Long-Term Exposure to Ambient Air Pollution and Metabolic Syndrome in Adults

Air pollutants (AP) play a role in subclinical inflammation, and are associated with cardiovascular morbidity and mortality. Metabolic syndrome (MetS) is inflammatory and precedes cardiovascular morbidity and type 2 diabetes. Thus, a positive association between AP and MetS may be hypothesized. We explored this association, (taking into account, pathway-specific MetS definitions), and its potential modifiers in Swiss adults. We studied 3769 participants of the Swiss Cohort Study on Air Pollution and Lung and Heart Diseases in Adults, reporting at least four-hour fasting time before venepuncture. AP exposures were 10-year mean residential PM₁₀ (particulate matter <10μm in diameter) and NO₂ (nitrogen dioxide). Outcomes included MetS defined by World Health Organization (MetS-W), International Diabetes Federation (MetS-I) and Adult Treatment Panel-III (MetS-A) using four- and eight-hour fasting time limits. We also explored associations with individual components of MetS. We applied mixed logistic regression models to explore these associations. The prevalence of MetS-W, MetS-I and MetS-A were 10%, 22% and 18% respectively. Odds of MetS-W, MetS-I and MetS-A increased by 72% (51-102%), 31% (11-54%) and 18% (4-34%) per 10μg/m³ increase in 10-year mean PM₁₀. We observed weaker associations with NO₂. Associations were stronger among physically-active, ever-smokers and non-diabetic participants especially with PM₁₀ (p<0.05). Associations remained robust across various sensitivity analyses including ten imputations of missing observations and exclusion of diabetes cases. The observed associations between AP exposure and MetS were sensitive to MetS definitions. Regarding the MetS components, we observed strongest associations with impaired fasting glycemia, and positive but weaker associations with hypertension and waist-circumference-based obesity. Cardio-metabolic effects of AP may be majorly driven by impairment of glucose homeostasis, and to a less-strong extent, visceral adiposity. Well-designed prospective studies are needed to confirm these findings.     

Ambient Air Pollution and the Progression of Atherosclerosis in Adults

Background

Cross-sectional studies suggest an association between exposure to ambient air pollution and atherosclerosis. We investigated the association between outdoor air quality and progression of subclinical atherosclerosis (common carotid artery intima-media thickness, CIMT).

Methodology/Principal Findings

We examined data from five double-blind randomized trials that assessed effects of various treatments on the change in CIMT. The trials were conducted in the Los Angeles area. Spatial models and land-use data were used to estimate the home outdoor mean concentration of particulate matter up to 2.5 micrometer in diameter (PM2.5), and to classify residence by proximity to traffic-related pollution (within 100 m of highways). PM2.5 and traffic proximity were positively associated with CIMT progression. Adjusted coefficients were larger than crude associations, not sensitive to modelling specifications, and statistically significant for highway proximity while of borderline significance for PM2.5 (P = 0.08). Annual CIMT progression among those living within 100 m of a highway was accelerated (5.5 micrometers/yr [95%CI: 0.13–10.79; p = 0.04]) or more than twice the population mean progression. For PM2.5, coefficients were positive as well, reaching statistical significance in the socially disadvantaged; in subjects reporting lipid lowering treatment at baseline; among participants receiving on-trial treatments; and among the pool of four out of the five trials.

Conclusion

Consistent with cross-sectional findings and animal studies, this is the first study to report an association between exposure to air pollution and the progression of atherosclerosis – indicated with CIMT change – in humans. Ostensibly, our results suggest that air pollution may contribute to the acceleration of cardiovascular disease development – the main causes of morbidity and mortality in many countries. However, the heterogeneity of the volunteering populations across the five trials, the limited sample size within trials and other relevant subgroups, and the fact that some key findings reached statistical significance in subgroups rather than the sample precludes generalizations to the general population.     

