ARS | Publication request: Effects of fluidized gas desulfurization (FGD) gypsum on non-target freshwater and sediment dwelling organims

Submitted to: Bulletin of Environmental Contamination and Toxicology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 9, 2011
Publication Date: April 27, 2011
Citation: Greenway, S.L., Moore, M.T., Farris, J.L., Rhoton, F.E. 2011. Effects of fluidized gas desulfurization (FGD) gypsum on non-target freshwater and sediment dwelling organims. Bulletin of Environmental Contamination and Toxicology. 86(5):480-483.

Interpretive Summary: Gypsum is gaining popularity as an efficient and effective agricultural soil amendment. As with other agricultural amendments, the environmental consequences of their use must be determined. Standardized laboratory organisms were exposed to expected environmental concentrations of gypsum. Based on the lack of observed toxicity in laboratory experiments, recommended agricultural gypsum applications posed no observed threat to downstream aquatic macroinvertebrates.

Technical Abstract: Fluidized gas desulfurization gypsum is a popular agricultural soil amendment used to increase calcium and sulfur contents, and reduce aluminum toxicity. Due to its surface application in conservation tillage systems and high solubility, the soluble components of gypsum may be transferred with agricultural runoff into receiving waters. The current study measured toxicity of gypsum to Ceriodaphnia dubia, Pimephales promelas, Chironomus dilutus, and Hyalella azteca. Solutions at 2400 mg gypsum / L (maximum solubility) produced no observable toxicity to C. dubia and P. promelas. Mixtures of a control sediment and gypsum indicated no observed toxicity effects for H. azteca, although effects were noted at 25% dilution for C. dilutus. Data suggests gypsum is not harmful to freshwater organisms at concentrations expected in the agricultural environment.