Abstract  This paper describes a novel school-based, visual environmental public health educational intervention intended to help reduce the exposure of children-and adults-to outdoor air pollution, including known environmental asthma triggers like ozone and particles. The overarching goal was to enhance the learning, recreational, and work environments of students and staff, The specific purpose of the Asthma-Friendly Outdoor (Ambient) Air Quality Flag Program was to establish an education and communication tool for Central California communities that would accomplish two things: 1) Establish permanent local policy change to existing operating procedures in school districts and schools to help reduce the exposure of students, teachers, staff, and nearby communities to outdoor environmental asthma triggers and 2) provide education on air quality and potential health effects of exposure to air pollutants. Data on the program from its initial years are presented, To date, the following important lessons have been learned: 1) Science-based, simple, visual, low-cost school-based educational interventions to help reduce human exposure to outdoor environmental asthma triggers (i.e., ozone, particles, and pollens) can work in socioeconomically and ethnic. ally diverse urban and rural or agricultural communities, and 2) local health and environmental justice groups such as asthma coalitions can successfully lead school-based environmental interventions to help improve children's quality of life.

Abstract  Natural emissions adopted in current regional air quality modeling are updated to better describe natural background ozone and PM concentrations for North America. The revised natural emissions include organosulfur from the ocean, NO from lightning, sea salt, biogenic secondary organic aerosol (SOA) precursors, and pre-industrial levels of background methane. The model algorithm for SOA formation was also revised. Natural background ozone concentrations increase by up to 4 ppb in annual average over the southeastern US and Gulf of Mexico due to added NO from lightning while the revised biogenic emissions produced less ozone in the central and western US. Natural PM2.5 concentrations generally increased with the revised natural emissions. Future year (2018) simulations were conducted for several anthropogenic emission reduction scenarios to assess the impact of the revised natural emissions on anthropogenic emission control strategies. Overall, the revised natural emissions did not significantly alter the ozone responses to the emissions reductions in 2018. With revised natural emissions, ozone concentrations were slightly less sensitive to reducing NOx in the southeastern US than with the current natural emissions due to higher NO from lightning. The revised natural emissions have little impact on modeled PM2.5 responses to anthropogenic emission reductions. However, there are substantial uncertainties in current representations of natural sources in air quality models and we recommend that further study is needed to refine these representations. (C) 2010 Elsevier Ltd. All rights reserved.

Abstract  We studied the relationships between environmental variables and the physiology of two (semi-)aquatic mosses (Bryum pseudotriquetrum and Fontinalis antipyretica) in an unforested headwater stream over a three year period. Neither environmental or physiological variables showed significant interannual variations. Most environmental variables (water temperature, stratospheric ozone, and photosynthetic, UV-A and UV-B radiation) showed distinct seasonal variations, but only a few physiological ones did. In both species, photoprotection variables (the activity of the xanthophyll cycle and the bulk UV absorbance of the methanol-extractable UV-absorbing compounds, MEUVAC) varied more seasonally than variables related to physiological activity, such as the sclerophylly index and chlorophyll fluorescence parameters (F-v/F-m and Phi(PSII)). Changes in physiological activity would be attenuated by the buffering capacity of water with respect to the influence of environmental factors, and dynamic variables like F-v/F-m and Phi(PSII) would be little determined by cyclic environmental factors. In B. pseudotriquetrum, both MEUVAC and kaempferol 3,7-O-diglycoside (a potentially UV-protective flavonoid) were positively associated with radiation levels, whereas in F. antipyretica photoprotection mechanisms were not correlated with any environmental variable. In addition, MEUVAC was 3-4 fold higher in B. pseudotriquetrum than in F. antipyretica. Thus, different photoprotection mechanisms, with a different environmental regulation, can be suggested for these two species. DNA damage was not found in any sample, probably because both species displayed efficient DNA repair mechanisms.

