Acute toxicity of oils to four Shatt Al-Arab river species

Abstract EN

Short-term lethal toxicity tests were conducted with different oils (Basrah regular crude oil, Nahran Omar crude oil, fuel oil, kerosene and used lubricating oil) and four species of Shatt Al-Arab River (the fishes, sailfin molly Poecilia latipinna and black molly Poecilia sphenops and the larvae of frogs, Rana ridibunda and Runa esculenta).

The oils were tested in a different ways of their association with an aqueous phase as floating oils, oils water-soluble fractions and oil-in water emulsions in static and renewal toxicity test systems.

The values of median lethal concentration (LC50) ranged from 25 ppm (24 hours LC50) and 17 ppm (96 hours LC50) of emulsified kerosene for frog larvae R.

ridibunda in renewal toxicity test to 98 ppm (24 hours LC50) and 82 ppm (96 hours LC50) of floating fuel oil for fish P.

sphenops in static toxicity test.

The LC50 values were quite variable depending on the type of organism tested ; the type, quantity and form of the oil used ; the type of toxicity test system utilized ; the exposure time applied ; and the influence of oil water contact time.