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Till date, conventional indoor air quality (IAQ) ventilation systems have controlled the IAQ using fixed ventilation rate strategy without consideration of ventilation energy consumption and outdoor air quality. In this paper, a multiobjective optimization (MOO) method was used to find optimal set-points of IAQ ventilation system which balance the IAQ improvement and ventilation energy saving, where logistic regression was suggested to classify the current IAQ data with the healthy risk level. The results show that the proposed ventilation system with varying set- points can save the ventilation energy and also improve the IAQ level better than the existing ventilation system.

A year-round air monitoring program for sulfur dioxide, sulfates, nitrogen dioxide, nitrates, ozone, and total suspended particulates was conducted in three towns with population densities ranging from 29/km2 to 1178/km2. The results showed significant differences in concentrations of several pollutants between the urban town and the two rural towns. However, site-to-site variation over distances of 1 mile or less within the urban area was considerable. To express pollutant loads in each town in a single number, we calculated a combined pollutant index on premises similar to those used for combined occupational exposures, but with U.S. primary air quality standards rather than threshold limit values as indices of minimal health effects. The combined index exceeded unity in all three towns, suggesting either that total pollutant loads may be excessive even in the sparsely populated town of Lebanon, Connecticut, or, more likely, that the U.S. primary air quality standards have been set at low levels without due regard for additive effects.

The emphasizing of feasible methods easy to implement in monitoring air quality at laboratory scale was the objective of our research. The research was performed during October 2007 and February 2008 within the Laboratory of Air Quality from the University of Agricultural Sciences and Veterinary Medicine Cluj – Napoca. The average values recorded in analyzed parameters of the laboratory indoor air gualities were within the admitted values. A positive, relatively strong correlation (r = 0.78487) was recorded between NO and NOx evolution of the laboratory indoor concentrations. The laboratory indoor air conditions being maintained within the same parameters during the entire experimental interval, the big increase of the majority of analyzed indices in the end of 2007 may be explained only due to some alterations of the outdoor air quality. The air monitoring system made up of HORIBA air pollution devices (APMA-370, APNA-370, APOA-370 and APSA-370) is feasible, environmentally friendly and easy to use for indoor air monitoring.

Proximity to road traffic involves higher health risks because of atmospheric pollutants. In addition to outdoor air, indoor air quality contributes to overall exposure. In the framework of the BREATHE study, indoor and outdoor air pollution was assessed in 39 schools in Barcelona. The study quantifies indoor and outdoor air quality during school hours of the BREATHE schools. High levels of fine particles (PM2.5), nitrogen dioxide (NO2), equivalent black carbon (EBC), ultrafine particle (UFP) number concentration and road traffic related trace metals were detected in school playgrounds and indoor environments. PM2.5 almost doubled (factor of 1.7) the usual urban background (UB) levels reported for Barcelona owing to high school-sourced PM2.5 contributions: [1] an indoor-generated source characterised mainly by organic carbon (OC) from organic textile fibres, cooking and other organic emissions, and by calcium and strontium (chalk dust) and; [2] mineral elements from sand-filled playgrounds, detected both indoors and outdoors. The levels of mineral elements are unusually high in PM2.5 because of the breakdown of mineral particles during playground activities. Moreover, anthropogenic PM components (such as OC and arsenic) are dry/wet deposited in this mineral matter. Therefore, PM2.5 cannot be considered a good tracer of traffic emissions in schools despite being influenced by them. On the other hand, outdoor NO2, EBC, UFP, and antimony appear to be good indicators of traffic emissions. The concentrations of NO2 are 1.2 times higher at schools than UB, suggesting the proximity of some schools to road traffic. Indoor levels of these traffic-sourced pollutants are very similar to those detected outdoors, indicating easy penetration of atmospheric pollutants. Spatial variation shows higher levels of EBC, NO2, UFP and, partially, PM2.5 in schools in the centre than in the outskirts of Barcelona, highlighting the influence of traffic emissions. Mean child exposure to pollutants in schools in Barcelona attains intermediate levels between UB and traffic stations. The research leading to these results has received funding from the European Community's Seventh Framework Program (ERC-Advanced Grant) under grant agreement number 268479 — the BREATHE project. Thanks are due to the following schools: Antoni Brusi, Baloo, Betània-Patmos, Centre d'estudis Montseny, Col·legi Shalom, Costa i Llobera, El Sagrer, Els Llorers, Escola Pia de Sarrià, Escola Pia Balmes, Escola concertada Ramon Llull, Escola Nostra Sra. de Lourdes, Escola Tècnica Professional del Clot, Ferran i Clua, Francesc Macià, Frederic Mistral, Infant Jesús, Joan Maragall, Jovellanos, La Llacuna del Poblenou, Lloret, Menéndez Pidal, Nuestra Señora del Rosario, Miralletes, Ramon Llull, Rius i Taulet, Pau Vila, Pere Vila, Pi d'en Xandri, Projecte, Prosperitat, Sant Ramon Nonat-Sagrat Cor, Santa Anna, Sant Gregori, Sagrat Cor Diputació, Tres Pins, Tomàs Moro, Torrent d'en Melis and Virolai. The authors are thankful to the colleagues participating in the fieldwork and carrying the analitycal analysis, especially to Jesús Parga, Rafael Bartrolí, Mercè Cabanas, Iria Castro, Maria Foraster, Jordi Gil, Silvia Martínez, Carmen Muñoz, Rebeca Vázquez and Pau Ymbern. Additional instrumentation was kindly provided by national projects IMPACT (CGL2011-26574), VAMOS (CLG2010-19464-CLI) and CECAT (CTM2011-14730-E). Support from the Generalitat de Catalunya 2009 SGR8 is gratefully acknowledged.