Abstract  Levels of atmospheric CO2 have been Increasing steadily over the last century and are projected to increase even mote dramatically in the future. Soybeans (Glycine max L) grown under elevated levels of CO2, have larger herbivore populations than soybeans grown under ambient levels of CO2. Increased abundance could leflect the fact that these herbivores are drawn in by increased amounts of volatiles or changes in the composition of volatiles released by plants grown under elevated CO, conditions To determine impacts of elevated CO, on olfactory preferences, Japanese beetles (Popillia japonica Newman) and soybean aphids (Aphis glycines Matsumura) were placed in Y-tube olfactometers with a choice between ambient levels of CO, gas versus elevated levels of CO, gas or damaged and undamaged leaves and plants grown under ambient levels of CO, versus damaged and undamaged plants grown under elevated levels of CO All plants had been grown from seeds under ambient or elevated levels of CO.,. Painted lady butterflies (Vanessa cardui L.) were placed in an oviposition chamber with a choice between plants grown under ambient and elevated levels of CO,. A glycincs and V cardui showed no significant preference for plants in either treatment. P japonica showed no significant preference between ambient levels and elevated levels of CO, gas. There was a significant P japonica preference for damaged plants growunder ambient CO, versus undamaged plants but no preference for damaged plants grown under elevated CO, versus undamaged plants P japonica also preferred damaged plants grown under elevated levels of CO versus damaged plants grown under ambient levels of CO, This lack of preference for damaged plants grown under elevated CO2 versus undamaged plants could be the result of the identical elevated levels of a green leaf volatile (2-hexenal) present in all foliage grown under elevated CO, regardless of damage status. Green leaf volatiles are typically released from damaged leaves and are used as kairomones by many herbivorous insects for host plant location. An increase in production of volatiles in soybeans grown under elevated CO2 conditions may lead to larger herbivore outbreaks in the future.

Abstract  Within the framework of the Natural Environment Research Council (NERC) Oxidant and Particle Photochemical Processes (OP3) project, a pulsed Doppler lidar was deployed for a 3 month period in the tropical rain forest of Borneo to remotely monitor vertical and horizontal transport, aerosol distributions and clouds in the lower levels of the atmosphere. The Doppler velocity measurements reported here directly observe the mixing process and it is suggested that this is the most appropriate methodology to use in analysing the dispersion of canopy sourced species into the lower atmosphere. These data are presented with a view to elucidating the scales and structures of the transport processes, which effect the chemical and particulate concentrations in and above the forest canopy, for applications in the parameterisation of climate models.

Abstract  A risk assessment of ozone (O-3) impact on the annual carbon absorption (ACA) of Japanese representative conifers was conducted based on the results of an experimental study, monitoring data of oxidant concentrations and vegetation surveys. The areas with high O-3-induced reduction in ACA did not necessarily correspond to the areas with relatively high O-3-exposure. Widespread distribution of O-3-sensitive tree species such as Pinus densiflora and Larix kaempferi, and high ACA were important factors that induced a high risk of O-3 impact on the ACA. Therefore, we concluded that not only the accumulated O-3-exposure but also the variety of tree habitat, the tree sensitivity to O-3 and the ACA among the tree species must be taken into account to assess the risk of O-3 impact on the ACA of Japanese conifers. The O-3-induced reduction in the total ACA of the three tree species in Japan was estimated to be 0.8%.

Abstract  In order to reveal effect mechanism of crop reactive oxygen species metabolic system under exogenous chitosan to ozone stress, open top chambers were utilized to investigate the change of reactive oxygen species production rate, lipid peroxidation extent, anti-oxidative enzymes activities and antioxidant content in soybean (Glycine max) leaves. Exogenous chitosan treatment relieves the aggravation of reactive oxygen species damage through ozone stress, which represents protective efficacy to soybean, the superoxide anion production rate, hydrogen peroxide content, malondialdehyde content and membrane permeability decreased, while anti-oxidative enzymes activity and anti-oxidative substances increased. But the alleviation of exogenous chitosan to ozone is limited.

Abstract  Potato plants were grown in open-top chambers under three ozone concentrations during two complete cropping seasons (93 and 77 d in 2004 and 2005, respectively). The effects of chronic exposure to ozone on leaf anatomy, cell ultrastructure and crop yield were studied. Severe cell damage was found, even at ambient ozone levels, mainly affecting the spongy parenchyma and areas near the stomata. Damage to the cell wall caused loss of cell contact, and loss of turgor pressure due to tonoplast disintegration, contributed to cell collapse. Phloem sieve plates were obstructed by callose accumulation, and damaged mesophyll cells increased their starch stores. Tuber yield fell sharply (24-44%), due to the biggest tubers becoming smaller, which affected commercial yield. These anatomical findings show the mechanisms of ozone effect on assimilate partitioning, and thus crop yield decrease, in potato. Further implications of ozone causing reductions in below-ground biomass are also discussed.

