Pediatric Respiratory and Systemic Effects of Chronic Air Pollution Exposure: Nose, Lung, Heart, and Brain Pathology

Community views about the health and exposure of children living near a coal ash storage site

Coal ash, a waste product generated from burning coal, is composed of small particles comprised of highly toxic elements. Coal ash particles contain heavy metals such as arsenic, lead, and mercury, as well as polyaromatic hydrocarbons and radioactive elements. Most coal ash is stored in landfills and ponds, often located in close proximity to low income communities. Currently, there are no federal regulations governing the storage and transport of coal ash; however the Environmental Protection Agency proposed a coal ash rule in 2010, which could designate coal ash as a hazardous waste. This is the first article to assess community impact from coal ash storage, by exploring parents' perceptions of their children's health and its relationship to chronic exposure to coal ash. This was a community-based study involving four neighborhoods adjacent to a large coal ash storage facility. Focus groups were conducted with community members and the transcripts were analyzed to identify themes regarding children's health, children's exposure to coal ash, and behaviors done to protect children from exposure. The majority of parents (85 %) reported that their children suffered from health conditions; specifically respiratory and emotional and behavioral disorders. Parents highlighted ways in which their children were exposed to coal ash, although many felt they were constantly exposed just by living in the area. Parents felt strongly that exposure to coal ash from the landfill is affecting the health and well-being of their children. Some parents attempted protective behaviors, but most parents felt helpless in reducing children's exposure.

Under the Dome: Air Pollution, Wellbeing, and Pro-Environmental Behaviour Among Beijing Residents

The conflict between economic development and environmental protection has been made salient by increasingly severe air pollution in China, a visible consequence of the costs of rapid economic progress. How does air pollution affect people's psychological experiences? How are newly rich Chinese beginning to think about this social dilemma and are they willing to take any action to deal with the problem? Are there individual differences that contribute to the effect of air pollution on mental experience and concern for environmental protection? The present work explores answers to these questions through two studies among convenience samples of participants residing in Beijing, which is the capital of China and plagued by toxic haze. Study 1 recruited 50 undergraduates and applied a 10-day experience sampling method. Results revealed that the real-time objective air pollution index was negatively associated with immediate subjective wellbeing (SWB) but positively associated with eudaimonic wellbeing (EWB). Study 2 investigated a sample of 288 working adults living in Beijing for their perceptions of air quality, wellbeing, pro-environmental behaviour (PEB) intentions, future orientation, and place attachment. Results revealed that perceived air pollution could not predict general SWB but improved the sense of purpose and meaning in life (i.e., EWB). Furthermore, this association was heightened in individuals who were future-orientated. In addition, perceived air pollution increased PEB intentions, partially through the promotion of EWB, and this effect was stronger in those who were more emotionally attached to Beijing.

Systems pharmacology-based dissection of mechanisms of Chinese medicinal formula Bufei Yishen as an effective treatment for chronic obstructive pulmonary disease

The present work adopted a systems pharmacology-based approach to provide new insights into the active compounds and therapeutic targets of Bufei Yishen formula (BYF) for the treatment of chronic obstructive pulmonary disease (COPD). In addition, we established a rat model of cigarette smoke- and bacterial infection-induced COPD to validate the mechanisms of BYF action that were predicted in systems pharmacology study. The systems pharmacology model derived 216 active compounds from BYF and 195 potential targets related to various diseases. The compound-target network showed that each herbal drug in the BYF formula acted on similar targets, suggesting potential synergistic effects among these herbal drugs. The ClueGo assay, a Cytoscape plugin, revealed that most targets were related to activation of MAP kinase and matrix metalloproteinases. By using target-diseases network analysis, we found that BYF had great potential to treatment of multiple diseases, such as respiratory tract diseases, immune system, and cardiovascular diseases. Furthermore, we found that BYF had the ability to prevent COPD and its comorbidities, such as ventricular hypertrophy, in vivo. Moreover, BYF inhibited the inflammatory cytokine, and hypertrophic factors expression, protease-antiprotease imbalance and the collagen deposition, which may be the underlying mechanisms of action of BYF.

Interstitial Lung Disease in Childhood: Clinical and Genetic Aspects

Interstitial lung disease (ILD) in childhood is a heterogeneous group of rare pulmonary conditions presenting chronic respiratory disorders. Many clinical features of ILD still remain unclear, making the treatment strategies mainly investigative. Guidelines may provide physicians with an overview on the diagnosis and therapeutic directions. However, the criteria used in different clinical studies for the classification and diagnosis of ILDs are not always the same, making the development of guidelines difficult. Advances in genetic testing have thrown light on some etiologies of ILD, which were formerly classified as ILDs of unknown origins. The need of genetic testing for unexplained ILD is growing, and new classification criteria based on the etiology should be adopted to better understand the disease. The purpose of this review is to give an overview of the clinical and genetic aspects of ILD in children.

In utero exposure of mice to diesel exhaust particles affects spatial learning and memory with reduced N-methyl-D-aspartate receptor expression in the hippocampus of male offspring

Diesel exhaust consists of diesel exhaust particles (DEPs) and gaseous compounds. Previous studies reported that in utero exposure to diesel exhaust affects the central nervous system. However, there was no clear evidence that these effects were caused by diesel exhaust particles themselves, gaseous compounds, or both. Here, we explored the effects of in utero exposure to DEPs on learning and memory in male ICR mice. DEP solutions were administered subcutaneously to pregnant ICR mice at a dose of 0 or 200 μg/kg body weight on gestation days 6, 9, 12, 15, and 18. We examined learning and memory in 9-to-10-week-old male offspring using the Morris water maze test and passive avoidance test. Immediately after the behavioral tests, hippocampi were isolated. Hippocampal N-methyl-D-aspartate receptor (NR) expression was also measured by quantitative RT-PCR analysis. Mice exposed to DEPs in utero showed deficits in the Morris water maze test, but their performance was not significantly different from that of control mice in the passive avoidance test. In addition, DEP-exposed mice exhibited decreased hippocampal NR2A expression. The present results indicate that maternal DEP exposure disrupts learning and memory in male offspring, which is associated with reduced hippocampal NR2A expression.

Megacities air pollution problems: Mexico City Metropolitan Area critical issues on the central nervous system pediatric impact

The chronic health effects associated with sustained exposures to high concentrations of air pollutants are an important issue for millions of megacity residents and millions more living in smaller urban and rural areas. Particulate matter (PM) and ozone (O3) concentrations close or above their respective air quality standards during the last 20 years affect 24 million people living in the Mexico City Metropolitan Area (MCMA). Herein we discuss PM and O3 trends in MCMA and their possible association with the observed central nervous system (CNS) effects in clinically healthy children. We argue that prenatal and postnatal sustained exposures to a natural environmental exposure chamber contribute to detrimental neural responses. The emerging picture for MCMA children shows systemic inflammation, immunodysregulation at both systemic and brain levels, oxidative stress, neuroinflammation, small blood vessel pathology, and an intrathecal inflammatory process, along with the early neuropathological hallmarks for Alzheimer and Parkinson's diseases. Exposed brains are briskly responding to their harmful environment and setting the bases for structural and volumetric changes, cognitive, olfactory, auditory and vestibular deficits and long term neurodegenerative consequences. We need to improve our understanding of the PM pediatric short and long term CNS impact through multidisciplinary research. Public health benefit can be achieved by integrating interventions that reduce fine PM levels and pediatric exposures and establishing preventative screening programs targeting pediatric populations that are most at risk. We fully expect that the health of 24 million residents is important and blocking pediatric air pollution research and hiding critical information that ought to be available to our population, health, education and social workers is not in the best interest of our children.

