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Biomedical subjects

D R McFee

Publications and source records attributed to D R McFee.

8 recordsLinked to original sources

Airborne concentrations of asbestos in 71 school buildings.

A total of 473 air samples from 71 schools scheduled for abatement (328 indoor static samples, 51 personal samples, and 94 outdoor samples) were analyzed by transmission electron microscopy techniques. Six measures of asbestos-in-air concentration were considered: (1) total asbestos structures per cubic centimeter: (2) chrysotile structures per cubic centimeter; (3) amphibole structures per cubic centimeter; (4) structures per cubic centimeter at least 0.5 micron long and at least five times wide; (5) structures per cubic centimeter at least 5 microns long; and (6) structures per cubic centimeter at least 5 microns long and at least 0.2 micron wide. The average concentration of chrysotile structures in indoor air samples was 0.017 structures/cm3; the average concentration of amphibole structures was 0.0015 structure/cm3. Ninety-five percent of structures found were chrysotile. The average concentrations of all structures were significantly higher indoors than outdoors (P less than 0.001). The average concentration of structures more than 5 microns long indoors was 0.00023 structure/cm3. None of the following factors were significantly correlated with asbestos concentrations in air: type of asbestos-containing materials (ACM) present, condition of ACM, accessibility of ACM to students, whether ACM were covered, air flow, or whether sweeping was noted during sample collection. In addition, asbestos-in-air concentrations were not significantly different in different types of schools (high, intermediate or elementary) or in schools constructed in different time periods. Lastly, there was no correlation between the mineral type of asbestos found in the air and the type found in samples of bulk material.

Air

Confined spaces--a case for ventilation.

Many exposures, some leading to deaths and injuries, in confined spaces could have been prevented by ventilating the space prior to and during the entry. Current standards and guidelines generally do not require ventilation. Nor do they sufficiently emphasize the need for ventilation or provide guidance on how to ventilate confined spaces. Mechanical ventilation is a positive engineering control action that can usually be taken and that will reduce the hazards of adverse atmospheric conditions inside a confined space. Natural ventilation usually is not sufficiently reliable to serve as a primary means of control. Unfortunately, very little specific information is available for designing and implementing ventilation strategies for confined spaces. More published information is needed, such as examples of effective policy and procedures in use by industry and findings from research on confined space ventilation. Basic and applied research can help to demonstrate effective ventilation actions and develop useful design guidelines. Additional published information should increase hazard awareness and reduce the likelihood of accidents.

Industry

Health examination and air monitoring evaluation for workers exposed to 2-nitropropane.

Comprehensive employee health examinations along with work-place area and personal monitoring were conducted to evaluate potential exposure to 2-nitropropane. The employee cross section included in the study consisted of nearly all workers at the plant. The entire workforce was represented, including those who did not have contact with 2-nitropropane. No adverse health effects were found which could be connected with work experience. Body systems evaluated included: lungs, liver, kidney, blood, skin and cardiovascular. Work area levels at specific locations sometimes exceeded 25 ppm, but personal time-weighted average levels generally were below 25 ppm.

Air Pollutants, Occupational

Odor threshold determination for 2-nitropropane.

The odor threshold of 2-nitropropane (2-NP) has been characterized as not capable of providing warning that air concentrations possibly exceed acceptable guidelines. However, recent testing indicates that the odor threshold is significantly lower than previously thought. In particular, the odor threshold has been indicated by this study to be below the current TLV for 2-NP.

Alkanes