- and long-term adverse effects of PM2.5 exposure. The components that originate from the Residual Oil Combustion and Traffic source categories were most closely associated with short-term effects; and components from the Coal Combustion category were more closely associated with long-term effects.

Inflammatory response to fine particulate air pollution exposure: neutrophil versus monocyte

OBJECTIVES

Studies have shown that chronic exposure to ambient fine particulate matter (less than 2.5 µm in aerodynamic diameter, PM₂.₅) pollution induces insulin resistance through alterations in inflammatory pathways. It is critical to study how the immune system responds to this stimulant, which has been linked to cardiovascular and autoimmune diseases, but few studies have been focused on such involvement of both neutrophils and monocytes in a timely manner. We hypothesized that the neutrophil was involved in the inflammatory response to air pollution.

METHODS AND RESULTS

C57BL/6 mice were exposed to PM₂.₅ or filtered air (6 hours/day, 5 days/week) for 5, 14, and 21 days, respectively, in Columbus, OH. At the end of each of the exposure periods, we investigated the inflammatory response through flow cytometry, histology, intravital microscopy, and real-time PCR. PM₂.₅-exposed mice demonstrated a significant inflammatory response after 5 days of exposure. In the lung tissue and bronchoalveolar lavage fluid, monocytes/macrophages showed a transient response, while neutrophils showed a cumulative response. In addition, exposure to PM₂.₅ resulted in elevation of the monocyte chemoattractant protein 1 (MCP-1) cytokine, a monocyte/macrophage attractant in blood, at an early stage of exposure.

CONCLUSIONS

These findings suggest that PM₂.₅ exposure induces the inflammatory responses from both macrophages and neutrophils involvement.

Effect of co-exposure to nickel and particulate matter on insulin resistance and mitochondrial dysfunction in a mouse model

Background

It has been well recognized that toxicity of fine ambient air particulate matter (PM_2.5) may depend on its chemical constituents, including components such as soluble metals that may theoretically exert distinctive effects. We have recently demonstrated an important effect of PM_2.5 on metabolic function. Since transition metals, such as nickel (Ni), represent an important component of exposure in certain environments, and may significantly influence the toxicity of inhalational exposure, we investigated the effects of Ni as a variable component of ambient PM_2.5 exposure.

Methods

Male ApoE knockout mice were exposed to filtered air (FA), fine-sized nickel sulfate particles alone (Ni) at 0.44 μg/m³, concentrated ambient air PM_2.5 (CAPs) at a mean of 70 μg/m³, or CAPs+Ni in Tuxedo, NY, 6 hours/day, 5 days/week, for 3 months.

Results

Exposure to Ni, irrespective of co-exposure to CAPs, resulted in body weight gain, while exposure to CAPs+Ni significantly enhanced fasting glucose and worsened insulin resistance measures (HOMA-IR), when compared with exposure to CAPs alone. CAPs+Ni exposure induced a significant decrease in phosphorylation of AMP-activated protein kinase (AMPK) α. Exposure to Ni or CAPs+Ni significantly induced microcirculatory dysfunction and increased monocytic cell infiltration into lung and adipose, and decreased uncoupling protein 1 expression at gene and protein levels and several brown adipocyte-specific genes in adipose tissue.

Conclusions

Ni exposure has effects on metabolic and inflammatory parameters that are comparable to that of CAPs. Additionally, Ni synergistically exacerbates CAPs-induced adverse effects on some of, but not all of, these parameters, that may be mediated via the AMPK signaling pathway. These findings have important implications for inhaled transition metal toxicity that may exert synergistic effects with other PM_2.5 components.

Factors affecting personal exposure to thoracic and fine particles and their components

