Effects of road de-icing salt (NaCl) on larval wood frogs (Rana sylvatica).
Vast networks of roads cover the earth and have numerous environmental effects including pollution. A major component of road runoff in northern countries is salt (mostly NaCl) used as a winter de-icing agent, but few studies of effects of road salts on aquatic organisms exist. Amphibians require aquatic habitats and chemical pollution is implicated as a major factor in global population declines. We exposed wood frog tadpoles to NaCl. Tests revealed 96-h LC50 values of 2,636 and 5,109 mg/l and tadpoles experienced reduced activity, weight, and displayed physical abnormalities. A 90 d chronic experiment revealed significantly lower survivorship, decreased time to metamorphosis, reduced weight and activity, and increased physical abnormalities with increasing salt concentration (0.00, 0.39, 77.50, 1,030.00 mg/l). Road salts had toxic effects on larvae at environmentally realistic concentrations with potentially far-ranging ecological impacts. More studies on the effects of road salts are warranted.
Sanzo
Domenico
D
Department of Biology, Lakehead University, 955 Oliver Road, Thunder Bay, ON, P7B 5E1, Canada.
Hecnar
Stephen J
SJ
D000818:Animals; D004781:Environmental Exposure / Q000009:adverse effects; D004785:Environmental Pollutants / Q000032:analysis / Q000633:toxicity*; D007053:Ice; D007814:Larva / Q000187:drug effects; D008675:Metamorphosis, Biological; D011898:Ranidae / Q000502:physiology*; D012965:Sodium Chloride / Q000032:analysis / Q000633:toxicity*; D013997:Time Factors; D014186:Transportation
D004785:Environmental Pollutants; D007053:Ice; D012965:Sodium Chloride