Suppressed swimming activity in Zebrafish (Danio rerio) exposed to 1,4,5-oxadithiepane, a sulphur mustard degradation product*

Abstract

This rapid communication presents novel data on the ecotoxicity of the cyclic sulphur mustard degradation compound, 1,4,5-oxadithiepane. Groups of adult male Zebrafish (Danio rerio) were exposed to 1,4,5-oxadithiepane at 40.3 ± 2.9 μg L-1, 133.3 ± 6.7 μg L-1 and 1533.3 ± 266.7 μg L-1, respectively. After 14 days of exposure, fitness and lethality were accessed and the swimming behaviour of the Zebrafish was measured by an automated video tracking system. The average swimming velocity was decreased significantly from 40.4 ± 2.5 mm s-1 in the control group to 31.8 ± 1.6 mm s-1 in the low dose. The low and high doses demonstrated suppressed average velocities, partly due to elevated immobile periods (rest time). Thus, at 40.3 ± 2.9 μg L-1 and 1533.3 ± 266.7 μg L-1 both parameters were significantly different from the control group. No adverse effects were found at the 1533.3 ± 266.7 μg L-1 treatment level and no lethality, associated with the toxic properties of 1,4,5-oxadithiepane, was observed during the 14 days of exposure suggesting a 14 days No-Observed-Effect-Concentration above 1533.3 μg L-1.