Environmental conditions,air pollutants,and airway cells in runners: A longitudinal field study

Abstract

Runners have increased numbers of neutrophils in the airways at rest and after exercise compared with sedentary individuals. The aim of this study was to determine whether Mediterranean seasonal changes in temperature, humidity or airborne pollutants affect the airway cells of runners training outdoors in an urban environment. In nine male amateur runners, cell composition, apoptosis, and inflammatory mediators were measured in induced sputum collected at rest (baseline) and the morning after races held in the fall (21 km), winter (12 km), and summer (10 km). Concentrations of air pollutants were below the alert threshold at all times. Neutrophil differential counts tended to increase after all races (P = 0.055). Apoptosis of neutrophils increased with ozone (P < 0.005) and particulate matter <10 μm (PM₁₀) (P < 0.05) exposure. Bronchial epithelial cell counts were low at all times and weakly correlated with ozone and PM₁₀ concentrations. Apoptotic bronchial epithelial cells increased after all races (P < 0.05). Inflammatory mediators in induced sputum were low at baseline and after the races, and correlated with neutrophil differential counts only at rest. In conclusion, apoptosis of airway cells in runners appears to be affected by both exercise and environmental conditions. Apoptosis of neutrophils increased with exposure to environmental pollutants while apoptosis of bronchial epithelial cells increased after intense exercise. Since no relationship was observed between neutrophil counts and inflammatory mediators 20 h after races, airways inflammation at this time point appears blunted in healthy runners and little affected by exposure to mild seasonal changes and airborne pollutants.     

一种简单快速测定臭氧浓度的方法

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北京夏季近地层臭氧垂直变化及其环境效应的观测研究

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基于单片机AT89C51医用臭氧治疗仪

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饮用水消毒技术是我国目前城市给水工程面临的一道难题。文章介绍了传统的氯消毒工艺的现状及存在问题，提出于改进方法，并探讨了其它的一些消毒工艺。     

臭氧分子的离域π键与分子性质

用休克尔分子轨道法从本质上说明了臭氧分子的磁性和极性.     

Prospective Primary Teachers' Understanding of Climate Change, Greenhouse Effect, and Ozone Layer Depletion

Climate change is one of the most serious global environmental problems and for that reason there has been lately a great interest in educating pupils, the future citizens, about it. Previous research has shown that pupils of all ages and teachers hold many misconceptions and misunderstandings concerning this issue. This paper reports on research concerning student teachers' perceptions about aspects of climate change as well as about greenhouse effect and ozone layer depletion. The aim of this research is to take findings into account for teaching student teachers about these issues. An open-ended questionnaire was used in order to gain a more comprehensive understanding of their thought. From their answers it appeared that these students believe that climate change is under way and base their beliefs on their own experience. They are unaware of the proper actions to be taken for slowing down the climate change, they also hold the misconception that ozone depletion, acid rain, and pollution in general are conducive to climate change. They confuse greenhouse effect with ozone depletion as far as the mechanisms through which they occur is concerned and the causal compounds. By taking into account these research findings the possible implications for teaching are discussed and some suggestions for more effective teaching are made.     

Kindergarten Teachers’ Conceptual Framework on the Ozone Layer Depletion. Exploring the Associative Meanings of a Global Environmental Issue

This paper reports on a study conducted among Greek kindergarten teachers aiming to explore their conceptual frameworks on a major environmental issue of our times: the ozone layer depletion. The choice of this particular issue was premised on its novelty, complexity and abstractness which present teachers with difficulties in its teaching. A free word association task was employed to identify the associative meaning of the issue among the participant teachers. The study’s results revealed the existence of a simplistic, linear, cause-and-effect scheme in the teachers’ conceptual frameworks, the two poles of which are “solar radiation” and “its harmful results for human health”. Some of the well-known misconceptions and misunderstandings already emerged in previous research also arise in this study. Prominent among them are the deeply rooted confusion between the “ozone hole” and “greenhouse effect”, a general fusion of ideas concerning all environmental problems and an overemphasis on the harmful consequences of the ozone depletion on human health. Implications for kindergarten teacher education are also discussed.The present study is part of a research project that is co-funded by the European Social Fund and National Resources – (EPEAEK II) PYTHAGORAS II.