The significance of air pollution and the problems associated with it are fueling deployments of air quality monitoring stations worldwide. The most common approach for air quality monitoring is to rely on environmental monitoring stations, which unfortunately are very expensive both to acquire and to maintain. Hence, environmental monitoring stations are typically sparsely deployed, resulting in limited spatial resolution for measurements. Recently, low-cost air quality sensors have emerged as an alternative that can improve the granularity of monitoring. The use of low-cost air quality sensors, however, presents several challenges: They suffer from cross-sensitivities between different ambient pollutants; they can be affected by external factors, such as traffic, weather changes, and human behavior; and their accuracy degrades over time. Periodic re-calibration can improve the accuracy of low-cost sensors, particularly with machine-learning-based calibration, which has shown great promise due to its capability to calibrate sensors in-field. In this article, we survey the rapidly growing research landscape of low-cost sensor technologies for air quality monitoring and their calibration using machine learning techniques. We also identify open research challenges and present directions for future research.

Energy audits and a parallel investigation of indoor air quality in 30 air-conditioned and naturally ventilated office buildings in Athens, as well as a hospital building, have been underway since 1990. These audits have been conducted for the first time in Hellas and include information on the buildings' energy consumption, indoor and outdoor air quality, employee health symptoms and comfort conditions. The results indicate that there are serious IAQ problems in office buildings, which have been found to be the direct cause for a number of employee health problems related to the working environment. Preliminary measurements of NO 2 and SO 2 in the indoor environment of a hospital show that the concentrations do not exceed the WHO limit values.

Indoor air quality was investigated at eight shopping malls in Wuhan. Results demonstrate that there are different concentrations of CO2 and HCHO at different floors of a shopping mall. Even at different merchandise zones of a floor for the same mall, there are apparent variations in the concentrations of CO2 and HCHO. These findings should be considered in designing air-conditioning systems. The indoor/outdoor ratios of TSP, PM10, PM2.5, and PM1 are below unity for the three shopping malls when the air-conditioning systems are operating and they are near unity when the air-conditioning systems are not operating.

The sources and major environmental pathways of important primary and secondary air pollutants are reviewed, and typical concentrations in background, polluted outdoor, and indoor air defined. Indoor/outdoor concentration relationships indicate that pollutant levels indoors are normally lower than those outdoors due to enhanced deposition processes in the indoor environment. The converse is found where a major source of pollutants is present indoors, and in some instances extremely elevated pollutant levels have been observed.

