chlorophyll-a and perfluorooctane-sulfonic-acid

Despite previous efforts and the rapid progress on elucidating the impact of perfluorooctanesulfonate (PFOS) on the environment, its effects on riparian plants, a key component of aquatic ecosystems, are still poorly understood. A 48-day hydroponic experiment was carried out on two typical riparian species (Acorus calamus and Phragmites communis) to examine the toxic effects of PFOS on these plants. The results showed that, at high concentration (more than 10 mg L

Topics: Acorus; Alkanesulfonic Acids; Antioxidants; Catalase; Chlorophyll; Fluorocarbons; Hydrogen Peroxide; Malondialdehyde; Oxidative Stress; Peroxidase; Plant Leaves; Plant Roots; Poaceae; Superoxide Dismutase

We studied the effects of perfluorooctane sulfonate (PFOS) on the chlorophyll content, cell permeability, and antioxidant defense systems of the green alga Chlorella vulgaris. The results showed that the production of reactive oxygen species increased in a concentration-dependent manner after exposure to PFOS for 96 h. Superoxide dismutase and catalase activity was elevated after exposure to the lower concentrations and then decreased with higher concentrations. Malondialdehyde content was significantly higher than that of controls at the higher PFOS concentrations. Cell membrane permeability increased. These results indicate that PFOS exposure leads to oxidative damage in C. vulgaris. At these concentrations, chlorophyll and the structure of chloroplasts were destroyed.

Topics: Alkanesulfonic Acids; Antioxidants; Catalase; Cell Membrane Permeability; Chlorella vulgaris; Chlorophyll; Fluorocarbons; Malondialdehyde; Oxidative Stress; Reactive Oxygen Species; Superoxide Dismutase

A vegetation study was conducted to investigate the interactive effects of perfluoroalkyl substances (PFASs), including perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), and Cadmium (Cd) on soil enzyme activities, phytotoxicity and bioaccumulation of wheat (Triticum aestivum L.) and rapeseed (Brassica campestris L.) from co-contaminated soil. Soil urease activities were inhibited significantly but catalase activities were promoted significantly by interaction of PFASs and Cd which had few effects on sucrase activities. Joint stress with PFASs and Cd decreased the biomass of plants and chlorophyll (Chl) content in both wheat and rapeseed, and malondialdehyde (MDA) content, superoxide dismutase (SOD) and peroxidase (POD) activities were increased in wheat but inhibited in rapeseed compared with single treatments. The bioconcentration abilities of PFASs in wheat and rapeseed were decreased, and the translocation factor of PFASs was decreased in wheat but increased in rapeseed with Cd addition. The bioaccumulation and translocation abilities of Cd were increased significantly in both wheat and rapeseed with PFASs addition. These findings suggested important evidence that the co-existence of PFASs and Cd reduced the bioavailability of PFASs while enhanced the bioavailability of Cd in soil, which increased the associated environmental risk for Cd but decreased for PFASs.

Topics: Alkanesulfonic Acids; Biomass; Brassica rapa; Cadmium; Caprylates; Chlorophyll; Drug Interactions; Environmental Pollution; Fluorocarbons; Malondialdehyde; Soil; Soil Pollutants; Superoxide Dismutase; Triticum

Toxic effects of different concentrations (0.1-200mgL(-1)) of perfluorooctane sulfonate (PFOS) on wheat (Triticumaestivum L.) were investigated using the growing and developmental indexes of wheat, including length and biomass of roots and leaves, chlorophyll, soluble protein, peroxidase (POD), superoxide dismutase (SOD) in the seedlings and permeability of root cells. The results showed that PFOS had significant (p<0.05) effects on the growth of wheat seedlings under the experimental conditions. At the low concentration (less than 10mgL(-1)), PFOS could slightly stimulate the growth of wheat seedlings and induce the synthesis of chlorophyll and soluble protein in wheat seedlings, and whereas exceeding 10mgL(-1) PFOS treatment could exert inhibition to the elongation and biomass of roots and leaves, and lead to damage to chlorophyll accumulation and soluble protein synthesis. Furthermore, the activities of SOD and POD in wheat roots and leaves were enhanced in the tested PFOS concentrations of 0.1-10mgL(-1). However, when the concentration of PFOS was raised up to 200mgL(-1), the activity of SOD and POD decreased significantly with 12.6% and 33.7% inhibition for roots compared to the control respectively, which indicated the antioxidative defensive system in wheat seedlings might be damaged by PFOS. In addition, the permeability of wheat root cells was enhanced at the tested concentration of 0.1-200mgL(-1). When the concentration was increased to 200mgL(-1), the electrolyte leakage was promoted 2.73 times higher than in the control.

