Ambient air pollution and population health: overview

A comprehensive overview of genotoxicity and mutagenicity associated with outdoor air pollution exposure in Brazil

This review examined the mutagenicity and genotoxicity associated with exposure to outdoor air pollutants in Brazil. A search was performed on the Web of Science database using a combination of keywords that resulted in 134 articles. After applying exclusion criteria, a total of 75 articles were obtained. The articles were classified into three categories: (1) studies with plants and animals, (2) in vitro studies, and (3) human biomonitoring. The investigations were conducted in 11 of 27 Brazilian states with the highest prevalence in the southeast and south regions. Only 5 investigations focused on the effects of burning biomass on the quality of outdoor air. Plants, especially Tradescantia pallida, were the main air pollution biomonitoring tool. When available, a significant association between levels of air pollutants and genetic damage was described. Among the in vitro studies, Salmonella/microsome is the most used test to evaluate mutagenesis of outdoor air in Brazil (n = 26). Human biomonitoring studies were the least frequent category (n = 18). Most of the investigations utilized micronucleus bioassay, in oral mucosa cells (n = 15) and lymphocytes (n = 5), and the comet assay (n = 6). The analysis in this study points to the existence of gaps in genotoxicity studies and our findings indicate that future studies need to address the variety of potential sources of pollution existing in Brazil. In addition to extent of the impacts, consideration should be given to the enormous Brazilian biodiversity, as well as the determination of the role of socioeconomic inequality of the population in the observed outcomes.

Maternal exposure to air pollution alters energy balance transiently according to gender and changes gut microbiota

Introduction

The timing of maternal exposure to air pollution is crucial to define metabolic changes in the offspring. Here we aimed to determine the most critical period of maternal exposure to particulate matter (PM_2.5) that impairs offspring's energy metabolism and gut microbiota composition.

Methods

Unexposed female and male C57BL/6J mice were mated. PM_2.5 or filtered air (FA) exposure occurred only in gestation (PM_2.5/FA) or lactation (FA/PM_2.5). We studied the offspring of both genders.

Results

PM_2.5 exposure during gestation increased body weight (BW) at birth and from weaning to young in male adulthood. Leptin levels, food intake, Agrp, and Npy levels in the hypothalamus were also increased in young male offspring. Ikbke, Tnf increased in male PM_2.5/FA. Males from FA/PM_2.5 group were protected from these phenotypes showing higher O₂ consumption and Ucp1 in the brown adipose tissue. In female offspring, we did not see changes in BW at weaning. However, adult females from PM_2.5/FA displayed higher BW and leptin levels, despite increased energy expenditure and thermogenesis. This group showed a slight increase in food intake. In female offspring from FA/PM_2.5, BW, and leptin levels were elevated. This group displayed higher energy expenditure and a mild increase in food intake. To determine if maternal exposure to PM_2.5 could affect the offspring's gut microbiota, we analyzed alpha diversity by Shannon and Simpson indexes and beta diversity by the Linear Discriminant Analysis (LDA) in offspring at 30 weeks. Unlike males, exposure during gestation led to higher adiposity and leptin maintenance in female offspring at this age. Gestation exposure was associated with decreased alpha diversity in the gut microbiota in both genders.

Discussion

Our data support that exposure to air pollution during gestation is more harmful to metabolism than exposure during lactation. Male offspring had an unfavorable metabolic phenotype at a young age. However, at an older age, only females kept more adiposity. Ultimately, our data highlight the importance of controlling air pollution, especially during gestation.

Monocyte exposure to fine particulate matter results in miRNA release: A link between air pollution and potential clinical complication

Chronic exposure to PM_2.5 contributes to the pathogenesis of numerous disorders, although the underlying mechanisms remain unknown. The study investigated whether exposure of human monocytes to PM_2.5 is associated with alterations in miRNAs. Monocytes were exposed in vitro to PM_2.5 collected during winter and summer, followed by miRNA isolation from monocytes. Additionally, in 140 persons chronically exposed to air pollution, some miRNA patterns were isolated from serum seasonally. Between-season differences in chemical PM_2.5 composition were observed. Some miRNAs were expressed both in monocytes and in human serum. MiR-34c-5p and miR-223-5p expression was more pronounced in winter. Bioinformatics analyses showed that selected miRNAs were involved in the regulation of several pathways. The expression of the same miRNA species in monocytes and serum suggests that these cells are involved in the production of miRNAs implicated in the development of disorders mediated by inflammation, oxidative stress, proliferation, and apoptosis after exposure to PM_2.5.

Investigation of the PM2.5, NO2 and O3 I/O ratios for office and school microenvironments

Differentiation of the exposure to PM_2.5 (particulate matter less than 2.5 μm in aerodynamic diameter), NO₂ and O₃ i.e. pollutants of outdoor origin, due to the occupation of office and school microenvironments, was investigated through the quantification of the respective Indoor to Outdoor (I/O) ratios, in simple statistical terms. For that cause, indoor and outdoor observation data were retrieved from the HEALS EDMS database, and more specifically the data from the OFFICAIR and the SINPHONIE EU projects. The I/O ratios were produced and were statistically analyzed in order to be able to study the influence of the indoor environment against the pollutants coming from outdoors. The present statistical approach highlighted also the differences of I/O ratios between the two studied microenvironments for each pollutant. For exposure estimation to the above-mentioned pollutants, the probability and cumulative distribution function (pdf/cdf) empirical approximations led to the conclusion that for offices the I/O ratios of PM_2.5 follow a normal distribution, while NO₂ and O₃ a gamma distribution. Respectively, for schools the I/O ratios of all pollutants follow a lognormal distribution.

Concentration-response curve and cumulative effects between ozone and daily mortality: an analysis in Wallonia, Belgium

Many studies have shown an association between ozone and mortality. However, little data is available on the cumulative effects of ozone on health. A time-series analysis using a Poisson regression was used to measure the impact of ozone on non-traumatic mortality in Wallonia over the period 2000-2012. Initially, a single-lag model was tested. Then a distributed-lag non-linear model was used in order to verify the cumulative effects of ozone on mortality. Our study confirms the existence of an association between ozone and mortality. The linear model without threshold shows a higher sensitivity in persons aged 75 and over (ERR = 0.7, 95 % CI: 0.4; 1.0 %) compared to younger people (ages 25-74) (ERR = 0.2, 95 % CI: - 0.2; 0.6 %). Taking cumulative effects into account, men and women aged 25-74 have an ozone sensitivity equivalent to those over 75.