Central monitoring site (CMS) concentrations have been used to represent population-based personal exposures to particulate matter (PM) of ambient origin. We investigated the associations of the concentrations of PM(2.5) and PM(10) and their elemental components for elderly clinic patients with chronic obstructive pulmonary disease in two cities with different PM compositions, that is, New York City (NYC) and Seattle. Daily measurements of CMS, outdoor residential, and indoor PM(10) and PM(2.5) concentrations, as well as personal PM(10), were made concurrently for 12-consecutive winter days at 9 NYC and 15 Seattle residences, as well for 9 NYC residences in summer. Filters were analyzed for elemental components using X-ray fluorescence (XRF), and for black carbon (BC) by light reflectance, and outdoor-indoor-personal relationships of PM components were examined using mixed-effect models. Using sulfur (S) as a tracer of PM of ambient origin, the mean contributions of outdoor PM(2.5) was 55.2% of the indoor concentrations in NYC, and 80.0% in Seattle, and outdoor PM(2.5) in NYC and Seattle were 19.7 and 18.5% of personal PM(2.5) concentration. S was distributed homogeneously in both cities (R(2)=0.65), whereas nickel (R(2)=0.23) was much more spatially heterogeneous. Thus, CMS measurements can adequately reflect personal exposures for spatially uniform components, such as sulfate, but they are not adequate for components from more local sources.

Association of systemic inflammation with marked changes in particulate air pollution in Beijing in 2008

Many studies have linked ambient fine particulate matter (aerodynamic diameters less than 2.5 μm, PM₂.₅) air pollution to increased morbidity and mortality of cardiovascular diseases in the general population, but the biologic mechanisms of these associations are yet to be elucidated. In this study, we aimed to evaluate the relationship between daily variations in exposure to PM₂.₅ and inflammatory responses in mice during and for 2 months after the Beijing Olympic Games. Male C57BL/6 mice were exposed to Beijing PM₂.₅ or filtered air (FA) in 2008 during the 2 months of Beijing Olympic and Paralympic Games, and for 2 months after the end of the Games. During the Games, circulating monocyte chemoattractant protein 1 and interleukin 6 were increased significantly in the PM₂.₅ exposure group, when compared with the FA control group, although there were no significant inter-group differences in tumor necrosis factor-α or interferon-γ, or in macrophages, neutrophils or lymphocytes in the spleen or thymus between these 2 groups. However, macrophages were significantly increased in the lung and visceral fat with increasing PM₂.₅. After the Olympic Games, there were no significant PM₂.₅-associated differences for macrophages, neutrophils or lymphocytes in the thymus, but macrophages were significantly elevated in the lung, spleen, subcutaneous and visceral fat with increasing PM₂.₅, and the numbers of macrophages were even higher after than those during the Games. Moreover, the number of neutrophils was markedly higher in the spleen for the PM₂.₅-exposed- than the FA-group. These data suggest that short-term increases in exposure to ambient PM₂.₅ leads to increased systemic inflammatory responses, primarily macrophages and neutrophils in the lung, spleen, and visceral adipose tissue. Short-term air quality improvements were significantly associated with reduced overall inflammatory responses.

Particulate matter neurotoxicity in culture is size-dependent

Exposure to particulate matter (PM) air pollution produces inflammatory damage to the cardiopulmonary system. This toxicity appears to be inversely related to the size of the PM particles, with the ultrafine particle being more inflammatory than larger sizes. Exposure to PM has more recently been associated with neurotoxicity. This study examines if the size-dependent toxicity reported in cardiopulmonary systems also occurs in neural targets. For this study, PM ambient air was collected over a 2 week period from Sterling Forest State Park (Tuxedo, New York) and its particulates sized as Accumulation Mode, Fine (AMF) (>0.18-1μm) or Ultrafine (UF) (<0.18μm) samples. Rat dopaminergic neurons (N27) were exposed to suspensions of each PM fraction (0, 12.5, 25, 50μm/ml) and cell loss (as measured by Hoechst nuclear stain) measured after 24h exposure. Neuronal loss occurred in response to all tested concentrations of UF (>12.5μg/ml) but was only significant at the highest concentration of AMF (50μg/ml). To examine if PM size-dependent neurotoxicity was retained in the presence of other cell types, dissociated brain cultures of embryonic rat striatum were exposed to AMF (80μg/ml) or UF (8.0μg/ml). After 24h exposure, a significant increase of reactive nitrogen species (nitrite) and morphology suggestive of apoptosis occurred in both treatment groups. However, morphometric analysis of neuron specific enolase staining indicated that only the UF exposure produced significant neuronal loss, relative to controls. Together, these data suggest that the inverse relationship between size and toxicity reported in cardiopulmonary systems occurs in cultures of isolated dopaminergic neurons and in primary cultures of the rat striatum.