Topics: Alkanesulfonic Acids; Cell Membrane Permeability; Chlorophyll; Fluorocarbons; Peroxidases; Plant Leaves; Plant Proteins; Plant Roots; Seedlings; Soil Pollutants; Superoxide Dismutase; Triticum

Perfluorooctane sulfonic acid (PFOS) is an anthropogenic contaminant detected in various environmental and biologic matrices. This compound is a fluorinated surfactant, a class of molecules renowned for their persistence and their global distribution but for which few ecotoxicological data are currently available, especially under field conditions. The toxicity of PFOS to the aquatic macrophytes Myriophyllum sibiricum and M. spicatum was investigated using 12,000 L outdoor microcosms. Replicate microcosms (n = 3) were treated with 0.3, 3, 10, and 30 mg/L PFOS as the potassium salt and assessed at regular intervals during a period of 42 days. M. sibiricum was more sensitive to PFOS under these simulated field conditions than M. spicatum. Toxicity was observed in the evaluated end points at > 3 mg/L PFOS for EC10s and > 12 mg/L PFOS for EC50s for M. spicatum and in M. sibiricum at > 0.1 mg/L PFOS for EC10s and > 1.6 mg/L PFOS for EC50s. The no observed-effect concentration (NOEC) for M. spicatum was consistently > or = 11.4 mg/L PFOS, whereas the NOEC for M. sibiricum was > or = 0.3 mg/L PFOS. A risk assessment for these plants estimated a negligible probability of toxicity being observed in these plants from PFOS exposure at current environmental concentrations.

Topics: Alkanesulfonic Acids; Carotenoids; Chlorophyll; Chlorophyll A; Fluorocarbons; Magnoliopsida; No-Observed-Adverse-Effect Level; Plant Roots; Risk Assessment; Water Pollutants, Chemical

There is presently a substantial amount of information being gathered concerning the environmental risk associated with the perfluorooctane sulfonate (PFOS) compound. The U.S. Environmental Protection Agency (U.S. EPA) is requiring that more research be completed before making definitive decisions concerning the regulatory issues covered in the significant new use rule (18/10-2000) under the Toxic Substance Control Act. However, there are no risk assessment requirements under seminatural conditions in microcosms. The PFOS can enter, and has been found in, the aquatic environment through different pathways, including spills associated with use of fire-fighting foams containing PFOS, leaching from washing Scotchgard-treated clothes with the wastewater, leaching from various coatings, discharges as residual waste from fluorochemical production, or volatilization and transportation atmospherically. The biota is the sink of PFOS rather than the sediment or soil. The aim of this article is to determine a 35-d community no-observable-effect concentration (NOECcommunity) for freshwater zooplankton and the fate of PFOS during the course of study. The PFOS persisted in the water phase with only slight reductions over the study; only the decrease from 33.9 mg/L at day 1 to 29.8 mg/L at day 35 was significant. A 90 to 100% reduction (p < 0.01) of the total zooplankton population was found after one week of exposure to 30 mg PFOS/L and a similar reduction after two weeks at 10 mg PFOS/L. The Daphnia magna 21-d NOECsurvival of 12 mg/L has previously been found in a standard laboratory bioassay by 3M. The rank order of susceptibility for the test community was Copepoda > Cladocera > Rotifera, assuming all adverse direct effects.

Topics: Alkanesulfonic Acids; Animals; Chlorophyll; Chromatography, Ion Exchange; Cladocera; Copepoda; Ecology; Environment; Fluorocarbons; No-Observed-Adverse-Effect Level; Risk Assessment; Rotifera; Species Specificity; Water Pollutants, Chemical; Zooplankton