Short-term effects of nitrogen dioxide on hospital admissions for cardiovascular disease in Wallonia, Belgium

Many studies have shown a short-term association between NO₂ and cardiovascular disease. However, few data are available on the delay between exposure and a health-related event. The aim of the present study is to determine the strength of association between NO₂ and cardiovascular health in Wallonia for the period 2008-2011. This study also seeks to evaluate the effects of age, gender, season and temperature on this association. The effect of the delay between exposure and health-related event was also investigated. The daily numbers of hospital admissions for arrhythmia, acute myocardial infarction, ischemic and haemorrhagic stroke were taken from a register kept by Belgian hospitals. Analyses were performed using the quasi-Poisson regression model adjusted for seasonality, long-term trend, day of the week, and temperature. Our study confirms the existence of an association between NO₂ and cardiovascular disease. Apart from haemorrhagic stroke, the strongest association between NO₂ concentrations and number of hospital admissions is observed at lag 0. For haemorrhagic stroke, the association is strongest with a delay of 2days. All associations calculated without stratification are statistically significant and range from an excess relative risk of 2.8% for myocardial infarction to 4.9% for haemorrhagic strokes. The results of this study reinforce the evidence of the short-term effects of NO₂ on hospital admissions for cardiovascular disease. The different delay between exposure and health-related event for haemorrhagic stroke compared to ischemic stroke suggests different mechanisms of action.

Clean air matters: an overview of traffic-related air pollution and pregnancy

The right to a healthy pregnancy and to giving birth in a safe environment is source of comprehensive research. Decent birth facilities, respect, and no discrimination are already recognized as fundamental rights, but an accurate look at the outdoor environment is required. Air pollution is a dangerous factor to pregnant women and newborns, many of whom highly exposed to traffic-related atmospheric pollutants in urban areas. Such exposure can lead to low birth weight and long-lasting effects, such as respiratory diseases and premature death. Thus, this commentary, based on the analysis of literature, presents the importance of the exposome concept and of epigenetics in identifying the role of the environment for better health conditions of pregnant women and newborns. In the final considerations, this study proposes the deepening of the subject and the mobilization in this regard, with a human rights-based approach to environmental health and to the increased awareness of pregnant women on the risks of air pollution and its effects on health.

Short-term effects of air pollution on hospitalization for acute myocardial infarction: age effect on lag pattern

The aim of the present study is to analyse the age effect on the lag patterns of relative risk of hospitalization for acute myocardial infarction and NO₂, PM₁₀ and O₃. Daily hospitalizations for AMI during the period 2008-2011 were extracted from administrative data. Analyses were performed using the quasi-Poisson regression model adjusted for seasonality, long-term trend, day of the week and temperature. We observed very different patterns depending on age. For NO₂ and PM₁₀, the younger group (25-54 years) shows a more delayed effect in comparison with the two older age groups (55-64 and ≥ 65 years). Overall, the associations between NO₂ and AMI are higher compared to PM₁₀. There are no associations between O₃ and AMI. This study indicates that age plays a major role in the lag pattern. Younger people have delayed effects, but they are nevertheless sensitive to air pollution.

Air quality mapping using GIS and economic evaluation of health impact for Mumbai City, India

Mumbai, a highly populated city in India, has been selected for air quality mapping and assessment of health impact using monitored air quality data. Air quality monitoring networks in Mumbai are operated by National Environment Engineering Research Institute (NEERI), Maharashtra Pollution Control Board (MPCB), and Brihanmumbai Municipal Corporation (BMC). A monitoring station represents air quality at a particular location, while we need spatial variation for air quality management. Here, air quality monitored data of NEERI and BMC were spatially interpolated using various inbuilt interpolation techniques of ArcGIS. Inverse distance weighting (IDW), Kriging (spherical and Gaussian), and spline techniques have been applied for spatial interpolation for this study. The interpolated results of air pollutants sulfur dioxide (SO2), nitrogen dioxide (NO2) and suspended particulate matter (SPM) were compared with air quality data of MPCB in the same region. Comparison of results showed good agreement for predicted values using IDW and Kriging with observed data. Subsequently, health impact assessment of a ward was carried out based on total population of the ward and air quality monitored data within the ward. Finally, health cost within a ward was estimated on the basis of exposed population. This study helps to estimate the valuation of health damage due to air pollution.

IMPLICATIONS

Operating more air quality monitoring stations for measurement of air quality is highly resource intensive in terms of time and cost. The appropriate spatial interpolation techniques can be used to estimate concentration where air quality monitoring stations are not available. Further, health impact assessment for the population of the city and estimation of economic cost of health damage due to ambient air quality can help to make rational control strategies for environmental management. The total health cost for Mumbai city for the year 2012, with a population of 12.4 million, was estimated as USD8000 million.

Size resolved metal distribution in the PM matter of the city of Turin (Italy)

A work on the characterization of the air quality in the city of Turin was carried out in different sampling periods, reflecting early autumn and winter conditions, including a snow episode during the early 2012 European cold wave. The concentrations of 13 elements in eight size fractions of the aerosol were determined using inductively coupled plasma-mass spectrometry. The collection was carried out with a Andersen MkII cascade impactor. The size distribution of elements allowed the identification of three main behavioural types: (a) elements associated with coarse particles (Cd, Cr, Cu, Fe, Mn, Mo and Sn); (b) elements found within fine particles (As, Co, Pb and V) and (c) elements spread throughout the entire size range (Ni and Zn). Principal Component Analysis allowed to examine the relationships between the inorganic elements and to infer about their origin. Chemometric investigation and assessment of similarity in the distribution led to similar conclusions on the sources. The concentration of gaseous trace pollutants (O3, NOx and VOCs) was determined. The concentrations of these pollutants are scarcely correlated with the metal contents of all the size classes of the PM. The differences found in the O3, NO2 and VOCs levels of the two winter campaigns due to the high photochemical reactivity in the period after the snow episode, do not reflect in differences in the metals distribution in the PM. Since PM metals, NOx and VOC have common sources, this behaviour is due to relevant differences in the transformation and deposition processes.

The Effect of Park and Urban Environments on Coronary Artery Disease Patients: A Randomized Trial

Aim. To test the hypothesis that walking in a park has a greater positive effect on coronary artery disease (CAD) patients' hemodynamic parameters than walking in an urban environment. Methods. Twenty stable CAD patients were randomized into two groups: 30-minute walk on 7 consecutive days in either a city park or busy urban street. Wilcoxon signed-rank test was employed to study short-term (30 min) and cumulative changes (following 7 consecutive days of exposure) in resting hemodynamic parameters in different environments. Results. There were no statistically significant differences in the baseline and peak exercise systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), exercise duration, or HR recovery in urban versus park exposure groups. Seven days of walking slightly improved all hemodynamic parameters in both groups. Compared to baseline, the city park group exhibited statistically significantly greater reductions in HR and DBP and increases in exercise duration and HR recovery. The SBP and DBP changes in the urban exposed group were lower than in the park exposed group. Conclusions. Walking in a park had a greater positive effect on CAD patients' cardiac function than walking in an urban environment, suggesting that rehabilitation through walking in green environments after coronary events should be encouraged.

