Abstract  This study characterized the time-location pattern of 107 residents living in air pollution hotspots, the Waterfront South and Copewood/Davis Streets communities in Camden, NJ. Most residents in the two communities are minority and impoverished individuals. Results showed that employment status played the fundamental role in determining time-location patterns of this study population, and the variations of time-location pattern by season and by day-type were partially attributed to employment status. Compared to the National Human Activity Pattern Survey, the Camden cohort spent significantly more time outdoors (3.8 hours versus 1.8 hours) and less time indoors (19.4 hours versus 20.9 hours) than the general US population, indicating a higher risk of exposure to ambient air pollution for the Camden cohort. The findings of the study are important for understanding exposure routes and sources for the socioeconomically disadvantaged subgroup and ultimately help develop effective strategies to reduce community exposure to ambient air pollution in "hotspots".

Abstract  BACKGROUND: The prevalence of Autistic Disorder (AD), a serious developmental condition, has risen dramatically over the past two decades but high-quality population-based research addressing etiology is limited. OBJECTIVES: We studied the influence of exposures to traffic-related air pollution during pregnancy on the development of autism using data from air monitoring stations and a land use regression (LUR) model to estimate exposures. METHODS: Children of mothers who gave birth in Los Angeles who were diagnosed with a primary AD diagnosis at ages 3-5 years during 1998-2009 were identified through the California Department of Developmental Services and linked to 1995-2006 California birth certificates. For 7,603 children with autism and 10 controls per case matched by sex, birth year, and minimum gestational age, birth addresses were mapped and linked to the nearest air monitoring station and a LUR model. We used conditional logistic regression, adjusting for maternal and perinatal characteristics including indicators of SES. RESULTS: Per interquartile range (IQR) increase, we estimated a 12-15% relative increase in odds of autism for O3 (OR = 1.12, 95% CI: 1.06, 1.19; per 11.54 ppb increase) and PM2.5 (OR = 1.15, 95% CI: 1.06, 1.24; per 4.68 μg/m3 increase) when mutually adjusting for both pollutants. Furthermore, we estimated 3-9% relative increases in odds per IQR increase for LUR-based NO and NO2 exposure estimates. LUR-based associations were strongest for children of mothers with less than a high school education. CONCLUSION: Measured and estimated exposures from ambient pollutant monitors and LUR model suggest associations between autism and prenatal air pollution exposure, mostly related to traffic sources.

Abstract  The term 'air pollution' is used to describe the presence of chemicals or materials in the atmosphere that produce poor air quality. Air pollutants may be classified into four principal categories which include anthropogenic (man-made; e.g. combustion products), biogenic (biological; e.g. pollen, allergens), technogenic (technology; e.g. metal aerosols or smelter) and geogenic (geological; e.g. erosion of earth, i.e. minerals, volcanic ash). From these categories are derived the seven main pollutants of human health concern, i.e. carbon monoxide, nitrogen dioxide, ozone, sulphur dioxide, hydrocarbons, lead, and particulate matter (PM). The common provenance of all these emissions is from the combustion of fossil fuels (e.g. coal, petrol and diesel), biomass (e.g. cooking) and tobacco smoke. PM is now considered to be the most precarious of pollutants, with the combustion-derived nano-particles being linked to a myriad of premature and excess deaths world-wide; especially for persons with pre-existing cardiovascular disorders. This meeting intended to bring together scientists from a host of disciplines (toxicologists, biologists, chemists, physicists and material scientists) that work at the bio-particulate interface. It aimed to present and discuss, via topical 'break-out' sessions, the current thoughts on the 'burden to human health' following exposure to and harm from combustion-derived particles. Furthermore, strategies for 'harm reduction' were another feature of this cross-disciplinary meeting. The final objectives were to identify biomarkers of exposure and harm to these inhalation hazards. All topics covered sought to find biomarker indices for human health effects.