39种木本植物对大气污染的生理生态反应与敏感性

39种1-2a生盆栽木本植物在生长季前期放置在污染区（佛山南海区小塘镇五星)和清洁区(广州华南植物园),5个月后进行植物叶片和叶绿素荧光特征参数的测定。大气监测结果表明,污染区有相当高的酸性硫酸盐化速率、氟化物浓度和降尘量,分别是清洁医的15．4、17.5和28倍,明显高于国家排放标准。生长在污染区的大多数植物的净光合速率（Pn)、蒸腾速率(E)和气孔导度(gs)均出现不同程度的下降,下降幅度因植物种类不同而存在较大差异。Pn、E与gs之间存在一定程度的线性相关关系,但污染胁迫下Pn与gs线性相关的显著程度波削弱,而E与gs的相关性则得到提高,表现出不同植物种类Pn和E的变化与gs变化的不协同性、复杂性以及适应策略的多样性。根据Pn、E和水分利用效率(WUE)的变化,将植物对大气污染响应的敏感程度划分为：(1)高度敏感组,包括仪花、灰木莲、格木、阿丁枫、白桂木、海南木莲、白木香和海南红豆;(2)中度敏感组,包括幌伞枫、无忧树、红花木莲、小叶胭脂、蝴蝶树、山玉兰、灰莉、柳叶楠、刺果番荔枝、厚皮香、猫尾木、红桂木、竹节树、红花油茶、观光木、桂花、铁冬青、日本杜英、火焰木、铁力术和密仡树：(3)轻度敏感组,包括毛黄肉楠、华润楠、吊瓜木、大头茶、茶花、傅园榕、小叶榕、环榕、菩提榕和石笔木。     

Detection of Coxiella burnetii in Ambient Air after a Large Q Fever Outbreak

One of the largest Q fever outbreaks ever occurred in the Netherlands from 2007–2010, with 25 fatalities among 4,026 notified cases. Airborne dispersion of Coxiella burnetii was suspected but not studied extensively at the time. We investigated temporal and spatial variation of Coxiella burnetii in ambient air at residential locations in the most affected area in the Netherlands (the South-East), in the year immediately following the outbreak. One-week average ambient particulate matter < 10 μm samples were collected at eight locations from March till September 2011. Presence of Coxiella burnetii DNA was determined by quantitative polymerase chain reaction. Associations with various spatial and temporal characteristics were analyzed by mixed logistic regression. Coxiella burnetii DNA was detected in 56 out of 202 samples (28%). Airborne Coxiella burnetii presence showed a clear seasonal pattern coinciding with goat kidding. The spatial variation was significantly associated with number of goats on the nearest goat farm weighted by the distance to the farm (OR per IQR: 1.89, CI: 1.31–2.76). We conclude that in the year after a large Q fever outbreak, temporal variation of airborne Coxiella burnetii is suggestive to be associated with goat kidding, and spatial variation with distance to and size of goat farms. Aerosol measurements show to have potential for source identification and attribution of an airborne pathogen, which may also be applicable in early stages of an outbreak.     

The Loss of Structural Integrity in Damaged Spruce Needles from Locations Exposed to Air Pollution

Abstract Within the framework of appraising the new type of forest damage, the epidermis of two-year-old spruce ( Picea abies ) needles was investigated as a possible site for primary attack by air pollutants using light and scanning electron microscopy.
Depending upon the extent of the macroscopically visible needle leaf disease, a degeneration process of the cuticular, stomatal and epidermal structures leading to the lethal destruction of the needle surface was observed.
Stomatal and epidermal cells become increasingly deformed or collapsed showing increasing discolouration due to phenolic deposits. Additionally, the erosion of stomatal waxes is accelerated, leading initially to a temporary occlusion of the stomata, and then to a wide opening of the antechamber following a complete decomposition of the plug.
Surface lesions indicating early damage to the epidermal tissue already occur on slightly yellowed needles. The barrier effect of the spruce needle epidermis on exogenous stressors could thereby already be reduced at an early stage, triggering incipient losses of structural resistance.     

