Particles, and not gases, are associated with the risk of death in patients with chronic obstructive pulmonary disease

Comparing the Therapeutic Efficacies of Lung Cancer: Network Meta-Analysis Approaches

BACKGROUND

In recent years, reduction of nuclear power generation and the use of coal-fired power for filling the power supply gap might have increased the risk of lung cancer. This study aims to explore the most effective treatment for different stages of lung cancer patients.

METHODS

We searched databases to investigate the treatment efficacy of lung cancer. The network meta-analysis was used to explore the top three effective therapeutic strategies among all collected treatment methodologies.

RESULTS

A total of 124 studies were collected from 115 articles with 171,757 participants in total. The results of network meta-analyses showed that the best top three treatments: (1) in response rate, for advanced lung cancer were Targeted + Targeted, Chemo + Immuno, and Targeted + Other Therapy with cumulative probabilities 82.9, 80.8, and 69.3%, respectively; for non-advanced lung cancer were Chemoradio + Targeted, Chemoradi + Immuno, and Chemoradio + Other Therapy with cumulative probabilities 69.0, 67.8, and 60.7%, respectively; (2) in disease-free control rate, for advanced lung cancer were Targeted + Others, Chemo + Immuno, and Targeted + Targeted Therapy with cumulative probabilities 93.4, 91.5, and 59.4%, respectively; for non-advanced lung cancer were Chemo + Surgery, Chemoradio + Targeted, and Surgery Therapy with cumulative probabilities 80.1, 71.5, and 43.1%, respectively.

CONCLUSION

The therapeutic strategies with the best effectiveness will be different depending on the stage of lung cancer patients.

Ambient Particulate Air Pollution and Daily Hospital Admissions in 31 Cities in Poland

A strong and consistent association has been observed between morbidity or mortality rates and PM concentration, and is well documented in many countries. In Poland, despite poor air quality, studies concerning the evaluation of acute health effects of ambient air pollution on morbidity from respiratory or cardiovascular diseases are rare. We examined the short-term impact of PMx concentration on hospital admission in 31 Polish cities based on the daily PM10, PM2.5 concentration, meteorological variables, and hospital data. The generalized additive model (GAM) and a random-effects meta-analysis were used to assess the impact of air pollution on morbidity within the exposed population. Almost 1.6 million cardiovascular admissions and 600 thousand respiratory disorders were analyzed. The RR values for PM10-related cardiovascular and respiratory hospital admissions in Poland are equal to 1.0077 (95% confidence interval, 1.0062 to 1.0092) and 1.0218 (95% confidence interval, 1.0182 to 1.0253), respectively, while for PM2.5 1.0088 (95% confidence interval, 1.0072 to 1.0103) and 1.0289 (95% confidence interval, 1.0244 to 1.0335), respectively. Moreover, a moderate heterogeneity of RR estimates was observed between the analyzed cities (I2 values from 27% to 45%). The presented analysis confirms the significant association between hospital admission and PMx concentration, especially during heating seasons.

Increasing mortality caused by chronic obstructive pulmonary disease (COPD) in relation with exposure to ambient fine particulate matters: an analysis in Southeastern China

The objective of this study was to investigate the association between ambient particulate matters (PMs) and chronic obstructive pulmonary disease (COPD) mortality. generalized additive mixed model was employed to investigate the effects of ambient fine and coarse PMs on COPD mortality using 13,066 deaths from 2014 to 2016 among six cities in Zhejiang Province in Southeastern China. The daily average death count due to COPD was 3, varying from 1 to 7 among six cities. The daily 24-h mean concentrations were diverse among cities, from 29.7 to 56.8 μg/m³ for PM_2.5, 16.7 to 30.3 μg/m³ for PM_2.5-10, and 50.3 to 87.1 μg/m³ for PM₁₀, respectively. The analysis showed that daily exposure to PM_2.5 and PM₁₀ was associated with increased mortality due to COPD and that weak effects were observed between PM_2.5-10 and COPD mortality. Our results provided solid evidence that the fine particles in air pollution have stronger functions on adverse health effects other than coarser particles in Southeastern China, which may be considered as a potential clinic target in PM-associated COPD.

Association between ambient air pollution and mortality from chronic obstructive pulmonary disease in Wuhan, China: a population-based time-series study

Evidence on the short-term effects of ambient air pollution on chronic obstructive pulmonary disease (COPD) mortality is still not conclusive. The aim of this study was to investigate the relationships between them in Wuhan China. Daily death numbers, concentrations of air pollutants (PM2.5, PM10, SO2, NO2, and O3), and meteorological characteristics in Wuhan from January 1, 2014, to December 31, 2019, were collected. Time-series analysis using generalized additive model was applied. The results showed that a total of 16,150 deaths (7.37 deaths per day) from COPD were observed. The daily average concentrations of PM2.5, PM10, SO2, NO2, and O3 were 59.03, 90.48, 12.91, 48.84, and 91.77 μg/m3, respectively. In single pollutant model, for every increase of 10 μg/m3 in PM10, SO2, and NO2 levels, COPD mortality increased by 0.583% (95% CI: 0.055-1.113%), 4.299% (95% CI: 0.978-7.729%), and 1.816% (95% CI: 0.515-3.313%) at lag03, respectively. No significant associations were found for PM2.5 and O3. Subgroup analysis demonstrated that females were more susceptible to PM2.5, PM10, SO2, and NO2. The concentrations of PM10, SO2, and NO2 were significantly associated with COPD mortality for older adults. The effects of PM2.5 and O3 on COPD mortality were higher in warm period. In two-pollutant models, the significantly positive associations between SO2 and NO2 and COPD mortality remained after adjusting for PM2.5 or O3. In conclusions, short-term exposure to PM10, SO2, and NO2 are significantly associated with a higher risk of COPD mortality. Female or elderly are more susceptible to air pollution. It is urgent to implement the environmental protection policy.

Effects of short-term exposure to ambient airborne pollutants on COPD-related mortality among the elderly residents of Chengdu city in Southwest China

Background

Chronic obstructive pulmonary disease (COPD) has become a severe global burden in terms of both health and the economy. Few studies, however, have thoroughly assessed the influence of air pollution on COPD-related mortality among elderly people in developing areas in the hinterland of southwestern China. This study is the first to examine the association between short-term exposure to ambient airborne pollutants and COPD-related mortality among elderly people in the central Sichuan Basin of southwestern China.

Methods

Data on COPD-related mortality among elderly people aged 60 and older were obtained from the Population Death Information Registration and Management System (PDIRMS). Data on airborne pollutants comprised of particulate matter < 2.5 μm in aerodynamic diameter (PM_2.5), sulfur dioxide (SO₂), nitrogen dioxide (NO₂), carbon monoxide (CO), and ozone (O₃) were derived from 23 municipal environmental monitoring sites. Data on weather conditions, including daily mean temperature and relative humidity, were obtained from the Chengdu Meteorological Bureau. All data were collected from January 1, 2015, to December 31, 2018. A quasi-Poisson general additive model (GAM) was utilized to assess the effects of short-term exposure to airborne pollutants on COPD-related mortality among elderly people.

Results

A total of 61,058 COPD-related deaths of people aged 60 and older were obtained. Controlling the influences of daily temperature and relative humidity, interquartile range (IQR) concentration increases of PM_2.5 (43 μg/m³), SO₂ (8 μg/m³), NO₂ (18 μg/m³), CO (0.4 mg/m³), and O₃ (78 μg/m³) were associated with 2.7% (95% CI 1.0–4.4%), 4.3% (95% CI 2.1–6.4%), 3.6% (95% CI 1.7–5.6%), 2.7% (95% CI 0.6–4.8%), and 7.4% (95% CI 3.6–11.3%) increases in COPD-related mortality in people aged 60 and older, respectively. The exposure-response curves between each pollutant and the log-relative risk of COPD-related mortality exhibited linear relationships. Statistically significant differences in the associations between pollutants and COPD-related mortality were not observed among sociodemographic factors including age, gender, and marital status. The effects of O₃ remained steady after adjusting for PM_2.5, SO₂, NO₂, and CO each time in the two-pollutant models.

