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Biomedical subjects

H E Ayer

Publications and source records attributed to H E Ayer.

18 recordsLinked to original sources
PubMed1984

Permeation of chlorinated aromatic compounds through Viton and nitrile glove materials.

The ASTM cell was utilized to study permeation of chloro-, o-dichloro-, and m-dichloro-benzenes and o- and p-chlorotoluenes through Viton (unsupported) and nitrile (supported and unsupported) glove materials using isopropanol as collecting solvent, and FID/gas chromatography for quantitation. Adequate mixing in the collection chamber was accomplished by externally agitating the ASTM cell at the required speed in a moving-tray water bath at 25 degrees C. The Viton glove did not show permeation even after 4 hours. The nitrile gloves showed breakthrough times of less than 1 hour. The steady state molar flux rates for unsupported or supported nitrile gloves, or for the different challenge solvents were not statistically different. Thus, breakthrough times were better indicators of permeation than steady state molar flux rates. A "mixed" permeation mechanism was proposed, depending on swelling of the glove material.

Chlorobenzenes↗
PubMed1983

A report on silica exposure levels in United States foundries.

Is silicosis still a serious threat to foundry workers? Medical and epidemiological information has been scant for the past 30 years. However, several recent surveys of silica dust levels in United States foundries give substantial indication of a continuing exposure hazard. The present research effort was aimed at collecting silica dust exposure data in the foundry environment. OSHA industrial hygiene records were collected from foundry inspections in which air sampling of silica-bearing dusts had been conducted. Two hundred and five foundries supplied 1743 personal air samples. The results present a detailed exposure profile of specific work areas, job titles, type and size of foundry. Based on the results of this and other similar studies reported in the past decade, it appears that silica dust continues to be a serious health hazard to foundry workers. If such is the case, then an epidemiological investigation of the industry should be undertaken to determine a prevalence rate of silicosis. Such a study could provide much needed information on the dose-response relation of silica exposure and silicosis, as well as information with which to reevaluate the adequacy of the current TLV for crystalline-free silica.

Air Pollutants↗
PubMed1982

Irritants in cigarette smoke plumes.

Concentrations of the irritants formaldehyde and acrolein in side stream cigarette smoke plumes are up to three orders of magnitude above occupational limits, readily accounting for eye and nasal irritation. "Low-tar" cigarettes appear at least as irritating as other cigarettes. More than half the irritant is associated with the particulate phase of the smoke, permitting deposition throughout the entire respiratory tract and raising the issue of whether formaldehyde in smoke is associated with bronchial cancer.

Acrolein↗
PubMed1979

Phorate intoxication at an insecticide formulating plant.

The use of phorate requires precautions similar to those taken with other organophosphate pesticides, as demonstrated by the case histories and environmental concentrations found in a formulating plant using phorate. Routine supply of personal protective equipment is not necessarily adequate to prevent poisoning.

Adolescent↗
PubMed1975

Noise exposure and hearing levels of workers in the sheet metal construction trade.

Hearing and noise levels were measured at a jobsite involving sheet metal construction work and at a sheet metal fabrication shop. Noise levels up to 114 dBA (slow response) were measured when various powered hand tools were used. Noise levels exceeded 85 dBA between one-fourth and one-third of the time. Impact noise levels averaged about 120-125 dB peak SPL. Audiometric examinations showed that this group of construction workers had hearing losses, with the majority of the loss occurring in the 3KH(Z) to 6 KH(Z) range. In addition the loss became more severe with increasing age. Temporary threshold shifts were observed both on the jobsite and in the shop after a single eight-hour exposure.

Audiometry↗