Abstract  Recent evidence from novel phytotron and free-air ozone (O-3) fumigation experiments in Europe and America on forest tree species is highlighted in relation to previous chamber studies. Differences in O-3 sensitivity between pioneer and climax species are examined and viewed for trees growing at the harsh alpine timberline ecotone. As O-3 apparently counteracts positive effects of elevated CO2 and mitigates productivity increases, response is governed by genotype, competitors, and ontogeny rather than species per se. Complexity in O-3 responsiveness increased under the influence of pathogens and herbivores. The new evidence does not conflict in principle with previous findings that, however, pointed to a low ecological significance. This new knowledge on trees' O-3 responsiveness beyond the juvenile stage in plantations and forests nevertheless implies limited predictability due to complexity in biotic and abiotic interactions. Unravelling underlying mechanisms is mandatory for assessing O-3 risks as an important component of climate change scenarios. (C) 2009 Elsevier Ltd. All rights reserved.

Abstract  Stomatal O-3 fluxes to a mixed beech/spruce stand (Fagus sylvatica/Picea abies) in Central Europe were determined using two different approaches. The sap flow technique yielded the tree-level transpiration, whereas the eddy covariance method provided the stand-level evapotranspiration. Both data were then converted into stomatal ozone fluxes, exemplifying this novel concept for July 2007. Sap flow-based stomatal O-3 flux was 33% of the total O-3 flux, whereas derivation from evapotranspiration rates in combination with the Penman-Monteith algorithm amounted to 47%. In addition to this proportional difference, the sap flow-based assessment yielded lower levels of stomatal O-3 flux and reflected stomatal regulation rather than O-3 exposure, paralleling the daily courses of canopy conductance for water vapor and eddy covariance-based total stand-level O-3 flux. The demonstrated combination of sap flow and eddy covariance approaches supports the development of O-3 risk assessment in forests from O-3 exposure towards flux-based concepts. (C) 2009 Elsevier Ltd. All rights reserved.

Abstract  An open-top chamber experiment was carried out in Curno (Northern Italy) in 2004 and 2005 on seedlings of Fagus sylvatica (FS), Quercus robur (QR), and an ozone-sensitive Populus (POP) clone, to investigate the role of two stress factors: tropospheric ozone and water shortage. Treatments were filtered air to achieve a 50% reduction in the environmental ozone concentrations (charcoal filtered, CF); and non-filtered air, with a 5% reduction in the environmental ozone concentrations (non-filtered, NF). Overall ozone exposure (AOT40) in open air (April-September) was 26,995 ppb h in 2004 and 25,166 ppb h in 2005. The plants were either watered (W) or not watered (dry, D). We investigated the above-ground biomass, tree-ring growth, stable carbon isotopes ratio, i.e. delta C-13 of tree rings, and the photosynthetic parameter Driving forces (DFABS), derived from chlorophyll a fluorescence analysis. Ozone-induced growth reduction (in terms of biomass) in POP, and that reduction was more pronounced in D plots. A synergistic effect of ozone and drought stress was evidenced by DFABS in POP and QR, but not in FS. The water availability was revealed as the main factor influencing the isotopic ratio delta C-13. In drought-stressed seedlings, the increase in delta C-13 value was accompanied by the reduction in stomatal conductance and increased DFABS. Fast-growing plant species with high water requirements are more susceptible to ozone and drought stress.