MRI and neuropathological validations of the involvement of air pollutants in cortical selective neuronal loss

Vehicles are a major source of air pollution, especially particulate matter (PM) pollution, throughout the world and auto-rickshaws are considered main contributors to this air pollution. PM, in addition to causing respiratory and cardiovascular disorders, has potential to gain access to the brain and could induce neuroinflammation leading to different neurological disorders. Therefore, in the current project, MRI and immunohistochemistry techniques were adopted to ascertain the neurotoxic potential of the chronic exposure to different PM generated by two-stroke auto-rickshaws (TSA), four-stroke auto-rickshaws (FSA), and aluminum sulfate (AS) solution in rats. The results highlighted that all treated groups followed a pattern of dose-dependent increase in pure cortical neuronal loss, selective neuronal loss (SNL), nuclear pyknosis, karyolysis, and karyorrhexis. Mild to moderate areas of penumbra were also observed with increase in the population of activated microglia and astrocytes, while no alteration in the intensities of T2W MRI signals was perceived in any group. When comparing the findings, TSA possess more neurotoxic potential than FSA and AS, which could be associated with increased concentration of certain elements in TSA emissions. The study concludes that chronic exposure to PM from TSA, FSA, and AS solutions produces diverse neuropathies in the brain, which may lead to different life-threatening neurological disorders like stroke, Alzheimer's, and Parkinson's disorders. Government and environmental agencies should take serious notice of this alarming situation, and immediate steps should be implemented to improve the standards of PM emissions from auto-rickshaws.

Environmental Public Health Applications Using Remotely Sensed Data

We describe a remote sensing and GIS-based study that has three objectives: (1) characterize fine particulate matter (PM_2.5), insolation and land surface temperature using NASA satellite observations, EPA ground-level monitor data and North American Land Data Assimilation System (NLDAS) data products on a national scale; (2) link these data with public health data from the REasons for Geographic And Racial Differences in Stroke (REGARDS) national cohort study to determine whether these environmental risk factors are related to cognitive decline, stroke and other health outcomes; and (3) disseminate the environmental datasets and public health linkage analyses to end users for decision-making through the Centers for Disease Control and Prevention (CDC) Wide-ranging Online Data for Epidemiologic Research (WONDER) system. This study directly addresses a public health focus of the NASA Applied Sciences Program, utilization of Earth Sciences products, by addressing issues of environmental health to enhance public health decision-making.

Exposure to vehicle emissions results in altered blood brain barrier permeability and expression of matrix metalloproteinases and tight junction proteins in mice

Background

Traffic-generated air pollution-exposure is associated with adverse effects in the central nervous system (CNS) in both human exposures and animal models, including neuroinflammation and neurodegeneration. While alterations in the blood brain barrier (BBB) have been implicated as a potential mechanism of air pollution-induced CNS pathologies, pathways involved have not been elucidated.

Objectives

To determine whether inhalation exposure to mixed vehicle exhaust (MVE) mediates alterations in BBB permeability, activation of matrix metalloproteinases (MMP) -2 and −9, and altered tight junction (TJ) protein expression.

Methods

Apolipoprotein (Apo) E^−/− and C57Bl6 mice were exposed to either MVE (100 μg/m³ PM) or filtered air (FA) for 6 hr/day for 30 days and resulting BBB permeability, expression of ROS, TJ proteins, markers of neuroinflammation, and MMP activity were assessed. Serum from study mice was applied to an in vitro BBB co-culture model and resulting alterations in transport and permeability were quantified.

Results

MVE-exposed Apo E^−/− mice showed increased BBB permeability, elevated ROS and increased MMP-2 and −9 activity, compared to FA controls. Additionally, cerebral vessels from MVE-exposed mice expressed decreased levels of TJ proteins, occludin and claudin-5, and increased levels of inducible nitric oxide synthase (iNOS) and interleukin (IL)-1β in the parenchyma. Serum from MVE-exposed animals also resulted in increased in vitro BBB permeability and altered P-glycoprotein transport activity.

Conclusions

These data indicate that inhalation exposure to traffic-generated air pollutants promotes increased MMP activity and degradation of TJ proteins in the cerebral vasculature, resulting in altered BBB permeability and expression of neuroinflammatory markers.

Brain immune interactions and air pollution: macrophage inhibitory factor (MIF), prion cellular protein (PrP(C)), Interleukin-6 (IL-6), interleukin 1 receptor antagonist (IL-1Ra), and interleukin-2 (IL-2) in cerebrospinal fluid and MIF in serum differentiate urban children exposed to severe vs. low air pollution

Mexico City Metropolitan Area children chronically exposed to high concentrations of air pollutants exhibit an early brain imbalance in genes involved in oxidative stress, inflammation, innate and adaptive immune responses along with accumulation of misfolded proteins observed in the early stages of Alzheimer and Parkinson's diseases. A complex modulation of serum cytokines and chemokines influences children's brain structural and gray/white matter volumetric responses to air pollution. The search for biomarkers associating systemic and CNS inflammation to brain growth and cognitive deficits in the short term and neurodegeneration in the long-term is our principal aim. We explored and compared a profile of cytokines, chemokines (Multiplexing LASER Bead Technology) and Cellular prion protein (PrP(C)) in normal cerebro-spinal-fluid (CSF) of urban children with high vs. low air pollution exposures. PrP(C) and macrophage inhibitory factor (MIF) were also measured in serum. Samples from 139 children ages 11.91 ± 4.2 years were measured. Highly exposed children exhibited significant increases in CSF MIF (p = 0.002), IL6 (p = 0.006), IL1ra (p = 0.014), IL-2 (p = 0.04), and PrP(C) (p = 0.039) vs. controls. MIF serum concentrations were higher in exposed children (p = 0.009). Our results suggest CSF as a MIF, IL6, IL1Ra, IL-2, and PrP(C) compartment that can possibly differentiate air pollution exposures in children. MIF, a key neuro-immune mediator, is a potential biomarker bridge to identify children with CNS inflammation. Fine tuning of immune-to-brain communication is crucial to neural networks appropriate functioning, thus the short and long term effects of systemic inflammation and dysregulated neural immune responses are of deep concern for millions of exposed children. Defining the linkage and the health consequences of the brain / immune system interactions in the developing brain chronically exposed to air pollutants ought to be of pressing importance for public health.