Spatial and seasonal distribution of aerosol chemical components in New York City: (2) road dust and other tracers of traffic-generated air pollution

We describe spatial and temporal patterns of seven chemical elements commonly observed in fine particulate matter (PM) and thought to be linked to roadway emissions that were measured at residential locations in New York City (NYC). These elements, that is, Si, Al, Ti, Fe, Ba, Br, and black carbon (BC), were found to have significant spatial and temporal variability at our 10 residential PM(2.5) sampling locations. We also describe pilot study data of near-roadway samples of both PM(10-2.5) and PM(2.5) chemical elements of roadway emissions. PM(2.5) element concentrations collected on the George Washington Bridge (GWB) connecting NYC and New Jersey were higher that similar elemental concentration measured at residential locations. Coarse-particle elements (within PM(10-2.5)) on the GWB were 10-100 times higher in concentration than their PM(2.5) counterparts. Roadway elements were well correlated with one another in both the PM(2.5) and PM(10-2.5) fractions, suggesting common sources. The same elements in the PM(2.5) collected at residential locations were less correlated, suggesting either different sources or different processing mechanisms for each element. Despite the fact that these elements are only a fraction of total PM(2.5) or PM(10-2.5) mass, the results have important implications for near-roadway exposures where elements with known causal links to health effects are shown to be at elevated concentrations in both the PM(2.5) and PM(10-2.5) size ranges.

Effects of thoracic and fine PM and their components on heart rate and pulmonary function in COPD patients

Population-based personal exposures to particulate matter (PM) and personal-ambient relationships of PM and component concentrations for outpatients with COPD and/or asthma were investigated in New York City (NYC) and Seattle for thoracic PM (PM(10)) and fine PM (PM(2.5)). Measurements of outdoor, indoor, and personal PM(10) and PM(2.5) concentrations were made concurrently for 12-consecutive days at 24 patients' residences. Filters were analyzed for elemental components, using XRF and black carbon (BC), by reflectance. Daily morning and evening measurements of heart rate (HR) and blood oxygen saturation (SpO(2)) by pulse oximeter, and forced expiratory volume in 1 s (FEV(1)) and peak expiratory flowrate (PEF) by spirometry were also measured, and symptom data were collected. Central monitoring site, outdoor, indoor, and personal concentration-response relationships of PM(2.5), PM(10-2.5), and their components were examined using mixed-effect models. The relatively small sample size of the study limited the interpretation of results, but of the PM chemical components examined, only nickel concentrations showed consistent associations, and only with HR in the NYC COPD patients.

Spatial and seasonal distribution of aerosol chemical components in New York City: (1) Incineration, coal combustion, and biomass burning

We describe spatial and temporal patterns of fine particulate matter (PM(2.5)) and of 12 of its constituent chemical elements commonly observed in measurements at residential locations in New York City (NYC). These elements, that is, Ni, V, As, Se, S, Cl, Na, K, Pb, Cu, Zn, and Mn, had significant spatial and temporal variability at 10 PM(2.5) sampling locations during our winter and summer sampling campaigns. By grouping the elements into traditional source apportionment categories, we show that specific chemical components of PM(2.5) considered to have a common source category, such as As and Se for coal combustion, do not always follow the same temporal or spatial pattern. PM(2.5) mass had only limited spatial variability and a slight summertime concentration enhancement. Measurements at residential locations were, on average, consistent with EPA sampling network measurements, although we found that during times of low regional concentration, EPA measurements underestimated the PM(2.5) concentration at residential locations. These results have implications for improved understanding of exposures to specific sources of PM(2.5), and raise some concerns about source profiles used in source-receptor modeling tracer input selection.

Long-term exposure to ambient fine particulate pollution induces insulin resistance and mitochondrial alteration in adipose tissue

