Effects of formulations of the fungicide, pentachloronitrobenzene on early life stage development of the Japanese medaka (Oryzias latipes) Original Research Article

Quintozene is a fungicide containing the active ingredient, pentachloronitrobenzene (PCNB) that is used to control “snow mold” on golf courses in temperate regions of North America. In this study, quintozene and a formulation of quintozene widely used on golf courses, FFIITM were tested for toxicity to early life stages of the Japanese medaka, Oryzias latipes. For medaka exposed in static non-renewal assays to quintozene for 17 d from the fertilized egg stage to yolk resorption at the fry stage, the LC50 for mortality was a nominal concentration of 707 μg l−1 and the effective concentration for 50% hatch (i.e. EC50) was a nominal concentration of 71 μg l−1. Eggs and fry showed developmental abnormalities, including ocular malformations and retarded development of the brain, notochord, organs and body segmentation, which were interpreted as teratogenic responses to exposure to PCNB. For medaka exposed to quintozene, the LOECs for abnormalities of the eye and all other developmental abnormalities were 750 and 100 μg l−1, respectively. In medaka exposed to the FFIITM formulation, similar patterns of mortalities, reduced hatching success and developmental abnormalities were observed, but at higher test concentrations that were consistent with the proportion of quintozene in the formulation. For medaka exposed to the formulation, the LOECs for abnormalities of the eye and all other developmental abnormalities were 10 000 and 1000 μg l−1, respectively. Overall, these data indicate that studies should be conducted to assess the risk of exposure of early life stages of fish to quintozene in watersheds impacted by golf courses.