A Study of Air Microbe Levels in Different Areas of a Hospital

Airborne transmission is an important route for many microbial pathogens in outdoor and indoor environments, including hospitals. A 2-year-long survey of bioaerosol quality in operating theatres (OT), hospital rooms (HR) and maternity wards (MW) at a hospital in Murcia, Spain, was performed. Total aerobic counts (TAC) and fungal load (FL) were assessed using a microbiological air sampler (MAS-100 single-stage impactor). While fungal levels were below 1 cfu/m³ (0–7.33 cfu/m³) in OT, they were higher in MW (mean, 6.9 cfu/m³; range 0.44–44.67 cfu/m³) and in HR (mean, 10.6 cfu/m³; range, 0–266 cfu/m³). In OT the aerobic counts were considerably higher, with a mean of 25.6 cfu/m³ (range, 1.67–157 cfu/m³). MW and HR also showed higher means for total aerobic counts compared to OT. Seasonal changes were not detected in mould and bacteria levels in OT. Hospital renovation occurred during this study and OT adjacent to renovated areas were closed. A survey of TAC and FL in OT resumed when renovation was completed. We observed an outstanding increase in FL (more than 100 cfu/m³), particularly Aspergillus spp., during this period, but no significant changes in TAC were observed after renovation.     

Levels of Porphyromonas gingivalis Fimbriae and Inflammatory Cytokines in Gingival Crevicular Fluid from Adult Human Subjects

The Porphyromonas gingivalis fimbriae level was examined in the gingival crevicular fluid (GCF) from adult human subjects using an immunoblot assay with a monoclonal antibody. The cytokines, interleukin-1α (IL-1α), IL-1β, IL-6 and tumor necrosis factor-a (TNF-α) levels in the GCF were quantified by enzyme-linked immunosorbent assay (ELISA). The reactivity of the GCF samples with the monoclonal antibody against P. gingivalis fimbriae was related to the IL-1β, IL-6 and TNF-α levels. Moreover, the fimbriae content was associated with the gingival index (GI). In contrast, no significant correlation was seen between the fimbriae content and IL-1α level. These results suggest that there are possible associations between P. gingivalis fimbriae and IL-1β, IL-6 and TNF-α in the gingival crevicular fluid.     

Diversity of ndo Genes in Mangrove Sediments Exposed to Different Sources of Polycyclic Aromatic Hydrocarbon Pollution

Polycyclic aromatic hydrocarbon (PAH) pollutants originating from oil spills and wood and fuel combustion are pollutants which are among the major threats to mangrove ecosystems. In this study, the composition and relative abundance in the sediment bacterial communities of naphthalene dioxygenase (ndo) genes which are important for bacterial adaptation to environmental PAH contamination were investigated. Three urban mangrove sites which had characteristic compositions and levels of PAH compounds in the sediments were selected. The diversity and relative abundance of ndo genes in total community DNA were assessed by a newly developed ndo denaturing gradient gel electrophoresis (DGGE) approach and by PCR amplification with primers targeting ndo genes with subsequent Southern blot hybridization analyses. Bacterial populations inhabiting sediments of urban mangroves under the impact of different sources of PAH contamination harbor distinct ndo genotypes. Sequencing of cloned ndo amplicons comigrating with dominant DGGE bands revealed new ndo genotypes. PCR-Southern blot analysis and ndo DGGE showed that the frequently studied nah and phn genotypes were not detected as dominant ndo types in the mangrove sediments. However, ndo genotypes related to nagAc-like genes were detected, but only in oil-contaminated mangrove sediments. The long-term impact of PAH contamination, together with the specific environmental conditions at each site, may have affected the abundance and diversity of ndo genes in sediments of urban mangroves.     

Increased Eotaxin and MCP-1 Levels in Serum from Individuals with Periodontitis and in Human Gingival Fibroblasts Exposed to Pro-Inflammatory Cytokines

Periodontitis is a chronic inflammatory disease of tooth supporting tissues resulting in periodontal tissue destruction, which may ultimately lead to tooth loss. The disease is characterized by continuous leukocyte infiltration, likely mediated by local chemokine production but the pathogenic mechanisms are not fully elucidated. There are no reliable serologic biomarkers for the diagnosis of periodontitis, which is today based solely on the degree of local tissue destruction, and there is no available biological treatment tool. Prompted by the increasing interest in periodontitis and systemic inflammatory mediators we mapped serum cytokine and chemokine levels from periodontitis subjects and healthy controls. We used multivariate partial least squares (PLS) modeling and identified monocyte chemoattractant protein-1 (MCP-1) and eotaxin as clearly associated with periodontitis along with C-reactive protein (CRP), years of smoking and age, whereas the number of remaining teeth was associated with being healthy. Moreover, body mass index correlated significantly with serum MCP-1 and CRP, but not with eotaxin. We detected higher MCP-1 protein levels in inflamed gingival connective tissue compared to healthy but the eotaxin levels were undetectable. Primary human gingival fibroblasts displayed strongly increased expression of MCP-1 and eotaxin mRNA and protein when challenged with tumor necrosis factor-α (TNF-α and interleukin-1β (IL-1β), key mediators of periodontal inflammation. We also demonstrated that the upregulated chemokine expression was dependent on the NF-κΒ pathway. In summary, we identify higher levels of CRP, eotaxin and MCP-1 in serum of periodontitis patients. This, together with our finding that both CRP and MCP-1 correlates with BMI points towards an increased systemic inflammatory load in patients with periodontitis and high BMI. Targeting eotaxin and MCP-1 in periodontitis may result in reduced leukocyte infiltration and inflammation in periodontitis and maybe prevent tooth loss.     

