The Movement, Persistence, and Fate of the Phenoxy Herbicides and TCDD in the Forest

Norris, Logan A.

doi:10.1007/978-1-4612-5913-8_2

Cited by 39 publications

(20 citation statements)

References 104 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[34,298] FIELD HALF LIFE (days): rapid decline in level of ester in soil (9.2 mglkg immediately after spraying, 1.6 mglkg 3 days later and <0.04 mglkg in 32 days) but no concomitant increase in acid form. [224]; butyl ester: rapid hydrolysis of the ester to the acid makes detection unlikely after a few days [193]; hydrolysis: after 24h in soil at wilting point moisture and above less than 20% of iso-propyl and n-butyl esters could be recovered. [153,245]; 500000 [326]; sodium salt very soluble > 600000 [245,246]; 4250 (acid) [294]; 5000 (methyl ester) [153]; 24C: 4000 [235]; 550000 [116] FIELD HALF LIFE (days): 5-15 [326,327] [59]; 400 (tlc) [232]; 2100 [120,236]; 1900 (30%) [247] VAPOR PRESSURE (mm Hg): 20C: < 10.…”

Section: Appendix B: the Datamentioning

confidence: 99%

Pesticide Properties in the Environment

1996

View full text Add to dashboard Cite

Section: Appendix B: the Datamentioning

confidence: 99%

Pesticide Properties in the Environment

1996

View full text Add to dashboard Cite

“…Soil moisture, temperature, pH, and the formulation of 2,4-D, however, are found to alter the degradation rate [Torstensson, 1975;Norris, 1981]. Degradation of dicamba in soil is thought to be primarily by microorganisms [USDA, 1999].…”

Section: Introductionmentioning

confidence: 99%

Modulation of the genotoxicity of pesticides reacted with redox‐modified smectite clay

Sorensen¹,

Stucki²,

Warner³

et al. 2005

Environ and Mol Mutagen

View full text Add to dashboard Cite

Pesticides are toxic agents intentionally released into the environment; their use raises public health and environmental concerns. In recent years there has been much attention to the biotic degradation of pesticides. Abiotic mechanisms in the soil can contribute to pesticide degradation yet the toxicological impact of such degradation is unclear. This study combines for the first time an investigation into abiotic mechanisms of degradation coupled with toxicological endpoints in mammalian cells. The genotoxicity of three commonly used agricultural pesticides was assessed before and after exposure to redox-modified clay minerals. The objectives of the study were to determine the genotoxicity of 2,4-dichlorophenoxy acetic acid (2,4-D), dicamba, and oxamyl, using single cell gel electrophoresis with Chinese hamster ovary (CHO) cells, and to determine the effect of the iron oxidation state in clay minerals (ferruginous smectite SWa-1) on the genotoxic potency of the pesticides. 2,4-D alone or following reaction with redox-modified clays did not induce DNA damage in CHO cells. Oxamyl alone induced a concentration-dependent increase in genomic DNA damage; however, its genotoxicity declined after reaction with reduced clay minerals. Dicamba was not genotoxic when directly analyzed. When dicamba was reacted with reduced clay, a concentration-dependent increase in genomic DNA damage was observed. This is the first reported case of a pesticide being converted into a genotoxin after exposure to redox-modified smectites. These data introduce a new paradigm on the interaction between redox-modified clays and pesticide-related environmental genotoxicity.

show abstract

“…The site had received some treatment with 2,4,5-T about 1 year before this trial so that it was not surprising to find detectable residues. Literature values for the soil half-life of 2,4,5-T (acid) are 35 ± 20 days (Cain 1980;Norris 1981) so that on this basis up to 2% of the original material might have still persisted in the soil as 2,4,5-T (acid) after 1 year. Little has been said previously about the persistence or mobility of 2,4,5-TCP and it is interesting to observe that this was the principal residue form in the first soil profiles ( -16 days).…”

Section: Vegetationmentioning

confidence: 97%

“…The esters are readily absorbed by plant tissue and are hydrolysed to the acid form, which is the active herbicide (Shaw et al 1960;Loos 1969). The acid form undergoes further slow hydrolysis in soil, vegetation, and water to give 2,4,S-trichlorophenol (2,4,S-TCP) (Loos 1969;Norris 1981). The products of further breakdown are unlikely to be of environmental significance.…”

Section: Environmental Significancementioning

confidence: 99%

“…Other studi~s on the environmental fate of 2,4,5-T reported m the literature have not observed the build-up of phenolic intermediates that might be toxic and have only monitored the disappearance of the parent material (NRCC 1978). The 2,4,5-T compounds tend not to accumulate in the food chain, although bio-accumulation ratios (i.e., concentration in organism divided by concentration in ambient water) of about 50 have been observed in algae (Norris 1981).…”

Section: Environmental Significancementioning

confidence: 99%

See 1 more Smart Citation

Soil, water, and vegetation residues of 2,4,5-T applied to a New Zealand hillside

Fox¹,

Wilcock²

1988

New Zealand Journal of Agricultural Research

View full text Add to dashboard Cite

A steep hill country area (1.66 hal of gorse and pasture was sprayed with 2,4,S-T butyl ester by air. Soil and vegetation samples were collected at regular intervals and a stream at the bottom of the trial area was monitored continuously over 6 months. Only 0.6070 of the applied herbicide entered the stream during the trial, with 0.4070 being washed out in the first storm. Measurable traces of the original ester formulation, 2,4,S-T (acid), and the principal breakdown product, 2,4,S-trichlorophenol (2,4,S-TCP), with a combined average of about 0.4 mg/kg, were found in pasture vegetation 6 months after initial application. The persistence of these residues may be a cause of dietary intake by grazing livestock. Soil residues (expressed as butyl ester) persisted throughout the study, principally as 2,4,S-TCP (12-100 ng/g after 18S days), and were also detected from a treatment 1 year before the trial began (20 -90 ng/ g). An estimate of the masses of residues and losses 6 days after spraying accounted for about 20% of the applied mass. A significant part of the balance (80%) is thought to have been lost in spray drift.

show abstract

The Movement, Persistence, and Fate of the Phenoxy Herbicides and TCDD in the Forest

Cited by 39 publications

References 104 publications

Pesticide Properties in the Environment

Pesticide Properties in the Environment

Modulation of the genotoxicity of pesticides reacted with redox‐modified smectite clay

Soil, water, and vegetation residues of 2,4,5-T applied to a New Zealand hillside

Contact Info

Product

Resources

About