Chemical characterization of outdoor and subway fine (PM(2.5-1.0)) and coarse (PM(10-2.5)) particulate matter in Seoul (Korea) by computer-controlled scanning electron microscopy (CCSEM)

Outdoor and indoor (subway) samples were collected by passive sampling in urban Seoul (Korea) and analyzed with computer-controlled scanning electron microscopy coupled with energy dispersive x-ray spectroscopy (CCSEM-EDX). Soil/road dust particles accounted for 42%–60% (by weight) of fine particulate matter larger than 1 µm (PM_2.5–1.0) in outdoor samples and 18% of PM_2.5–1.0 in subway samples. Iron-containing particles accounted for only 3%–6% in outdoor samples but 69% in subway samples. Qualitatively similar results were found for coarse particulate matter (PM_10–2.5) with soil/road dust particles dominating outdoor samples (66%–83%) and iron-containing particles contributing most to subway PM_10–2.5 (44%). As expected, soil/road dust particles comprised a greater mass fraction of PM_10–2.5 than PM_2.5–1.0. Also as expected, the mass fraction of iron-containing particles was substantially less in PM_10–2.5 than in PM_2.5–1.0. Results of this study are consistent with known emission sources in the area and with previous studies, which showed high concentrations of iron-containing particles in the subway compared to outdoor sites. Thus, passive sampling with CCSEM-EDX offers an inexpensive means to assess PM_2.5–1.0 and PM_10-2.5 simultaneously and by composition at multiple locations.

Comparison of four case-crossover study designs to analyze the association between air pollution exposure and acute myocardial infarction

The case-crossover design is frequently used for analyzing the acute health effects of air pollution. Nevertheless, only a few studies compared different methods for selecting control periods. In this study, the bidirectional method and three time-stratified methods were used to estimate the association between air pollution and acute myocardial infarction (AMI) in Charleroi, Belgium, during 1999-2008. The strongest associations between air pollution and AMI were observed for PM10 and NO(2) during the warm period, OR = 1.095 (95 % CI: 1.003-1.169) and OR = 1.120 (95 % CI: 1.001-1.255), respectively. The results of this study reinforce the evidence of the acute effects of air pollution on AMI, especially during the warm season. This study suggests that the different methods of case-crossover study design are suitable to studying the association between acute events and air pollution. The temperature-stratified design is useful to exclude temperature as a potential confounder.

Trace Elements in Ambient Air at Porto Metropolitan Area-Checking for Compliance with New European Union (EU) Air Quality Standards

Because of the scientific evidence showing that arsenic (As), cadmium (Cd), and nickel (Ni) are human genotoxic carcinogens, the European Union (EU) recently set target values for metal concentration in ambient air (As: 6 ng/m(3), Cd: 5 ng/m(3), Ni: 20 ng/m(3)). The aim of our study was to determine the concentration levels of these trace elements in Porto Metropolitan Area (PMA) in order to assess whether compliance was occurring with these new EU air quality standards. Fine (PM2.5) and inhalable (PM10) air particles were collected from October 2011 to July 2012 at two different (urban and suburban) locations in PMA. Samples were analyzed for trace elements content by inductively coupled plasma-mass spectrometry (ICP-MS). The study focused on determination of differences in trace elements concentration between the two sites, and between PM2.5 and PM10, in order to gather information regarding emission sources. Except for chromium (Cr), the concentration of all trace elements was higher at the urban site. However, results for As, Cd, Ni, and lead (Pb) were well below the EU limit/target values (As: 1.49 ± 0.71 ng/m(3); Cd: 1.67 ± 0.92 ng/m(3); Ni: 3.43 ± 3.23 ng/m(3); Pb: 17.1 ± 10.1 ng/m(3)) in the worst-case scenario. Arsenic, Cd, Ni, Pb, antimony (Sb), selenium (Se), vanadium (V), and zinc (Zn) were predominantly associated to PM2.5, indicating that anthropogenic sources such as industry and road traffic are the main source of these elements. High enrichment factors (EF > 100) were obtained for As, Cd, Pb, Sb, Se, and Zn, further confirming their anthropogenic origin.

Children's Indoor Exposures to (Ultra)Fine Particles in an Urban Area: Comparison Between School and Home Environments

Due to their detrimental effects on human health, scientific interest in ultrafine particles (UFP), has been increasing but available information is far from comprehensive. Children, who represent one of the most susceptible subpopulation, spend the majority of time in schools and homes. Thus, the aim of this study is to (1) assess indoor levels of particle number concentrations (PNC) in ultrafine and fine (20-1000 nm) range at school and home environments and (2) compare indoor respective dose rates for 3- to 5-yr-old children. Indoor particle number concentrations in range of 20-1000 nm were consecutively measured during 56 d at two preschools (S1 and S2) and three homes (H1-H3) situated in Porto, Portugal. At both preschools different indoor microenvironments, such as classrooms and canteens, were evaluated. The results showed that total mean indoor PNC as determined for all indoor microenvironments were significantly higher at S1 than S2. At homes, indoor levels of PNC with means ranging between 1.09 × 10(4) and 1.24 × 10(4) particles/cm(3) were 10-70% lower than total indoor means of preschools (1.32 × 10(4) to 1.84 × 10(4) particles/cm(3)). Nevertheless, estimated dose rates of particles were 1.3- to 2.1-fold higher at homes than preschools, mainly due to longer period of time spent at home. Daily activity patterns of 3- to 5-yr-old children significantly influenced overall dose rates of particles. Therefore, future studies focusing on health effects of airborne pollutants always need to account for children's exposures in different microenvironments such as homes, schools, and transportation modes in order to obtain an accurate representation of children overall exposure.

Modeling of human exposure to benzene in urban environments

Urban areas characterized by high spatial and temporal variability in air pollution levels require implementation of comprehensive approaches to address exposure of individuals. The main objective of this study was to implement a quantitative assessment of individual exposure to benzene in urban environments. For this purpose, ExPOSITION model based on a global positioning system (GPS) tracking approach was applied to estimate individual exposure in different microenvironments. The current investigation provides an application example and validation of the modeling approach against personal and biological exposure measurements collected during the measurements campaign. The probabilistic approach using the Johnson system of distributions was implemented to characterize variability of indoor concentrations. The results obtained for daily average individual exposure to benzene corresponded to mean levels of 1.6 and 0.8-2.7 μg/m(3) in terms of 5th-95th percentiles. Validation of the model results against several personal exposure samples collected for the selected individuals revealed a Pearson's correlation coefficient of .66. This modeling approach explicitly addressed the temporal and spatial variability in the exposure and established a source-receptor relationship.

