title: High Concentrations of Ozone Air Pollution on Mount Everest: Health Implications for Sherpa Communities and Mountaineers.
abstract: Semple, John L., G.W. Kent Moore, Petros Koutrakis, Jack M. Wolfson, Paolo Cristofanelli, and Paolo Bonasoni. High concentrations of ozone air pollution on Mount Everest: health implications for Sherpa communities and mountaineers. High Alt Med Biol. 17:365-369, 2016.-Introduction: Populations in remote mountain regions are increasingly vulnerable to multiple climate mechanisms that influence levels of air pollution. Few studies have reported on climate-sensitive health outcomes unique to high altitude ecosystems. In this study, we report on the discovery of high-surface ozone concentrations and the potential impact on health outcomes on Mount Everest and the high Himalaya.
  
  
  METHODS
  Surface ozone measurements were collected during ascending transects in the Mount Everest region of Nepal with passive nitrite-coated Ogawa filter samplers to obtain 8-hour personal exposures (2860-5364 m asl). In addition, the Nepal Climate Observatory-Pyramid, a GAW-WMO Global Station sited in the Khumbu Valley (5079 m asl), collected ozone mixing ratios with photometric gas analyzer.
  
  
  RESULTS
  Surface ozone measurements increased with altitude with concentrations that exceed 100 ppb (8-hour exposure). Highest values were during the spring season and the result of diverse contributions: hemispheric background values, the descent of ozone-rich stratospheric air, and the transport of tropospheric pollutants occurring at different spatial scales.
  
  
  CONCLUSIONS
  Multiple climate factors, including descending stratospheric ozone and imported anthropogenic air masses from the Indo-Gangetic Plain, contribute to ambient ozone exposure levels in the vicinity of Mount Everest that are similar to if not higher than those reported in industrialized cities.
authors.affiliation: 1 Department of Surgery, University of Toronto , Toronto, Canada .
authors.forename: John L
authors.initials: JL
authors.lastname: Semple
authors.affiliation: 2 Department of Physics, University of Toronto , Toronto, Canada .
authors.forename: G W Kent
authors.initials: GW
authors.lastname: Moore
authors.affiliation: 3 Department of Environmental Health, School of Public Health, Harvard University , Boston, Massachusetts.
authors.forename: Petros
authors.initials: P
authors.lastname: Koutrakis
authors.affiliation: 3 Department of Environmental Health, School of Public Health, Harvard University , Boston, Massachusetts.
authors.forename: Jack M
authors.initials: JM
authors.lastname: Wolfson
authors.affiliation: 4 Institute of Atmospheric Sciences and Climate , National Research Council of Italy, Bologna, Italy .
authors.forename: Paolo
authors.initials: P
authors.lastname: Cristofanelli
authors.affiliation: 4 Institute of Atmospheric Sciences and Climate , National Research Council of Italy, Bologna, Italy .
authors.forename: Paolo
authors.initials: P
authors.lastname: Bonasoni
mesh_terms: D000393:Air Pollutants / Q000032:analysis* / Q000633:toxicity; D000397:Air Pollution / Q000009:adverse effects / Q000032:analysis*; D000531:Altitude; D004781:Environmental Exposure / Q000009:adverse effects / Q000032:analysis*; D006801:Humans; D009051:Mountaineering; D009390:Nepal; D010126:Ozone / Q000032:analysis* / Q000633:toxicity; D012621:Seasons
chemical_list: D000393:Air Pollutants; D010126:Ozone
keywords: Himalaya; Mt. Everest; climate change; health effects; ozone pollution