Abstract  Objectives: As demonstrated by many studies, emergency department (ED) visits for asthma can be associated with air pollution exposures. The aim of this study was to examine and assess the potential relations between ED visits for asthma and the concentrations of ambient air pollutants. Materials and Methods: Generalized linear mixed model was applied to study 62,563 ED visits for asthma (ICD-9: 493) in Edmonton, Canada. Two age groups, with 10 years of age as a separator, were considered by gender and season of the year: all (I–XII), warm (IV–IX) and cold (X–III). Results: The percentage increase in daily ED visits for asthma was 17.8% (95% CI: 7.1–29.5) and 13.8% (95% CI: 3.3–25.3) for females below 10 years of age, in the period of IV–IX, for current day and 1-day lagged exposure to ozone (O3), respectively. The percentage increase was 19.2% (95% CI: 11.4–27.6) for males below 10 years of age, in the period of IV–IX, for 2-day lagged exposure to nitrogen dioxide (NO2). Conclusions: The fi ndings provide support for the hypothesis that ED visits for asthma are associated with exposure to O3. This study underlines the signifi cant role of air pollutants as triggering asthma attacks.

Abstract  Estimates of carbon uptake and storage based on global nitrogen deposition, C:N ratios for typical terrestrial ecosystems, and recent ecosystem-scale nutrient studies indicate that 1.0-2.3 Gt C yr-1 of carbon storage may be stimulated by anthropogenically caused increases in nitrogen deposition in the past century. Sixty four to eighty four percent of global nitrogen uptake appears to occur on northern continents, with the remainder largely in northern coastal oceans. Increased nitrogen input by terrestrial ecosystems causes increased accumulation of carbon as plant tissue, with C:N ratios generally 50 to 200:1. Calculations suggest that northern continents are a major sink for carbon and that nitrogen-stimulated carbon uptake may more or less balance global carbon losses to the atmosphere from deforestation and agriculture. Much of the uptake appears to occur in aggrading forests, and the question of how long it can continue has important consequences for global carbon budgets.

Abstract  Short-term effects of air pollution on common morbidity are largely unknown. The authors explored links between daily levels of air pollution (nitrogen dioxide, ozone, and particulate matter less than 10 lm in diameter (PM10)) and medical home visits made for diverse reasons in Bordeaux, France, during 2000–2006. Daily numbers of visits were obtained from a network of general practitioners. The excess relative risk (ERR) of a visit for each indicator associated with increased pollutant levels was estimated by fitting a Poisson regression model, controlling for well known confounding factors and temporal trends. Positive and significant associations were found between air pollution and most health indicators. A 10-lg/m3 increase in PM10 levels was associated with increases in visits for upper and lower respiratory diseases (ERRs were 1.5% (95% confidence interval (CI): 0.3, 2.7) and 2.5% (95% CI: 0.5, 4.4), respectively), headache and asthenia (ERR = 3.5%, 95% CI: 1.3, 5.9), and skin rash and conjunctivitis (ERR= 3.2%, 95% CI: -0.2, 6.8). Significant associations were also found between nitrogen dioxide and ozone and several health indicators. Distributed-lag models showed no harvesting effect, and some effects persisted up to 15 days after exposure increased. These results suggest that considering only the most severe effects of air pollution leads to underestimation of its impact on public health.

Abstract  Purpose: To investigate the effects of subchronic ozone exposure on rat lung ventilation using hyperpolarized (HP) 3He MRI. Materials and Methods: A total of 24 Sprague-Dawley rats, distributed in one control group and four groups exposed to 0.5 ppm ozone concentration for two days or six days, either continuously (22 hours/day) or alternatingly (12 hours/day). A three-step MRI protocol was designed and applied to each animal, including: 1) 3He gas distribution images acquired at inspiratory capacity, 2) measurements of intrapulmonary 3He diffusion coefficients, and 3) dynamic ventilation acquisitions performed during lung filling with 3He. Results: No differentiation between animals exposed to ozone and control animals was observed from the ventilation images obtained at inspiratory capacity. The 3He diffusion coefficients were not statistically different from one group to another. Ventilation defects, appearing as delayed lung filling regions and heterogeneous lung filling, were observed in the dynamic lung ventilation image series. The percentage of animals with ventilation defects in the control, two-day, and six-day exposed groups were equal to 20%, 43% and 75%, respectively. In the subgroup of the animals exposed six days for 12 hours per day, the percentage of animals exhibiting ventilation defects was equal to 85%. Conclusion: Heterogeneous obstructive patterns in an experimental animal model of subchronic ozone exposure were observed using HP 3He MRI.