Conclusions

Increased concentrations of ambient airborne pollutants composed of PM_2.5, SO₂, NO₂, O₃, and CO were significantly and positively associated with COPD-related mortality in the central Sichuan Basin, which is located in the hinterland of southwestern China. The adverse effects of O₃ were stable, a finding that should receive more attention.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12199-020-00925-x.

Unexpected association between increased levels of ambient carbon monoxide and reduced daily outpatient visits for vaginitis: A hospital-based study

Carbon monoxide (CO) is a well-known "toxic gas". It represents a toxic inhalation hazard at high concentration and is commonly found in polluted air. However, a series of recent studies have suggested that low concentration of CO can also produce protective functions. This study was performed to investigate the association between ambient CO exposure and vaginitis outpatient visits. Daily baseline outpatient data of vaginitis from January 1, 2013 to December 31, 2015 were obtained from Xi'an, a heavily-polluted metropolis in China. The over-dispersed Poisson generalized additive model was applied to discover the relations between short-term ambient CO exposure and the number of vaginitis outpatient visits by adjusting day of the week and weather conditions. A total of 16,825 outpatient hospital visits for vaginitis were recorded. The mean daily concentration of carbon monoxide (CO) was well below Chinese and WHO guidelines. During the study period, increased levels of ambient CO was associated with reduced outpatient-visits through concurrent to lag 5 days, and the most significant association was evidenced at lag 05. A 0.1 mg/m³ increase in daily average CO at lag 05 corresponded to -1.25% (95%CI: -1.85%, -0.65%) change in outpatient-visits for vaginitis. Moreover, the association was more significant in those women aged 20-29 years. After adjustment for PM₁₀, PM_2.5, SO₂, and NO₂, and O₃, the negative associations of CO with vaginitis kept significant, suggesting relative stability of effect estimates. In summary, this is the first evidence that increased ambient CO exposure can be related to reduced daily outpatient visits for vaginitis. The results of our study may not only help to establish more comprehensive understanding of the health effects of ambient air on vaginitis and other gynecological diseases, but also provide a clue to new potential interventions.

Particulate-Matter Related Respiratory Diseases

Particulate matter (PM) is suspended dust that has a diameter of <10 µm and can be inhaled by humans and deposited in the lungs, particularly the alveoli. Recent studies have shown that PM has an adverse effect on respiratory diseases. The aim of this article is to review respiratory diseases associated with PM. According to existing studies, PM is associated with chronic obstructive pulmonary disease, bronchial asthma, and several other respiratory diseases and increases the mortality rates of these diseases. Moreover, increased exposure in the high concentration of atmospheric PM is associated with the development of lung cancer. The most simple and common way to protect an individual from airborne PM is to wear a face mask that filters out PM. In areas of high concentration PM, it is recommended to wear a face mask to minimize the exposure to PM. However, the use of N95 or KF94 masks can interfere with respiration in patients with chronic respiratory diseases who exhibit low pulmonary function, leading to an increased risk of respiratory failure. Conclusionally, reduction of the total amount of PM is considered to be important factor and strengthening the national warning notification system to vulnerable patients and proper early management of exacerbated patients will be needed in the future.

Analysis of environmental risk factors for chronic obstructive pulmonary disease exacerbation: A case-crossover study (2004-2013)

Purpose

We aim to assess if air pollution levels and climatological factors are associated with hospital admissions for exacerbation of chronic obstructive pulmonary disease (COPD) in Spain from 2004 to 2013.

Methods

We conducted a retrospective study. Information on pollution level and climatological factors were obtained from the Spanish Meteorological Agency and hospitalizations from the Spanish hospital discharge database. A case-crossover design was used to identify factors associated with hospitalizations and in hospital mortality. Postal codes were used to assign climatic and pollutant factors to each patient.

Results

We detected 162,338 hospital admissions for COPD exacerbation. When seasonal effects were evaluated we observed that hospital admissions and mortality were more frequent in autumn and winter. In addition, we found significant associations of temperature, humidity, ozone (O₃), carbon monoxide (CO), particulate matter up to 10 μm in size (PM₁₀) and nitrogen dioxide (NO₂) with hospital admissions. Lower temperatures at admission with COPD exacerbation versus 1, 1.5, 2 and 3 weeks prior to hospital admission for COPD exacerbation, were associated with a higher probability of dying in the hospital. Other environmental factors that were related to in-hospital mortality were NO₂, O₃, PM₁₀ and CO.

Conclusions

Epidemiology of hospital admissions by COPD exacerbation was negatively affected by colder climatological factors (seasonality and absolute temperature) and short-term exposure to major air pollution (NO₂, O₃, CO and PM₁₀).

COPD Patients as Vulnerable Subpopulation for Exposure to Ambient Air Pollution

PURPOSE OF REVIEW

The prevalence of chronic obstructive pulmonary disease (COPD) is increasing worldwide with no known cure and an increasing number of triggers that exacerbate symptoms and speed up progression. This review aims to summarize the evidence for COPD patients being more vulnerable to air pollution exposure assessed as acute effects.

RECENT FINDINGS

Several recent systematic reviews show consistently increased risks for COPD mortality and COPD hospital admission, ranging between 2 and 3% with increasing PM_2.5 or PM₁₀. Similar adverse impacts were shown for NO_2. Also_, adverse health effects among COPD patients were also found for other gaseous pollutants such as ozone and SO₂; most of these studies could not be included in the meta-analysis we reviewed. Data from ten panel studies of COPD patients reported a small but statistically significant decline of FEV1 [- 3.38 mL (95% CI - 6.39 to - 0.37)] per increment of 10 μg/m³ PM₁₀, supporting an impact on respiratory health with increasing PM₁₀ exposure. The combined information from systematic reviews and more recent findings lead us to conclude that COPD patients are more vulnerable to ambient air pollution than healthier people.

The Interaction between Ambient PM10 and NO₂ on Mortality in Guangzhou, China

Air pollution is now a significant environmental issue in China. To better understand the health impacts of ambient air pollution, this study investigated the potential interaction between PM₁₀ and NO₂ on mortality in Guangzhou, China. Time series data of daily non-accidental mortality and concentrations of PM₁₀ and NO₂ from 2006 to 2010 were collected. Based on generalized additive model, we developed two models (bivariate model and stratified model) to explore the interaction both qualitatively and quantitatively. At lag of 0–2 days, greater interactive effects between PM₁₀ and NO₂ were presented in the graphs. Positive modified effects were also found between the two pollutants on total non-accidental death and cardiovascular death. When the NO₂ concentration was at a high level (>76.14 μg/m³), PM₁₀ showed the greatest excess relative risk percentage (ERR%) for total non-accidental mortality (0.46, 95% CI: 0.13–0.79) and cardiovascular disease mortality (0.61, 95% CI: 0.06–1.16) for each 10 μg/m³ increase. During the period of high PM₁₀ concentration (>89.82 μg/m³), NO₂ demonstrated its strongest effect for total non-accidental mortality (ERR%: 0.92, 95% CI: 0.42–1.42) and cardiovascular disease mortality (ERR%: 1.20, 95% CI: 0.38–2.03). Our results suggest a positive interaction between PM₁₀ and NO₂ on non-accidental mortality in Guangzhou.

To Investigate the Effects of Air Pollution (PM10 and SO2) on the Respiratory Diseases Asthma and Chronic Obstructive Pulmonary Disease

OBJECTIVES

Effects of air pollution parameters of sulfur dioxide (SO2) and particulate matter (PM10) values on the respiratory system were investigated.