We have previously shown that chronic exposure to ambient fine particulate matter (less than 2.5 μm in aerodynamic diameter, PM₂.₅) pollution in conjunction with high-fat diet induces insulin resistance through alterations in inflammatory pathways. In this study, we evaluated the effects of PM₂.₅ exposure over a substantive duration of a rodent's lifespan and focused on the impact of long-term exposure on adipose structure and function. C57BL/6 mice were exposed to PM₂.₅ or filtered air (FA) (6 h/day, 5 days/week) for duration of 10 months in Columbus, OH. At the end of the exposure, PM₂.₅-exposed mice demonstrated insulin resistance (IR) and a decrease in glucose tolerance compared with the FA-exposed group. Although there were no significant differences in circulating cytokines between PM₂.₅- and FA-exposed groups, circulating adiponectin and leptin were significantly decreased in PM₂.₅-exposed group. PM₂.₅ exposure also led to inflammatory response and oxidative stress as evidenced by increase of Nrf2-regulated antioxidant genes. Additionally, PM₂.₅ exposure decreased mitochondrial count in visceral adipose and mitochondrial size in interscapular adipose depots, which were associated with reduction of uncoupling protein 1 (UCP1) expression and downregulation of brown adipocyte-specific gene profiles. These findings suggest that long-term ambient PM₂.₅ exposure induces impaired glucose tolerance, IR, inflammation, and mitochondrial alteration, and thus, it is a risk factor for the development of type 2 diabetes.

Ambient particulate air pollution induces oxidative stress and alterations of mitochondria and gene expression in brown and white adipose tissues

Background

Prior studies have demonstrated a link between air pollution and metabolic diseases such as type II diabetes. Changes in adipose tissue and its mitochondrial content/function are closely associated with the development of insulin resistance and attendant metabolic complications. We investigated changes in adipose tissue structure and function in brown and white adipose depots in response to chronic ambient air pollutant exposure in a rodent model.

Methods

Male ApoE knockout (ApoE^-/-) mice inhaled concentrated fine ambient PM (PM < 2.5 μm in aerodynamic diameter; PM_2.5) or filtered air (FA) for 6 hours/day, 5 days/week, for 2 months. We examined superoxide production by dihydroethidium staining; inflammatory responses by immunohistochemistry; and changes in white and brown adipocyte-specific gene profiles by real-time PCR and mitochondria by transmission electron microscopy in response to PM_2.5 exposure in different adipose depots of ApoE^-/- mice to understand responses to chronic inhalational stimuli.

Results

Exposure to PM_2.5 induced an increase in the production of reactive oxygen species (ROS) in brown adipose depots. Additionally, exposure to PM_2.5 decreased expression of uncoupling protein 1 in brown adipose tissue as measured by immunohistochemistry and Western blot. Mitochondrial number was significantly reduced in white (WAT) and brown adipose tissues (BAT), while mitochondrial size was also reduced in BAT. In BAT, PM_2.5 exposure down-regulated brown adipocyte-specific genes, while white adipocyte-specific genes were differentially up-regulated.

Conclusions

PM_2.5 exposure triggers oxidative stress in BAT, and results in key alterations in mitochondrial gene expression and mitochondrial alterations that are pronounced in BAT. We postulate that exposure to PM_2.5 may induce imbalance between white and brown adipose tissue functionality and thereby predispose to metabolic dysfunction.

Time-series analysis of mortality effects of fine particulate matter components in Detroit and Seattle

BACKGROUND

Recent toxicological and epidemiological studies have shown associations between particulate matter (PM) and adverse health effects, but which PM components are most influential is less well known.

OBJECTIVES

In this study, we used time-series analyses to determine the associations between daily fine PM [PM ≤ 2.5 µm in aerodynamic diameter (PM2.5)] concentrations and daily mortality in two U.S. cities-Seattle, Washington, and Detroit, Michigan.

METHODS

We obtained daily PM2.5 filters for the years of 2002-2004 and analyzed trace elements using X-ray fluorescence and black carbon using light reflectance as a surrogate measure of elemental carbon. We used Poisson regression and distributed lag models to estimate excess deaths for all causes and for cardiovascular and respiratory diseases adjusting for time-varying covariates. We computed the excess risks for interquartile range increases of each pollutant at lags of 0 through 3 days for both warm and cold seasons.

RESULTS

The cardiovascular and respiratory mortality series exhibited different source and seasonal patterns in each city. The PM2.5 components and gaseous pollutants associated with mortality in Detroit were most associated with warm season secondary aerosols and traffic markers. In Seattle, the component species most closely associated with mortality included those for cold season traffic and other combustion sources, such as residual oil and wood burning.

CONCLUSIONS

The effects of PM2.5 on daily mortality vary with source, season, and locale, consistent with the hypothesis that PM composition has an appreciable influence on the health effects attributable to PM.