Abstract  The purpose of this study was to analy/e lhe possible morphological reL-overy of lhe granule cells in the olfactory bulb as a consequence of oxidative stress after an acute ozone exposure. Rats were divided in two groups: Control (air exposed) and experimental group, exposed 4 h. to I ppni ozone and divided into 4 subgroups, which were sacrificed al 2 and 24 h. 10 and 15 days, respectively. Olfactory bulbs were processed with the rapid Golgi method and for transmission electron microscopy. The granule cells of the olfactory bulb disclosed less dendritic spine density at 2. 24 h. and If) days after the exposure compared with conirols. At 15 days, the number of spines increased to values similar to those found in controls. The granule cells ultrastructure demonstrated an increment in lipofucsin granules, as well as swollen orgunelles, changes that decreased overtime. This change decline might be related to a partial recovery of the asst.K.-iative granule cells funciion.

Abstract  Jasmonates, composed of jasmonic acid (JA) and methyl jasmonate (MeJA), are widely distributed signaling compounds in plants. Jasmonate-mediated signaling suppresses ozone-induced ethylene biosynthesis as well as cellular injury since an ozone-sensitive Arabidopsis mutant, ojil, showed increased ozone-induced ethylene production and reduced sensitivity to MeJA (KANNA & al. 2003). Although ojil plants had higher JA contents than the wild-type (Ws-2) plants during exposure to 0.2ppm ozone,. microarray analysis revealed decreased expression of genes for enzymes in JA biosynthesis in this mutant. On the other hand, salicylic acid contents and expression of salicylic-acid inducible and biosynthetic genes in ojil plants were similar to those in the wild-type plants until 12 h after the beginning of ozone exposure. In spite of foliar injury, ascorbate contents increased in Arabidopsis by ozone exposure. While ojil plants revealed lower ascorbate contents than the wild-type plants, exogenous MeJA suppressed the increase in ascorbate contents in the wild-type plants at 6 h after the beginning of ozone exposure. These results imply that jasmonate-mediated signaling is involved in the regulation of the defense system in the surviving cells under stress conditions.

Abstract  The causal relationships among ethylene emission, oxidative burst and tissue damage, and the temporal expression patterns of some ethylene biosynthetic and responsive genes, were examined in the Never ripe (Nr) tomato (Lycopersicon esculentum) mutant and its isogenic wild type (cv. Pearson), to investigate the role played by the ethylene receptor LE-ETR3 (NR) in mediating the plant response to ozone (O-3). Tomato plants were used in a time-course experiment in which they were exposed to acute O-3 fumigation with 200 nl l(-1) O-3 for 4 h. The pattern of leaf lesions indicated similar sensitivities to O-3 for cv. Pearson and Nr. In both genotypes, O-3 activated a hydrogen peroxide (H2O2)-dependent oxidative burst, which was also ethylene-driven in Nr leaves. Ozone induced some ethylene and jasmonate biosynthetic and inducible genes, although with different timings and to different extents in the two genotypes. The overall data indicate that Nr retains partial sensitivity to ethylene, suggesting only a marginal role of the NR receptor in mediating the complex response of tomato plants to O-3.

Abstract  Ozone, a major photochemical oxidant, induces leaf injury. Salicylic acid (SA) is a kind of plant hormone and an important regulator of plant resistance to pathogens. In ozone-exposed plants, SA participates in both the formation of leaf injury and the defense response. In pathogen-infected plants, SA is synthesized via two pathways involving phenylalanine or isochorismate. Biosynthesis of SA in ozone-fumigated plants had not been well defined, so we examined it in tobacco and Arabidopsis. Salicylic acid accumulated in tobacco exposed to 0.2 ppm ozone for 6 h. At the same time, phenylalanine ammonia-lyase (PAL) activity, its mRNA level, and the level of chorismate mutase (CM) transcripts increased remarkably, whereas isochorismate synthase (ICS) activity did not increase. These results may suggest that ozone-exposed tobacco synthesized SA via the phenylalanine pathway. Salicylic acid levels also increased in ozone-exposed Arabidopsis, but not in sid2 (salicylic acid induction-deficient 2) mutants, in which ICSI is defective. Furthermore, ICS activity and the mRNA level of ICSI increased dramatically in wild-type Arabidopsis after the start of ozone exposure. These results suggest that ozone-exposed Arabidopsis synthesizes SA from isochorismate. Therefore, our results imply that the main pathway of ozone-induced SA biosynthesis differs between tobacco and Arabidopsis.

