aqueous mixtures, boron can be toxic to plants or animals at relatively low concentrations. The
objectives of this study were: 1) to measure responses of Typha latifolia (seed germination and root and
shoot elongation) to aqueous exposures of boron in 7-day static experiments; and 2) to measure
responses of Ceriodaphnia dubia (survival and reproduction) to aqueous boron concentrations in 7-day
static/renewal experiments. The responses of these sentinel species can be contrasted for purposes of
risk characterization. T. latifolia seeds were exposed to boron (boric acid) at concentrations of 30, 35,
40, 45, 50, 100, 300 mg/L. Root elongation was negatively affected at boron concentrations of 30, 35,
and 40 mg/L, in comparison to shoot elongation for which concentrations ≥45 mg/L were statistically
different from controls. Seed germination was not negatively affected at the highest boron concentration
tested (i.e. 300 mg/L). C. dubia were exposed to aqueous boron concentrations of 10, 50, 100, 150,
200, and 300 mg/L. Survival was negatively affected for aqueous concentrations ≥100 mg/L (50%
survival), and reproduction was impaired at a concentration ≥50mg/L. This study indicates that T.
latifolia was more sensitive to boron concentrations for the measurement parameters versus responses
of C. dubia. This study provides data for risk assessment of boron contaminated waters.