scholarly journals DDT—The Persistent Pesticide (Onscreen)

2013 ◽  
Vol 59 (4) ◽  
pp. 196-198
Author(s):  
May Berenbaum
Keyword(s):  
Persistent Pesticide

Fabrication of Pd-TiO2 nanotube photoactive junctions via Atomic Layer Deposition for persistent pesticide pollutants degradation

2019 ◽  
Vol 483 ◽  
pp. 219-230 ◽  
Author(s):  
Andrea Merenda ◽  
Matthieu Weber ◽  
Mikhael Bechelany ◽  
Francois-Marie Allioux ◽  
Lachlan Hyde ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Atomic Layer ◽  
Tio2 Nanotube ◽  
Layer Deposition ◽  
Persistent Pesticide

scholarly journals Microbial Communities Associated with Sustained Anaerobic Reductive Dechlorination of α-, β-, γ-, and δ-Hexachlorocyclohexane Isomers to Monochlorobenzene and Benzene

2019 ◽  
Author(s):  
Wenjing Qiao ◽  
Luz A. Puentes Jácome ◽  
Xianjin Tang ◽  
Line Lomheim ◽  
Minqing Ivy Yang ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Amplicon Sequencing ◽  
Contaminated Sites ◽  
Molar Ratio ◽  
Rrna Gene ◽  
Absolute Abundance ◽  
Hch Isomers ◽  
Persistent Pesticide ◽  
Hexachlorocyclohexane Isomers ◽  
Archaeal Communities

AbstractIntensive historical and worldwide use of the persistent pesticide technical-grade hexachlorocyclohexane (HCH), composed of the active ingredient γ-HCH (called lindane) along with several other HCH isomers, has led to widespread contamination. We derived four anaerobic enrichment cultures from HCH-contaminated soil capable of sustainably dechlorinating each of α-, β-, γ-, and δ-HCH isomers stoichiometrically and completely to benzene and monochlorobenzene (MCB). For each isomer, the dechlorination rates increased progressively from <3 µM/day to ∼12 µM/day over two years. The molar ratio of benzene to MCB produced was a function of the substrate isomer, and ranged from β (0.77±0.15), α (0.55±0.09), γ (0.13±0.02) to δ (0.06±0.02) in accordance with pathway predictions based on prevalence of antiperiplanar geometry. Cultivation with a different HCH isomer resulted in distinct bacterial communities, but similar archaeal communities. Data from 16S rRNA gene amplicon sequencing and quantitative PCR revealed significant increases in the absolute abundance of Pelobacter and Dehalobacter, especially in the α-HCH and δ-HCH cultures. This study provides the first direct comparison of shifts in anaerobic microbial communities induced by the dechlorination of distinct HCH isomers. It also uncovers candidate microorganisms responsible for the dechlorination of α-, β-, γ-, and δ-HCH, a key step towards better understanding and monitoring of natural attenuation processes and improving bioremediation technologies for HCH-contaminated sites.

Concentration of Pesticides Slowly Released by Diffusion

Weed Science ◽  
1973 ◽  
Vol 21 (4) ◽  
pp. 343-349 ◽  
Author(s):  
R. L. Collins ◽  
S. Doglia
Keyword(s):  
Order Rate Constant ◽  
Degradable Polymers ◽  
First Order ◽  
Plant Parts ◽  
Order Rate ◽  
Active Concentration ◽  
Persistent Pesticide ◽  
Long Term Behavior ◽  
Approximate Result

The active concentration of a pesticide declines with time due to volatilization, absorption and translocation, microbial degradation, adsorption on soil particles and plant parts, chemical reactions, photodecomposition, and other reactions with the environment. However, slow-release formulations can provide a continuing input of pesticide. This leads to a rise and subsequent fall in the active concentration. Because diffusion is a factor in most controlled release methodologies, the concentration to be expected for release by diffusion of a substance, which then decays with time by a first order rate law, is examined theoretically. This provides guidance to the experimenter for separating the effects due to diffusion from these attributable to other and newer concepts such as water-degradable polymers. An approximate result of this exact solution is that the persistence of the substance can be increased. More precisely, the long-term behavior is like that of a more persistent pesticide with smaller first-order rate constant.

Photocatalytic degradation of Triclopyr, a persistent pesticide by ZnO/SnO2 nano-composities

2019 ◽  
Vol 19 ◽  
pp. 642-645 ◽  
Author(s):  
Suprabha Yadav ◽  
Naveen Kumar ◽  
Vijaya Kumari ◽  
Anuj Mittal ◽  
Shankar Sharma
Keyword(s):  
Photocatalytic Degradation ◽  
Persistent Pesticide

Mirex: Persistent Pesticide on Its Way Out

Science ◽  
1976 ◽  
Vol 194 (4262) ◽  
pp. 301-303 ◽  
Author(s):  
C. HOLDEN
Keyword(s):  
Persistent Pesticide

scholarly journals Effects of Chlorophenoxy Herbicides and Their Main Transformation Products on DNA Damage and Acetylcholinesterase Activity

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Sofia Benfeito ◽  
Tiago Silva ◽  
Jorge Garrido ◽  
Paula B. Andrade ◽  
M. J. Sottomayor ◽  
...  
Keyword(s):  
Double Helix ◽  
Acetylcholinesterase Activity ◽  
Transformation Products ◽  
Transformation Product ◽  
Dna Interaction ◽  
Visible Absorption ◽  
Persistent Pesticide ◽  
Chlorophenoxy Herbicides ◽  
Pesticide Transformation Products ◽  
The Stability

Persistent pesticide transformation products (TPs) are increasingly being detected among different environmental compartments, including groundwater and surface water. However, there is no sufficient experimental data on their toxicological potential to assess the risk associated with TPs, even if their occurrence is known. In this study, the interaction of chlorophenoxy herbicides (MCPA, mecoprop, 2,4-D and dichlorprop) and their main transformation products with calf thymus DNA by UV-visible absorption spectroscopy has been assessed. Additionally, the toxicity of the chlorophenoxy herbicides and TPs was also assessed evaluating the inhibition of acetylcholinesterase activity. On the basis of the results found, it seems that AChE is not the main target of chlorophenoxy herbicides and their TPs. However, the results found showed that the transformation products displayed a higher inhibitory activity when compared with the parent herbicides. The results obtained in the DNA interaction studies showed, in general, a slight effect on the stability of the double helix. However, the data found for 4-chloro-2-methyl-6-nitrophenol suggest that this transformation product can interact with DNA through a noncovalent mode.

DDT: In Field and Courtroom a Persistent Pesticide Lives On

Science ◽  
1971 ◽  
Vol 174 (4014) ◽  
pp. 1108-1110 ◽  
Author(s):  
R. Gillette
Keyword(s):  
Persistent Pesticide

Mussel watch of PCBs and persistent pesticide residues in Perna viridis Linnaeus from Malaysian and Singapore waters

1982 ◽  
Vol 2 (3) ◽  
pp. 231-237 ◽  
Author(s):  
P.M. Sivalingam ◽  
I. Allapitchay ◽  
H. Kojima ◽  
T. Yoshida
Keyword(s):  
Pesticide Residues ◽  
Perna Viridis ◽  
Mussel Watch ◽  
Persistent Pesticide
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