Abstract  The role of an interleukin (IL)-1 receptor antagonist (IL-1Ra) on the development of airway hyperresponsiveness (AHR) and airway inflammation following acute O(3) exposure in mice was investigated. Exposure of C57/BL6 mice to O(3) at a concentration of 2.0 ppm or filtered air for 3 h resulted in increases in airway responsiveness to inhaled methacholine (MCh) 8 and 16 h after the exposure, and an increase in neutrophils in the bronchoalveolar lavage (BAL) fluid. IL-1beta expression, assessed by gene microarray, was increased 2-fold 4 h after O(3) exposure, and returned to baseline levels by 24 h. Levels of IL-1beta in lung homogenates were also increased 8 h after O(3) exposure. Administration of (human) IL-1Ra before and after O(3) exposure prevented development of AHR and decreased BAL fluid neutrophilia. Increases in chemokine levels in lung homogenates, tumor necrosis factor-alpha, MIP-2, and keratinocyte chemoattractant following O(3) exposure were prevented by IL-1Ra. Inhalation of dexamethasone, an inhibitor of IL-1 production, blocked the development of AHR, BAL fluid neutrophilia, and decreased levels of IL-1 following O(3) exposure. In summary, acute exposure to O(3) induces AHR, neutrophilic inflammation, epithelial damage, and IL-1. An IL-1Ra effectively prevents the development of altered airway function, inflammation, and structural damage.

Abstract  Floral scent is used by pollinators during foraging to identify and discriminate among flowers. The ability to discriminate among scents may depend on both scent intensity and the ratios of the concentrations of the volatile compounds of a complex mixture rather than on the presence of a few compounds. We used four scent-emitting cultivars of snapdragon (Antirrhinum majus) to test this hypothesis by examining the ability of honeybees to differentiate among their scents. Each cultivar produced three monoterpenes (myrcene, E-β-ocimene, and linalool) and five phenylpropanoids (methylbenzoate, acetophenone, dimethoxytoluene, cis-methylcinnamate, and trans-methylcinnamate). Cultivars were reliably classified by their scents in a canonical discriminant analysis. Honeybees were unable to discriminate among the scents of flowers of the same cultivar in our assay. The ability of honeybees to discriminate among the scents of different cultivars was a function of the intensity of the floral scent. Discrimination was also correlated to the distance among the scents described by the discriminant analysis; the cultivars that had the greatest differences observed in the discriminant analysis were the easiest to discriminate. Our results show that honeybees are capable of using all of the floral volatiles to discriminate subtle differences in scent.

Abstract  Many chronic diseases are the result of a complex sequence of biochemical reactions involving exposures to various environmental agents, metabolized by a number of different genes. Routine epidemiologic analyses of such associations have tended to rely on standard contingency table or logistic regression methods, typically focusing on one variable at a time or pairwise combinations. We consider two statistical alternatives to this approach, one based on Bayesian model averaging, one based on pharmacokinetic modeling of the biochemical pathways. These approaches are illustrated using data from a case-control study of colorectal polyps in relation to tobacco smoking and consumption of well done red meat, both viewed as sources of heterocyclic amines and polycyclic aromatic hydrocarbons. The new analyses are structured in a manner that attempts to take advantage of prior knowledge of the metabolism of these classes of compounds and the various genes that regulate these pathways.

Abstract  In this article we discuss statistical techniques for modeling data from cohort studies that examine long-term effects of air pollution on children’s health by comparing data from multiple communities with a diverse pollution profile. Under a general multilevel modeling paradigm, we discuss models for different outcome types along with their connections to the generalized mixed effects models methodology. The model specifications include linear and flexible models for continuous lung function data, logistic and/or time-to-event models for symptoms data that account for misspecifications via hidden Markov models and Poisson models for school absence counts. The main aim of the modeling scheme is to be able to estimate effects at various levels (e.g., within subjects across time, within communities across subjects and between communities). We also discuss in detail various recurring issues such as ecologic bias, exposure measurement error, multicollinearity in multipollutant models, interrelationships between major endpoints and choice of appropriate exposure metrics. The key conceptual issues and recent methodologic advances are reviewed, with illustrative results from the Southern California Children’s Health Study, a 10-year study of the effects of air pollution on children’s respiratory health.