Chronic exposure to volcanogenic air pollution as cause of lung injury

Few studies were made regarding the pulmonary effects of exposure to volcanogenic air pollution, representing an unrecognized health risk for humans inhabiting non-eruptive volcanically active areas (10% of world human population). We tested the hypothesis whether chronic exposure to air pollution of volcanogenic origin causes lung injury, using wild mice (Mus musculus) as model. Lung injury was determined using histological morphometric parameters, inflammatory status (InfS) and the amount of black silver deposits (BSD). Mice exposed to volcanogenic air pollution have decreased percentage of alveolar space, alveolar perimeter and lung structural functionality (LSF) ratio and, increased alveolar septal thickness, amount of BSD and InfS. For the first time it is evidenced that non-eruptive active volcanism has a high potential to cause lung injury. This study also highlights the usefulness of M. musculus as bioindicator species, and of the developed biomarker of effect LSF ratio, for future animal and/or human biomonitoring programs.

Amyloid beta inhibits olfactory bulb activity and the ability to smell

Early olfactory dysfunction has been consistently reported in both Alzheimer's disease (AD) and in transgenic mice that reproduce some features of this disease. In AD transgenic mice, alteration in olfaction has been associated with increased levels of soluble amyloid beta protein (Aβ) as well as with alterations in the oscillatory network activity recorded in the olfactory bulb (OB) and in the piriform cortex. However, since AD is a multifactorial disease and transgenic mice suffer a variety of adaptive changes, it is still unknown if soluble Aβ, by itself, is responsible for OB dysfunction both at electrophysiological and behavioral levels. Thus, here we tested whether or not Aβ directly affects OB network activity in vitro in slices obtained from mice and rats and if it affects olfactory ability in these rodents. Our results show that Aβ decreases, in a concentration- and time-dependent manner, the network activity of OB slices at clinically relevant concentrations (low nM) and in a reversible manner. Moreover, we found that intrabulbar injection of Aβ decreases the olfactory ability of rodents two weeks after application, an effect that is not related to alterations in motor performance or motivation to seek food and that correlates with the presence of Aβ deposits. Our results indicate that Aβ disrupts, at clinically relevant concentrations, the network activity of the OB in vitro and can trigger a disruption in olfaction. These findings open the possibility of exploring the cellular mechanisms involved in early pathological AD as an approach to reduce or halt its progress.

Fine particulate matter and incident cognitive impairment in the REasons for Geographic and Racial Differences in Stroke (REGARDS) cohort

Studies of the effect of air pollution on cognitive health are often limited to populations living near cities that have air monitoring stations. Little is known about whether the estimates from such studies can be generalized to the U.S. population, or whether the relationship differs between urban and rural areas. To address these questions, we used a satellite-derived estimate of fine particulate matter (PM_2.5) concentration to determine whether PM_2.5 was associated with incident cognitive impairment in a geographically diverse, biracial US cohort of men and women (n = 20,150). A 1-year mean baseline PM_2.5 concentration was estimated for each participant, and cognitive status at the most recent follow-up was assessed over the telephone using the Six-Item Screener (SIS) in a subsample that was cognitively intact at baseline. Logistic regression was used to determine whether PM_2.5 was related to the odds of incident cognitive impairment. A 10 µg/m³ increase in PM_2.5 concentration was not reliably associated with an increased odds of incident impairment, after adjusting for temperature, season, incident stroke, and length of follow-up [OR (95% CI): 1.26 (0.97, 1.64)]. The odds ratio was attenuated towards 1 after adding demographic covariates, behavioral factors, and known comorbidities of cognitive impairment. A 10 µg/m³ increase in PM_2.5 concentration was slightly associated with incident impairment in urban areas (1.40 [1.06–1.85]), but this relationship was also attenuated after including additional covariates in the model. Evidence is lacking that the effect of PM_2.5 on incident cognitive impairment is robust in a heterogeneous US cohort, even in urban areas.

The effect of air pollutants on the microecology of the respiratory tract of rats

To study the effect of air pollution on the microecology of the respiratory tracts and the relationship of the biotopes with respiratory diseases, Wistar rats exposed to mixed air pollutants were used as poisoning models. The bacterial floras of respiratory tract were analyzed as well as expression of pro-inflammatory mediators of the respiratory epithelium. The mRNA and protein expression levels of pro-inflammatory factor and cytokines measured showed that there were significant changes in the microbiocenosis of the respiratory tract. The microorganisms underwent quantitative and qualitative changes following exposure to mixed air pollutants including a decline of indigenous microflora and increase of the content of conditionally pathogenic microorganisms. These changes depended on the degree of air pollution severity. Measurement of pro-inflammatory factors CC16, TNF-α and IL-6 revealed a similar time-dependent relationship between the content of conditionally pathogenic microorganisms and the interference of CC16 secretion, as well as up-expression of TNF-α and IL-6.

Gene expression changes in rat brain after short and long exposures to particulate matter in Los Angeles basin air: Comparison with human brain tumors

Air pollution negatively impacts pulmonary, cardiovascular, and central nervous systems. Although its influence on brain cancer is unclear, toxic pollutants can cause blood-brain barrier disruption, enabling them to reach the brain and cause alterations leading to tumor development. By gene microarray analysis validated by quantitative RT-PCR and immunostaining we examined whether rat (n=104) inhalation exposure to air pollution particulate matter (PM) resulted in brain molecular changes similar to those associated with human brain tumors. Global brain gene expression was analyzed after exposure to PM (coarse, 2.5-10μm; fine, <2.5μm; or ultrafine, <0.15μm) and purified air for different times, short (0.5, 1, and 3 months) and chronic (10 months), for 5h per day, four days per week. Expression of select gene products was also studied in human brain (n=7) and in tumors (n=83). Arc/Arg3.1 and Rac1 genes, and their protein products were selected for further examination. Arc was elevated upon two-week to three-month exposure to coarse PM and declined after 10-month exposure. Rac1 was significantly elevated upon 10-month coarse PM exposure. On human brain tumor sections, Arc was expressed in benign meningiomas and low-grade gliomas but was much lower in high-grade tumors. Conversely, Rac1 was elevated in high-grade vs. low-grade gliomas. Arc is thus associated with early brain changes and low-grade tumors, whereas Rac1 is associated with long-term PM exposure and highly aggressive tumors. In summary, exposure to air PM leads to distinct changes in rodent brain gene expression similar to those observed in human brain tumors.

