Physiological Response of Daphnia magna to Linear Anionic Polyacrylamide: Ecological Implications for Receiving Waters

Abstract

Linear anionic polyacrylamide (LA-PAM) is being considered as a soil amendment to reduce seepage and infiltration in unlined earthen canals. While polyacrylamides have been extensively used for potable water treatment, dewatering sewage sludge, coal and mine processing, paper manufacturing, and agriculture, little is known about its ecological impact to aquatic ecosystems. Acute toxicity (LC 50 , 24 and 48 h) and chronic exposure tests (limited and continuous exposures) were conducted on Daphnia magna. In the chronic limited exposure experiments, Daphnia were exposed to LA-PAM for only 24 h whereas for the chronic continuous exposure the concentrations of 0, 0.5, 1, 5, 10, and 100 mg/L were tested and the endpoints of growth, onset to reproduction, fecundity, and mortality were measured for the duration of 32 days. There was no significant difference among the chronic, limitedly exposed organisms. The acute toxicity for LA-PAM was measured at 100, 150, 200, 250, and 300 mg/L. The acute test showed that the LC 50 for LA-PAM was at 152 mg/L. Overall in the chronic, continuous exposure test, D. magna was negatively impacted by LA-PAM at levels as low as 1 mg/L. Growth was reduced by 37% and 89% at 1 and 100 mg/L, respectively. Fecundity and onset to reproduction was impaired at 10 and 100 mg/L. Kinematic viscosity ranged from 0.98 cSt at 1 mg/L to 2.9 at 100 mg/L. At these levels, mechanical and physiological impairments due to the viscous properties of LA-PAM are the proposed mechanisms of reduction in the life history traits of D. magna.

Evaluation of the embryotoxicity in zebrafish (Danio rerio) of the flocculant and coagulant compounds used for water remediation

“…In a search in the database of the US Environmental Protection Agency using the keyword polyacrylamide, we did not find studies showing lethal and sublethal effects on aquatic organisms. Acharya et al (2010) studied physiological responses in Daphnia magna exposed to Linear Anionic Polyacrylamide, in which they determined the acute LC50 at 152 mg/L. In order to evaluate the acute toxicity of acrylamide to non-target organisms (macroinvertebrates and fish), through determination of LC50 values, Krautter et al (1986) found: Daphnia magna = 160 mg/L; Paratanytarsus parthenogenetica = 410 mg/L; Salmo gairdneri = 110 mg/L; Pimephales promelas = 120 mg/L; Lepomis macrochirus = 100 mg/L.…”

Acute toxicity of polyacrylamide flocculants to early life stages of freshwater mussels

“…The concentration range of polyacrylamide used during toxicity testing (0-1000 mg/L) was selected to guide applied management decisions regarding turbidity control in the presence of common and imperiled freshwater mussels. The highest test concentration of 1000 mg/L exceeded the current recommended concentration for turbidity control by a factor of 200 and was also based on previous aquatic organism toxicity data (Table 1) [24,[49][50][51] and preliminary tests in our laboratory. Our pilot studies indicated that 1000 mg/L was the greatest homogeneous stock concentration of polyacrylamide that could be confidently achieved for use in toxicity testing because of desired dilution in water and the extreme viscosity of this concentration for accurate pipetting and recovering mussels.…”

Growth evaluation method by live imaging of Daphnia magna and its application to the estimation of an insect growth regulator

“…Recently, based on the progress of imaging equipment and image processing software, a new evaluation method to observe the growth of daphnids by measuring the area has been demonstrated (Acharya et al ., ). This method is promising to evaluate the growth of living daphnids, but the process is almost the same as measurement of the length under a stereomicroscope, and the animals removed for growth measurements are sometimes damaged during image capture for measurement of their length (Acharya et al ., ).…”

“…In addition, some studies proposed that the information of growth rate in cost‐effective acute tests could be replaced by the reproductive rate in Daphnia life history observation (Hanazato, , Lazorchak et al ., ). Actually, use of the growth rate of daphnids to evaluate toxicants such as hydrogen peroxide has been demonstrated (Meinertz et al ., ), as well as ammonium chloride, phenol (Lazorchak et al ., ), copper (De Schamphelaere and Janssen, ), linear anionic polyacrylamide (Acharya et al ., ) and fenoxycarb (Hosmer et al ., ). Fenoxycarb (ethyl [2‐(4‐phenoxy‐phenoxy) ethyl] carbamate) is used as an insect growth regulator because of its juvenile hormone‐like effect (Hosmer et al ., ).…”