Canine exposure to herbicide-treated lawns and urinary excretion of 2,4-dichlorophenoxyacetic acid

• Published in: Cancer epidemiology, biomarkers & prevention Vol. 3; no. 3; p. 233
• Main Authors: Reynolds, P M, Reif, J S, Ramsdell, H S, Tessari, J D
• Format: Journal Article
• Language: English
• Published: United States American Association for Cancer Research 01.04.1994
• Subjects: 2,4-Dichlorophenoxyacetic Acid - adverse effects; 2,4-Dichlorophenoxyacetic Acid - pharmacokinetics; 2,4-Dichlorophenoxyacetic Acid - urine; Animals; Confidence Intervals; Dog Diseases - chemically induced; Dog Diseases - epidemiology; Dogs - urine; Environmental Monitoring; Epidemiological Monitoring; Lymphoma - chemically induced; Lymphoma - epidemiology; Lymphoma - veterinary; Metabolic Clearance Rate; Odds Ratio; Poaceae; Risk Factors; Sampling Studies; Surveys and Questionnaires; Time Factors
• ISSN: 1055-9965; 1538-7755

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.