Integrated chemical species analysis with source-receptor modeling results to characterize the effects of terrain and monsoon on ambient aerosols in a basin

This study integrated estimated oxidation ratio of sulfur (SOR) and oxidation ratio of nitrogen (NOR) with source-receptor modeling results to identify the effects of terrain and monsoons on ambient aerosols in an urban area (north basin) and a rural area (south basin) of the Taichung Basin. The estimated results indicate that the conversion of sulfur mainly occurs in fine particles (PM₂.₅), whereas the conversion of nitrogen occurs in approximately equal quantities of PM₂.₅ and coarse particles (PM₂.₅-₁₀). The results show a direct relationship for PM₂.₅ between the modeling results with SOR and NOR. The high PM₂.₅ SOR, NOR, and secondary aerosol values all occurred in the upwind area during both monsoons; this shows that the photochemical reaction and the terrain effect on the pollutant transmission were significant in the basin. Additionally, the urban heat island effect on the urban area and the valley effect on the rural area were significant. The results show that secondary aerosol in PM₂.₅-₁₀ contributed approximately 10 % during both monsoons, and the difference in the contribution from secondary aerosol between both areas was small. Vehicle exhaust emissions and wind-borne dust were two crucial PM2.5-10 contributors during both monsoons; their average contributions in both areas were higher than 34 and 32 %, respectively.

Programming of respiratory health in childhood: influence of outdoor air pollution

PURPOSE OF REVIEW

This overview highlights recent experimental and epidemiological evidence for the programming effects of outdoor air pollution exposures during early development on lung function and chronic respiratory disorders, such as asthma and related allergic disorders.

RECENT FINDINGS

Air pollutants may impact anatomy and/or physiological functioning of the lung and interrelated systems. Programming effects may result from pollutant-induced shifts in a number of molecular, cellular, and physiological states and their interacting systems. Specific key regulatory systems susceptible to programming may influence lung development and vulnerability to respiratory diseases, including both central and peripheral components of neuroendocrine pathways and autonomic nervous system (ANS) functioning which, in turn, influence the immune system. Starting in utero, environmental factors, including air pollutants, may permanently organize these systems toward trajectories of enhanced pediatric (e.g., asthma, allergy) as well as adult disease risk (e.g., chronic obstructive pulmonary disease). Evidence supports a central role of oxidative stress in the toxic effects of air pollution. Additional research suggests xenobiotic metabolism and subcellular components, such as mitochondria are targets of ambient air pollution and play a role in asthma and allergy programming. Mechanisms operating at the level of the placenta are being elucidated. Epigenetic mechanisms may be at the roots of adaptive developmental programming.

SUMMARY

Optimal coordinated functioning of many complex processes and their networks of interaction are necessary for normal lung development and the maintenance of respiratory health. Outdoor air pollution may play an important role in early programming of respiratory health and is potentially amenable to intervention.

Prevalence and severity of atherosclerosis in different arterial territories and its relation with obesity

BACKGROUND

There is uneven association between obesity, traditional risk factors, and cardiovascular events. We aimed to analyze the relation between cardiovascular risk factors, including obesity, with the severity of atherosclerosis in different arterial territories.

METHODS

Arteries from five territories (circle of Willis, carotids, coronaries, aorta, and renal) were taken from 185 persons, newborn to 90 years undergoing autopsy in the Forensic Medical Service in Mexico City, to determine atherosclerotic lesions by histopathological study. Lesions were classified according to the American Heart Association grading system as early (types I-III) and advanced (types IV-VI). The degree of atherosclerosis was correlated with arterial territories and risk factors.

RESULTS

Frequencies of advanced lesions according to arterial territories were as follows: circle of Willis, 28%; right carotid, 36%; left carotid, 25%; right coronary, 71%; left coronary, 85%; right renal, 26%; left renal, 29%; and aorta, 52%; P=.0001, for all analyses. There was a higher risk for advanced lesions with increasing body mass index (BMI) (P=.004). However, after adjusting for age, gender, smoking status, hypertension, and diabetes mellitus, BMI was not independently associated with advanced lesions.

CONCLUSIONS

Coronary arteries are significantly more affected than other arterial territories regardless of risk factors, showing the effect of local and systemic factors in the severity of atherosclerosis. We did not find an independent association between advanced atherosclerotic lesions and obesity.

Milano summer particulate matter (PM10) triggers lung inflammation and extra pulmonary adverse events in mice

Recent studies have suggested a link between particulate matter (PM) exposure and increased mortality and morbidity associated with pulmonary and cardiovascular diseases; accumulating evidences point to a new role for air pollution in CNS diseases. The purpose of our study is to investigate PM10sum effects on lungs and extra pulmonary tissues. Milano PM10sum has been intratracheally instilled into BALB/c mice. Broncho Alveolar Lavage fluid, lung parenchyma, heart and brain were screened for markers of inflammation (cell counts, cytokines, ET-1, HO-1, MPO, iNOS), cytotoxicity (LDH, ALP, Hsp70, Caspase8-p18, Caspase3-p17) for a putative pro-carcinogenic marker (Cyp1B1) and for TLR4 pathway activation. Brain was also investigated for CD68, TNF-α, GFAP. In blood, cell counts were performed while plasma was screened for endothelial activation (sP-selectin, ET-1) and for inflammation markers (TNF-α, MIP-2, IL-1β, MPO). Genes up-regulation (HMOX1, Cyp1B1, IL-1β, MIP-2, MPO) and miR-21 have been investigated in lungs and blood. Inflammation in the respiratory tract of PM10sum-treated mice has been confirmed in BALf and lung parenchyma by increased PMNs percentage, increased ET-1, MPO and cytokines levels. A systemic spreading of lung inflammation in PM10sum-treated mice has been related to the increased blood total cell count and neutrophils percentage, as well as to increased blood MPO. The blood-endothelium interface activation has been confirmed by significant increases of plasma ET-1 and sP-selectin. Furthermore PM10sum induced heart endothelial activation and PAHs metabolism, proved by increased ET-1 and Cyp1B1 levels. Moreover, PM10sum causes an increase in brain HO-1 and ET-1. These results state the translocation of inflammation mediators, ultrafine particles, LPS, metals associated to PM10sum, from lungs to bloodstream, thus triggering a systemic reaction, mainly involving heart and brain. Our results provided additional insight into the toxicity of PM10sum and could facilitate shedding light on mechanisms underlying the development of urban air pollution related diseases.

Association between PM₁₀ exposure and sleep of Egyptian school children

PURPOSE

This study aims to investigate the potential association between exposure to particulate matter with an aerodynamic diameter <10 μm (PM10) and sleep disturbances among Egyptian school children.

METHODS

In this cross-sectional study, parents of school children from four elementary schools in areas with different PM10 exposures filled out the Sleep Disturbance Scale for Children questionnaire in Arabic. Air pollution data were obtained from the Egyptian Environmental Affairs Agency.

RESULTS

The sample consisted of 276 children, 121 (44 %) of them were boys with a mean age of 9.26 ± 1.96 years. Disorders of initiating and maintaining sleep (DIMS), disorders of excessive somnolence, and the total score were reported in the clinical range (T score > 70) in 19.9, 24.3, and 24.3 % of the sample, respectively. A generalized additive model with adjustment for potential confounding factors was used to examine the association between PM10 exposure and sleep disturbances. There were statistically significant associations between PM10 exposure and DIMS and sleep hyperhidrosis (P < 0.05).

CONCLUSIONS

Air pollution exposure has a negative impact on children's sleep with significant association between exposure to PM10 and sleep disturbances.

