SOME EFFECTS OF DE-ICING CHEMICALS ON ROADSIDE TREES

THE AMOUNT OF SALT USED ON HIGHWAYS IN THE UNITED STATES IS INCREASING AT THE RATE OF ABOUT ONE MILLION TONS PER YEAR. IT IS ESTIMATED THAT 95 PERCENT OF THIS SALT IS SODIUM CHLORIDE AND ONLY 5 PERCENT IS THE LESS TOXIC CALCIUM CHLORIDE. NEW HAMPSHIRE HAS BEEN A LEADER IN THE USE OF SALT FOR ITS WINTER HIGHWAY MAINTENANCE PROGRAM. INVESTIGATIONS IN NEW HAMPSHIRE HAVE REVEALED THAT TREES WITHIN 30 FT OF THE HIGHWAY ARE MODERATELY TO SEVERLY AFFECTED, WHEREAS TREES MORE THAN 30 FT AWAY ARE ALMOST ALWAYS HEALTHY. ANALYSIS SHOWS THAT CHLORIDE CONTENT IS A BETTER INDICATOR OF SALT INJURY THAN SODIUM CONTENT. SALT TOLERANCE VARIES CONSIDERABLY WITH BOTH CONIFEROUS AND DECIDUOUS SPECIES. CONIFEROUS SPECIES INTOLERANT TO SALT INCLUDE CANADIAN HEMLOCK, BALSAM FIR, WHITE PINE, AND RED PINE. DECIDUOUS SPECIES SENSITIVE TO SALT INCLUDE SUGAR MAPLE, RED MAPLE, BASS WOOD, AND AMERICAN ELM. APPLICATIONS OF GYPSUM TO THE SOIL HAVE A TENDENCY TO IMPROVE SOIL STRUCTURE, REDUCE THE UPTAKE OF SODIUM, AND REDUCE THE VISIBLE INJURY TO FOILAGE. HOWEVER, IT IS DIFFICULT TO INCORPORATE THE GYPSUM INTO THE SOIL AROUND GROWING TREES. ALTHOUGH RESEARCH DATA INDICATE THAT SALT IS HARMFUL TO ROADSIDE VEGETATION, IT IS UNREALISTIC TO ADVOCATE DISCONTINUATION OF ITS USE, SINCE NO SUBSTITUTE HAS BEEN FOUND. THE ONLY ALTERNATIVE IS TO USE SALT, BUT WITH MORE DISCRETION.

• Record URL:
  http://onlinepubs.trb.org/Onlinepubs/hrr/1973/425/425-003.pdf
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/0309021545
• Supplemental Notes:
  • Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved.
• Authors:
  • Rich, Avery E
• Publication Date: 1973

Media Info

• Media Type: Digital/other
• Features: References; Tables;
• Pagination: pp 14-16
• Monograph Title: Environmental degradation by de-icing chemicals and effective countermeasures
• Serial:
  • Highway Research Record
  • Issue Number: 425
  • Publisher: Highway Research Board

Subject/Index Terms

• TRT Terms: Calcium chloride; Chlorides; Concentration (Chemistry); Deicers (Equipment); Deicing; Gypsum; Injuries; Roadside; Snow and ice control; Sodium chloride; Sodium chloride; Trees; Vegetation
• Uncontrolled Terms: Concentration; Deicers
• Subject Areas: Design; Environment; Highways; Safety and Human Factors; Vehicles and Equipment;

Filing Info

• Accession Number: 00205246
• Record Type: Publication
• ISBN: 0309021545
• Files: TRIS, TRB
• Created Date: Aug 15 1973 12:00AM