MATERIAL AND METHODS

Data of SO₂ and PM10 were obtained daily for air pollution and classified into two groups: Group I (2006-2007), coal burning years and Group II (2008-2009), natural gas+ coal burning. Groups I and II were divided into two subgroups according to the months of combustion as combustible (November-April) and noncombustible (May-October). The number of patients with asthma and chronic obstructive pulmonary disorder (COPD) was recorded between 2006 and 2009.

RESULTS

There was no statistically significant difference between Groups I and II for PM10 and SO₂ (p>0.05). Within the years, the values of SO₂ and PM10 were statistically different between the groups defined by month (p<0.01). The number of patients in the combustible and noncombustible subgroups were found to be different for every 4 years, and the numbers of patients with COPD or asthma were not changed through the years. There was a strong correlation between PM10 and COPD (r=0.59, p<0.01) and a weak correlation between PM10 and asthma (r=0.25, p>0.05). A correlation was found between SO₂ and COPD (p<0.01) but not between SO₂ and asthma (p>0.05). The number of visits for COPD and asthma was statistically different between combustible and noncombustible subgroups (X2:58.61, p=0.000; X2:34.55, p=0.000, respectively). The r2 values for SO₂ and PM10 for COPD patients were 17% and 24%, respectively, in contrast to 8% and 5%, respectivley for asthma patients.

CONCLUSION

Air pollution is known to increase respiratory disease occurrences. With decrease in the usage of solid fuel, air pollution could be reduced and may be effective in preventing respiratory diseases.

Effectiveness of traffic-related elements in tree bark and pollen abortion rates for assessing air pollution exposure on respiratory mortality rates

The majority of epidemiological studies correlate the cardiorespiratory effects of air pollution exposure by considering the concentrations of pollutants measured from conventional monitoring networks. The conventional air quality monitoring methods are expensive, and their data are insufficient for providing good spatial resolution. We hypothesized that bioassays using plants could effectively determine pollutant gradients, thus helping to assess the risks associated with air pollution exposure. The study regions were determined from different prevalent respiratory death distributions in the Sao Paulo municipality. Samples of tree flower buds were collected from twelve sites in four regional districts. The genotoxic effects caused by air pollution were tested through a pollen abortion bioassay. Elements derived from vehicular traffic that accumulated in tree barks were determined using energy-dispersive X-ray fluorescence spectrometry (EDXRF). Mortality data were collected from the mortality information program of Sao Paulo City. Principal component analysis (PCA) was applied to the concentrations of elements accumulated in tree barks. Pearson correlation and exponential regression were performed considering the elements, pollen abortion rates and mortality data. PCA identified five factors, of which four represented elements related to vehicular traffic. The elements Al, S, Fe, Mn, Cu, and Zn showed a strong correlation with mortality rates (R²>0.87) and pollen abortion rates (R²>0.82). These results demonstrate that tree barks and pollen abortion rates allow for correlations between vehicular traffic emissions and associated outcomes such as genotoxic effects and mortality data.

The effect of particulate matter size on cardiovascular health in Taipei Basin, Taiwan

BACKGROUND

Although the overall effect of particulate matter (PM) on cardiovascular disease (CVD) has been previously documented, the effect of different PM sizes (PM₁₀, PM_2.5-10 and PM_2.5) has not been well studied. This study estimates the effect of different PM sizes on the incidence of CVD in Taipei, Taiwan.

METHODS

We collected outpatients with CVD from 2006 to 2010 and data on the concentrations of air pollutants such as PM₁₀, PM_2.5-10, PM_2.5, sulfur dioxide, carbon monoxide, nitrogen dioxide, and ozone. A Distributed Lag Non-linear Model (DLNM) was used to explore the effect of different PM sizes on CVD risk.

RESULTS

In high air pollution events, PM_2.5 was significantly associated with elevated risk (4.9%) [95% confidence interval (CI): 1.010-1.089] for CVD with increasing interquartile range (IQR) in single air pollutant model. PM_2.5-10 and PM₁₀ did not show a significant positive association with CVD in this study. After adjusting for other air pollutants such as SO₂, CO, NO₂, and O₃, the estimated effect of PM_2.5 only decreased 0.2%. Moreover, patients under 40 years old did not show a significant association between PM_2.5 and CVD.

CONCLUSION

This study demonstrates that only PM_2.5 is significantly positively correlated with the number of daily outpatient visits for CVD during high air pollution events.

High particulate matter emission from additive-free Natural American Spirit cigarettes

BACKGROUND

Involuntary exposure to health-threatening environmental tobacco smoke (Combined Mainstream and Side-stream Smoke, CMSS) is a worldwide problem, causing premature death of thousands of people. CMSS consists of particulate matter (PM), one of the main sources of indoor air pollution. PM constitutes a considerable health risk for passive smokers. It is important to inform the public about brand-specific differences in CMSS-associated PM, especially in the case of brands without additives, which are therefore promoted as natural and less health-threatening.

METHODS

Mean concentrations and the area under the curve of PM10, PM2.5 and PM1 generated by Natural American Spirit cigarettes without additives and the 3R4F standard research cigarette (University of Kentucky, USA) were measured, analyzed and compared with each other. An automatic environmental tobacco smoke emitter was used to smoke 100 cigarettes, 20 of each brand, according to a standardized smoking protocol.

RESULTS

This study could show that CMSS-associated PM released from tobacco brands without additives, which are therefore promoted as natural and less harmful, are higher than expected.

CONCLUSIONS

It is highly improbable that Natural American Spirit tobacco products are a less harmful choice-at least not for passive smokers as this study could show. We conclude, the CMSS-associated PM level of every single customized brand should be measured because the origin of the tobacco and not the amount of CO, tar and nicotine (given as product information) seem to be responsible for the brand-specific PM release. This data is urgently needed to adequately inform the public about CMSS-associated PM exposure and the related health risk especially for passive smokers.

Outdoor Air Pollution and COPD-Related Emergency Department Visits, Hospital Admissions, and Mortality: A Meta-Analysis

A systematic literature review was performed to identify all peer-reviewed literature quantifying the association between short-term exposures of particulate matter <2.5 microns (PM_2.5), nitrogen dioxide (NO₂), and sulfur dioxide (SO₂) and COPD-related emergency department (ED) visits, hospital admissions (HA), and mortality. These results were then pooled for each pollutant through meta-analyses with a random effects model. Subgroup meta-analyses were explored to study the effects of selected lag/averaging times and health outcomes. A total of 37 studies satisfied our inclusion criteria, contributing to a total of approximately 1,115,000 COPD-related acute events (950,000 HAs, 80,000 EDs, and 130,000 deaths) to our meta-estimates. An increase in PM_2.5 of 10 ug/m³ was associated with a 2.5% (95% CI: 1.6-3.4%) increased risk of COPD-related ED and HA, an increase of 10 ug/m³ in NO₂ was associated with a 4.2% (2.5-6.0%) increase, and an increase of 10 ug/m³ in SO₂ was associated with a 2.1% (0.7-3.5%) increase. The strength of these pooled effect estimates, however, varied depending on the selected lag/averaging time between exposure and outcome. Similar pooled effects were estimated for each pollutant and COPD-related mortality. These results suggest an ongoing threat to the health of COPD patients from both outdoor particulates and gaseous pollutants. Ambient outdoor concentrations of PM_2.5, NO₂, and SO₂ were significantly and positively associated with both COPD-related morbidity and mortality.