Ultrafine particles in ambient air of an urban area: dose implications for elderly

Due to their detrimental effects on human health, the scientific interest in ultrafine particles (UFP) has been increasing, but available information is far from comprehensive. Compared to the remaining population, the elderly are potentially highly susceptible to the effects of outdoor air pollution. Thus, this study aimed to (1) determine the levels of outdoor pollutants in an urban area with emphasis on UFP concentrations and (2) estimate the respective dose rates of exposure for elderly populations. UFP were continuously measured over 3 weeks at 3 sites in north Portugal: 2 urban (U1 and U2) and 1 rural used as reference (R1). Meteorological parameters and outdoor pollutants including particulate matter (PM10), ozone (O3), nitric oxide (NO), and nitrogen dioxide (NO2) were also measured. The dose rates of inhalation exposure to UFP were estimated for three different elderly age categories: 64-70, 71-80, and >81 years. Over the sampling period levels of PM10, O3 and NO2 were in compliance with European legislation. Mean UFP were 1.7 × 10(4) and 1.2 × 10(4) particles/cm(3) at U1 and U2, respectively, whereas at rural site levels were 20-70% lower (mean of 1 ×10(4) particles/cm(3)). Vehicular traffic and local emissions were the predominant identified sources of UFP at urban sites. In addition, results of correlation analysis showed that UFP were meteorologically dependent. Exposure dose rates were 1.2- to 1.4-fold higher at urban than reference sites with the highest levels noted for adults at 71-80 yr, attributed mainly to higher inhalation rates.

Individual exposure to air pollutants in a Portuguese urban industrialized area

Industrial development from the second half of the 20th century coupled with population growth and concentration in urban areas has accentuated the concern for potential effects and impacts from air pollutant emissions on environmental and human health. This study examined the Estarreja region, an urban area that has one of the largest chemical complexes in Portugal, a complex that was recently under expansion. In the scope of the INSPIRAR project, individual daily exposure of a group of individuals to particulate matter of 10 μm aerodynamic diameter (PM10) and nitrogen dioxide (NO2) in two phases was determined using a microenvironmental approach. In this context, personal daily activity profiles of individuals were established for their normal routine by personal interviews. These profiles enabled determination of where each individual was at each moment of the day. Utilizing this information with hourly air quality maps simulated with URBAIR air quality model and indoor/outdoor relationships, it was possible to calculate personal daily exposure of each individual to air pollutants. Results from the analysis of daily activity profiles showed a high level of sedentariness of this population and long durations spent indoors. The studied individuals displayed high personal PM10 and NO2 exposure variability. Data demonstrated possible error when a single concentration measurement was assumed as a proxy of exposure. In general, no significant differences were found between the two population groups, indicating that workers of the chemical complex were not exposed to a greater extent to PM10 and NO2 than the general population working in the same area.

Particles influence allergic responses in mice--role of gender and particle size

Epidemiological evidence suggesting that exposure to traffic air pollution may enhance sensitization to common allergens in children is increasing, and animal studies support biological plausibility and causality. The effect of air pollution on respiratory symptoms was suggested to be gender dependent. Previous studies showed that allergy-promoting activity of polystyrene particles (PSP) increased with decreasing particle size after footpad injection of mice. The primary aim of this study was to confirm the influence of particle size on the immunoglobulin E (IgE)-promoting capacity of particles in an airway allergy model. A second aim was to examine whether the allergy-promoting capacity of particles was influenced by gender. Female and male mice were intranasally exposed to the allergen ovalbumin (OVA) with or without ultrafine, fine, or coarse PSP modeling the core of ambient air particles. After intranasal booster immunizations with OVA, serum levels of OVA-specific IgE antibodies, and also markers of airway inflammation and cellular responses in the lung-draining mediastinal lymph nodes (MLN), were determined. PSP of all sizes promoted allergic responses, measured as increased serum concentrations of OVA-specific IgE antibodies. Further, PSP produced eosinophilic airway inflammation and elevated MLN cell numbers as well as numerically reducing the percentage of regulatory T cells. Ultrafine PSP produced stronger allergic responses to OVA than fine and coarse PSP. Although PSP enhanced sensitization in both female and male mice, significantly higher IgE levels and numbers of eosinophils were observed in females than males. However, the allergy-promoting effect of PSP was apparently independent of gender. Thus, our data support the notion that ambient air particle pollution may affect development of allergy in both female and male individuals.

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.

Characterization of summertime coarse particulate matter in the Desert Southwest--Arizona, USA

A year-long study was conducted in Pinal County, AZ, to characterize coarse (2.5 - 10 microm aerodynamic diameter, AD) and fine (< 2.5 microm AD) particulate matter (PMc and PMf, respectively) to further understand spatial and temporal variations in ambient PM concentrations and composition in rural, arid environments. Measurements of PMc and PMf mass, ions, elements, and carbon concentrations at one-in-six day resolution were obtained at three sites within the region. Results from the summer of 2009 and specifically the local monsoon period are presented. The summer monsoon season (July - September) and associated rain and/or high wind events, has historically had the largest number of PM10 NAAQS exceedances within a year. Rain events served to clean the atmosphere, decreasing PMc concentrations resulting in a more uniform spatial gradient among the sites. The monsoon period also is characterized by high wind events, increasing PMc mass concentrations, possibly due to increased local wind-driven soil erosion or transport. Two PM10 NAAQS exceedances at the urban monitoring site were explained by high wind events and can likely be excluded from PM10 compliance calculations as exceptional events. At the more rural Cowtown site, PM10 NAAQS exceedances were more frequent, likely due to the impact from local dust sources. PM mass concentrations at the Cowtown site were typically higher than at the Pinal County Housing and Casa Grande sites. Crustal material was equal to 52-63% of the PMc mass concentration on average. High concentrations of phosphate and organic carbon found at the rural Cowtown were associated with local cattle feeding operations. A relatively high correlation between PMc and PMf (R2 = 0.63) indicated that the lower tail of the coarse particle fraction often impacts the fine particle fraction, increasing the PMf concentrations. Therefore, reductions in PMc sources will likely also reduce PMf concentrations, which also are near the value of the 24-hr PM2.5 NAAQS.

IMPLICATIONS

In the desert southwest, summer monsoons are often associated with above average PM10 (< 10 microm AD) mass concentrations. Competing influences of monsoon rain and wind events showed that rain suppresses ambient concentrations while high wind increase them. In this region, the PMc fraction dominates PM10 and crustal sources contribute 52-63% to local PMc mass concentrations on average. Cattle feedlot emissions are also an important source and a unique chemical signature was identified for this source. Observations suggest monsoon wind events alone cannot explain PM10 NAAQS exceedances, thus requiring these values to remain in compliance calculations rather than being removed as exceptional wind events.

The role of in vitro gene expression profiling in particulate matter health research

Exposure to particulate matter (PM) is consistently associated with increased morbidity and mortality rate. The mechanisms for these adverse health effects have been vigorously investigated for many years, but remain uncertain, in part due to the complex interactions between host and exposure. Over the past decade, the use of global gene expression profiling has increased to investigate molecular changes in an attempt to gain more insight into the complex mechanisms that underlie the adverse health effects induced by PM. These experiments have been performed mostly in cell cultures, in part due to the easy availability and maneuverability of different cell types. Whether or not the results obtained from these in vitro experiments are relevant to human exposure is unclear. In this study, cell culture studies were reviewed that used microarray technology to measure global gene expression in response to PM and the findings discussed in the context of global gene expression results obtained from animal and human exposure studies. Ten in vitro studies were identified from PubMed that reported global gene expression results in response to PM exposure. Despite difference in cell types, microarray platforms, incubation time, and PM sources and doses, these experiments showed commonality in the expression of genes and pathways, especially xenobiotic metabolism, oxidative stress, and inflammation. These gene expression profiles were consistent with results from animal and human controlled exposure experiments. The in vitro experiments also uncovered novel biological mechanisms that may be important in PM-induced health effects reported in epidemiological studies. Data indicate that in vitro microarray experiments complement animal and human exposure studies and allow the PM-associated health research to focus on the "toxic" components in PM and novel mechanisms, and may enhance risk assessment beyond the current mass-based standards.