Health effects for the population living near a cement plant: an epidemiological assessment

Epidemiological studies have shown the association between the exposure to air pollution and several adverse health effects. To evaluate the possible acute health effects of air pollution due to the emissions of a cement plant in two small municipalities in Italy (Mazzano and Rezzato), a case-control study design was used. The risks of hospital admission for cardiovascular or respiratory diseases for increasing levels of exposure to cement plant emissions were estimated, separately for adults (age>34 years) and children (0-14 years). Odds ratios (OR) were estimated using unconditional regression models. Attributable risks were also calculated. Statistically significant risks were found mainly for respiratory diseases among children: OR 1.67 (95% CI 1.08-2.58) for the moderately exposed category (E1), OR 1.88 (95% CI 1.19-2.97) for the highly exposed category (E2), with an attributable risk of 38% of hospital admissions due to the exposure to cement plant exhausts. Adults had a weaker risk: OR 1.38 (95% CI 1.18-1.61) for group E1, OR 1.31 (95% CI 1.10-1.56) for group E2; the attributable risk was 23%. Risks were higher for females and for the age group 35-64. These results showed an association between the exposure to plant emissions and the risk of hospital admission for cardiovascular or respiratory causes; this association was particularly strong for children.

Particulate matter (PM10) exposure induces endothelial dysfunction and inflammation in rat brain

Epidemiological studies suggest that particulate matter (PM(10)) inhalation was associated with adverse effects on brain-related health, however, existing experimental data lacked relevant evidences. In this study, we treated Wistar rats with PM(10) at different concentrations (0.3, 1, 3 and 10 mg/kg body weight (bw)), and investigated endothelial dysfunction and inflammatory responses in the brain. The results indicate that mild pathological abnormal occurred after 15-day exposure (five times with 3 days each), followed by the changes of endothelial mediators (ET-1 and eNOS) and inflammatory markers (IL-1β, TNF-α, COX-2, iNOS and ICAM-1). Also, the sample up-regulated bax/bcl-2 ratio and p53 expression, and induced neuronal apoptosis. It implicates that PM(10) exerted injuries to mammals' brain, and the mechanisms might be involved in endothelial dysfunction and inflammatory responses.

Indoor air pollution from gas cooking and infant neurodevelopment

BACKGROUND

Gas cooking is a main source of indoor air pollutants, including nitrogen dioxide and particles. Because concerns are emerging for neurodevelopmental effects of air pollutants, we examined the relationship between indoor gas cooking during pregnancy and infant neurodevelopment.

METHODS

Pregnant mothers were recruited between 2004 and 2008 to a prospective birth cohort study (INfancia y Medio Ambiente) in Spain during the first trimester of pregnancy. Third-trimester questionnaires collected information about the use of gas appliances at home. At age 11 to 22 months, children were assessed for mental development using the Bayley Scales of Infant Development. Linear regression models examined the association of gas cooking and standardized mental development scores (n = 1887 mother-child pairs).

RESULTS

Gas cookers were present in 44% of homes. Gas cooking was related to a small decrease in the mental development score compared with use of other cookers (-2.5 points [95% confidence interval = -4.0 to -0.9]) independent of social class, maternal education, and other measured potential confounders. This decrease was strongest in children tested after the age of 14 months (-3.1 points [-5.1 to -1.1]) and when gas cooking was combined with less frequent use of an extractor fan. The negative association with gas cooking was relatively consistent across strata defined by social class, education, and other covariates.

CONCLUSIONS

This study suggests a small adverse effect of indoor air pollution from gas cookers on the mental development of young children.

The adverse effects of air pollution on the nervous system

Exposure to ambient air pollution is a serious and common public health concern associated with growing morbidity and mortality worldwide. In the last decades, the adverse effects of air pollution on the pulmonary and cardiovascular systems have been well established in a series of major epidemiological and observational studies. In the recent past, air pollution has also been associated with diseases of the central nervous system (CNS), including stroke, Alzheimer's disease, Parkinson's disease, and neurodevelopmental disorders. It has been demonstrated that various components of air pollution, such as nanosized particles, can easily translocate to the CNS where they can activate innate immune responses. Furthermore, systemic inflammation arising from the pulmonary or cardiovascular system can affect CNS health. Despite intense studies on the health effects of ambient air pollution, the underlying molecular mechanisms of susceptibility and disease remain largely elusive. However, emerging evidence suggests that air pollution-induced neuroinflammation, oxidative stress, microglial activation, cerebrovascular dysfunction, and alterations in the blood-brain barrier contribute to CNS pathology. A better understanding of the mediators and mechanisms will enable the development of new strategies to protect individuals at risk and to reduce detrimental effects of air pollution on the nervous system and mental health.

Exposure to severe urban air pollution influences cognitive outcomes, brain volume and systemic inflammation in clinically healthy children

Exposure to severe air pollution produces neuroinflammation and structural brain alterations in children. We tested whether patterns of brain growth, cognitive deficits and white matter hyperintensities (WMH) are associated with exposures to severe air pollution. Baseline and 1 year follow-up measurements of global and regional brain MRI volumes, cognitive abilities (Wechsler Intelligence Scale for Children-Revised, WISC-R), and serum inflammatory mediators were collected in 20 Mexico City (MC) children (10 with white matter hyperintensities, WMH(+), and 10 without, WMH(-)) and 10 matched controls (CTL) from a low polluted city. There were significant differences in white matter volumes between CTL and MC children - both WMH(+) and WMH(-) - in right parietal and bilateral temporal areas. Both WMH(-) and WMH(+) MC children showed progressive deficits, compared to CTL children, on the WISC-R Vocabulary and Digit Span subtests. The cognitive deficits in highly exposed children match the localization of the volumetric differences detected over the 1 year follow-up, since the deficits observed are consistent with impairment of parietal and temporal lobe functions. Regardless of the presence of prefrontal WMH, Mexico City children performed more poorly across a variety of cognitive tests, compared to CTL children, thus WMH(+) is likely only partially identifying underlying white matter pathology. Together these findings reveal that exposure to air pollution may perturb the trajectory of cerebral development and result in cognitive deficits during childhood.

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.

Aryl hydrocarbon receptor-dependent upregulation of Cyp1b1 by TCDD and diesel exhaust particles in rat brain microvessels

Background

AhR activates the transcription of several target genes including CYP1B1. Recently, we showed CYP1B1 as the major cytochrome P450 (CYP) enzyme expressed in human brain microvessels. Here, we studied the effect of AhR activation by environmental pollutants on the expression of Cyp1b1 in rat brain microvessels.

Methods

Expression of AhR and Cyp1b1 was detected in isolated rat brain microvessels. AhR was immunovisualised in brain microvessel endothelial cells. The effect of AhR ligands on Cyp1b1 expression was studied using isolated brain microvessels after ex vivo and/or in vivo exposure to TCDD, heavy hydrocarbons containing diesel exhaust particles (DEP) or Δ⁹-tetrahydrocannabinol (Δ⁹-THC).

