Factors affecting the exposure of ground- rig applicators to 2,4-D dimethylamine salt

Research paper by R. Grover, A. J. Cessna, N. I. Muir, D. Riedel, C. A. Franklin, K. Yoshida

Indexed on: 01 Nov '86Published on: 01 Nov '86Published in: Archives of Environmental Contamination and Toxicology


This is a report on exposure to and absorption of the herbicide 2,4-D dimethylamine salt by farmers carrying out spray operations with tractor-drawn ground-rigs, involving handling, transferring, mixing, and applying the herbicide to wheat. The 30 individual spray operations lasted 55 to 870 min, and involved 1 to 11 tank fills, and application of 6.7 to 88.3 kg 2,4-D (acid equivalent, a.e.) to 16 to 194 ha.Air sampling, hand washes and clothing patch techniques served as a basis to calculate the amount of 2,4-D available for inhalation, and deposition on the hands and under the clothing. The “cumulative potential exposure” was calculated as the total amount of 2,4-D (a.e.) which could have come into contact with the body by both the inhalation and dermal routes of exposure. The calculated amount inhaled accounted for less than 2% of the calculated potential cumulative exposure, while deposition on the hands accounted for 80 to 90% of the potential cumulative exposure. The 2,4-D deposition on the rest of the body ranged from 10 to 20% of the potential cumulative exposure.Urinary 2,4-D excretion accounted for 1 to 2% of the potential cumulative exposure. The total calculated amount of 2,4-D deposited on the body (minus the hands) and the total amount excreted in the urine were highly correlated with the number of tank fills, area sprayed, amount sprayed, and duration of the spray operation.