Impact of road traffic emissions on ambient air quality in an industrialized area

Several epidemiological studies showed a correlation between airborne particulate matter(PM) and the incidence of several diseases in exposed populations. Consequently, the European Commission reinforced the need and obligation of member-states to monitor exposure levels of PM and adopt measures to reduce this exposure. However, in order to plan appropriate actions, it is necessary to understand the main sources of air pollution and their relative contributions to the formation of the ambient aerosol. The aim of this study was to develop a methodology to assess the contribution of vehicles to the atmospheric aerosol,which may constitute a useful tool to assess the effectiveness of planned mitigation actions.This methodology is based on three main steps: (1) estimation of traffic emissions provided from the vehicles exhaust and resuspension; (2) use of the dispersion model TAPM (“The Air Pollution Model”) to estimate the contribution of traffic for the atmospheric aerosol; and(3) use of geographic information system (GIS) tools to map the PM10 concentrations provided from traffic in the surroundings of a target area. The methodology was applied to an industrial area, and results showed that the highest contribution of traffic for the PM10 concentrations resulted from dust resuspension and that heavy vehicles were the type that most contributed to the PM10 concentration.

Short-term effects of fine particulate air pollution on emergency room visits for cardiac arrhythmias: a case-crossover study in Taipei

This study was undertaken to determine whether there was an association between fine particles (PM₂.₅) levels and number of emergency room (ER) visits for cardiac arrhythmias in Taipei, Taiwan. ER visits for cardiac arrhythmias and ambient air pollution data for Taipei were obtained for the period 2006-2010. The relative risk (RR) of ER visits was estimated using a case-crossover approach, controlling for weather variables, day of the week, seasonality, and long-term time trends. For the single-pollutant model (without adjustment for other pollutants), increased numbers of ER cardiac arrhythmia visits were significantly associated with PM₂.₅ on both warm days (>23°C) and cool days (< 23°C), with an interquartile range rise associated with a 10% (95% CI = -15%) and 4% (95% CI = 0-8%) elevation in number of ER visits for cardiac arrhythmias, respectively. In the two-pollutant models, PM₂.₅ levels remained significant after inclusion of sulfur dioxide (SO₂) or ozone (O₃) on both warm and cool days. This study provides evidence that higher levels of PM₂.₅ increase the risk of number of ER visits for cardiac arrhythmias.

Impact of different welding techniques on biological effect markers in exhaled breath condensate of 58 mild steel welders

Total mass and composition of welding fumes are predominantly dependent on the welding technique and welding wire applied. The objective of this study was to investigate the impact of welding techniques on biological effect markers in exhaled breath condensate (EBC) of 58 healthy welders. The welding techniques applied were gas metal arc welding with solid wire (GMAW) (n=29) or flux cored wire (FCAW) (n=29). Welding fume particles were collected with personal samplers in the breathing zone inside the helmets. Levels of leukotriene B(4) (LTB(4)), prostaglandin E(2) (PGE(2)), and 8-isoprostane (8-iso-PGF(2α)) were measured with immunoassay kits and the EBC pH was measured after deaeration. Significantly higher 8-iso-PGF(2α) concentrations and a less acid pH were detected in EBC of welders using the FCAW than in EBC of welders using the GMAW technique. The lowest LTB(4) concentrations were measured in nonsmoking welders applying a solid wire. No significant influences were found in EBC concentrations of PGE(2) based upon smoking status or type of welding technique. This study suggests an enhanced irritative effect in the lower airways of mild steel welders due to the application of FCAW compared to GMAW, most likely associated with a higher emission of welding fumes.

Composition of air pollution particles and oxidative stress in cells, tissues, and living systems

Epidemiological studies demonstrated an association between increased levels of ambient air pollution particles and human morbidity and mortality. Production of oxidants, either directly by the air pollution particles or by the host response to the particles, appears to be fundamental in the biological effects seen after exposure to particulate matter (PM). However, the precise components and mechanisms responsible for oxidative stress following PM exposure are yet to be defined. Direct oxidant generation by air pollution particles is attributed to organic and metal components. Organic compounds generate an oxidative stress through redox cycling of quinone-based radicals, by complexing of metal resulting in electron transport, and by depletion of antioxidants by reactions between quinones and thiol-containing compounds. Metals directly support electron transport to generate oxidants and also diminish levels of antioxidants. In addition to direct generation of oxidants by organic and metal components, cellular responses contribute to oxidative stress after PM exposure. Reactive oxygen species (ROS) production occurs in the mitochondria, cell membranes, phagosomes, and the endoplasmic reticulum. Oxidative stress following PM exposure initiates a series of cellular reactions that includes activation of kinase cascades and transcription factors and release of inflammatory mediators, which ultimately lead to cell injury or apoptosis. Consequently, oxidative stress in cells and tissues is a central mechanism by which PM exposure leads to injury, disease, and mortality.

Traffic air pollution and risk of death from ovarian cancer in Taiwan: fine particulate matter (PM2.5) as a proxy marker

The relationship between mortality attributed to ovarian cancer and exposure to ambient air pollutants was examined using an ecological design. The study areas consisted of 61 municipalities in Taiwan. Air quality data for recorded concentrations of fine particulate matter (PM2.5) from study municipalities for 2006-2009 were obtained as a marker of traffic emissions. These were used as a proxy for polycyclic aromatic hydrocarbons (PAH) exposure. Age-standardized mortality rates for ovarian cancer were calculated for the study municipalities for the years 1999-2008. A weighted multiple regression model was employed to calculate the adjusted risk ratio (RR) in relation to PM2.5 levels. After adjusting for urbanization level and fertility rate, the adjusted RR values (95% confidence interval [CI]) for ovarian cancer were 1.2 (1.02-1.41) for the municipalities with PM2.5 levels between 30.48 μg/m3 and 39.41 μg/m3 and 1.2 (1.03-1.39) for the municipalities with PM2.5 levels between 39.48 μg/m3 and 51.1 μg/m3, compared to the municipalities with PM2.5 levels less than 30.39 μg/m3. Results showed that individuals who resided in municipalities with higher levels of PM2.5, a proxy measure of PAH, were at an increased risk of death from ovarian cancer compared to those subjects living in municipalities with the lowest PM2.5. The findings of this study warrant further investigation into the role of exposure to air pollutants in the etiology of ovarian cancer development.