Ambient Air Pollution Associated with Suppressed Serologic Responses to Pneumocystis jirovecii in a Prospective Cohort of HIV-Infected Patients with Pneumocystis Pneumonia

Background

Ambient air pollution (AAP) may be associated with increased risk for Pneumocystis pneumonia (PCP). The mechanisms underlying this association remain uncertain.

Objectives

To determine if real-life exposures to AAP are associated with suppressed IgM antibody responses to P. jirovecii in HIV-infected (HIV+) patients with active PCP, and to determine if AAP, mediated by suppressed serologic responses to Pneumocystis, is associated with adverse clinical outcomes.

Methods

We conducted a prospective cohort study in HIV+ patients residing in San Francisco and admitted to San Francisco General Hospital with microscopically confirmed PCP. Our AAP predictors were ambient air concentrations of particulate matter of < 10 µm in diameter (PM₁₀) and < 2.5 µm in diameter (PM_2.5), nitrogen dioxide (NO₂), ozone (O₃), and sulfur dioxide (SO₂) measured immediately prior to hospital admission and 2 weeks prior to admission. Our primary outcomes were the IgM serologic responses to four recombinant P. jirovecii major surface glycoprotein (Msg) constructs: MsgC1, MsgC3, MsgC8, and MsgC9.

Results

Elevated PM₁₀ and NO₂ exposures immediately prior to and two weeks prior to hospital admission were associated with decreased IgM antibody responses to P. jirovecii Msg. For exposures immediately prior to admission, every 10 µg/m³ increase in PM₁₀ was associated with a 25 to 35% decrease in IgM responses to Msg (statistically significant for all the Msg constructs), and every 10 ppb increase in NO₂ was associated with a 19-45% decrease in IgM responses to Msg (statistically significant for MsgC8 and MsgC9). Similar findings were seen with exposures two weeks prior to admission, but for fewer of the Msg constructs.

Conclusions

Real life exposures to PM₁₀ and NO₂ were associated with suppressed IgM responses to P. jirovecii Msg in HIV+ patients admitted with PCP, suggesting a mechanism of immunotoxicity by which AAP increases host susceptibility to pulmonary infection.     

In Vitro NADH Oxidation as an Early Indicator for Growth Reduction in Spinach Exposed to H2S in the Ambient Air

H₂S reduced growth of spinach at levels higher than 0.075 µl/literand inhibited NADH oxidation by shoot extracts. Inhibition ofNADH oxidation was maximum after a 48-h exposure. Oxidationof NADH was equally sensitive to sulfide and cyanide. NADH oxidationshowed promise as an early indicator for growth reduction byH₂S. ¹Present address: Centre for Agrobiological Research, P.O. Box14, 6700 AA Wageningen, The Netherlands. (Received May 18, 1987; Accepted February 9, 1988)     

Trends in Intake and Outcome Data for Animal Shelters in a Large U.S. Metropolitan Area, 1989 to 2010

Trends in nonhuman animal shelter intake and outcomes for dogs and cats in Metro Denver, CO, between 1989 and 2010 were assessed by linear regression analyses of data from 4 of the largest facilities covering 3 counties. The data were analyzed for trends on 3 scales: actual numbers per year, number per 1,000 residents per year, and as a percentage of total intake. Approximately 21,000 dogs and 16,000 cats were taken into the shelters in 2010, representing a 24% decrease for each since 1989. For dogs on a per-1,000-residents basis, intake decreased by 44%, euthanasia by 77%, and adoption by 13%; the live release rate (LRR) increased by 39%. For cats on the same scale, there was a 53% decrease in intake until 1998 followed by an 11% increase through 2010, and an 82% decrease in euthanasia until 2000 followed by a 24% increase through 2010. Adoption of cats per 1,000 residents remained unchanged, but the overall LRR for cats doubled during the study period. Substantially increasing trends in the transfer of dogs and cats from shelters to rescue organizations reflect efforts to optimize adoptions.     

