Temporal and spatial patterns of ambient endotoxin concentrations in Fresno, California
| Autor: | Bryan Penfold, S. Katharine Hammond, Siana Alcorn, Ira B. Tager, Thaddeus J. Haight, Frederick Lurmann |
|---|---|
| Rok vydání: | 2010 |
| Předmět: |
endotoxin
010504 meteorology & atmospheric sciences Health Toxicology and Mutagenesis Indoor bioaerosol Air pollution 010501 environmental sciences Spatial distribution medicine.disease_cause Combustion Toxicology complex mixtures 01 natural sciences Medical and Health Sciences California Cohort Studies Air pollutants 11. Sustainability medicine Humans Child 0105 earth and related environmental sciences Air Pollutants Ecology Research Public Health Environmental and Occupational Health Asthma Endotoxins bioaerosols 13. Climate action Environmental chemistry Children's Health Spatial ecology Environmental science Environmental Sciences Bioaerosol |
| Zdroj: | Environmental health perspectives, vol 118, iss 10 Environmental Health Perspectives |
| Popis: | Background Endotoxins are found in indoor dust generated by human activity and pets, in soil, and adsorbed onto the surfaces of ambient combustion particles. Endotoxin concentrations have been associated with respiratory symptoms and the risk of atopy and asthma in children. Objective We characterized the temporal and spatial variability of ambient endotoxin in Fresno/Clovis, California, located in California’s Central Valley, to identify correlates and potential predictors of ambient endotoxin concentrations in a cohort of children with asthma [Fresno Asthmatic Children’s Environment Study (FACES)]. Methods Between May 2001 and October 2004, daily ambient endotoxin and air pollutants were collected at the central ambient monitoring site of the California Air Resources Board in Fresno and, for shorter time periods, at 10 schools and indoors and outdoors at 84 residences in the community. Analyses were restricted to May–October, the dry months during which endotoxin concentrations are highest. Results Daily endotoxin concentration patterns were determined mainly by meteorologic factors, particularly the degree of air stagnation. Overall concentrations were lowest in areas distant from agricultural activities. Highest concentrations were found in areas immediately downwind from agricultural/pasture land. Among three other measured air pollutants [fine particulate matter, elemental carbon (a marker of traffic in Fresno), and coarse particulate matter (PMc)], PMc was the only pollutant correlated with endotoxin. Endotoxin, however, was the most spatially variable. Conclusions Our data support the need to evaluate the spatial/temporal variability of endotoxin concentrations, rather than relying on a few measurements made at one location, in studies of exposure and and respiratory health effects, particularly in children with asthma and other chronic respiratory diseases. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|