Abstract  Oxidant air pollution symptoms were first reported in bioindicator plants in the Mexico City Air Basin (MCAB) in 1971 (de Bauer 1972). Classic injury symptoms on well-known bioindicator plants strongly supported the presumption that symptoms were caused by photochemical oxidants, of which ozone (O3) is the primary pollutant. Symptoms in indicator plants characteristic of injury caused by peroxyacetyl nitrate (PAN), ethylene, and sulfur dioxide (SO2) were also reported (de Bauer 1972; de Bauer and Hernández-Tejeda 1986). These discoveries were followed in 1976 by the observation of O3 injury symptoms in native pine species in forests in Ajusco (AJ), just south of Mexico City (de Bauer and Hernández-Tejeda 1986; Krupa and de Bauer 1976). Then in the 1980s, a dramatic and severe decline occurred in sacred fir (Abies religiosa) stands in the highly polluted area of the Desierto de los Leones (DL) National Park southwest of Mexico City (Alvarado-Rosales and Hernández-Tejeda 2002). Thousands of trees died, leaving dead zones called cemeteries. Air pollution was widely believed to be an important causal factor in the widespread mortality of sacred fir within the park (Ciesla and Macias-Samano 1987). Topographic conditions, including volcanic mountain ranges circumscribing much of the Basin, thermal atmospheric inversions, and prevailing winds which carry pollutants from the urban zone to forested areas to the south-southwest (SSW), create conditions favoring high pollution exposure for these forests (Bravo and Torres 2002; Jáuregui 2002).

Abstract  The aim was to study the influence of abiotic (elevated ozone) or biotic stress (Phytophthora citricola) or their combination on soil biological components and processes in the rhizosphere of young beech trees. Ectomycorrhizal and overall microbial community composition was studied at two soil depths in a lysimeter experiment with 7 year old trees of Fagus sylvatica. As a functional parameter, potential enzyme activities were measured in mycorrhizosphere soil and on excised mycorrhizal tips. The degree of mycorrhization, structure and potential enzymatic activities of mycorrhizal communities were only slightly influenced by treatments. Soil enzyme activities were depressed under elevated ozone and stimulated by P. citricola under ambient but not under elevated ozone. Overall microbial community composition (PLFA) and ectomycorrhizal diversity changed with depth. PLFA analyses not only suggested a reaction of the microbial community to elevated ozone but also indicated an increase in plant stress related components. No influence of the biotic stress on ectomycorrhizal or overall microbial community structure was detected. Changes in the mycorrhizosphere community structure and function due to ozone may be explained by the quality of plant derived carbon.

Abstract  In the study of complex diseases, it may be important to test hypotheses related to gene-gene (G x G) interaction. The success of such studies depends critically on obtaining adequate sample sizes. In this paper, the author investigates sample size requirements for studies of G x G interaction, focusing on four study designs: the matched-case-control design, the case-sibling design, the case-parent design, and the case-only design. All four designs provide an estimate of interaction on a multiplicative scale, which is used as a unifying theme in the comparison of sample size requirements. Across a variety of genetic models, the case-only and case-parent designs require fewer sampling units (cases and case-parent trios, respectively) than the case-control (pairs) or case-sibling (pairs) design. For example, the author describes an asthma study of two common recessive genes for which 270 matched case-control pairs would be required to detect a G x G interaction of moderate magnitude with 80% power. By comparison, the same study would require 319 case-sibling pairs but only 146 trios in the case-parent design or 116 cases in the case-only design. A software program that computes sample size for studies of G x G interaction and for studies of gene-environment (G x E) interaction is freely available (http://hydra.usc.edu/gxe).