Traffic air pollution and risk of death from gastric cancer in Taiwan: petrol station density as an indicator of air pollutant exposure

To investigate the relationship between air pollution and risk of death attributed to gastric cancer, a matched cancer case-control study was conducted using deaths that occurred in Taiwan from 2004 through 2008. Data for all eligible gastric cancer deaths were obtained and compared to a control group consisting of individuals who died from causes other than neoplasms and diseases that were associated with gastrointestinal (GIT) disorders. The controls were pair-matched to the cancer cases by gender, year of birth, and year of death. Each matched control was randomly selected from the set of possible controls for each cancer case. Data for the number of petrol stations in study municipalities were collected from two major petroleum supply companies. The petrol station density (per square kilometer) (PSD) for study municipalities was used as an indicator of a subject's exposure to benzene and other hydrocarbons present in ambient evaporative losses of petrol or to air emissions from motor vehicles. The exposed individuals were subdivided into three categories (≤25th percentile; 25th-75th percentile; >75th percentile) according to PSD in the residential municipality. Results showed that individuals who resided in municipalities with the highest PSD were at an increased risk of death attributed to gastric cancer compared to those subjects living in municipalities with the lowest PSD. The findings of this study warrant further investigation of the role of traffic air pollution exposure in the etiology of gastric cancer.

Chemical characterisation and cytotoxic effects in A549 cells of urban-air PM10 collected in Torino, Italy

Human type II alveolar cells (A549) were exposed to aqueous- and organic-solvent PM10 extracts to evaluate their effects on cell proliferation, proinflammatory cytokine release and cytotoxicity (assayed by lactate dehydrogenase, LDH, activity). PM10 samples collected in Torino (northwest Italy) were analysed for inorganic chemical species (bioavailable iron and secondary particulates) and endotoxins, which are potentially inflammatory promoters in human airways. During the sampling period, PM10 concentration was 55.4±39.1μg/m(3), secondary particles constituted 42±9% of the PM10 total mass, and bioavailable iron concentration was 0.078±0.095μg/m(3). PM10 inhibits cell proliferation and induces both IL-6 and LDH release in a dose- and time-dependent manner, with a seasonal trend. The different effects of aqueous and organic PM10 extracts demonstrate the importance of particle composition for the induction of cytotoxic effects on A549 cells. A first comparison between the biological effects induced by PM10 extracts and PM10 components was performed.

Relative contributions of geographic, socioeconomic, and lifestyle factors to quality of life, frailty, and mortality in elderly

BACKGROUND

To date, few studies address disparities in older populations specifically using frailty as one of the health outcomes and examining the relative contributions of individual and environmental factors to health outcomes.

METHODOLOGY/PRINCIPAL FINDINGS

Using a data set from a health survey of 4,000 people aged 65 years and over living in all regions of Hong Kong, we examined regional variations in self-rated health, frailty, and four-year mortality, and analyzed the relative contributions of lifestyle, socioeconomic status, and geographical location of residence to these outcomes using path analysis. We hypothesize that lifestyle, socioeconomic status, and regional characteristics directly and indirectly through interactions contribute to self-rated physical and psychological health, frailty, and four-year mortality. District variations directly affect self-rated physical health, and also exert an effect through socioeconomic position as well as lifestyle factors. Socioeconomic position in turn directly affects self-rated physical health, as well as indirectly through lifestyle factors. A similar pattern of interaction is observed for self-rated mental health, frailty, and mortality, although there are differences in different lifestyle factors and district associations. Lifestyle factors also directly affect physical and mental components of health, frailty, and mortality. The magnitude of direct district effect is comparable to those of lifestyle and socioeconomic position.

CONCLUSIONS/SIGNIFICANCE

We conclude that district variations in health outcomes exist in the Hong Kong elderly population, and these variations result directly from district factors, and are also indirectly mediated through socioeconomic position as well as lifestyle. Provision and accessibility to health services are unlikely to play a significant role. Future studies on these district factors would be important in reducing health disparities in the older population.

Relative contributions of geographic, socioeconomic, and lifestyle factors to quality of life, frailty, and mortality in elderly

Background

To date, few studies address disparities in older populations specifically using frailty as one of the health outcomes and examining the relative contributions of individual and environmental factors to health outcomes.

Methodology/Principal Findings

Using a data set from a health survey of 4,000 people aged 65 years and over living in all regions of Hong Kong, we examined regional variations in self-rated health, frailty, and four-year mortality, and analyzed the relative contributions of lifestyle, socioeconomic status, and geographical location of residence to these outcomes using path analysis. We hypothesize that lifestyle, socioeconomic status, and regional characteristics directly and indirectly through interactions contribute to self-rated physical and psychological health, frailty, and four-year mortality.

District variations directly affect self-rated physical health, and also exert an effect through socioeconomic position as well as lifestyle factors. Socioeconomic position in turn directly affects self-rated physical health, as well as indirectly through lifestyle factors. A similar pattern of interaction is observed for self-rated mental health, frailty, and mortality, although there are differences in different lifestyle factors and district associations. Lifestyle factors also directly affect physical and mental components of health, frailty, and mortality. The magnitude of direct district effect is comparable to those of lifestyle and socioeconomic position.

Conclusions/Significance

We conclude that district variations in health outcomes exist in the Hong Kong elderly population, and these variations result directly from district factors, and are also indirectly mediated through socioeconomic position as well as lifestyle. Provision and accessibility to health services are unlikely to play a significant role. Future studies on these district factors would be important in reducing health disparities in the older population.

Characterization of metal and trace element contents of particulate matter (PM10) emitted by vehicles running on Brazilian fuels-hydrated ethanol and gasoline with 22% of anhydrous ethanol

Emission of fine particles by mobile sources has been a matter of great concern due to its potential risk both to human health and the environment. Although there is no evidence that one sole component may be responsible for the adverse health outcomes, it is postulated that the metal particle content is one of the most important factors, mainly in relation to oxidative stress. Data concerning the amount and type of metal particles emitted by automotive vehicles using Brazilian fuels are limited. The aim of this study was to identify inhalable particles (PM(10)) and their trace metal content in two light-duty vehicles where one was fueled with ethanol while the other was fueled with gasoline mixed with 22% of anhydrous ethanol (gasohol); these engines were tested on a chassis dynamometer. The elementary composition of the samples was evaluated by the particle-induced x-ray emission technique. The experiment showed that total emission factors ranged from 2.5 to 11.8 mg/km in the gasohol vehicle, and from 1.2 to 3 mg/km in the ethanol vehicle. The majority of particles emitted were in the fine fraction (PM(2.5)), in which Al, Si, Ca, and Fe corresponded to 80% of the total weight. PM(10) emissions from the ethanol vehicle were about threefold lower than those of gasohol. The elevated amount of fine particulate matter is an aggravating factor, considering that these particles, and consequently associated metals, readily penetrate deeply into the respiratory tract, producing damage to lungs and other tissues.

