Safe decontamination of hospital autopsy rooms and ventilation system by formaldehyde generation.

Space decontamination was required prior to the onset of a remodeling project in the autopsy suite of a large university-hospital complex. The National Institutes of Health procedure using formaldehyde gas as a disinfectant was modified to decontaminate not only the three autopsy rooms but also the exhaust ductwork and the three associated air incinerators. Modifications included an automated formaldehyde gas generator, a smoke test procedure for leaks, and an exhausting technique. This procedure proved to be successful and has the advantage of including the safety features necessary to conduct such a potentially hazardous decontamination in an occupied hospital.

Occupational exposure to formaldehyde in a medical center autopsy service.

The formaldehyde exposures occurring in the autopsy service of a medical complex were evaluated as part of a study to detect genetically harmful effects of chemical exposures. Determination of time-weighted average (TWA) exposures and characterization of the patterns of exposure experienced by individuals with different work responsibilities in this occupational setting were sought. Both general area and breathing zone samples were evaluated. Estimated weekly time-weighted average exposures for pathologists, residents and technicians were determined to be between 0.61 and 1.32 parts per million with little difference between work roles. While the averages were similar, the patterns of exposure of technicians and physicians were different. Technicians were exposed to a baseline level of formaldehyde for a prolonged period of time. In contrast, physicians were exposed for shorter times but experienced higher levels during specific tasks, particularly tissue-sectioning and examination. Evaluations of work procedures and environmental conditions in autopsy services are recommended to reduce personnel exposure to formaldehyde vapor.

A study of the use of polyethylene glycol in estimating cholesterol in high-density lipoprotein.

We studied polyethylene glycol 6000 precipitation of lipoproteins other than high-density lipoproteins, before cholesterol is estimated in the supernate. Other lipoproteins in the supernatant fractions were detected by using rocket immunoelectrophoresis. A polyethylene glycol concentration of 75 g/L in the final mixture appeared to be optimal, and results agreed with those obtained by ultracentrifugation. Differences in serum pH, use of polyethylene glycol from different suppliers, or the presence of ethylenediaminetetraacetate resulted in values that differed significantly (by 40 to 60 mumol/L) from the reference values. Polyethylene glycol did not interfere in four different methods for determination of cholesterol. In combination with an enzymic cholesterol method, the polyethylene glycol method appeared to be very precise, even when lipemic sera (triglycerides up to 5.5 mmol/L) were analyzed that had diminished high-density lipoprotein cholesterol values. We consider this method a method of choice, especially when lipemic sera are tested and enzymic cholesterol analysis is used.

Evaluation of the dual-precipitation method by comparison with the ultracentrifugation method for measurement of lipoproteins in serum.

We evaluated the dual-precipitation method for quantitative measurement of lipoproteins as described by Wilson and Spiger [J. Lab. Clin. Med. 82, 473 (1973)] for normo- and hyperlipemic sera, by comparison with the results obtained with ultracentrifugation. If serum with an above-normal triglyceride concentration is analyzed, the very-low-density lipoprotein cholesterol value obtained with the precipitation method is usually too low. For measurement of high-density lipoprotein cholesterol the ultracentrifugation and precipitation procedures give comparable results, but the latter method is preferred because sinking pre-beta-lipoproteins present in the high-density lipoprotein fraction isolated by means of the ultracentrifuge may result in falsely high values for cholesterol in that fraction. Therefore, at least for the determination of very-low-density lipoprotein cholesterol in hyperlipemic serum, the use of an ultracentrifuge remains necessary. Because few laboratories have an ultracentrifuge at their disposal, it seemed important to look at the stability of sera in view of the forwarding of samples. Also, a way of increasing the efficiency of the ultracentrifuge was studied. Sera can be stored for a week at 4 degrees C or for 54 h at room temperature without noticeable effect on lipoprotein values. Moreover, reliable values can be obtained with an ultracentrifugation time of 8 h (0.8 X 10(8) g-min).