The Effects of Air Pollution and Temperature on COPD

Chronic Obstructive Pulmonary Disease (COPD) affects 12-16 million people in the United States and is the third-leading cause of death. In developed countries, smoking is the greatest risk factor for the development of COPD, but other exposures also contribute to the development and progression of the disease. Several studies suggest, though are not definitive, that outdoor air pollution exposure is linked to the prevalence and incidence of COPD. Among individuals with COPD, outdoor air pollutants are associated with loss of lung function and increased respiratory symptoms. In addition, outdoor air pollutants are also associated with COPD exacerbations and mortality. There is much less evidence for the impact of indoor air on COPD, especially in developed countries in residences without biomass exposure. The limited existing data suggests that indoor particulate matter and nitrogen dioxide concentrations are linked to increased respiratory symptoms among patients with COPD. In addition, with the projected increases in temperature and extreme weather events in the context of climate change there has been increased attention to the effects of heat exposure. Extremes of temperature-both heat and cold-have been associated with increased respiratory morbidity in COPD. Some studies also suggest that temperature may modify the effect of pollution exposure and though results are not conclusive, understanding factors that may modify susceptibility to air pollution in patients with COPD is of utmost importance.

Impact of air quality guidelines on COPD sufferers

Background

COPD is one of the leading causes of morbidity and mortality in both high- and low-income countries and a major public health burden worldwide. While cigarette smoking remains the main cause of COPD, outdoor and indoor air pollution are important risk factors to its etiology. Although studies over the last 30 years helped reduce the values, it is not very clear if the current air quality guidelines are adequately protective for COPD sufferers.

Objective

This systematic review was to summarize the up-to-date literature on the impact of air pollution on the COPD sufferers.

Methods

PubMed and Google Scholar were utilized to search for articles related to our study’s focus. Search terms included “COPD exacerbation”, “air pollution”, “air quality guidelines”, “air quality standards”, “COPD morbidity and mortality”, “chronic bronchitis”, and “air pollution control” separately and in combination. We focused on articles from 1990 to 2015. We also used articles prior to 1990 if they contained relevant information. We focused on articles written in English or with an English abstract. We also used the articles in the reference lists of the identified articles.

Results

Both short-term and long-term exposures to outdoor air pollution around the world are associated with the mortality and morbidity of COPD sufferers even at levels below the current air quality guidelines. Biomass cooking in low-income countries was clearly associated with COPD morbidity in adult nonsmoking females.

Conclusion

There is a need to continue to improve the air quality guidelines. A range of intervention measures could be selected at different levels based on countries’ socioeconomic conditions to reduce the air pollution exposure and COPD burden.

Association between dietary behavior and esophageal squamous cell carcinoma in Yanting

BACKGROUND

Yanting is one of high risk areas for esophageal cancer and the screening program was therefore initiated there. This study was aimed to investigate the dietary behaviors on the risk of esophageal squamous cell carcinoma (ESCC), among the individuals with normal and abnormal esophagus mucosa.

MATERIALS AND METHODS

A frequency matched case-controls study was proposed to estimate the different distribution of dietary behavior between individuals of control, esophagitis and cancer groups. Cancer cases were selected from hospitals. Esophagitis cases and controls were selected from screening population for ESCC. Health workers collected data for 1 year prior to interview, in terms of length of finishing a meal, temperature of eaten food and interval between water boiling and drinking. Chi-square, Kruskal-Wallis tests and unconditional logistic regression model were used to estimate differences and associations between groups.

RESULTS

Compared with controls, length of finishing a meal≥15 mins was related to a reduced OR for cancer (OR=0.46, 95%CI, 0.22- 0.97) and even compared with cases of esophagitis, the OR of cancer was reduced to 0.30 (95%CI, 0.13-0.72). The OR for often eating food at a high temperature was 2.48 (95%CI 1.06, 5.82) for ESCC as compared with controls. Interval between water boiling and drinking of ≥10 mins was associated with lower risk of cancer: the OR was 0.18 compared with controls and 0.49 with esophagitis cases (p<0.05).

CONCLUSIONS

Length of eating food≥15 mins and interval between water boiling and drinking ≥10 mins are potentially related to reduced risk of esophageal SCC, compared with individuals with normal and abnormal esophageal mucosa. Recommendations to Yanting residents to change their dietary behaviors should be made in order to reduce cancer risk.

Effect of naturally occurring ozone air pollution episodes on pulmonary oxidative stress and inflammation

This study aimed to determine if naturally occurring episodes of ozone air pollution in the Salt Lake Valley in Utah, USA, during the summer are associated with increased pulmonary inflammation and oxidative stress, increased respiratory symptoms, and decreased lung function in individuals with chronic obstructive pulmonary disease (COPD) compared to controls. We measured biomarkers (nitrite/nitrate (NO_x), 8-isoprostane) in exhaled breath condensate (EBC), spirometry, and respiratory symptoms in 11 former smokers with moderate-to-severe COPD and nine former smokers without airflow obstruction during periods of low and high ozone air pollution. High ozone levels were associated with increased NO_x in EBC in both COPD (8.7 (±8.5) vs. 28.6 (±17.6) μmol/L on clean air vs. pollution days, respectively, p < 0.01) and control participants (7.6 (±16.5) vs. 28.5 (±15.6) μmol/L on clean air vs. pollution days, respectively, p = 0.02). There was no difference in pollution effect between COPD and control groups, and no difference in EBC 8-isoprostane, pulmonary function, or respiratory symptoms between clean air and pollution days in either group. Former smokers both with and without airflow obstruction developed airway oxidative stress and inflammation in association with ozone air pollution episodes.

Tobacco smoke particles and indoor air quality (ToPIQ-II) - a modified study protocol and first results

Background

Environmental tobacco smoke (ETS)-associated particulate matter (PM) has to be seen as an independent health hazard and needs to be discussed separately from the already well-known toxic and carcinogenic compounds contained in cigarette smoke. We believe that brand-specific amounts of PM are of public interest and should be investigated.

Methods

An automatic environmental tobacco smoke emitter was developed and placed into a glass-chamber to generate cigarette smoke as reliably as possible. Cigarettes were smoked automatically according to a standardized protocol. Mean concentrations (C_mean) and area under the curve (AUC) of PM2.5 released by the brands P&S, Virginia (without filter) and the 3R4F standard research cigarette of the University of Kentucky, USA, were measured and compared with each other.

Results

C_mean PM2.5 of 3R4F reference was 1,725 μg/m³, for P&S: 1,982 μg/m³ and for Virginia without filter: 1,525 μg/m³. AUC PM2.5 for 3R4F reference was: 527,644 μg/m³×sec, for P&S: 606,171 μg/m³×sec, and for Virginia without filter: 464,788 μg/m³×sec.

Conclusions

Our modified ToPIQ-II study protocol shows significant brand-specific differences in the amounts of PM2.5 released by cigarettes into the environment, when compared to 3R4F reference cigarettes. We believe that information about PM-release of all relevant brands in relation to reference cigarettes should be published. In the light of PM as an independent risk factor for morbidity and mortality, this may serve as a basis for further epidemiologic investigations.

Health impact assessment of air pollution in Valladolid, Spain

OBJECTIVE

To estimate the attributable and targeted avoidable deaths (ADs; TADs) of outdoor air pollution by ambient particulate matter (PM10), PM2.5 and O3 according to specific WHO methodology.

DESIGN

Health impact assessment.

SETTING

City of Valladolid, Spain (around 300 000 residents).

DATA SOURCES

Demographics; mortality; pollutant concentrations collected 1999-2008.

MAIN OUTCOME MEASURES

Attributable fractions; ADs and TADs per year for 1999-2008.

RESULTS

Higher TADs estimates (shown here) were obtained when assuming as 'target' concentrations WHO Air Quality Guidelines instead of Directive 2008/50/EC. ADs are considered relative to pollutant background levels. All-cause mortality associated to PM10 (all ages): 52 ADs (95% CI 39 to 64); 31 TADs (95% CI 24 to 39).All-cause mortality associated to PM10 (<5 years): 0 ADs (95% CI 0 to 1); 0 TADs (95% CI 0 to 1). All-cause mortality associated to PM2.5 (>30 years): 326 ADs (95% CI 217 to 422); 231 TADs (95% CI 153 to 301). Cardiopulmonary and lung cancer mortality associated to PM2.5 (>30 years): Cardiopulmonary: 186 ADs (95% CI 74 to 280); 94 TADs (95% CI 36 to 148). Lung cancer : 51 ADs (95% CI 21 to 73); 27 TADs (95% CI 10 to 41).All-cause, respiratory and cardiovascular mortality associated to O3 (all ages): All-cause: 52ADs (95% CI 25 to 77) ; 31 TADs (95% CI 15 to 45). Respiratory: 5ADs (95% CI -2 to 13) ; 3 TADs (95% CI -1 to 8). Cardiovascular: 30 ADs (95% CI 8 to 51) ; 17 TADs (95% CI 5 to 30). Negative estimates which should be read as zero were obtained when pollutant concentrations were below counterfactuals or assumed risk coefficients were below one.

