Exposures to respirable, airborne Penicillium from a contaminated ventilation system: clinical, environmental and epidemiological aspects.

Symptoms compatible with hypersensitivity pneumonitis (HP) in two of fourteen employees in a clerical office prompted an investigation of their work environment. Forced-air heater-cooler units which had not been properly maintained were implicated when they were found to be grossly contaminated with predominantly Penicillium molds. Air-sampling for viable, respirable-size particulates in the affected office and an unaffected office in the same building demonstrated a 50- to 80-fold excess in the number of colony-forming-units per cubic meter of air in the affected office. Persistent alveolitis was documented by repeated bronchoalveolar lavage, gallium scan, and other studies in one affected worker whose peripheral lymphocytes underwent blast transformation in response to Penicillium antigens obtained by air-sampling in the work environment. The other affected worker had asthma, presumably exacerbated by exposures to a variety of inhaled environmental irritants and antigens. Despite a documented reduction of airborne fungi to background exposure levels after clean-up of the forced-air units, the worker with persistent alveolitis has had occasional recurrences of symptoms consistent with HP. Further research is needed to establish health guidelines for control of occupational and non-occupational exposures to respirable fungal organisms which may contaminate cooling, heating and humidifying systems in these settings. A multidisciplinary method of approach to such research is described.

Respiratory morbidity among processing and mill workers. A cross-sectional survey in three tire-manufacturing plants.

Three hundred seventy workers in three tire-manufacturing plants were studied to determine the presence of respiratory morbidity among workers with relatively low current exposure to respirable dust (range, 0.04 to 0.70 mg/m3). Workers in the processing, milling, and less dusty areas of the plants were divided into three groups on the basis of their current and past exposure to respirable dust. Significantly more eye irritation (p less than .01) was found among workers in the milling areas. Workers in the milling areas who were current cigarette smokers had significantly (p less than .05) more chronic bronchitis and loose or productive objective cough than all other current cigarette smokers. The mean forced expiratory volume in 1 s (FEV1), when corrected for age and height, decreased significantly (p less than .01) with increasing duration of cigarette smoking. The mean FEV1 and the forced vital capacity (FVC), when corrected for age, height and cigarette smoking, were the lowest in the group with the lowest dust exposure and highest in the group with moderate dust exposure (the milling areas). The measurement of the difference in flow at 50% of FVC on air and on a helium-oxygen mixture is a sensitive test for small-airway obstruction in the laboratory. In the field, however, the helium-oxygen flow difference did not vary with duration of cigarette smoking as expected, and there was no significant variation by exposure category.

Air contaminants encountered by firefighters.

The concentrations of eight air contaminants suspected of causing acute and chronic health problems for firefighters were measured in over 200 fires in the City of Boston using a personal air sampler. Threatening concentrations of both carbon monoxide and acrolein were found in a small proportion of the fires. Less hazardous levels of hydrogen chloride, hydrogen cyanide, nitrogen dioxide and carbon dioxide were also noted. Benzene was found in most fires, but at concentrations well below those expected to cause acute injury. The air sampling data have application in treatment of smoke inhalation victims, development of firefighting strategies and selection of respiratory protection devices.