Results

After ex vivo exposure to TCDD (a highly potent AhR ligand) for 3 h, Cyp1b1 expression was significantly increased by 2.3-fold in brain microvessels. A single i.p. dose of TCDD also increased Cyp1b1 transcripts (22-fold) and Cyp1b1 protein (2-fold) in rat brain microvessels at 72 h after TCDD. Likewise, DEP treatment (in vivo and ex vivo) strongly induced Cyp1b1 protein in brain microvessels. DEP-mediated Cyp1b1 induction was inhibited by actinomycin D, cycloheximide, or by an AhR antagonist. In contrast, a sub-chronic in vivo treatment with Δ⁹-THC once daily for 7 seven days had no effect on Cyp1b1 expression

Conclusions

Our results show that TCDD and DEP strongly induced Cyp1b1 in rat brain microvessels, likely through AhR activation.

Air pollution: An environmental factor contributing to intestinal disease

The health impacts of air pollution have received much attention and have recently been subject to extensive study. Exposure to air pollutants such as particulate matter (PM) has been linked to lung and cardiovascular disease and increases in both hospital admissions and mortality. However, little attention has been given to the effects of air pollution on the intestine. The recent discovery of genes linked to susceptibility to inflammatory bowel diseases (IBD) explains only a fraction of the hereditary variance for these diseases. This, together with evidence of increases in incidence of IBD in the past few decades of enhanced industrialization, suggests that environmental factors could contribute to disease pathogenesis. Despite this, little research has examined the potential contribution of air pollution and its components to intestinal disease. Exposure of the bowel to air pollutants occurs via mucociliary clearance of PM from the lungs as well as ingestion via food and water sources. Gaseous pollutants may also induce systemic effects. Plausible mechanisms mediating the effects of air pollutants on the bowel could include direct effects on epithelial cells, systemic inflammation and immune activation, and modulation of the intestinal microbiota. Although there is limited epidemiologic evidence to confirm this, we suggest that a link between air pollution and intestinal disease exists and warrants further study. This link may explain, at least in part, how environmental factors impact on IBD epidemiology and disease pathogenesis.

Air pollution from traffic and cancer incidence: a Danish cohort study

BACKGROUND

Vehicle engine exhaust includes ultrafine particles with a large surface area and containing absorbed polycyclic aromatic hydrocarbons, transition metals and other substances. Ultrafine particles and soluble chemicals can be transported from the airways to other organs, such as the liver, kidneys, and brain. Our aim was to investigate whether air pollution from traffic is associated with risk for other cancers than lung cancer.

METHODS

We followed up 54,304 participants in the Danish Diet Cancer and Health cohort for 20 selected cancers in the Danish Cancer Registry, from enrolment in 1993-1997 until 2006, and traced their residential addresses from 1971 onwards in the Central Population Registry. We used modeled concentration of nitrogen oxides (NO(x)) and amount of traffic at the residence as indicators of traffic-related air pollution and used Cox models to estimate incidence rate ratios (IRRs) after adjustment for potential confounders.

RESULTS

NO(x) at the residence was significantly associated with risks for cervical cancer (IRR, 2.45; 95% confidence interval [CI], 1.01;5.93, per 100 μg/m(3) NO(x)) and brain cancer (IRR, 2.28; 95% CI, 1.25;4.19, per 100 μg/m(3) NO(x)).

CONCLUSIONS

This hypothesis-generating study indicates that traffic-related air pollution might increase the risks for cervical and brain cancer, which should be tested in future studies.

Air pollution is associated with brainstem auditory nuclei pathology and delayed brainstem auditory evoked potentials

We assessed brainstem inflammation in children exposed to air pollutants by comparing brainstem auditory evoked potentials (BAEPs) and blood inflammatory markers in children age 96.3±8.5 months from highly polluted (n=34) versus a low polluted city (n=17). The brainstems of nine children with accidental deaths were also examined. Children from the highly polluted environment had significant delays in wave III (t(50)=17.038; p<0.0001) and wave V (t(50)=19.730; p<0.0001) but no delay in wave I (p=0.548). They also had significantly longer latencies than controls for interwave intervals I-III, III-V, and I-V (all t(50)>7.501; p<0.0001), consisting with delayed central conduction time of brainstem neural transmission. Highly exposed children showed significant evidence of inflammatory markers and their auditory and vestibular nuclei accumulated α synuclein and/or β amyloid(1-42). Medial superior olive neurons, critically involved in BAEPs, displayed significant pathology. Children's exposure to urban air pollution increases their risk for auditory and vestibular impairment.

Critical modifier role of membrane-cystic fibrosis transmembrane conductance regulator-dependent ceramide signaling in lung injury and emphysema

Ceramide accumulation mediates the pathogenesis of chronic obstructive lung diseases. Although an association between lack of cystic fibrosis transmembrane conductance regulator (CFTR) and ceramide accumulation has been described, it is unclear how membrane-CFTR may modulate ceramide signaling in lung injury and emphysema. Cftr(+/+) and Cftr(-/-) mice and cells were used to evaluate the CFTR-dependent ceramide signaling in lung injury. Lung tissue from control and chronic obstructive pulmonary disease patients was used to verify the role of CFTR-dependent ceramide signaling in pathogenesis of chronic emphysema. Our data reveal that CFTR expression inversely correlates with severity of emphysema and ceramide accumulation in chronic obstructive pulmonary disease subjects compared with control subjects. We found that chemical inhibition of de novo ceramide synthesis controls Pseudomonas aeruginosa-LPS-induced lung injury in Cftr(+/+) mice, whereas its efficacy was significantly lower in Cftr(-/-) mice, indicating that membrane-CFTR is required for controlling lipid-raft ceramide levels. Inhibition of membrane-ceramide release showed enhanced protective effect in controlling P. aeruginosa-LPS-induced lung injury in Cftr(-/-) mice compared with that in Cftr(+/+) mice, confirming our observation that CFTR regulates lipid-raft ceramide levels and signaling. Our results indicate that inhibition of de novo ceramide synthesis may be effective in disease states with low CFTR expression like emphysema and chronic lung injury but not in complete absence of lipid-raft CFTR as in ΔF508-cystic fibrosis. In contrast, inhibiting membrane-ceramide release has the potential of a more effective drug candidate for ΔF508-cystic fibrosis but may not be effectual in treating lung injury and emphysema. Our data demonstrate the critical role of membrane-localized CFTR in regulating ceramide accumulation and inflammatory signaling in lung injury and emphysema.

Using coalitional games on biological networks to measure centrality and power of genes

MOTIVATION

The interpretation of gene interaction in biological networks generates the need for a meaningful ranking of network elements. Classical centrality analysis ranks network elements according to their importance but may fail to reflect the power of each gene in interaction with the others.