Ozone increases airway hyperreactivity and mucus hyperproduction in mice previously exposed to allergen

Acute exacerbations of asthma represent a common clinical problem with major economic impact. Air pollutants including ozone have been shown to contribute to asthma exacerbation, but the mechanisms underlying ozone-induced asthma exacerbation are only partially understood. The present study aimed to develop a mouse model to gain insight into the development of airway hyperresponsiveness (AHR) to methacholine (MCh) in mice after exposure to both allergen and ozone. Mice were exposed for 20 min per day for 10 consecutive days to an aerosol of 1% ovalbumin (OVA) or saline followed by a single 3-h exposure to clean air or 100, 250, or 500 ppb ozone. Ozone induced AHR in mice previously exposed to OVA when compared to non-exposed (saline) control mice. After a 10-d exposure to OVA, a single exposure to a low (100 ppb) ozone concentration was sufficient to induce AHR. The AHR response was associated with goblet-cell metaplasia. Even the lowest concentration of ozone tested, 100 ppb, which may be exceeded in urban environments and in the workplace, resulted in a significant increase in AHR, most prominent 24 h after exposure in the OVA-exposed mice.

Traffic air pollution and risk of death from bladder cancer in Taiwan using petrol station density as a pollutant indicator

To investigate the relationship between air pollution and risk of death from bladder cancer, a matched cancer case-control study was conducted using deaths that occurred in Taiwan from 1997 through 2006. Data for all eligible bladder cancer deaths were obtained from the Bureau of Vital Statistics of the Taiwan Provincial Department of Health. The control group consisted of individuals who died from causes other than cancer or diseases associated with genitourinary problems. The controls were pair matched to the cases by gender, year of birth, and year of death. Each matched control was selected randomly from the set of possible controls for each case. Data for the number of petrol stations in study municipalities were collected from the two major petroleum supply companies, Chinese Petroleum Corporation (CPC) and Formosa Petrochemical Corporation (FPCC). The petrol station density (per square kilometer) (PSD) for study municipalities was used as an indicator of a subject's exposure to benzene and other hydrocarbons present in ambient evaporative losses of petrol or to air emissions from motor vehicles. The subjects were divided into tertiles according to PSD in their residential municipality. The present study showed that individuals who resided in municipalities with high PSD levels were at an increased risk of death from bladder cancer compared to subjects living in municipalities with a low PSD level; however, the differences are not statistically significant. The findings of this study warrant further investigation of the role of vehicular air pollutant emissions in the etiology of bladder cancer development.

Effects of titanium dioxide nanoparticle exposure on neuroimmune responses in rat airways

Exposure to ambient nanoparticles (defined as particulate matter [PM] having one dimension <100 nm) is associated with increased risk of childhood and adult asthma. Nanomaterials feature a smaller aerodynamic diameter and a higher surface area per unit mass ratio compared to fine or coarse-sized particles, resulting in greater lung deposition efficiency and an increased potential for biological interaction. The neurotrophins nerve growth factor and brain-derived neurotrophic factor are key regulatory elements of neuronal development and responsiveness of airway sensory neurons. Changes in their expression are associated with bronchoconstriction, airway hyperresponsiveness, and airway inflammation. The neurogenic-mediated control of airway responses is a key pathophysiological mechanism of childhood asthma. However, the effects of nanoparticle exposure on neurotrophin-driven airway responses and their potential role as a predisposing factor for developing asthma have not been clearly elucidated. In this study, in vivo inhalation exposure to titanium dioxide nanoparticles (12 mg/m(3); 5.6 h/d for 3 d) produced upregulation of lung neurotrophins in weanling (2-wk-old) and newborn (2-d-old) rats but not in adult (12-wk-old) animals compared to controls. This effect was associated with increased airway responsiveness and upregulation of growth-related oncogene/keratine-derived chemokine (GRO/KC; CXCL1, rat equivalent of human interleukin [IL]-8) in bronchoalveolar lavage fluid. These data show for the first time that exposure to nanoparticulate upregulates the expression of lung neurotrophins in an age-dependent fashion and that this effect is associated with airway hyperresponsiveness and inflammation. These results suggest the presence of a critical window of vulnerability in earlier stages of lung development, which may lead to a higher risk of developing asthma.

Air pollution and increased levels of fractional exhaled nitric oxide in children with no history of airway damage

Air pollution is associated with a wide range of adverse respiratory events. In order to study the mechanism associated with these effects, the relationships between fractional exhaled nitric oxide (FeNO), a potential marker of airway inflammation, and exposure to air pollution were examined in schoolchildren. FeNO was measured in 104 children (34 asthmatics and 70 non-asthmatics) drawn from the general population simultaneously with air pollution assessments (fine particles with an aerodiameter under 2.5 microm, nitrogen dioxide, acetaldehyde, and formaldehyde, with pumps and passive samplers) in schoolyards and classrooms. Asthmatics exhaled more FeNO than non-asthmatics. FeNO levels were significantly elevated in both asthmatic and non-asthmatic children exposed to high concentrations of formaldehyde, acetaldehyde, and PM(2.5). Differences between high versus low exposure in non-asthmatics resulted in an FeNO increase ranging from 45% for indoor acetaldehyde to 62% for indoor PM(2.5). Stronger associations were found in non-asthmatic children who were atopic, suggesting that atopic children may be more sensitive to air pollution than non-atopic children. Exposure to air pollution may lead to airway inflammation, as measured by FeNO, in schoolchildren. These associations occur even in children with no history of airway damage and seem to be enhanced in atopic subjects.

Susceptibility of inflamed alveolar and airway epithelial cells to injury induced by diesel exhaust particles of varying organic carbon content

Exposure to traffic-related ambient air pollution, such as diesel exhaust particles (DEP), is associated with adverse health outcomes, especially in individuals with preexisting inflammatory respiratory diseases. Using an analogous novel in vitro system to model both the healthy and inflamed lung, the susceptibility of epithelial cells exposed to DEP of varying organic carbon content was studied. Murine LA-4 alveolar type II-like epithelial cells, as well as primary murine tracheal epithelial cells (MTE), were treated with exogenous cytokines (tumor necrosis factor [TNF] alpha + interleukin [IL]-1 beta + interferon [IFN] gamma) to model a mild inflammatory state. Epithelial cells were subsequently exposed to DEP of varying organic carbon content, and the resultant cytotoxic, cytoprotective, or antioxidant cell responses were inferred by changes in lactate dehydrogenase (LDH) release, heme oxygenase-1 (HO-1) expression, or glutathione levels, respectively. Data showed that exposure of healthy LA-4 cells to organic carbon-rich DEP (25 microg/cm(2); 24 h) induced adaptive cytoprotective/antioxidant responses with no apparent cell injury. In contrast, exposure of inflamed LA-4 cells resulted in oxidative stress culminating in significant cytotoxicity. Exposure of healthy MTE cells to organic carbon-rich DEP (20 microg/cm(2); 24 h) was seemingly without effect, whereas exposure of inflamed MTE cells resulted in increased epithelial solute permeability. Thus, surface lung epithelial cells stressed by a state of inflammation and then exposed to organic carbon-rich DEP appear unable to respond to the additional oxidative stress, resulting in epithelial barrier dysfunction and injury. Adverse health outcomes associated with exposure to traffic-related air pollutants, like DEP, in patients with preexisting inflammatory respiratory diseases may be due, in part, to similar mechanisms.

