Andresen, J. W. 1974. Survey of growth and survival of trees in 19 American cities indicated no detrimental effects caused by high-pressure sodium street lighting. Chicago Department of Streets and Sanitation Report. 35 p. (Available free of charge from Street and Highway Lighting Bureau, 131 East 38th Street, New York, N.Y. 10016)
This study was undertaken to provide comparative data on the role of high-pressure sodium vapor lighting in the growth and survival patterns of trees contiguous to the lights along city streets. Data were personally collected in Chicago, Cleveland, and Milwaukee with observations made on 200 trees. Additional information was gathered via telephone interviews with officials of 16 cities where high-pressure sodium (HPS) lamps have illuminated trees for the past several years. Not one personal observation nor any telephone conversation comment indicated any harmful effect to trees by the light created by HPS. All indicators, to date, suggest that HPS has no detrimental influence on trees grown in cities of the eastern half of the United States in general and our Midwest in particular. Based on the compiled data it would be safe to install HPS lamps of 150, 250, 400, or even 1000-watt output in the presence of transplant or mature trees.
- © 1975, International Society of Arboriculture. All rights reserved.