Noise exposures during potato processing and manufacture of animal feed.

A noise exposure survey was conducted at an agricultural facility to evaluate noise exposures during potato processing and during the manufacture of alfalfa pellets. Of the 19 employees monitored, five reached or exceeded the National Institute for Occupational Safety and Health recommended exposure limit for occupational noise. Four of these employees were from the potato processing area, and one was from the alfalfa pellet-mill operation. Two of the five (bagger and pellet-mill operator) also exceeded the Occupational Safety and Health Administration action level. The facility has a well-managed hearing conservation program for employees in the potato processing area, but not in the alfalfa manufacturing area.

Temporal variation of indoor air quality in an enclosed swine confinement building.

Human health hazards can exist in swine confinement buildings due to poor indoor air quality (IAQ). During this study, airborne dust and ammonia concentrations were monitored within a working farrowing facility as indicators of IAQ. The purposes of this study were to assess the temporal variability of the airborne dust and ammonia levels over both a daily and seasonal basis, and to determine the accuracy of real-time sensors relative to actively sampled data. An ammonia sensor, aerosol photometer, indoor relative humidity sensor, and datalogger containing an indoor temperature sensor were mounted on a board 180 cm above the floor in the center of a room in the facility. Sensor readings were taken once every 4 minutes during animal occupancy (3-week intervals). Measurements of total and respirable dust concentrations by standard method, aerosol size distribution, and ammonia concentrations were taken once per week, in addition to temperature and relative humidity measurements using a thermometer and sling psychrometer, respectively. Samples were taken between September 1999 and August 2000. Diurnal variations in airborne dust revealed an inverse relationship with changes in indoor temperature and, by association, changes in airflow rate. Ammonia levels changed despite relatively stable internal temperatures. This change may be related to both changes in flow rates and in volatility rates. As expected, contaminant concentrations increased during the cold weather months, but these differences were not significantly different from other seasons. However, total dust concentrations were very low (geometric mean = 0.8 mg/m3) throughout the year. Likewise, ammonia concentrations averaged only 3.6 ppm in the well-maintained study site.