Spatially Explicit Characterization of Acidifying and Eutrophying Air Pollution in Life-Cycle Assessment

Abstract: Simple models are often used to assess the potential impact of acidifying and eutrophying substances released during the life cycle of products. As fate, background depositions, and ecosystem sensitivity are not included in these models, environmental life-cycle assessment of products (LCA) may produce incorrect results for these impact categories. This paper outlines the spatially explicit regional air pollution information and simulation model (RAINSLCA), which was developed for the calculation of acidification and terrestrial eutrophication potentials of ammonia (NH3) and nitrogen oxide (NOx) air emissions and acidification potentials for sulfur dioxide (SO2) air emissions for Europe and a number of European regions, taking fate,     

The Regulation of Photosynthesis in Leaves of Field-Grown Spring Wheat (Triticum aestivum L., cv Albis) at Different Levels of Ozone in Ambient Air

Wheat (Triticum aestivum L. cv Albis) was grown in open-top chambers in the field and fumigated daily with charcoal-filtered air (0.015 microliters per liter O₃), nonfiltered air (0.03 microliters per liter O₃), and air enriched with either 0.07 or 0.10 microliters per liter ozone (seasonal 8 hour/day [9 am-5 pm] mean ozone concentration from June 1 until July 10, 1987). Photosynthetic ¹⁴CO₂ uptake was measured in situ. Net photosynthesis, dark respiration, and CO₂ compensation concentration at 2 and 21% O₂ were measured in the laboratory. Leaf segments were freeze-clamped in situ for the determination of the steady state levels of ribulose 1,5-bisphosphate, 3-phosphoglycerate, triose-phosphate, ATP, ADP, AMP, and activity of ribulose, 1,5-bisphosphate carboxylase/oxygenase. Photosynthesis of flag leaves was highest in filtered air and decreased in response to increasing mean ozone concentration. CO₂ compensation concentration and the ratio of dark respiration to net photosynthesis increased with ozone concentration. The decrease in photosynthesis was associated with a decrease in chlorophyll, soluble protein, ribulose bisphosphate carboxylase/oxygenase activity, ribulose bisphosphate, and adenylates. No decrease was found for triose-phosphate and 3-phosphoglycerate. The ratio of ATP to ADP and of triosephosphate to 3-phosphoglycerate were increased suggesting that photosynthesis was limited by pentose phosphate reductive cycle activity. No limitation occurred due to decreased access of CO₂ to photosynthetic cells since the decrease in stomatal conductance with increasing ozone concentration did not account for the decrease in photosynthesis. Ozonestressed leaves showed an increased degree of activation of ribulose bisphosphate carboxylase/oxygenase and a decreased ratio of ribulose bisphosphate to initial activity of ribulose bisphosphate carboxylase/oxygenase. Nevertheless, it is suggested that photosynthesis in ozone stressed leaves is limited by ribulose bisphosphate carboxylation possibly due to an effect of ozone on the catalysis by ribulose bisphosphate carboxylase/oxygenase.     

The Loss of Structural Integrity in Damaged Spruce Needles from Locations Exposed to Air Pollution I. Mesophyll and Central Cylinder