RESULTS

We introduce a new approach using coalitional games to evaluate the centrality of genes in networks keeping into account genes' interactions. The Shapley value for coalitional games is used to express the power of each gene in interaction with the others and to stress the centrality of certain hub genes in the regulation of biological pathways of interest. The main improvement of this contribution, with respect to previous applications of game theory to gene expression analysis, consists in a finer resolution of the gene interaction investigated in the model, which is based on pairwise relationships of genes in the network. In addition, the new approach allows for the integration of a priori knowledge about genes playing a key function on a certain biological process. An approximation method for practical computation on large biological networks, together with a comparison with other centrality measures, is also presented.

Is the air pollution health research community prepared to support a multipollutant air quality management framework?

Ambient air pollution is always encountered as a complex mixture, but past regulatory and research strategies largely focused on single pollutants, pollutant classes, and sources one-at-a-time. There is a trend toward managing air quality in a progressively "multipollutant" manner, with the idealized goal of controlling as many air contaminants as possible in an integrated manner to achieve the greatest total reduction of adverse health and environmental impacts. This commentary considers the current ability of the environmental air pollution exposure and health research communities to provide evidence to inform the development of multipollutant air quality management strategies and assess their effectiveness. The commentary is not a literature review, but a summary of key issues and information gaps, strategies for filling the gaps, and realistic expectations for progress that could be made during the next decade. The greatest need is for researchers and sponsors to address air quality health impacts from a truly multipollutant perspective, and the most limiting current information gap is knowledge of personal exposures of different subpopulations, considering activities and microenvironments. Emphasis is needed on clarifying the roles of a broader range of pollutants and their combinations in a more forward-looking manner; that is not driven by current regulatory structures. Although advances in research tools and outcome data will enhance progress, the greater need is to direct existing capabilities toward strategies aimed at placing into proper context the contributions of multiple pollutants and their combinations to the health burdens, and the relative contributions of pollutants and other factors influencing the same outcomes. The authors conclude that the research community has very limited ability to advise multipollutant air quality management and assess its effectiveness at this time, but that considerable progress can be made in a decade, even at current funding levels, if resources and incentives are shifted appropriately.

Air pollution and hospitalization for epilepsy in Chile

OBJECTIVE

To determine the association between gaseous and fine particulate air pollution (PM(2.5)) and epilepsy in a general population sample.

METHOD

A daily time-series analyses tested the association between daily hospitalization for epilepsy in seven Chilean urban centers during the period 2001 and 2005. Results were adjusted for long term trends, day-of-the-week, and average humidex on the day of hospitalization and the day before.

RESULTS

Pooled city estimates of relative risk (95% CI) of hospitalization for epilepsy associated with changes in pollutant concentrations equivalent to their interquartile range were: 1.098(1.045, 1.155) for carbon monoxide (CO); 1.100 (1.025, 1.181) for ozone O(3); 1.085 (1.03, 1.144) for sulfur dioxide (SO(2)); 1.108 (1.021, 1.204) for nitrogen dioxide (NO(2)); 1.083(1.038, 1.13) for particulate matter <or= 10 microm diameter (PM(10)); and 1.065(1.002, 1.132) for fine particulate matter <or=2.5 microm diameter (PM(2.5)). These results were not significantly influenced by age, sex, or season.

INTERPRETATION

Air pollution may be a risk factor for hospitalization for epilepsy.

Regulation of P-glycoprotein and other ABC drug transporters at the blood-brain barrier

ATP-binding cassette (ABC) transporters are important selective elements of the blood-brain barrier. They line the luminal plasma membrane of the brain capillary endothelium, facing the vascular space, and both protect the central nervous system from entry of neurotoxicants and limit the access of therapeutic drugs to the brain parenchyma. Recent studies highlight the multiple signaling pathways through which the expression and activity of P-glycoprotein and other ABC transporters are modulated in response to xenobiotics, stress and disease. The results show that increased transporter expression occurs in response to signals that activate specific transcription factors, including pregnane-X receptor, constitutive androstane receptor, nuclear factor-kappaB and activator protein-1, and that reduced transporter activity occurs rapidly and reversibly in response to signaling through Src kinase, protein kinase C and estrogen receptors. A detailed understanding of such regulation can provide the basis for improved neuroprotection and enhanced therapeutic drug delivery to the brain.

Neurogenic-committed human pre-adipocytes express CYP1A isoforms

Stem cell models offer an opportunity both for therapeutic use and for the assessment of alternative in vitro models. Human lipoaspirate is a source of adult stem cells (pre-adipocytes), which are able to differentiate into various phenotypes, such as neurogenic lineage. Here, we analyse the suitability of these in vitro models in screening exogenous compounds, such as environmental pollutants, that may affect adipose cells and neurogenic development. To evaluate neurogenic differentiation, we analysed expression of cholinergic system and acetylcholinesterase immunoreactivity. Heterocyclic derivatives of polycyclic aromatic hydrocarbons (PAHs) are often significant components of environmental contaminants. As they contain inducers of cytochrome P450 1A1 (CYP1A1), we explored the activity of CYP1A1-related enzymes, i.e. 7-ethoxycoumarin- and 7-ethoxyresorufin-O-deethylase (ECOD and EROD) in both cell systems in basal conditions and after exposure to non-cytotoxic doses of beta-naphthoflavone (BNF), a well-known PAH-type inducer. Both cell models showed basal and inducible levels of ECOD. Analysis of CYP1A1 protein expression and EROD-related enzyme activity confirmed the inducibility of the CYP1A1 isoform by BNF. These results demonstrate that mesenchymal adult stem cells can constitute innovative models. We therefore propose the use of pre-adipocytes and their neurogenic derivates to evaluate the cytotoxic/biological effects of unintended exposure to contaminants.

Long-term exposure to traffic-related particulate matter impairs cognitive function in the elderly

Animal studies have suggested that fine particulate matter (PM) can translocate from the upper respiratory tract to the brain and cause brain inflammation. Brain inflammation is involved in the pathogenesis of neurodegenerative diseases. Hypothesizing therefore that long-term exposure to fine PM might contribute to the development of Alzheimer's disease (AD), the objective of this study was to investigate the association between exposure to fine PM and mild cognitive impairment (MCI) which is associated with a high risk of progression to AD. A study group of 399 women aged 68-79 years who lived for more than 20 years at the same residential address has been assessed for long-term exposure to PM and tested for MCI. The exposure assessment comprised background concentration of PM(10) and traffic-related PM indicated by the distance of the residential address to the next busy road. The women were assessed for MCI by a battery of several neuropsychological tests and their odor identification ability. Consistent effects of traffic-related air pollution exposure on test performances including a dose-response relation were found. The associations were adjusted for potential confounders using regression analysis. These results indicate that chronic exposure to traffic-related PM may be involved in the pathogenesis of AD.