Abstract  Reactive gases and aerosols are produced by terrestrial ecosystems, processed within plant canopies, and can then be emitted into the above-canopy atmosphere. Estimates of the above-canopy fluxes are needed for quantitative earth system studies and assessments of past, present and future air quality and climate. The Model of Emissions of Gases and Aerosols from Nature (MEGAN) is described and used to quantify net terrestrial biosphere emission of isoprene into the atmosphere. MEGAN is designed for both global and regional emission modeling and has global coverage with ~1 km2 spatial resolution. Field and laboratory investigations of the processes controlling isoprene emission are described and data available for model development and evaluation are summarized. The factors controlling isoprene emissions include biological, physical and chemical driving variables. MEGAN driving variables are derived from models and satellite and ground observations. Tropical broadleaf trees contribute almost half of the estimated global annual isoprene emission due to their relatively high emission factors and because they are often exposed to conditions that are conducive for isoprene emission. The remaining flux is primarily from shrubs which have a widespread distribution. The annual global isoprene emission estimated with MEGAN ranges from about 500 to 750 Tg isoprene (440 to 660 Tg carbon) depending on the driving variables which include temperature, solar radiation, Leaf Area Index, and plant functional type. The global annual isoprene emission estimated using the standard driving variables is ~600 Tg isoprene. Differences in driving variables result in emission estimates that differ by more than a factor of three for specific times and locations. It is difficult to evaluate isoprene emission estimates using the concentration distributions simulated using chemistry and transport models, due to the substantial uncertainties in other model components, but at least some global models produce reasonable results when using isoprene emission distributions similar to MEGAN estimates. In addition, comparison with isoprene emissions estimated from satellite formaldehyde observations indicates reasonable agreement. The sensitivity of isoprene emissions to earth system changes (e.g., climate and land-use) demonstrates the potential for large future changes in emissions. Using temperature distributions simulated by global climate models for year 2100, MEGAN estimates that isoprene emissions increase by more than a factor of two. This is considerably greater than previous estimates and additional observations are needed to evaluate and improve the methods used to predict future isoprene emissions.

Abstract  A new ligand, pyridine-3,5-bis(benzimidazole-2-yl) (pbb), and four complexes containing pbb, namely [pbb(Hpbb)(2)]SO(4)center dot 7H(2)o (1), [Zn(pbb)(2)(H(2)O)(4)](NO(3))(2) center dot 2C(2)H(5)OH center dot 4H(2)O (2), [Cd(pbb)(2)(H(2)O)(4)](NO(3))(2)center dot 2C(2)H(5)OH center dot 4H(2)O (3) and [Zn(2)(pbb)(2)([L-OH)(mu-CAc)](OAc)(2)center dot 7H(2)O (4) (HOAc = acetic acid), have been designed, synthesized and characterized. Complexes 1-4 show 3D supramolecular architectures that are connected through hydrogen bonds and aromatic pi-pi interactions. A self-assembled (H(2)O)(12) cluster with a chair conformation (H(2)O)(6) ring core is observed in 1, which exhibits an unusual association mode of water molecules. Compounds 2 and 3 present 3D supramolecular structures involving I D open channels encapsulating NO(3)(-) ions, and crown-like rings are found in 4. In addition, the preliminary antibacterial activity of pbb and its complexes were investigated by two methods, which indicate a selective inhibition property for the tested strains. Strong emissions from the complexes were also changed by the coordination modes in the sold state. (C) 2008 Elsevier Ltd. All rights reserved.

Abstract  In this study, an assessment of indoor air quality (IAQ) and thermal comfort in the Athens Traffic Control Tower (ATCT) offices of Hellinicon building complex, which is mechanically ventilated, is presented. Measurements of PM10, PM2.5, TVOCs and CO2 concentrations were performed during three experimental cycles, while the Thom Discomfort Index was calculated to describe the employees' feeling of discomfort. The aim of the first cycle was to identify the IAQ status, the second to investigate the effectiveness of certain measures taken, and the third to continuously monitor and control IAQ. During the first two cycles, daily spot measurements of TVOCs and CO2 were performed at various indoor locations and at the respective outdoor air intake positions, in addition with mean 24-h spot measurements of indoor PM10 and PM2.5. Results revealed that pollution levels vary according to the occupancy and the kind of activity. Following that, an automated system (IMAS) was designed and employed to continuously monitor indoor and outdoor CO2, TVOCs, temperature and relative humidity. The ultimate scope was to control the IAQ and offer acceptable comfort conditions to the employees, whose work is of special nature and extremely demanding. Intervention scenarios were formulated and applied to the system to improve indoor conditions, when and where necessary. Regarding the third cycle, 1-year measurements collected from the system to examine its effectiveness. While it was shown that discomfort may be attributed to co-existence of unsatisfactory thermal comfort conditions and IAQ, usually the sole predominant factor of discomfort feeling is thermal comfort.

