The fate of 2,4-dichlorophenoxyacetic acid (2,4-D) following oral administration to man

Strategic Biomonitoring Initiatives: Moving the Science Forward

“…An exposure was usually a single event; there was a known period of chemical handling; and multiple urine samples were collected around the event. Urinary excretion rates of 2,4-D showed a pattern consistent with previously reported uptake and elimination rates (Sauerhoff et al, 1977). The relationship between exposure measurements and urine concentrations was statistically significant.…”

Strategic Biomonitoring Initiatives: Moving the Science Forward

“…An exposure was usually a single event; there was a known period of chemical handling; and multiple urine samples were collected around the event. Urinary excretion rates of 2,4-D showed a pattern consistent with previously reported uptake and elimination rates (Sauerhoff et al, 1977). The relationship between exposure measurements and urine concentrations was statistically significant.…”

(2,4-Dichlorophenoxy)acetic acid exposure received by aerial application crews during forest spray operations

“…The differences between T-l and T-2 might have been greater if all the 2,4-D absorbed during T-l had been excreted before T-2 began. Nevertheless, if 2,4-D in this study was excreted in a manner similar to the data presented by Sauerhoff et al (1977), then over 95% of the 2.4-D dose from T-l would have been excreted in the week prior to initiating T-2. Five workers in crews 2 and 3, with duties as pilot, mechanics, and batchman-loaders, came into T-l with low levels of 2,4-D in their urine (Table VI). These findings were confirmed by using two gas chromatographic columns and two different methylating agents.…”

Phenoxy Herbicides (2,4-D)

“…Lower doses (i.e., 3 mg/kg body weight) in rats showed half-lives of 0.5 to 0.8 hours (Khanna and Fang, 1966), indicating that clearance rates are highly dependent on dose. In human studies, plasma clearance of orally administered 2,4-D was found to follow first-order kinetics with urinary excretion half-lives ranging from 10.2 to 28.4 hours (Sauerhoff et al, 1977), which is consistent with the findings (urinary excretion half-life  18 hours) from a forestry worker who exhibited the highest amount of 2,4-D excretion among two groups exposed over a period of 11 or 18 days (Frank et al, 1985).…”

Strategic Biomonitoring Initiatives: Moving the Science Forward

“…An exposure was usually a single event; there was a known period of chemical handling; and multiple urine samples were collected around the event. Urinary excretion rates of 2,4-D showed a pattern consistent with previously reported uptake and elimination rates (Sauerhoff et al, 1977). The relationship between exposure measurements and urine concentrations was statistically significant.…”

(2,4-Dichlorophenoxy)acetic acid exposure received by aerial application crews during forest spray operations

“…The differences between T-l and T-2 might have been greater if all the 2,4-D absorbed during T-l had been excreted before T-2 began. Nevertheless, if 2,4-D in this study was excreted in a manner similar to the data presented by Sauerhoff et al (1977), then over 95% of the 2.4-D dose from T-l would have been excreted in the week prior to initiating T-2. Five workers in crews 2 and 3, with duties as pilot, mechanics, and batchman-loaders, came into T-l with low levels of 2,4-D in their urine (Table VI). These findings were confirmed by using two gas chromatographic columns and two different methylating agents.…”

Phenoxy Herbicides (2,4-D)

“…Lower doses (i.e., 3 mg/kg body weight) in rats showed half-lives of 0.5 to 0.8 hours (Khanna and Fang, 1966), indicating that clearance rates are highly dependent on dose. In human studies, plasma clearance of orally administered 2,4-D was found to follow first-order kinetics with urinary excretion half-lives ranging from 10.2 to 28.4 hours (Sauerhoff et al, 1977), which is consistent with the findings (urinary excretion half-life  18 hours) from a forestry worker who exhibited the highest amount of 2,4-D excretion among two groups exposed over a period of 11 or 18 days (Frank et al, 1985).…”

Strategic Biomonitoring Initiatives: Moving the Science Forward

“…An exposure was usually a single event; there was a known period of chemical handling; and multiple urine samples were collected around the event. Urinary excretion rates of 2,4-D showed a pattern consistent with previously reported uptake and elimination rates (Sauerhoff et al, 1977). The relationship between exposure measurements and urine concentrations was statistically significant.…”

(2,4-Dichlorophenoxy)acetic acid exposure received by aerial application crews during forest spray operations

“…The differences between T-l and T-2 might have been greater if all the 2,4-D absorbed during T-l had been excreted before T-2 began. Nevertheless, if 2,4-D in this study was excreted in a manner similar to the data presented by Sauerhoff et al (1977), then over 95% of the 2.4-D dose from T-l would have been excreted in the week prior to initiating T-2. Five workers in crews 2 and 3, with duties as pilot, mechanics, and batchman-loaders, came into T-l with low levels of 2,4-D in their urine (Table VI). These findings were confirmed by using two gas chromatographic columns and two different methylating agents.…”

Phenoxy Herbicides (2,4-D)

“…Lower doses (i.e., 3 mg/kg body weight) in rats showed half-lives of 0.5 to 0.8 hours (Khanna and Fang, 1966), indicating that clearance rates are highly dependent on dose. In human studies, plasma clearance of orally administered 2,4-D was found to follow first-order kinetics with urinary excretion half-lives ranging from 10.2 to 28.4 hours (Sauerhoff et al, 1977), which is consistent with the findings (urinary excretion half-life  18 hours) from a forestry worker who exhibited the highest amount of 2,4-D excretion among two groups exposed over a period of 11 or 18 days (Frank et al, 1985).…”