Abstract  In this paper optical indices calculated from leaf reflectance measurements, acquired with a high resolution spectroradiometer, were investigated to monitor 03 stress on Fagus sylvatica L. from the strain phase to the damage phase when visible symptoms occur (e.g. chlorosis, leaf browning). The CI (Chlorophyll Index) was the most sensible index to a wide range of chlorophyll (Chl) concentrations (R-2=0.93), the simple ratio R-695/R-740 (Ctr2) was the most correlated to carotenoids/chlorophyll (Car/Chl) ratio (R-2=0.65), while Yl (Yellowness Index) was sensible to Car/Chl ratio and to low Chl values but tends to saturate at moderate to high Chl concentrations. PRI (Photochemical Reflectance Index) was correlated with the physiological parameters NPQ (Non Photochemical Quenching) and Delta F/F-m' confirming this index is a good indicator of photosynthetic efficiency. Results from this experiment showed that Cl, Ctr2 and PRI were reliable indices of 03 effects on Fagus sylvatica L. before visible symptoms occurred, while Yl was able to detect the senescence anticipation when visible symptoms already spread. These results were confirmed by physiological parameters measured in field (F-v/F-m, NPQ and Delta F/F-m').

Abstract  A new parameterisation of ozone uptake by vegetation, based on the observational determination of functional dependence of stomala ozone conductances on environmental parameters such as temperature, wind speed, top-of-canopy ozone concentrations, water vapour pressure deficit, and soil water content, is proposed. Measurements of ozone fluxes and related parameters have been made using micrometeorological methods over wheat in the Po river plain, Nor-them Italy. The results show the discrepancy between the AOT40 index, based on the ozone concentration cumulated function over the season, and the cumulated stomatal ozone flux. The new parameterisation proposes a corrected AOT index, which takes environmental and plant physiological effects into account. The corrected AOT is in agreement with the cumulated stomatal ozone uptake flux.

Abstract  This study is part of a three-year project on biogenic volatile organic compound (VOC) emissions from trees of the temperate warm Atlantic rainforest found in the metropolitan area of Sao Paulo City ( MASP). No study of VOC emission rates from plant species has been carried out in the temperate warm Atlantic rainforest of Brazil prior to this work. Eleven species were selected (Alchornea sidifolia, Cupania oblongifolia, Cecropia pachystachia, Syagrus romanzoffiana, Casearia sylvestris, Machaerium villosum, Trema micrantha, Croton floribundus, Myrcia rostrata, Solanum erianthum and Ficus insipida) and some of them were studied in urban, sub-urban and forest areas inside the MASP in order to evaluate biogenic VOC composition at sites characterized by different emission sources. Biogenic VOC emissions were determined by placing branches of plants in a dynamic enclosure system, an all-Teflon cuvette, and by sampling the compounds in the air leaving the cuvette. Pre-concentration using adsorbents to retain the VOC, followed by GC-MS after thermal desorption of the sample, was employed to determine the amount of biogenic hydrocarbons. The collection of carbonyl compounds on a 2,4-dinitrophenylhydrazine coated silica followed by HPLC-UV was used to analyze low molecular weight carbonyl compounds. Emission rates of isoprene, α-pinene, camphene and limonene ranged from 0.01 to 2.16 μ g C h(-1) g(-1) and emission rates of aldehydes (C-2-C-6), acrolein, methacrolein and 2-butanone ranged from 1.5 x 10(-2) to 2.3 μ g C h(-1) g(-1). Ambient and leaf temperatures, relative humidity, light intensity, O-3 and NOx levels in the local atmosphere were monitored during experiments. It was possible to identify different biogenic VOCs emitted from typical plants of temperate warm Atlantic rainforest. The emission rates were reported as a function of the type of site investigated and were only provided for compounds for which quanti. cation was feasible. Other biogenic compounds were only identified.