CONCLUSIONS

Our estimates suggest a not negligible negative impact on mortality of outdoor air pollution. The implementation of WHO methodology provides critical information to distinguish an improvement range in air pollution control.

Long-term dynamics of death rates of emphysema, asthma, and pneumonia and improving air quality

BACKGROUND

The respiratory tract is a major target of exposure to air pollutants, and respiratory diseases are associated with both short- and long-term exposures. We hypothesized that improved air quality in North Carolina was associated with reduced rates of death from respiratory diseases in local populations.

MATERIALS AND METHODS

We analyzed the trends of emphysema, asthma, and pneumonia mortality and changes of the levels of ozone, sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), and particulate matters (PM2.5 and PM10) using monthly data measurements from air-monitoring stations in North Carolina in 1993-2010. The log-linear model was used to evaluate associations between air-pollutant levels and age-adjusted death rates (per 100,000 of population) calculated for 5-year age-groups and for standard 2000 North Carolina population. The studied associations were adjusted by age group-specific smoking prevalence and seasonal fluctuations of disease-specific respiratory deaths.

RESULTS

Decline in emphysema deaths was associated with decreasing levels of SO2 and CO in the air, decline in asthma deaths-with lower SO2, CO, and PM10 levels, and decline in pneumonia deaths-with lower levels of SO2. Sensitivity analyses were performed to study potential effects of the change from International Classification of Diseases (ICD)-9 to ICD-10 codes, the effects of air pollutants on mortality during summer and winter, the impact of approach when only the underlying causes of deaths were used, and when mortality and air-quality data were analyzed on the county level. In each case, the results of sensitivity analyses demonstrated stability. The importance of analysis of pneumonia as an underlying cause of death was also highlighted.

CONCLUSION

Significant associations were observed between decreasing death rates of emphysema, asthma, and pneumonia and decreases in levels of ambient air pollutants in North Carolina.

Geographical information systems and air pollution simulation for Megalopolis' electric power plant in Peloponnese, Greece

The growth and sophistication of geographic information systems (GIS) have propelled us into a new era of environmental analyses. Air pollution is a growing concern in populated areas as many recent studies have associated high levels of pollution with increased illnesses and mortality. The study will focus on the toxicity levels incurred by radioactive lignite-burning Power Generation facilities located in Megalopolis, Greece. An estimate of pollution emissions followed by dispersion simulations for various atmospheric conditions will be given. The exercise will be integrated with a Geographical Information System (GIS) for defining the emission sources and visualizing the dispersion of pollutants over the geographical terrain. Data samples were collected from vegetation in the surrounding areas and analyzed for radioactivity. High energy levels (up to 4-5 times higher than recommended standards, (UNCEAR, 1982) were found in several samples containing (226)Ra, (232)Th, (234)Th, (40)K and (238)U. The study concludes that air quality and vegetation of the neighbouring areas is adversely affected by industrial waste. Greater pollution controls and air quality monitoring should be applied for the benefit and health of its citizens. Radioactivity in food and water and inhaled air become very dangerous for public health thus, the levels of radioactivity should be kept within UNCEAR 1982 limits.

Long- and short-term exposure to PM2.5 and mortality: using novel exposure models

BACKGROUND

Many studies have reported associations between ambient particulate matter (PM) and adverse health effects, focused on either short-term (acute) or long-term (chronic) PM exposures. For chronic effects, the studied cohorts have rarely been representative of the population. We present a novel exposure model combining satellite aerosol optical depth and land-use data to investigate both the long- and short-term effects of PM2.5 exposures on population mortality in Massachusetts, United States, for the years 2000-2008.

METHODS

All deaths were geocoded. We performed two separate analyses: a time-series analysis (for short-term exposure) where counts in each geographic grid cell were regressed against cell-specific short-term PM2.5 exposure, temperature, socioeconomic data, lung cancer rates (as a surrogate for smoking), and a spline of time (to control for season and trends). In addition, for long-term exposure, we performed a relative incidence analysis using two long-term exposure metrics: regional 10 × 10 km PM2.5 predictions and local deviations from the cell average based on land use within 50 m of the residence. We tested whether these predicted the proportion of deaths from PM-related causes (cardiovascular and respiratory diseases).

RESULTS

For short-term exposure, we found that for every 10-µg/m increase in PM 2.5 exposure there was a 2.8% increase in PM-related mortality (95% confidence interval [CI] = 2.0-3.5). For the long-term exposure at the grid cell level, we found an odds ratio (OR) for every 10-µg/m increase in long-term PM2.5 exposure of 1.6 (CI = 1.5-1.8) for particle-related diseases. Local PM2.5 had an OR of 1.4 (CI = 1.3-1.5), which was independent of and additive to the grid cell effect.

CONCLUSIONS

We have developed a novel PM2.5 exposure model based on remote sensing data to assess both short- and long-term human exposures. Our approach allows us to gain spatial resolution in acute effects and an assessment of long-term effects in the entire population rather than a selective sample from urban locations.

Regulation of particulate matter-induced mucin secretion by transient receptor potential vanilloid 1 receptors

Exposure to airborne particulate matter (PM) is a worldwide health problem. Previous studies have reported that PMs induced depolarizing currents and increased intracellular Ca(2+) in human bronchial epithelial cells. Ca(2+) plays important role in the regulation of mucus exocytosis, and mucin hypersecretion is a key pathological feature of inflammatory respiratory diseases. To explore more mechanisms underlying PM toxicity, we measured PM-induced mucin secretion in human bronchial epithelial (16HBE) cells. MUC5AC secretion and cyclic adenosine monophosphate (cAMP) level were detected by ELISA. Transient receptor potential vanilloid (TRPV)1 inward currents were examined by electrophysiology. Ca(2+) concentration was assessed by laser scanning confocal microscope. Exposure of PMs to 16HBE cells was found to induce mucin secretion, as a consequence of sustained Ca(2+) influx and cAMP increase through TRPV1 receptors. Mucin secretion was completely inhibited by TRPV1 receptor antagonist capsazepine. Removal of Ca(2+) by Ca(2+) chelator BAPTA or inhibition of protein kinase A (PKA) by the PKA inhibitors H-89 each partially reduced PC(2)s-induced mucin secretion. The combination of BAPTA and H-89 completely prevented mucin secretion mediated by PMs. These results suggest that PM induces mucin secretion through Ca(2+) influx and cAMP/PKA pathway by TRPV1 receptors in human bronchial epithelial cells, thereby providing a potential mechanism to reduce PM toxicity.

Synergy between particles and nitrogen dioxide on emergency hospital admissions for cardiac diseases in Hong Kong

BACKGROUND

Ambient air pollution is a complex mixture of particles and gaseous pollutants. Epidemiological studies are moving toward a multipollutant approach, requiring an understanding of possible interactions among the pollutants. We aim to estimate the joint effects of particles with an aerodynamic diameter less than 10 μm (PM10) and nitrogen dioxide (NO2) on emergency hospital admissions for cardiac diseases, and to explore the possible interactions between PM10 and NO2.

