Indoor radon concentrations, radon emanation rates from building surfaces, radioactivity contents of building materials and the indoor gamma dose rates for Hong Kong are all in general higher than values obtained elsewhere. An interesting phenomenon has been noted that the values of indoor radon concentrations and radon emanation rates from building surfaces in Hong Kong tend to decrease with the age of the buildings, while the absorbed gamma dose rate remains about the same.

The carbon dioxide concentration patterns in a large, high-rise, office building in Ottawa were examined experimentally using an automated data acquisition system. Daily C02 concentration profiles throughout the building and air change rates, using SF6 as a tracer gas, were measured at minimum outdoor air supply rates during much of a heating season.

Unlike conventional ventilation systems, the displacement ventilation system supplies air in the low region of a room, while the exhaust opening is usually placed near the ceiling. When partitions are used in the occupied zone, the diffusion of supply air may be obstructed; thus, the existence of the partition may present important effects on air diffusion, retarding the removal of a contaminant. The present study considers the effects of office partition layout on air diffusion and indoor contaminant control in a large partitioned office equipped with a displacement ventilation system.

In modern livestock barns, proper indoor air quality is imperative to maintain the health and productivity of farm workers and animals. Some problems related to the health of farm workers have been noticed, especially since the 1970's, coinciding with the rapid changes from small traditional farms to large intensive livestock operations.

The purposes of this Fac tsheet are to describe several farm worker health problems that are related to air quality in side livestock buildings and to consider poss ible methods to alleviate them.