MCPA permeation through protective gloves.

Permeation of 4-chloro-2-methylphenoxyacetic acid (MCPA) in commercial herbicide formulations through common protective glove types was evaluated to aid in the selection of appropriate skin protection. The ASTM test method F739-91 was used to measure the permeation of two undiluted formulations, one containing a salt, and the other an ester form of MCPA. The four glove types tested were natural rubber, neoprene 73, nitrile 37-145, and Viton-coated chloroprene. Triplicate tests of each combination of formulation and glove material were conducted. Permeation cells with a 0.01 M sodium hydroxide collection medium were used for the experiments. Aliquots of the collection medium were withdrawn at regular intervals and acidified, and quantification of the free acid was achieved using HPLC-UV (230 nm). There was no appreciable permeation of the salt formulation over a 24-hour test period. For the ester formulation, the following mean steady-state permeation rate (microg x cm(-2) min(-1)) and mean lag time (hours), respectively, were measured: Viton (0.06, 17.8), natural rubber (0.08, 15.4), neoprene 73 (0.21, 15.1), and nitrile (0.04, 24.2). Permeation was associated with significant swelling, averaging a nearly 30 percent increase from the pre-immersion thickness. All four glove types provide adequate protection against permeation by the salt formulation and at least eight-hour protection against the ester formulation. Given the greater permeation of the ester formulation, the salt formulation of MCPA herbicide should be used whenever possible.

The evaluation of exposure of printing trade employees to polycyclic aromatic hydrocarbons.

Epidemiological studies of the lung cancer experience of workers in the printing industry have been inconclusive. Where there have been positive findings, the effect has generally been attributed to polycyclic aromatic hydrocarbon (PAH) exposure, although no exposure measurements were made. This study was undertaken to determine the exposures of printing press operators to PAH and total particulate (TP), and to evaluate the factors contributing to exposure. Personal time-weighted average exposures of press room workers were determined on two consecutive days at nine sites, including two newspaper operations. The average PAH exposure was 16.5 micrograms m-3 (including naphthalene). The average TP exposure was 0.63 mg m-3. Examination of the data revealed that there were significant differences between sites for exposure both to TP and to PAH. Newspaper plants had significantly lower exposures than commercial printing operations. There were no significant differences in exposure between the various job classifications of workers in the press rooms. Factors identified as contributing to exposure to TP were: the effectiveness of the ventilation systems, the method of feeding the press, the type of paper and the print impression area.

Exposure of hospital operating room personnel to potentially harmful environmental agents.

Epidemiologic studies of risk to reproductive health arising from the operating room environment have been inconclusive and lack quantitative exposure information. This study was undertaken to quantify exposure of operating room (OR) personnel to anesthetic agents, x-radiation, methyl methacrylate, and ethylene oxide and to determine how exposure varies with different operating room factors. Exposures of anesthetists and nurses to these agents were determined in selected operating rooms over three consecutive days. Each subject was asked to wear an x-radiation dosimeter for 1 month. Exposure to anesthetic agents was found to be influenced by the age of the OR facility, type of surgical service, number of procedures carried out during the day, type of anesthetic circuitry, and method of anesthesia delivery. Anesthetists were found to have significantly greater exposures than OR nurses. Exposure of OR personnel to ethylene oxide, methyl methacrylate, and x-radiation were well within existing standards. Exposure of anesthetists and nurses to anesthetic agents, at times, was in excess of Ontario exposure guidelines, despite improvements in the control of anesthetic pollution.