Abstract In connection with the new type of forest damage, the individual disease situation of two-year-old spruce ( Picea abies ) needles was analyzed histopathologically in forest areas exposed to different levels of O₃-, SO₂- and NO₃- pollution.
Early damage results from losses of chlorophyll in the mesophyll cells. The bleaching is more intensive towards the apex in severely damaged needles. The cytoplasm is aggregated at the cell wall and the chloroplasts show definite structural damage as well.
The mesophyll cells below the epidermis, or the cells adjacent to the vascular bundle sheath, appear to be particularly susceptible. Collapsed cells (bone cells), which increase in number with damage, can lead to tissue death in certain needle areas, (brown tips, transverse bands).
Necrotic spots are manifested as groups of dissociated cells in which hypertrophic and collapsed cells as well as abnormal proliferations can be observed.
Hypertrophy and cell collapse appear in the central cylinder in addition to severe phenol deposits.
Bone cells and chlorophyll losses can already be detected in the green needles of damaged trees, indicating latent damage, which becomes macroscopically visible only after more extensive damage.
Our results indicate that no biotic stress factors take part in the damage of the spruce needles investigated here. Anthropogenic air pollutants in addition to abiotic stress factors must be regarded as a main cause of damage.     

Evaluation of Microbial Biomass and Activity in Different Soils Exposed to Increasing Level of Arsenic Pollution: A Laboratory Study

Soil contamination with arsenic is a widespread phenomenon in many parts of the world and it is well known that it may affect the soil microbial community. A laboratory experiment was performed to evaluate the acute toxicity effect of different As concentrations (0, 0.1, 1.0, 10, 100, and 200 mg/kg) on soil biological parameters like microbial biomass carbon (MBC), active microbial biomass carbon (AMBC), basal soil respiration (BSR), fluorescein diacetate hydrolase activity (FDA), and dehydrogenase activity (DHA) under three different soil types (Inceptisol, Vertisol, and Entisol). Soil enzyme activities, microbial biomass, and respiration were significantly decreased by arsenic exposure. The soil metabolic quotient increased with increasing As concentration, the maximum being observed for Entisol followed by Vertisol and Inceptisol. Except for soil enzyme activities, the majority of which started to decrease after the addition of 10 mg/kg arsenic, all other parameters decreased at arsenic dose ≥0.1 mg/kg. The decrease of AMBC/MBC ratio showed that acute arsenic stress affected the active microorganisms more than the dormant component of total microbial biomass. Among the three soils studied, Vertisol was comparatively more tolerant to As exposure in terms of soil enzymes and biomass, followed by Inceptisol and Entisol. MBC has evolved as a distinct parameter in cluster analysis, while some others, such as DHA and AMBC, and FDA and BSR, appeared essentially redundant.     

不同条件下香蕉幼苗对环境羟自由基水平的影响

在人工可控环境中,以香蕉幼苗在不同光强、不同温度、不同酸碱度条件下光系统Ⅱ叶绿素荧光参数的变化衡量香蕉幼苗光合特性的变化,同时测量培养环境中羟自由基水平以评价植物生长对环境羟自由基水平的影响。结果显示：香蕉幼苗生长的环境中羟自由基水平明显高于没有植物生长的同样环境,表明植物的生长可提高环境的羟自由基水平。环境条件变化引起香蕉幼苗叶片光系统Ⅱ叶绿素荧光参数发生明显变化,高光强、极端温度和极端酸碱条件下的叶绿素荧光参数变化显示幼苗不同程度的光抑制,同时也伴随环境中羟自由基水平的升高,二者具有一定程度的相关性。本研究证明了大气中羟自由基水平受植物生长状态的影响,指出植物生长状态与环境中羟自由基水平的密切关系,为研究大气中羟自由基水平的演变机制提供了依据。     

锌诱导金属硫蛋白在文蛤不同组织中的表达

采用体外暴露法对文蛤Meretrixmeretrix进行锌(0、1.5mg/L、3mg/L、6mg/L)染毒,研究不同染毒浓度的锌离子在不同染毒时间下,诱导金属硫蛋白(metallothionein,MT)在文蛤足、肝胰腺、鳃、外套膜组织中的表达差异。取经不同浓度的锌溶液在染毒2d及4d后的不同组织匀浆、离心后经Bio-GelP-10凝胶柱层析纯化,用TU-1810紫外可见分光光度计测定每个样品中金属硫蛋白的吸光值。实验结果显示:同一浓度锌离子染毒后,MT在文蛤4个不同组织中的表达量差异较显著,一般为足>肝胰腺>外套膜>鳃;不同染毒浓度的锌离子在不同染毒时间下诱导MT在不同组织中的表达也不同,具有一定的组织差异性和规律性。