Occupational exposure of herbicide applicators to herbicides used along electric power transmission line right-of-way.

Occupational exposures to herbicides were measured among 12 applicators in 1979 and 24 applicators in 1980, who were applying the three herbicides, 2,4-D, dichloroprop and picloram to electric power transmission rights of ways. In 1979 only urine was analyzed but in 1980 both breathing-zone air samples and urine were analyzed for herbicide residues. Dermal absorption was found to be the major absorption route being up to 50 times greater than exposure by the inhalation route when using a hand gun sprayer. Even with the mist blower herbicide application method, dermal absorption was 4 and 11 times greater than exposure by the inhalation route. Worker education on hazards of skin contact and improved protective equipment significantly reduced the 1980 urine concentrations of herbicide residues. A model is presented to relate the urinary concentrations to equivalent daily exposure levels.

Residues of polychlorinated phenols and anisoles in broilers raised on contaminated woodshaving litter.

Broilers were raised for 8 weeks on litter made up of woodshavings containing high (700 micrograms/g) levels of contamination with polychlorinated phenols (PCP). The PCP levels declined in the litter over the test period while polychlorinated anisoles (PCA) increased in the highly contaminated litter. Final weights of the birds was only slightly different; however, feed conversion was slightly higher for those birds raised in the highly contaminated pens. Panelists rated the cooked samples from the birds raised on highly contaminated litter significantly lower for flavor and overall acceptability than either of the lower PCP level treatments. Residues of the odiferous pentechloroanisole were present in muscle and fat of the birds raised on the highly contaminated litter; however, residues in muscles of the birds on low level contaminated litter could not be detected. Polychlorinated anisoles were present in the fat of birds raised on normal litter but adjacent to the contaminated pens.

Herbicide contamination and decontamination of well waters in Ontario, Canada, 1969-78.

OVER THE 10-YEAR period 1969-78, the waters of 237 wells were analyzed because of contamination from herbicide spillage in or near the well, complaints of impaired water flavor, or injury to seedling plants moistened with the well water. Herbicides were identified in 159 wells: 98 had a single herbicide, 46 had two, 12 had three, one had four, and another had five separate herbicides contributing to the contamination. Wells were grouped according to the mode of entry of the contaminant. Entry occurred most commonly as an aerial spray fdrift or in runoff. Serious contaminations were caused by spillage of herbicide concentrates and spray solutions in or around the well. Twenty-four of the contaminated wells were further investigated to determine the persistence of the contaminant and how to remove it. Some wells were decontaminated adequately to allow reuse within nine weeks, others required three years, and yet others had to be abandoned. Particularly persistent contaminants were amitrole, dinoseb, and picloram.

Organochlorine Insecticides and Industrial Pollutants in the Milk Supply of Southern Ontario, Canada - 1977.

During the summer of 1977 milk samples were collected from 308 bulk transporters picking up milk in the southern region of Ontario. These milk samples were subjected to a comprehensive analysis for organochlorine insecticides and selected halogenated industrial pollutants. Ninety-five percent of samples contained residues of p,p'-DDE, dieldrin, heptachlor epoxide and PCB, 68% contained residues of HCB, and 16% contained residues of p,p'-DDE and p,p'-TDE; chlordane and endosulfan were detected in only a few samples. Residues of aldrin, endrin, lindane, methoxychlor, mirex, PBB and chlorinated phenols were not detected. Mean residues of insecticides in milk fat were ∑DDT, 0.015 ppm; dieldrin, 0.011 ppm; heptachlor epoxide. 0.002 ppm; endosulfan, 0.001 ppm; and chlordane, <0.001 ppm. Mean residues of industrial pollutants in milk fat were 0.033 ppm PCB and 0.002 ppm HCB. Compared with a similar survey conducted in 1973 for an approximately identical geographical area, levels of ∑DDT, PCB, and HCB showed a significant decrease. dieldrin showed only a slight decrease and heptochlor epoxide and chlordane increased. Reports are presented on individual case histories involving the misapplication of endrin, lindane, and fenthion to dairy cattle. The rate of elimination of these compounds from milk is presented.