Effects of a cyclooxygenase-2 preferential inhibitor in young healthy dogs exposed to air pollution: a pilot study

Residency in cities with high air pollution is associated with neuroinflammation and neurodegeneration in healthy children, young adults, and dogs. Nonsteroidal anti-inflammatory drugs may offer neuroprotection. The authors measured the plasma concentrations of 3-nitrotyrosine and the cerebro-spinal-fluid concentrations of prostaglandin E2 metabolite and the oligomeric form of amyloid derived diffusible ligand; measured the mRNA expression of cyclooxygenase-2, interleukin 1beta, CD14, and Aquaporin-4 in target brain areas; and evaluated brain MRI, cognition, and neuropathology in 8 dogs treated with a preferential cyclooxygenase-2 inhibitor (Nimesulide) versus 7 untreated litter-matched Mexico City dogs. Nimesulide significantly decreased nitrotyrosine in plasma (p < .0001), frontal gray IL1beta (p = .03), and heart IL1beta (p = .02). No effect was seen in mRNA COX2, amyloid, and PGE2 in CSF or the MRI white matter lesions. All exposed dogs exhibited olfactory bulb and frontal accumulation of Abeta(42) in neurons and blood vessels and frontal vascular subcortical pathology. White matter hyperintense MRI frontal lesions were seen in 4/6 non-treated and 6/8 treated dogs. Nonsteroidal anti-inflammatory drugs may offer limited neuroprotection in the setting of severe air pollution exposures. The search for potentially beneficial drugs useful to ameliorate the brain effects of pollution represents an enormous clinical challenge.

The olfactory system is affected by steroid aerosol treatment in mice

Asthma needs continuous treatment often for years. In humans, some drugs are administered via aerosol, therefore they come in contact with both respiratory and olfactory mucosa. We explored the possibility that antiasthma corticosteroid treatment could influence the olfactory function by passage through the nose. A group of mice was exposed twice daily for 42 days to fluticasone propionate aerosol and was compared with a control group. Olfactory behavior, respiratory mechanics, histology, and immunoreactivity in the olfactory system were assessed. Fluticasone-treated mice were slower in retrieving a piece of hidden food, but both groups were similarly fast when the food was visible. When a clearly detectable odor was present in the environment, all mice behaved in a similar way. Respiratory mechanics indices were similar in all mice except for the viscose resistance, which was reduced in fluticasone-treated mice. Olfactory mucosa of fluticasone-treated mice was thicker than that of controls. Slight but consistent differences in staining were present for Olfactory Marker Protein but not for other proteins. A mild impairment of olfactory function is present in mice chronically treated with fluticasone aerosol, apparently accompanied by slight modifications of the olfactory receptor cells, and suggests monitoring of olfactory function modifications in long-term steroid users.

Urban air pollution: influences on olfactory function and pathology in exposed children and young adults

Mexico City (MC) residents are exposed to severe air pollution and exhibit olfactory bulb inflammation. We compared the olfactory function of individuals living under conditions of extreme air pollution to that of controls from a relatively clean environment and explore associations between olfaction scores, apolipoprotein E (APOE) status, and pollution exposure. The olfactory bulbs (OBs) of 35 MC and 9 controls 20.8+/-8.5 years were assessed by light and electron microscopy. The University of Pennsylvania Smell Identification Test (UPSIT) was administered to 62 MC/25 controls 21.2+/-2.7 years. MC subjects had significantly lower UPSIT scores: 34.24+/-0.42 versus controls 35.76+/-0.40, p=0.03. Olfaction deficits were present in 35.5% MC and 12% of controls. MC APOE epsilon 4 carriers failed 2.4+/-0.54 items in the 10-item smell identification scale from the UPSIT related to Alzheimer's disease, while APOE 2/3 and 3/3 subjects failed 1.36+/-0.16 items, p=0.01. MC residents exhibited OB endothelial hyperplasia, neuronal accumulation of particles (2/35), and immunoreactivity to beta amyloid betaA(42) (29/35) and/or alpha-synuclein (4/35) in neurons, glial cells and/or blood vessels. Ultrafine particles were present in OBs endothelial cytoplasm and basement membranes. Control OBs were unremarkable. Air pollution exposure is associated with olfactory dysfunction and OB pathology, APOE 4 may confer greater susceptibility to such abnormalities, and ultrafine particles could play a key role in the OB pathology. This study contributes to our understanding of the influences of air pollution on olfaction and its potential contribution to neurodegeneration.

Immunotoxicity and Environment: Immunodysregulation and Systemic Inflammation in Children

Environmental pollutants, chemicals, and drugs have an impact on children’s immune system development. Mexico City (MC) children exposed to significant concentrations of air pollutants exhibit chronic respiratory inflammation, systemic inflammation, neuroinflammation, and cognitive deficits. We tested the hypothesis that exposure to severe air pollution plays a role in the immune responses of asymptomatic, apparently healthy children. Blood measurements for markers of immune function, inflammatory mediators, and molecules interacting with the lipopolysaccharide recognition complex were obtained from two cohorts of matched children (aged 9.7 ± 1.2 years) from southwest Mexico City (SWMC) (n = 66) and from a control city (n = 93) with criteria pollutant levels below current standards. MC children exhibited significant decreases in the numbers of natural killer cells ( p = .003) and increased numbers of mCD14+ monocytes ( p < .001) and CD8+ cells ( p = .02). Lower concentrations of interferon γ ( p = .009) and granulocyte–macrophage colony-stimulating factor ( p < .001), an endotoxin tolerance-like state, systemic inflammation, and an anti-inflammatory response were also present in the highly exposed children. C-reactive protein and the prostaglandin E metabolite levels were positively correlated with twenty-four- and forty-eight-hour cumulative concentrations of PM2.5. Exposure to urban air pollution is associated with immunodysregulation and systemic inflammation in children and is a major health threat.

Cytological damage of nasal epithelium associated with decreased glutathione peroxidase in residents from a heavily polluted city

OBJECTIVE

To evaluate the cytological damage and glutathione peroxidase (GPX) content in the nasal epithelium of residents of Southwest Metropolitan Mexico City (SWMMC) along 1 year of ozone and PM(10) exposure.

METHOD

Four nasal scrapings were obtained in 20 volunteers from a control low polluted city and SWMMC permanent residents (n = 20) during 1 year. The scrapings were obtained in September and December 2004, and February and May 2005. One part of the scraping was stained by hematoxylin-eosin technique for cytological evaluation and a second part was stained by immunocytochemistry method to evaluate GPX concentration by morphometry.

RESULTS

Control subjects: in total, 30% had no cytological alterations and 70% showed only mild or moderate inflammation in four nasal scrapings. All SWMMC residents showed moderate to severe inflammatory processes in some scrapings. Additionally, dysplasia was found once (in 2 cases) or more than on scraping in five cases (25%). GPX concentration in the control group remained highest in median values throughout the study. SWMMC residents with the highest median values of GPX content were found in the May and September scrapings, and the lowest median values were found in December and February when Ozone and PM(10) levels are increased (P < or = 0.05). A lower GPX content was found as the cytological damage increased (P < or = 0.001).

CONCLUSION

Cytological evaluation of nasal epithelium and GPX immunodetection are satisfactory methods to evaluate the earliest damage produced by atmospheric pollution in heavily contaminated cities.