Air pollution and effects on reproductive-system functions globally with particular emphasis on the Brazilian population

In recent years, numerous studies showed that exposure to environmental air pollutants affected reproductive functions and, in particular, produced adverse effects on pregnancy outcomes, fertility, and fetal health. Epidemiological studies demonstrated that exposure to ambient levels of air pollutants are associated with low birth weight, intrauterine growth retardation, prematurity, neonatal death, and decreased fertility in males. Experimental animal data supported these findings and indicated that female fertility was also disturbed. Although there are various mechanisms of action suggested to show the manner in which air pollutants alter pregnancy and the reproductive systems in both genders, further studies are needed to correlate causal relationships. This information would serve to better understand the underlying physiologic changes in the reproductive system induced by exposure to air pollutants and possibly establish a link between the dose and response of individual or mixture of air pollutants.

Effect of exposure to natural environment on health inequalities: an observational population study

BACKGROUND

Studies have shown that exposure to the natural environment, or so-called green space, has an independent effect on health and health-related behaviours. We postulated that income-related inequality in health would be less pronounced in populations with greater exposure to green space, since access to such areas can modify pathways through which low socioeconomic position can lead to disease.

METHODS

We classified the population of England at younger than retirement age (n=40 813 236) into groups on the basis of income deprivation and exposure to green space. We obtained individual mortality records (n=366 348) to establish whether the association between income deprivation, all-cause mortality, and cause-specific mortality (circulatory disease, lung cancer, and intentional self-harm) in 2001-05, varied by exposure to green space measured in 2001, with control for potential confounding factors. We used stratified models to identify the nature of this variation.

FINDINGS

The association between income deprivation and mortality differed significantly across the groups of exposure to green space for mortality from all causes (p<0.0001) and circulatory disease (p=0.0212), but not from lung cancer or intentional self-harm. Health inequalities related to income deprivation in all-cause mortality and mortality from circulatory diseases were lower in populations living in the greenest areas. The incidence rate ratio (IRR) for all-cause mortality for the most income deprived quartile compared with the least deprived was 1.93 (95% CI 1.86-2.01) in the least green areas, whereas it was 1.43 (1.34-1.53) in the most green. For circulatory diseases, the IRR was 2.19 (2.04-2.34) in the least green areas and 1.54 (1.38-1.73) in the most green. There was no effect for causes of death unlikely to be affected by green space, such as lung cancer and intentional self-harm.

INTERPRETATION

Populations that are exposed to the greenest environments also have lowest levels of health inequality related to income deprivation. Physical environments that promote good health might be important to reduce socioeconomic health inequalities.

Negatively-charged air conditions and responses of the human psycho-neuro-endocrino-immune network

BACKGROUND

Against increasing environmental adverse effects on human health such as those associated with water and ground pollution, as well as out- and indoor air conditions, trials were conducted to support and promote human health by improving the indoor air atmosphere. This study was performed to estimate the effect of negatively-charged air conditions on human biological markers related to the psycho-neuro-endocrino-immune (PNEI) network.

OBJECTIVES

After construction of negatively-charged experimental rooms (NCRs), healthy volunteers were admitted to these rooms and control rooms (CTRs) and various biological responses were analyzed.

METHODS

NCRs were constructed using a fine charcoal coating and applying an electric voltage (72 V) between the backside of walls and the ground. Various biological markers were monitored that related to general conditions, autonomic nervous systems, stress markers, immunological parameters and blood flow.

RESULTS

Regarding the indoor environment, only negatively-charged air resulted in the difference between the CTR and NCR groups. The well-controlled experimental model-room to examine the biological effects of negatively-charged air was therefore established. Among the various parameters, IL-2, IL-4, the mean RR interval of the heart rate, and blood viscosity differed significantly between the CTR and NCR groups. In addition, the following formula was used to detect NCR-biological responses: Biological Response Value (BRV)=0.498+0.0005 [salivary cortisol]+0.072 [IL-2]+0.003 [HRM-SD]-0.013 [blood viscosity]-0.009 [blood sugar]+0.017 [pulse rate].

CONCLUSIONS

Negatively-charged air conditions activated the immune system slightly, smoothened blood flow and stabilized the autonomic nervous system. Although this is the first report to analyze negatively-charged air conditions on human biological responses, the long-term effects should be analyzed for the general use of these artificial atmospheres.

Cities of consumption: the impact of corporate practices on the health of urban populations

The increasing concentration of the world's population in cities and the growing accumulation of political and economic power by corporations create new threats to health and opportunities for improving global health. By considering the intersection of these two fundamental social determinants of well-being, we elucidate some of the mechanisms by which they influence the health of urban populations. After reviewing the changing historical impact of corporations on cities, we focus on the growth of consumption as a leading cause of mortality and morbidity and describe how the food, tobacco, automobile, and other industries promote unhealthy behaviors and lifestyles in urban settings. Cities are also sites for developing alternatives to unhealthy corporate practices, and we assess strategies used to modify practices that harm health.

Acute respiratory health effects of air pollution on children with asthma in US inner cities

BACKGROUND

Children with asthma in inner-city communities may be particularly vulnerable to adverse effects of air pollution because of their airways disease and exposure to relatively high levels of motor vehicle emissions.

OBJECTIVE

To investigate the association between fluctuations in outdoor air pollution and asthma morbidity among inner-city children with asthma.

METHODS

We analyzed data from 861 children with persistent asthma in 7 US urban communities who performed 2-week periods of twice-daily pulmonary function testing every 6 months for 2 years. Asthma symptom data were collected every 2 months. Daily pollution measurements were obtained from the Aerometric Information Retrieval System. The relationship of lung function and symptoms to fluctuations in pollutant concentrations was examined by using mixed models.

RESULTS

Almost all pollutant concentrations measured were below the National Ambient Air Quality Standards. In single-pollutant models, higher 5-day average concentrations of NO2, sulfur dioxide, and particles smaller than 2.5 microm were associated with significantly lower pulmonary function. Higher pollutant levels were independently associated with reduced lung function in a 3-pollutant model. Higher concentrations of NO2 and particles smaller than 2.5 microm were associated with asthma-related missed school days, and higher NO2 concentrations were associated with asthma symptoms.

CONCLUSION

Among inner-city children with asthma, short-term increases in air pollutant concentrations below the National Ambient Air Quality Standards were associated with adverse respiratory health effects. The associations with NO2 suggest that motor vehicle emissions may be causing excess morbidity in this population.