In several European rural communities, woody biomass is considered amongst the most important energy sources for heating and cooking. However, the use of old-fashioned fireplaces may affect indoor and outdoor air quality. To depict this situation and to plan the necessary improvement interventions, a pilot action was implemented in a typical mountainous Mediterranean area (town of Anogeia, Crete). The action involved: (i) identification of the quantities, use and source of the woody biomass used in the community based on the analysis of data collected through a systematic survey; (ii) on-site indoor and outdoor measurements of air quality (CO2, CO, NOX, PM), during wintertime and summertime. Based on the current survey, around 70% of the study area households in Anogeia using woody biomass for heating purposes in low energy efficiency systems resulted in high annual consumption of firewood. Fifty-three per cent of occupants didn’t consider indoor air quality as a result of wood burning. The analysis of the air quality showed very high concentrations of indoor air pollutants in the majority of old buildings with seniors using traditional heating systems. The type of main/supplementary heating system used in a dwelling depends on factors such as the size of the dwelling, year of construction, education level and age of occupants. The results also demonstrate a strong correlation/liaison between the heating season (summertime/wintertime), and the (significant increase in the) concentrations of air pollutants in the sampling sites.

Enclosed railway stations hosting diesel trains are at risk of reduced air quality as a result of exhaust emissions that may endanger passengers and workers. Air quality measurements were conducted inside London Paddington Station, a semi-enclosed railway station where 70% of trains are powered by diesel engines. Particulate matter (PM2.5) mass was measured at five station locations. PM size, PM number, oxides of nitrogen (NOx), and sulphur dioxide (SO2) were measured at two station locations. Paddington Station's hourly mean PM2.5 mass concentrations averaged 16 μg m−3 [min 2, max 68]. Paddington Station's hourly mean NO2 concentrations averaged 73 ppb [49, 120] and SO2 concentrations averaged 25 ppb [15, 37]. While UK train stations are not required to comply with air quality standards, there were five instances where the hourly mean NO2 concentrations exceeded the EU hourly mean limits (106 ppb) for outdoor air quality. PM2.5, SO2, and NO2 concentrations were compared against Marylebone, a busy London roadside 1.2 km from the station. The comparisons indicated that train station air quality was more polluted than the nearby roadside. PM2.5 for at least one measurement location within Paddington Station was shown to be statistically higher (P-value

Community noise levels throughout feeder areas serving 16 grammar schools in the Los Angeles County School District were monitored in order to determine the environmental noise exposure experienced by 3rd and 6th graders in socioeconomically matched groupings. Schools for this study were selected such that the noise environments for one‐half of the feeder areas would be largely controlled by freeway traffic noise. Noise monitoring at school sites within each feeder area was also conducted. Additionally, indoor and outdoor air quality monitoring was conducted on a rotational basis during December 1978 and January 1979 at each school site. Estimates of each feeder area's relative air quality have been extrapolated from the school studies which were in turn correlated to South Coastal Air Basin air quality data. Community noise levels, based upon approximately 350 site days of monitoring, are presented along with each feeder area's socioeconomic and ethnic population descriptors. The influence of freeway pro...

Background Low environmental air quality is a significant cause of mortality and morbidity and this question is now emerging as a main concern of governmental authorities. Airborne pollution results from the combination of chemicals, fine particles, and micro-organisms quantitatively or qualitatively dangerous for health or for the environment. Increasing regulations and limitations for outdoor air quality have been decreed in regards to chemicals and particles contrary to micro-organisms. Indeed, pertinent and reliable tests to evaluate this biohazard are scarce. In this work, our purpose was to evaluate the Caenorhaditis elegans killing test, a model considered as an equivalent to the mouse acute toxicity test in pharmaceutical industry, in order to monitor air bacterial quality. Findings The present study investigates the bacterial population in dust clouds generated during crop ship loading in harbor installations (Rouen harbor, Normandy, France). With a biocollector, airborne bacteria were impacted onto the surface of agar medium. After incubation, a replicate of the colonies on a fresh agar medium was done using a velvet. All the replicated colonies were pooled creating the "Total Air Sample". Meanwhile, all the colonies on the original plate were isolated. Among which, five representative bacterial strains were chosen. The virulence of these representatives was compared to that of the "Total Air Sample" using the Caenorhaditis elegans killing test. The survival kinetic of nematodes fed with the "Total Air Sample" is consistent with the kinetics obtained using the five different representatives strains. Conclusions Bacterial air quality can now be monitored in a one shot test using the Caenorhaditis elegans killing test.