Genotoxicity of mixtures of glyphosate and atrazine and their environmental transformation products before and after photoactivation

AbstractThe active herbicide ingredient glyphosate [N-(phosphonomethyl)glycine] is frequently detected as a contaminant in groundwater and surface waters. This study investigated effects of UV-A (365 nm), UV-B (302 nm) and UV-C (254 nm) irradiation of glyphosate in water on photolysis and toxicity to aquatic organisms from different trophic levels. A test battery with bacteria (Bacillus subtilis, Aliivibrio fischeri), a green microalga (Raphidocelis subcapitata), and a crustacean (Daphnia magna) was used to assess biological effect of glyphosate and bioactive transformation products before and after UV irradiation (4.7–70 J/cm2). UV-C irradiation at 20 J/cm2 resulted in a 2–23-fold decrease in toxicity of glyphosate to aquatic test organisms. UV-B irradiation at 70 J/cm2 caused a twofold decrease whereas UV-A did not affect glyphosate toxicity at doses ≤ 70 J/cm2. UV-C irradiation of glyphosate in drinking water and groundwater with naturally occurring organic and inorganic constituents showed comparable or greater reduction in toxicity compared to irradiation in deionized water. High-resolution mass spectrometry analyses of samples after UV-C irradiation showed > 90% decreases in glyphosate concentrations and the presence of multiple transformation products. The study suggests that UV mediated indirect photolysis can decrease concentrations of glyphosate and generate less toxic products with decreased overall toxicity to aquatic organisms.

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Submicron polymer particles may mask the presence of toxicants in wastewater effluents probed by reporter gene containing bacteria

Scientific Reports ◽

10.1038/s41598-021-86672-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Bhuvaneshwari Manivannan ◽

Evgeni Eltzov ◽

Mikhail Borisover

Keyword(s):

Transformation Products ◽

Toxic Chemicals ◽

Submicron Particles ◽

Treated Wastewater ◽

Masking Effect ◽

Polymer Particles ◽

Toxic Compounds ◽

Toxic Material ◽

Before And After ◽

Biomonitoring Tool

AbstractMicroplastics are ubiquitous in aquatic systems and break down into submicron particles that can interact with aquatic toxic chemicals. These interactions may affect the detection of toxicants when using bacteria as a biomonitoring tool. This study examined the effects of model polystyrene (PS)-based submicron particles on the detection of aqueous geno- and cytotoxicity by genetically modified bioluminescent (GMB) bacteria. The toxicities were tested in three treated wastewater (TWW) effluents before and after chlorination. The PS plastics included negatively charged sulfate-coated (S-PS) and pristine (P-PS) particles of different sizes (0.1, 0.5, and 1.0 µm) that were present at different concentrations. Chlorinated or not, the S-PS and P-PS particles per se were not toxic to the GMB bacteria. However, exposure of PS particles to TWW effluents can significantly reduce the measured geno- and cytotoxicity. Adsorption of toxic compounds to polymer particles can limit the ability of the bacteria to detect those compounds. This masking effect may be mitigated by TWW chlorination, possibly due to the formation of new toxic material. Due to interactions between toxic TWW constituents and the plastics particles, water samples containing particle-associated contaminants and/or their transformation products may be declared non-toxic, based on bacterial tests as a biomonitoring tool.

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Monitoring of malathion and its impurities and environmental transformation products on surfaces and in air following an aerial application

Environmental Science & Technology ◽

10.1021/es00039a020 ◽

1993 ◽

Vol 27 (2) ◽

pp. 388-397 ◽

Cited By ~ 31

Author(s):

Mark A. Brown ◽

Myrto X. Petreas ◽

Howard S. Okamoto ◽

Thomas M. Mischke ◽

Robert D. Stephens

Keyword(s):

Transformation Products ◽

Aerial Application ◽

Environmental Transformation

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Fate of triclosan in tertiary wastewater treatment: chlorination

Water Quality Research Journal ◽

10.2166/wqrjc.2013.108 ◽

2013 ◽

Vol 48 (4) ◽

pp. 333-343 ◽

Cited By ~ 1

Author(s):

Jennifer Pape ◽

Million B. Woudneh ◽

Richard Grace ◽

A. Ronald MacGillivray ◽

Thomas Fikslin ◽

...

Keyword(s):

Wastewater Treatment ◽

Municipal Wastewater ◽

Wastewater Treatment Plants ◽

Treatment Plant ◽

Transformation Products ◽

Residual Chlorine ◽

Municipal Wastewater Treatment ◽

Delaware River ◽

Before And After ◽

Wastewater Samples

Behavior of the antimicrobial triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol) was investigated under laboratory chlorination conditions and in a wastewater treatment plant discharging 380 million liters daily to the Delaware River, USA. Reactions of triclosan with chlorine were investigated using concentrations and exposure time typical of municipal wastewater treatment plants, i.e., 1 h contact time and average 1–2 mg/L residual chlorine. In reagent water, triclosan reacted quickly, transforming into mono- and dichlorinated species and further into dichlorophenol and trichlorophenol. However, triclosan remained stable for up to 2 h in wastewater samples chlorinated under these conditions. To confirm observed behavior under field conditions, a liquid chromatography tandem mass spectrometry-based analytical method capable of monitoring triclosan and its transformation products in wastewater was developed. Qualitative and quantitative wastewater characterization before and after chlorination are presented. Triclosan was present at the same concentration (P > 0.05) in pre-chlorination and post-chlorination aqueous wastewater samples (mean 368 ng/L). This finding is consistent with the non-detection of specific triclosan transformation products above sample reporting limits (30.0–100 ng/L), but contrasts markedly with detection of chlorination transformation products reported in reagent water. These data suggest the importance of influent matrix components in chlorination reactions of triclosan in contaminated wastewater under treatment plant conditions.

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Environmental transformation products of 2,4,6-trinitrotoluene

Chemical Speciation and Bioavailability ◽

10.3184/095422998782775844 ◽

1998 ◽

Vol 10 (2) ◽

pp. 47-52 ◽

Cited By ~ 7

Author(s):

Thomas Junk ◽

W. James Catallo

Keyword(s):

Transformation Products ◽

Environmental Transformation

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Framework for Evaluating the Fate, Transport, and Risks From Conventional Munitions Compounds in Underwater Environments

Marine Technology Society Journal ◽

10.4031/mtsj.45.6.10 ◽

2011 ◽

Vol 45 (6) ◽

pp. 35-46 ◽

Cited By ~ 6

Author(s):

Harry D. Craig ◽

Susan Taylor

Keyword(s):

Fate And Transport ◽

Transformation Products ◽

Ecological Risks ◽

Energetic Compounds ◽

Environmental Transformation

AbstractLegacy underwater munitions may leak munitions constituents and, thereby, contaminate the environment and expose people to energetic compounds. This paper reviews the sources of underwater munitions, how munitions compounds are released, and their fate and transport characteristics. Because some of these energetic compounds and their environmental transformation products are toxic, we also describe the types of data needed to evaluate potential human and ecological risks at underwater munitions sites.

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