Chlorine toxicity to early life stages of freshwater mussels (Bivalvia: Unionidae)

Abstract

Abstract-Chlorine (Cl) is a highly toxic, widely used halogen disinfectant that is present in point-source pollution discharges from wastewater treatment plants and industrial facilities. The U.S. Environmental Protection Agency freshwater criteria for Cl are 19 g total residual Cl (TRC)/L as a maximum 1-h average concentration and 11 g TRC/L as a maximum 4-d average; however, toxicological data for unionids were not used in these calculations. To address this void in the data, we conducted acute tests with glochidia from several species and 21-d bioassays with three-month-old Epioblasma capsaeformis and three-, six-, and 12-monthold Villosa iris juveniles. The 24-h lethal concentration 50 values for glochidia were between 70 and 220 g TRC/L, which are 2.5 to 37 times higher than those reported in other studies for cladocerans. Significant declines in growth and survivorship were observed in the 21-d test with E. capsaeformis at 20 g TRC/L. Lowest-observed-adverse-effects concentrations in bioassays with juvenile V. iris were higher (30-60 g TRC/L) but showed a significant trend of declining toxicity with increased age. Although endpoints were above water quality criteria, the long life spans of unionids and potential implications of chronic exposure to endangered juvenile mussels still warrant concern.

Reduction in toxicity of wastewater from three wastewater treatment plants to alga (Scenedesmus obliquus) in northeast China

“…This may attributed to that UV radiation was conducted with minimal production of DBPs (Hijnen et al, 2006;Li et al, 2009;USEPA, 1999). The toxic compounds produced by disinfectant treatment techniques may depend on the precursors occurring in the wastewater and the concentration of disinfectant used (Ferraris et al, 2005;Valenti et al, 2006;Petala et al, 2008). This research suggested that the choice of disinfection techniques for wastewater disinfection is also important considering the following eco-toxicity to the receiving water body.…”

Toxicity on aquatic organisms exposed to secondary effluent disinfected with chlorine, peracetic acid, ozone and UV radiation

“…Disinfection techniques should be analyzed case by case, because each effluent presents different chemical and physical characteristics. It is well known that some disinfectant treatments, despite promoting a reduction in pathogenic organisms and organic contaminants, can also produce toxic and genotoxic compounds, depending on the precursors present in the wastewater and the concentrations of disinfectant used (Ferraris et al 2005;Valenti et al 2006;Petala et al 2008). The risks of human infection by pathogenic microorganisms should be prioritized, but the environmental impacts on the recipient water body caused by the practice of disinfection also need to be taken into account.…”

The impact of small and large impoundments on freshwater mussel distribution in the Hawkesbury‐Nepean River, southeastern Australia

“…For small mussels, land use and level of riparian disturbance were also important. Small mussels are generally considered more vulnerable to a range of impacts including changes in water quality associated particularly with urbanization (Box and Mossa, 1999;Newton et al, 2003;Valenti et al, 2006). In contrast, larger mussels may respond to elevated nutrient loads, associated with urban or agricultural runoff with increased growth rates (Byrne, 1998).…”