Role of Secondary Organic Matter on Soot Particle Toxicity in Reconstituted Human Bronchial Epithelia Exposed at the Air-Liquid Interface.

Secondary organic matter (SOM) formed from gaseous precursors constitutes a major mass fraction of fine particulate matter. However, there is only limited evidence on its toxicological impact. In this study, air-liquid interface cultures of human bronchial epithelia were exposed to different series of fresh and aged soot particles generated by a miniCAST burner combined with a micro smog chamber (MSC). Soot cores with geometric mean mobility diameters of 30 and 90 nm were coated with increasing amounts of SOM, generated from the photo-oxidation of mesitylene and ozonolysis of α-pinene. At 24 h after exposure, the release of lactate dehydrogenase (LDH), indicating cell membrane damage, was measured and proteome analysis, i.e. the release of 102 cytokines and chemokines to assess the inflammatory response, was performed. The data indicate that the presence of the SOM coating and its bioavailability play an important role in cytotoxicity. In particular, LDH release increased with increasing SOM mass/total particle mass ratio, but only when SOM had condensed on the outer surface of the soot cores. Proteome analysis provided further evidence for substantial interference of coated particles with essential properties of the respiratory epithelium as a barrier as well as affecting cell remodeling and inflammatory activity.

Falling nickel concentrations in ambient air in South Wales - 50 years of progress.

Measurement of the composition of ambient air has become increasingly widespread over the last 50 years as the detrimental health effects of some air pollutants have become clearer and requirements for these measurements has been embedded in national and international legislation. The aim of this has been not only to assess exposure of the general population to air pollutants but also to assess the effectiveness of abatement strategies to reduce emissions of these pollutants at source. With a rich industrial heritage, the Swansea Valley (South Wales, UK) has long been associated with the refining and production of metal products, especially nickel. Despite a decline in output during the latter part of the twentieth century there is still sufficient activity to prompt a requirement for targeted air monitoring in the area. This is most important for nickel where there is a local history of measured concentrations exceeding legislative target values. This work demonstrates the effectiveness of nickel emissions abatement strategies over the last 50 years by tracking the falling air concentration of nickel over this period. It also demonstrates how the monitoring network in the Swansea Valley has expanded over this time and become significantly more sensitive to nickel emissions. The data presented represents a significant public health achievement - it is likely that the exposure to nickel in air of the population in the Swansea Valley has decreased more than 100-fold over the last 50 years - and reflects the progress in regulation, industrial efficiency, emissions abatement technology and air quality monitoring science achieved during this period.

Concentration trends of metals in ambient air in the UK: a review.

The monitoring of metals in ambient air has been undertaken for over 40 years on a national basis in the UK. During this period, the UK pollution landscape has continued to evolve in terms of emission sources, and the measurement framework for metals in ambient air, the UK Heavy Metals Monitoring Network, has also been subject to significant configuration changes. Therefore, this work provides a timely review of more recent concentration trends in the context of current emission profiles. Overall, throughout this time period, there has been a significant downward trend in the emissions and consequently, the measured concentrations of most metals in UK ambient air. Ambient concentrations were generally found to be well correlated with emission estimates. Analysis of the sensitivity of measured concentrations to emissions suggests that concentrations have fallen faster than the reduction in emission estimates would have predicted at typical median urban background sites.

Emotion recognition by children with Down syndrome: investigation of specific impairments and error patterns.

The ability of children with Down syndrome to recognize expressions of emotion was compared to performance in typically developing and nonspecific intellectual disability groups matched on either MA or a performance-related measure. Our goal was to (a) resolve whether specific emotions present recognition difficulties; (b) investigate patterns of errors; and (c) explore the relationships among emotion-recognition ability and cognitive, linguistic, and adaptive behavior levels. Emotion-recognition ability in the Down syndrome group was significantly poorer than in the typically developing group overall, particularly for fearful expressions. Error patterns and relationships between task performance and assessment measures also differed across groups. Findings are consistent with a neurological explanation of specific deficits in sociocognitive functioning in children with Down syndrome.