METHODS

We collected daily time series data from 1998 to 2007 on emergency hospital admissions for cardiac diseases in Hong Kong, as well as PM10 and NO2 concentrations. Generalized additive Poisson model was used to examine the relationship between air pollution and hospital admissions. We then used three parallel time series approaches (bivariate response surface model, joint effect model and parametric stratified model) to explore the possible interactions between PM10 and NO2.

RESULTS

Results showed the greatest joint effect of PM10 and NO2 on emergency cardiac hospitalizations when PM10 and NO2 concentrations were both at high levels. The effect of PM10 was significantly greatest on the days with high NO2 level, and vice versa. A 10 μg/m(3) increase of lag0 PM10 and NO2 was associated with an increase of emergency cardiac hospitalizations by 0.55% (95% CI: 0.29-0.80%) and 1.20% (95% CI: 0.87-1.53%) respectively, when the other pollutant was at high level.

CONCLUSIONS

We found consistent synergistic interaction between PM10 and NO2 on emergency cardiac hospitalizations in Hong Kong. These findings contribute to the development of a new paradigm for multipollutant air quality management.

Acute diesel exhaust particle exposure increases viral titre and inflammation associated with existing influenza infection, but does not exacerbate deficits in lung function

Please cite this paper as: Larcombe et al. (2012) Acute diesel exhaust particle exposure increases viral titre and inflammation associated with existing influenza infection, but does not exacerbate deficits in lung function. Influenza and Other Respiratory Viruses DOI:10.1111/irv.12012.

Background  Exposure to diesel exhaust particles (DEP) is thought to exacerbate many pre‐existing respiratory diseases, including asthma, bronchitis and chronic obstructive pulmonary disease, however, there is a paucity of data on whether DEP exacerbates illness due to respiratory viral infection.

Objectives  To assess the physiological consequences of an acute DEP exposure during the peak of influenza‐induced illness.

Methods  We exposed adult female BALB/c mice to 100 μg DEP (or control) 3·75 days after infection with 10^4·5 plaque forming units of influenza A/Mem71 (or control). Six hours, 24 hours and 7 days after DEP exposure we measured thoracic gas volume and lung function at functional residual capacity. Bronchoalveolar lavage fluid was taken for analyses of cellular inflammation and cytokines, and whole lungs were taken for measurement of viral titre.

Results  Influenza infection resulted in significantly increased inflammation, cytokine influx and impairment to lung function. DEP exposure alone resulted in less inflammation and cytokine influx, and no impairment to lung function. Mice infected with influenza and exposed to DEP had higher viral titres and neutrophilia compared with infected mice, yet they did not have more impaired lung mechanics than mice infected with influenza alone.

Conclusions  A single dose of DEP is not sufficient to physiologically exacerbate pre‐existing respiratory disease caused by influenza infection in mice.

Air pollution and chronic obstructive pulmonary disease

Limited data suggest that outdoor air pollution (such as ambient air pollution or traffic-related air pollution) and indoor air pollution (such as second-hand smoking and biomass fuel combustion exposure) are associated with the development of chronic obstructive pulmonary disease (COPD), but there is insufficient evidence to prove a causal relationship at this stage. It also appears that outdoor air pollution is a significant environmental trigger for acute exacerbation of COPD, leading to increasing symptoms, emergency department visits, hospital admissions and even mortality. Improving ambient air pollution and decreasing indoor biomass combustion exposure by improving home ventilation are effective measures that may substantially improve the health of the general public.

Smoking cessation and environmental hygiene

Although there are nonmodifiable genetic risk factors for COPD, most known risk factors for development and progression of COPD can be corrected. Continued efforts to encourage smoking cessation and measures to reduce exposure to SHS, outdoor air pollution, biomass smoke, and occupational and related amateur exposures will have a significant impact on worldwide health.

Tobacco smoke particles and indoor air quality (ToPIQ) - the protocol of a new study

Environmental tobacco smoke (ETS) is a major contributor to indoor air pollution. Since decades it is well documented that ETS can be harmful to human health and causes premature death and disease. In comparison to the huge research on toxicological substances of ETS, less attention was paid on the concentration of indoor ETS-dependent particulate matter (PM). Especially, investigation that focuses on different tobacco products and their concentration of deeply into the airways depositing PM-fractions (PM10, PM2.5 and PM1) must be stated. The tobacco smoke particles and indoor air quality study (ToPIQS) will approach this issue by device supported generation of indoor ETS and simultaneously measurements of PM concentration by laser aerosol spectrometry. Primarily, the ToPIQ study will conduct a field research with focus on PM concentration of different tobacco products and within various microenvironments. It is planned to extend the analysis to basic research on influencing factors of ETS-dependent PM concentration.

Ships, ports and particulate air pollution - an analysis of recent studies

The duration of use is usually significantly longer for marine vessels than for roadside vehicles. Therefore, these vessels are often powered by relatively old engines which may propagate air pollution. Also, the quality of fuel used for marine vessels is usually not comparable to the quality of fuels used in the automotive sector and therefore, port areas may exhibit a high degree of air pollution. In contrast to the multitude of studies that addressed outdoor air pollution due to road traffic, only little is known about ship-related air pollution. Therefore the present article aims to summarize recent studies that address air pollution, i.e. particulate matter exposure, due to marine vessels. It can be stated that the data in this area of research is still largely limited. Especially, knowledge on the different air pollutions in different sea areas is needed.

Air pollution and airway disease

Epidemiological and toxicological research continues to support a link between urban air pollution and an increased incidence and/or severity of airway disease. Detrimental effects of ozone (O(3)), nitrogen dioxide (NO(2)) and particulate matter (PM), as well as traffic-related pollution as a whole, on respiratory symptoms and function are well documented. Not only do we have strong epidemiological evidence of a relationship between air pollution and exacerbation of asthma and respiratory morbidity and mortality in patients with chronic obstructive pulmonary disease (COPD), but recent studies, particularly in urban areas, have suggested a role for pollutants in the development of both asthma and COPD. Similarly, while prevalence and severity of atopic conditions appear to be more common in urban compared with rural communities, evidence is emerging that traffic-related pollutants may contribute to the development of allergy. Furthermore, numerous epidemiological and experimental studies suggest an association between exposure to NO(2) , O(3) , PM and combustion products of biomass fuels and an increased susceptibility to and morbidity from respiratory infection. Given the considerable contribution that traffic emissions make to urban air pollution researchers have sought to characterize the relative toxicity of traffic-related PM pollutants. Recent advances in mechanisms implicated in the association of air pollutants and airway disease include epigenetic alteration of genes by combustion-related pollutants and how polymorphisms in genes involved in antioxidant pathways and airway inflammation can modify responses to air pollution exposures. Other interesting epidemiological observations related to increased host susceptibility include a possible link between chronic PM exposure during childhood and vulnerability to COPD in adulthood, and that infants subjected to higher prenatal levels of air pollution may be at greater risk of developing respiratory conditions. While the characterization of pollutant components and sources promise to guide pollution control strategies, the identification of susceptible subpopulations will be necessary if targeted therapy/prevention of pollution-induced respiratory diseases is to be developed.

Environmentally persistent free radicals induce airway hyperresponsiveness in neonatal rat lungs

Background

Increased asthma risk/exacerbation in children and infants is associated with exposure to elevated levels of ultrafine particulate matter (PM). The presence of a newly realized class of pollutants, environmentally persistent free radicals (EPFRs), in PM from combustion sources suggests a potentially unrecognized risk factor for the development and/or exacerbation of asthma.

Methods

Neonatal rats (7-days of age) were exposed to EPFR-containing combustion generated ultrafine particles (CGUFP), non-EPFR containing CGUFP, or air for 20 minutes per day for one week. Pulmonary function was assessed in exposed rats and age matched controls. Lavage fluid was isolated and assayed for cellularity and cytokines and in vivo indicators of oxidative stress. Pulmonary histopathology and characterization of differential protein expression in lung homogenates was also performed.