Abstract  oxygenated additives in gasoline are designed to decrease the ozone-forming hydrocarbons and total air toxics. yet they can increase the emissions of aldehydes and thus increase human exposure to these toxic compounds. This paper describes a study conducted to characterize targeted aldehydes in microenvironments in Sacramento, CA, and Milwaukee, WI, and to improve our understanding of the impact of the urban environment on human exposure to air toxics. Data were obtained from microenvironmental concentration measurements, integrated, 24-h personal measurements, indoor and outdoor pollutant monitors at the participants' residences, from ambient pollutant monitors at fixed-site locations in each city, and from real-time diaries and questionnaires completed by the technicians and participants. As part of this study, a model to predict personal exposures based on individual time/activity data was developed for comparison to measured concentrations. Predicted concentrations were generally within 25% of the measured concentrations. The microenvironments that people encounter daily provide for widely varying exposures to aldehydes. The activities that occur in those microenvironments can modulate the aldehyde concentrations dramatically, especially for environments such as "indoor at home." By considering personal activity, location (microenvironment), duration in the microenvironment. and a knowledge of the general concentrations of aldehydes in the various microenvironments, a simple model can do a reasonably good job of predicting the time-averaged personal exposures to aldehydes, even in the absence of monitoring data. Although concentrations of aldehydes measured indoors at the participants' homes tracked well with personal exposure, there were instances where personal exposures and indoor concentrations differed significantly. Key to the ability to predict exposure based on time/activity data is the quality and completeness of the microenvironmental characterizations for the chemicals of interest. Consistent with many earlier studies, personal exposures are difficult to predict using data from regional outdoor monitors. (C) 2009 Elsevier Ltd. All rights reserved.

Abstract  Up to 60 million people working indoors experience symptoms such as eye, nose and throat irritation, headache, and fatigue. Investigations into these complaints have ascribed the effects to volatile organic compounds (VOCs) emitted from building materials, cleaning formulations, or other consumer products. New compounds can result when the VOCs react with hydroxyl or nitrate radicals or ozone present in indoor environments. Several oxygenated organic compounds, such as glyoxal, methylglyoxal, glycolaldehyde, and diacetyl, have been identified as possible reaction products of indoor environment chemistry. Although research has previously identified diacetyl and glyoxal as sensitizers, additional experiments were conducted in these studies to further classify their sensitization potential. Sensitization potential of these four compounds was assessed using quantitative structure-activity relationship (QSAR) programs. Derek for Windows and National Institute for Occupational Safety and Health logistic regression predicted all compounds to be sensitizers, while TOPKAT 6.2 predicted all compounds except for methylglyoxal. All compounds were tested in a combined irritancy and local lymph node assay (LLNA). All compounds except for glyoxal were found to be irritants and all tested positive in the LLNA with EC3 values ranging from 0.42 to 1.9%. Methylglyoxal significantly increased both the B220(+) and IgE(+)B220(+) cell populations in the draining lymph nodes and total serum IgE levels. The four compounds generated by indoor air chemistry were predicted by QSAR and animal modeling to be sensitizers, with the potential for methylglyoxal to induce IgE. The identification of these compounds as sensitizers may help to explain some of the health effects associated with indoor air complaints.

Abstract  The EMECAM Project demonstrated the short-term effect of air pollution on the death rate in 14 cities in Spain throughout the 1990-1995 period. The Spanish Multicentre Study on Health Effects of Air Pollution (EMECAS) is broadening these objectives by incorporating more recent data, information on hospital disease admissions and totaling 16 Spanish cities. This is an ecological time series study in which the response variables are the daily deaths and the emergency hospitalizations due to circulatory system diseases and respiratory diseases among the residents in each city. Pollutants analyses: suspended particles, SO2, NO2, CO and O3. Control variables: meteorological, calendar, seasonality and influenza trend and incidence. Statistical analysis: estimate of the association in each city by means of the construction of generalized additive Poisson regression models and metanalysis for obtaining combined estimators. The EMECAS Project began with the creation of three working groups (Exposure, Epidemiology and Analysis Methodology) which defined the protocol. The average levels of pollutants were below those established under the current regulations for sulfur dioxide, carbon monoxide and ozone. The NO2 and PM10 values were around those established under the regulations (40 mg/m3). This is the first study of the relationship between air pollution and disease rate among one group of Spanish cities. The pollution levels studied are moderate for some pollutants, although for others, especially NO2 and particles, these levels could entail a problem with regard to complying with the regulations in force.