Abstract  Biogenic hydrocarbons emitted by vegetation are important contributors to secondary organic aerosol (SOA), but the aerosol formation mechanisms are incompletely understood. In this study, the formation of aerosols and gas-phase products from the ozonolysis and photooxidation of a series of biogenic hydrocarbons (isoprene, 8 monoterpenes, 4 sesquiterpenes, and 3 oxygenated terpenes) are examined. By comparing aerosol growth (measured by Differential Mobility Analyzers, DMAs) and gas-phase concentrations (monitored by a Proton Transfer Reaction Mass Spectrometer, PTR-MS), we study the general mechanisms of SOA formation. Aerosol growth data are presented in terms of a "growth curve", a plot of aerosol mass formed versus the amount of hydrocarbon reacted. From the shapes of the growth curves, it is found that all the hydrocarbons studied can be classified into two groups based entirely on the number of double bonds of the hydrocarbon, regardless of the reaction systems (ozonolysis or photooxidation) and the types of hydrocarbons studied: compounds with only one double bond and compounds with more than one double bond. For compounds with only one double bond, the first oxidation step is rate-limiting, and aerosols are formed mainly from low volatility first-generation oxidation products; whereas for compounds with more than one double bond, the second oxidation step may also be rate-limiting and second-generation products contribute substantially to SOA growth. This behavior is characterized by a vertical section in the growth curve, in which continued aerosol growth is observed even after all the parent hydrocarbon is consumed.

Abstract  Intra-genus and intra-specific variation and the influence of nitrogen enrichment on net assimilation and stomatal conductance of some annual Trifolium species of Mediterranean dehesa grasslands were assessed under experimental conditions. Also gas exchange rates were compared between some Leguminosae and Poaceae species growing in the field in a dehesa ecosystem in central Spain. The results showed that the previously reported different O-3 sensitivity of some Trifolium species growing in pots does not seem to be related to different maximum g(s) values. In addition, no clear differences on gas exchange rates could be attributed to Leguminosae and Poaceae families growing in the field, with intra-genus variation being more important than differences found between families. Further studies are needed to increase the database for developing a flux-based approach for setting O-3 critical levels for semi-natural Mediterranean species. (c) 2006 Elsevier Ltd. All rights reserved.

Abstract  Ozone-sensitive (NC-S clone) and resistant plants (NC-R clone) of Trifolium repens and Centaurea jacea were exposed to moderate ozone concentrations in ambient air. The aim of this study was the investigation of the relation between ozone-sensitivity and leaf concentrations of antioxidants (ascorbic acid, total phenolics and total antioxidant capacity). NC-R clone showed the highest concentrations of antioxidants with 50-70% more ascorbic acid than NC-S. NC-R had about 5 times more ascorbic acid in the young leaves and 9 times more in the old leaves than Centaurea. In a fumigation experiment with acute ozone stress (100 nl L-1) the antioxidant levels changed profoundly. The ozone-injured leaves of NC-S had 6-8 times more total phenolics than uninjured leaves. Generally older leaves had lower antioxidant concentrations and were more prone to ozone injury than younger leaves. Ascorbic acid concentrations were closer related to the appearance of visible ozone injury than the other antioxidative parameters. (c) 2006 Elsevier Ltd. All rights reserved.

Abstract  Modelling-based studies to assess the extent and magnitude of ozone (O-3) risk to agriculture in Asia suggest that yield losses of 5-20% for important crops may be common in areas experiencing elevated O-3 concentrations. These assessments have relied on European and North American dose-response relationships and hence assumed an equivalent Asian crop response to O-3 for local cultivars, pollutant conditions and climate. To test this assumption we collated comparable dose-response data derived from fumigation, filtration and EDU experiments conducted in Asia on wheat. rice and leguminous crop species. These data are pooled and compared with equivalent North American dose-response relationships. The Asian data show that at ambient O-3 concentrations found at the study sites (which vary between similar to 35-75 ppb 4-8 h growing season mean), yield losses for wheat, rice and legumes range between 5-48, 3-47 and 10-65%, respectively. The results indicate that Asian grown wheat and rice cultivars are more sensitive to O-3 than the North American dose-response relationships would suggest. For legumes the scatter in the data makes it difficult to reach any equivalent conclusion in relative sensitivities. As such, existing modelling-based risk assessments may have substantially underestimated the scale of the problem in Asia through use of North American derived dose-response relationships. (c) 2009 Elsevier Ltd. All rights reserved.