Results

Neonates exposed to EPFR-containing CGUFP developed significant pulmonary inflammation, and airway hyperreactivity. This correlated with increased levels of oxidative stress in the lungs. Using differential two-dimensional electrophoresis, we identified 16 differentially expressed proteins between control and CGUFP exposed groups. In the rats exposed to EPFR-containing CGUFP; peroxiredoxin-6, cofilin1, and annexin A8 were upregulated.

Conclusions

Exposure of neonates to EPFR-containing CGUFP induced pulmonary oxidative stress and lung dysfunction. This correlated with alterations in the expression of various proteins associated with the response to oxidative stress and the regulation of glucocorticoid receptor translocation in T lymphocytes.

A cross-shift study of lung function, exhaled nitric oxide and inflammatory markers in blood in Norwegian cement production workers

OBJECTIVES

To study possible effects of aerosol exposure on lung function, fractional exhaled nitric oxide (FeNO) and inflammatory markers in blood from Norwegian cement production workers across one work shift (0 to 8 h) and again 32 h after the non-exposed baseline registration.

METHODS

95 workers from two cement plants in Norway were included. Assessment of lung function included spirometry and gas diffusion pre- and post-shift (0 and 8 h). FeNO concentrations were measured and blood samples collected at 0, 8 and 32 h. Blood analysis included cell counts of leucocytes and mediators of inflammation.

RESULTS

The median respirable aerosol level was 0.3 mg/m(3) (range 0.02-6.2 mg/m(3)). FEV(1), FEF(25-75%) and DL(CO) decreased by 37 ml (p=0.04), 170 ml/s (p<0.001) and 0.17 mmol/min/kPa (p=0.02), respectively, across the shift. A 2 ppm reduction in FeNO between 0 and 32 h was detected (p=0.01). The number of leucocytes increased by 0.6×10(9) cells/l (p<0.001) across the shift, while fibrinogen levels increased by 0.02 g/l (p<0.001) from 0 to 32 h. TNF-α level increased and IL-10 decreased across the shift. Baseline levels of fibrinogen were associated with the highest level of respirable dust, and increased by 0.39 g/l (95% CI 0.06 to 0.72).

CONCLUSIONS

We observed small cross-shift changes in lung function and inflammatory markers among cement production workers, indicating that inflammatory effects may occur at exposure levels well below 1 mg/m(3). However, because the associations between these acute changes and personal exposure measurements were weak and as the long-term consequences are unknown, these findings should be tested in a follow-up study.

Pulmonary responses to printer toner particles in mice after intratracheal instillation

The release of ultrafine particles from office equipment is currently receiving great concerns due to its potential threat to human health when inhaled. Printer toner is one of the largest consumables in daily office work, and the particles released from printers and photocopiers may pose damage to respiratory system. In this study, we found the particles can be released into the surrounding environment during the printing process and the concentrations of PM(2.5) and PM(10) particles increased obviously. To evaluate the time-course pulmonary responses caused by toner particles, the toner suspension was instilled into the lungs of the male mice through intratracheally instillation every other day for four times and the pulmonary responses of the lung were monitored at days 9, 28, 56 and 84. Indeed, mice treated with toner particles displayed a slower body weight growth rate during the recovery phase. The total cell number in bronchoalveolar lavage fluids (BALF) of toner-exposed groups was much higher than the saline-treated groups. The total protein, lactate dehydrogenase and acid phosphatase in BALF exhibited significant changes (p<0.05 or p<0.01) at different time points. The nitric oxide synthase, interleukin 1-beta, and interleukin 6 in the lung tissue of the toner-exposed groups also exhibited significant changes (p<0.05 or p<0.01). The pathological examination showed that toner particles can adhere to the alveolar septal walls, then enter into the alveoli and cause pulmonary lesion. During the experimental period, particles phagocytosed by alveolar macrophages (AMs) led to an increase of both AMs number and apoptosis. The pulmonary stress still remained over time even with a clearance period for 12 weeks. These results indicate that exposure to toner particles can inhibit the normal growth of the mice and induce significant inflammatory responses and lesion in the lung tissues. The health and safety effects from working indoors in offices with fumes and particles released from photocopiers and printers need to be paid more attention.

Case-crossover analysis of air pollution health effects: a systematic review of methodology and application

BACKGROUND

Case-crossover is one of the most used designs for analyzing the health-related effects of air pollution. Nevertheless, no one has reviewed its application and methodology in this context.

OBJECTIVE

We conducted a systematic review of case-crossover (CCO) designs used to study the relationship between air pollution and morbidity and mortality, from the standpoint of methodology and application.

DATA SOURCES AND EXTRACTION

A search was made of the MEDLINE and EMBASE databases.Reports were classified as methodologic or applied. From the latter, the following information was extracted: author, study location, year, type of population (general or patients), dependent variable(s), independent variable(s), type of CCO design, and whether effect modification was analyzed for variables at the individual level.

DATA SYNTHESIS

The review covered 105 reports that fulfilled the inclusion criteria. Of these, 24 addressed methodological aspects, and the remainder involved the design's application. In the methodological reports, the designs that yielded the best results in simulation were symmetric bidirectional CCO and time-stratified CCO. Furthermore, we observed an increase across time in the use of certain CCO designs, mainly symmetric bidirectional and time-stratified CCO. The dependent variables most frequently analyzed were those relating to hospital morbidity; the pollutants most often studied were those linked to particulate matter. Among the CCO-application reports, 13.6% studied effect modification for variables at the individual level.

CONCLUSIONS

The use of CCO designs has undergone considerable growth; the most widely used designs were those that yielded better results in simulation studies: symmetric bidirectional and time-stratified CCO. However, the advantages of CCO as a method of analysis of variables at the individual level are put to little use.

The Geography of COPD Hospitalization in California

Exposure to tobacco smoke is an important risk factor for chronic obstructive pulmonary disease. We investigated the relationship between chronic obstructive pulmonary disease hospitalization counts (and hospitalization-related charges) in California and sociodemographic and smoking measures, employing geospatial techniques that permit more sensitive scrutiny at the zip code level while controlling for spatial confounding. We analyzed 1,707 zip code tabulation areas in California for chronic obstructive pulmonary disease hospitalization rates and related hospitalization charges (using 1999 hospital discharge data). After controlling for spatial auto-correlation, positive relationships were found for age, percentage Hispanics, number of tobacco outlets and level of smoking. Inverse relationships were found for percentage with undergraduate degrees and income level. When examining "hotspot" zip code tabulation areas (those with higher than expected model-based chronic obstructive pulmonary disease hospitalization counts), minority/immigrant status, depressed socioeconomic measures, and elevated tobacco use were clearly associated, suggesting the need for increased intervention among the poor and persons of color. Although limited by the availability of air pollution monitoring data, a preliminary descriptive analysis indicated that the numbers of particulate matter exceedances mirrored both the hotspots of the Los Angelesair basin and coldspots in the San Francisco Bay Area.

Particulate matter air pollution exposure: role in the development and exacerbation of chronic obstructive pulmonary disease

Due to the rapid urbanization of the world population, a better understanding of the detrimental effects of exposure to urban air pollution on chronic lung disease is necessary. Strong epidemiological evidence suggests that exposure to particulate matter (PM) air pollution causes exacerbations of pre-existing lung conditions, such as, chronic obstructive pulmonary disease (COPD) resulting in increased morbidity and mortality. However, little is known whether a chronic, low-grade exposure to ambient PM can cause the development and progression of COPD. The deposition of PM in the respiratory tract depends predominantly on the size of the particles, with larger particles deposited in the upper and larger airways and smaller particles penetrating deep into the alveolar spaces. Ineffective clearance of this PM from the airways could cause particle retention in lung tissues, resulting in a chronic, low-grade inflammatory response that may be pathogenetically important in both the exacerbation, as well as, the progression of lung disease. This review focuses on the adverse effects of exposure to ambient PM air pollution on the exacerbation, progression, and development of COPD.

