Canine exposure to herbicide-treated lawns and urinary excretion of 2,4-dichlorophenoxyacetic acid.
A recent study by Hayes et al. (J. Natl. Cancer. Inst., 83: 1226-1231, 1991) found an increased risk of malignant lymphoma associated with exposure to 2,4-dichlorophenoxyacetic acid (2,4-D) in pet dogs. We conducted a study to determine the extent to which dogs absorb and excrete 2,4-D in urine after contact with treated lawns under natural conditions. Among 44 dogs potentially exposed to 2,4-D-treated lawns an average of 10.9 days after application, 2,4-D concentrations greater than or equal to 10.0 micrograms/l were found in 33 dogs (75%) and concentrations of > or = 50 micrograms/l were found in 17 (39%). Among 15 dogs with no known exposure to a 2,4-D-treated lawn in the previous 42 days, 4 (27%) had evidence of 2,4-D in urine, 1 at a concentration of > or = 50 micrograms/l. The odds ratio for the association between exposure to a 2,4-D-treated lawn and the detection of > or = 50 micrograms/l 2,4-D in urine was 8.8 (95% confidence interval, 1.4-56.2). Dogs exposed to lawns treated within 7 days before urine collection were more than 50 times as likely to have 2,4-D at concentrations > or = 50 micrograms/l than dogs with exposure to a lawn treated more than 1 week previously (odds ratio = 56.0; 95% confidence interval, 10.0-312.2). The highest mean concentration of 2,4-D in urine (21.3 mg/l) was found in dogs sampled within 2 days after application of the herbicide.(ABSTRACT TRUNCATED AT 250 WORDS)
Reynolds
P M
PM
Department of Environmental Health, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins 80523.
Reif
J S
JS
Ramsdell
H S
HS
Tessari
J D
JD
D015084:2,4-Dichlorophenoxyacetic Acid / Q000009:adverse effects / Q000493:pharmacokinetics / Q000652:urine*; D000818:Animals; D016001:Confidence Intervals; D004283:Dog Diseases / Q000139:chemically induced / Q000453:epidemiology; D004285:Dogs / Q000652:urine*; D004784:Environmental Monitoring; D062665:Epidemiological Monitoring; D008223:Lymphoma / Q000139:chemically induced / Q000453:epidemiology / Q000662:veterinary; D008657:Metabolic Clearance Rate; D016017:Odds Ratio; D006109:Poaceae; D012307:Risk Factors; D012494:Sampling Studies; D011795:Surveys and Questionnaires; D013997:Time Factors
D015084:2,4-Dichlorophenoxyacetic Acid