Abstract  Ultraviolet-B (UV-B, 280-320 nm) radiation may have severe negative effects on plants including damage to their genetic information. UV protection and DNA-repair mechanisms have evolved to either avoid or repair such damage. Since autotrophic plants are dependent on sunlight for their energy supply, an increase in the amount of UV-B reaching the earth's surface may affect the integrity of their genetic information if DNA damage is not repaired efficiently and rapidly. Here we show that overexpression of cyclobutane pyrimidine dimer (CPD) photolyase (EC 4.1.99.3) in Arabidopsis thaliana (L.), which catalyses the reversion of the major UV-B photoproduct in DNA (CPDs), strongly enhances the repair of CPDs and results in a moderate increase of biomass production under elevated UV-B.

Abstract  Incomplete stomatal closure during the night is observed in a diverse range of C3 and C4 species (Fig. 1 ; Supplemental Table S1) and can lead to substantial nighttime transpirational water loss. Although water loss is an inevitable consequence of stomatal opening for photosynthetic carbon gain, nighttime stomatal opening is unexpected because carbon gain is not occurring and the need to cool leaves is reduced or absent. Most species have the ability to close stomata more than is commonly observed at night, as demonstrated by reduced nighttime leaf conductance (gnight) in response to water stress, abscisic acid (ABA), and other treatments reviewed in this Update.

Abstract  Tropospheric ozone represents a relevant atmospheric pollutant, because of its strong oxidizing potential. The risk for animal (human) and plant health, at molecular and cellular level, arises from the oxidative damage to lipids, proteins and nucleic acids, depending on the dose. Therefore, ozone concentration and exposure time determine the chronic or acute toxicity and, consequently, the severity of injury at biochemical and physiological level. In living organisms, reactive oxygen species (ROS), directly or indirectly derived from ozone exposure, are scavenged by enzymatic and non-enzymatic antioxidant defensive mechanisms, overall deputed to preserve cell structures and biomacromolecules from the oxidative damage. These defences are essentially those also involved in detoxifying the ROS inevitably produced by the metabolism of organisms living in oxygenic atmosphere.

Abstract  Tropospheric ozone is a growing environmental menace in Italy and in the whole Mediterranean basin. The importance of active biomonitoring of this pollutant with hypersensitive Bel-W3 tobacco plants is stressed, and several examples of field studies carried out in Italy with this technique are presented. Current limitations are discussed, with special emphasis on data quality assessment and the opportunity of adopting easy-to-use kits based on tobacco germlings instead of adult plants. A standardization of methodologies (from cultivation to scoring and data elaboration), also at an international level, is strongly felt to be needed, in order to get official acknowledgement of biomonitoring procedures. Potential educational implications, with the active involvement of students and environmentalists, are shown. Other biological indicators are used. namely sensitive and resistant white clover (Trifolium repens) clones (as descriptors of biomass reduction in crops species) and Centaurea jacea (brown knapweed) as a model species to evaluate the relationship between ozone exposure and effects on the performance and injury symptoms of native plants which are largely used in the framework of European programmes.

Abstract  This article reviews major impacts of climate change on agriculture and forestry.

Abstract  Experiments were conducted with two commonly grown mungbean varieties viz., M-28 and 6601, in open top chambers and ambient field conditions with the aim of ascertaining the effects of air pollution on yield. The 8-h daily mean ozone concentrations were 41-73 nl litre(-1). A considerable reduction of 47.06% and 51.12% in seed yield for M-28 and 6601, respectively were found which are substantially more than might be predicted elsewhere. These reductions in economic yield were due to decrease in both numbers of seed per pod and individual seed weight.