Coarse particles from Saharan dust and daily mortality

BACKGROUND

Winds from the Sahara-Sahel desert region regularly transport large amounts of dust to the Americas, North Africa, and Europe. The presence of high dust concentrations for long periods of time, and the interaction between dust and man-made air pollution, raise concerns about adverse health effects and appropriate interventions by health authorities. This study tested the hypothesis that outbreaks of Saharan dust exacerbate the effects of man-made pollution, specifically fine and coarse particulate matter (PM2.5 and PM10-2.5, respectively) on daily mortality.

METHODS

We investigated the effects of exposure to PM10-2.5 and PM2.5 between March 2003 and December 2004 in Barcelona (Spain) on daily mortality; changes of effects between Saharan and non-Saharan dust days were assessed using a time-stratified case-crossover design. We studied the chemical composition of particulate matter to explain changes of effects.

RESULTS

The study included 24,850 deaths. During Saharan dust days, a daily increase of 10 microg/m3 of PM10-2.5 increased daily mortality by 8.4% (95% confidence interval = 1.5%-15.8%) compared with 1.4% (-0.8% to 3.4%) during non-Saharan dust days (P value for interaction = 0.05). In contrast, there was no increased risk of daily mortality for PM2.5 during Saharan dust days. Although coarse particles seem to be more hazardous during Saharan dust days, differences in chemical composition did not explain these observations.

CONCLUSIONS

Saharan dust outbreaks may have adverse health effects. Further investigation is needed to understand the role of coarse particles and the mechanism by which Saharan dust increases mortality.

Air Pollution and Hospital Admissions for Congestive Heart Failure in a Tropical City: Kaohsiung, Taiwan

This study was undertaken to determine whether there was an association between air pollutant levels and hospital admissions for congestive heart failure (CHF) in Kaohsiung, Taiwan. Hospital admissions for CHF and ambient air pollution data for Kaohsiung were obtained for the period 1996-2004. The relative risk of hospital admission was estimated using a case-crossover approach, controlling for weather variables, day of the week, seasonality, and long-term time trends. In the single-pollutant models, on warm days (> 25 degrees C) statistically significant positive associations were found in all pollutants except sulfur dioxide (SO(2)). On cool days (< 25 degrees C), all pollutants were significantly associated with CHF admissions. For the two-pollutant model, CO and O(3) were significant in combination with each of the other four pollutants on warm days. On cool days, NO(2) remained statistically significant in all the two-pollutant models. This study provides evidence that higher levels of ambient air pollutants increase the risk of hospital admissions for CHF and that the effects of air pollutants on hospital admissions for CHF were temperature dependent.

Airborne particulate matter and human health: toxicological assessment and importance of size and composition of particles for oxidative damage and carcinogenic mechanisms

Air pollution has been considered a hazard to human health. In the past decades, many studies highlighted the role of ambient airborne particulate matter (PM) as an important environmental pollutant for many different cardiopulmonary diseases and lung cancer. Numerous epidemiological studies in the past 30 years found a strong exposure-response relationship between PM for short-term effects (premature mortality, hospital admissions) and long-term or cumulative health effects (morbidity, lung cancer, cardiovascular and cardiopulmonary diseases, etc). Current research on airborne particle-induced health effects investigates the critical characteristics of particulate matter that determine their biological effects. Several independent groups of investigators have shown that the size of the airborne particles and their surface area determine the potential to elicit inflammatory injury, oxidative damage, and other biological effects. These effects are stronger for fine and ultrafine particles because they can penetrate deeper into the airways of the respiratory tract and can reach the alveoli in which 50% are retained in the lung parenchyma. Composition of the PM varies greatly and depends on many factors. The major components of PM are transition metals, ions (sulfate, nitrate), organic compound, quinoid stable radicals of carbonaceous material, minerals, reactive gases, and materials of biologic origin. Results from toxicological research have shown that PM have several mechanisms of adverse cellular effects, such as cytotoxicity through oxidative stress mechanisms, oxygen-free radical-generating activity, DNA oxidative damage, mutagenicity, and stimulation of proinflammatory factors. In this review, the results of the most recent epidemiological and toxicological studies are summarized. In general, the evaluation of most of these studies shows that the smaller the size of PM the higher the toxicity through mechanisms of oxidative stress and inflammation. Some studies showed that the extractable organic compounds (a variety of chemicals with mutagenic and cytotoxic properties) contribute to various mechanisms of cytotoxicity; in addition, the water-soluble faction (mainly transition metals with redox potential) play an important role in the initiation of oxidative DNA damage and membrane lipid peroxidation. Associations between chemical compositions and particle toxicity tend to be stronger for the fine and ultrafine PM size fractions. Vehicular exhaust particles are found to be most responsible for small-sized airborne PM air pollution in urban areas. With these aspects in mind, future research should aim at establishing a cleared picture of the cytotoxic and carcinogenic mechanisms of PM in the lungs, as well as mechanisms of formation during internal engine combustion processes and other sources of airborne fine particles of air pollution.

Carbon black nanoparticles promote the maturation and function of mouse bone marrow-derived dendritic cells

Particulate matter including carbon black (CB) nanoparticles can enhance antigen-related inflammation and immunoglobulin production in vivo. Dendritic cells (DC) as antigen-presenting cells (APC) are the most capable inducers of immune responses. The present study was designed to determine whether CB nanoparticles affect the maturation/activation and function of DC in vitro. DC were differentiated from bone marrow (BM) cells of BALB/c mice by culture with granulocyte macrophage colony stimulating factor (GM-CSF). At day 8 of culture, BM-derived DC (BMDC) were exposed to CB nanoparticles with a diameter of 14nm or 56nm for 24h. The expression of major histocompatibility complex (MHC) class II, DEC205, CD80, and CD86 (maturation/activation markers of BMDC) was measured by flow cytometry. BMDC function was evaluated by an allogeneic mixed lymphocyte reaction (MLR) assay. CB nanoparticles significantly increased the expression of DEC205 and CD86 in BMDC and tended to increase MHC class II and CD80 expression; however, a size-dependent effect was not observed. On the other hand, BMDC-mediated MLR was significantly enhanced by the CB nanoparticles and the enhancement was greater by 14nm CB nanoparticles than by 56nm CB nanoparticles. Taken together, CB nanoparticles can promote the maturation/activation and function of BMDC, which could be related to their effects on allergic diseases and/or responses. In addition, BMDC-mediated MLR might be useful assay for in vitro screening for adjuvant activity of environmental toxicants.

The role of oxidative stress in ambient particulate matter-induced lung diseases and its implications in the toxicity of engineered nanoparticles

Ambient particulate matter (PM) is an environmental factor that has been associated with increased respiratory morbidity and mortality. The major effect of ambient PM on the pulmonary system is the exacerbation of inflammation, especially in susceptible people. One of the mechanisms by which ambient PM exerts its proinflammatory effects is the generation of oxidative stress by its chemical compounds and metals. Cellular responses to PM-induced oxidative stress include activation of antioxidant defense, inflammation, and toxicity. The proinflammatory effect of PM in the lung is characterized by increased cytokine/chemokine production and adhesion molecule expression. Moreover, there is evidence that ambient PM can act as an adjuvant for allergic sensitization, which raises the possibility that long-term PM exposure may lead to increased prevalence of asthma. In addition to ambient PM, rapid expansion of nanotechnology has introduced the potential that engineered nanoparticles (NP) may also become airborne and may contribute to pulmonary diseases by novel mechanisms that could include oxidant injury. Currently, little is known about the potential adverse health effects of these particles. In this communication, the mechanisms by which particulate pollutants, including ambient PM and engineered NP, exert their adverse effects through the generation of oxidative stress and the impacts of oxidant injury in the respiratory tract will be reviewed. The importance of cellular antioxidant and detoxification pathways in protecting against particle-induced lung damage will also be discussed.