English

An experiment was performed in a lecture hall on students, to assess the effect of ventilation noise on concentration and fatigue. The students were tested with the ventilation fans both on and off. As a group the students reported more fatigue during lectures when the fans were operating. States that this environmental effect explains about 39% of the variance in fatigue ratings and may be sufficient to affect adversely the attention of students within these settings.

The effectiveness of individual commercially available portable indoor air cleaning units were tested for their removal of dust particulates, tobacco smoke particulates and vapour phase constituents, viable and total fungal spores, pollen, and gaseous contaminants, and formaldehyde. A clean air test chamber was used. The results presented represent initial use. It was found that HEPA and electrostatic precipitator system demonstrated the highest efficiency in relation to particulate contaminants, with electret filter systems close behind. Least effective were ionizers and ozone generators.

Assesses sick building syndrome symptoms and perceived odours for daycare workers, in relation to ventilation rates in Finnish daycare centres. Thirty centres were chosen for the study, which consisted of 268 female nursing workers. The workers completed a questionnaire. Mechanical supply and exhaust ventilation systems constituted most of the centres' systems with 37% having mechanical exhaust alone. The authors noted a very varied exhaust air flow in the children's rooms, from 0 to 11 L/s per person. Air change rate varied from 0 to 5 m3/hm3.

The intensity and acceptability of body odour was assessed 29 times on entering an experimental auditorium occupied by 106 women, by 40 female and 39 male judges. The experiment lasted 3 hours 50 minutes and the ventilation rate was varied while the air temperature was maintained at around 20-21 deg C. CO2 was measured throughout. It was found that there were no substantial differences in the ventilation rates required in rooms occupied by men and women. In order to satisfy 80% of people entering a space, a steady-state ventilation rate of about 8 L/sec person is necessary.

Cat and dog allergens in settled dust and airborne cat allergen were studied in day-care centres, with links explored between pet ownership among children and staff, ventilation and cleaning. The special centres were allergen-avoidance day care units. Control was performed by 22 conventional day care centres. Allergen levels were measured using ELISA and personal air samplers, and air change rate per hour was noted. A questionnaire was distributed for the other data. No cats or dogs were kept by children at the allergen avoidance centres in contrast to the control.

The study evaluated the strength of tobacco smoke odour by sense of smell. Similar tests were done for other irritants in tobacco smoke. Concludes that an outside air supply of 35 to 40 cfm per smoker is required to remove objectionable odours of fresh cigarette smoke. Also concludes that there in no way to ascertain whether the ventilation requirements for controlling smoke, odour and irritation effects are adequate to protect a non-smoker from possible effects of nicotine and other poisonous elements of smoke of unknown toxicological thresholds.

Human exposure to nitrogen dioxide can have adverse health effects. Policymakers need accurate information on the number of people exposed, the severity and patterns of exposure and the health-related effects of the exposure, in order to assess health risks and bring in appropriate control strategies. Data from central monitoring sites have been used in the past to establish air pollution exposures. Attempts to provide a realistic estimate of nitrogen dioxide exposures.

A study was done to obtain a general understanding of the mechanisms involved in the emissions from building materials in ventilated rooms. The investigation was based on fundamental fluid dynamics and mass transfer theory. Also proposed a generally applicable method for the prediction of surface emissions. No particulate emissions were analysed, and the work focused on the emission of vapours and gases. Numerical calculations by CFD and full-scale laboratory experiments were used.

States that emission rate of organic compounds from building materials varies according to the type of material, material loading, compound emitted, temperature, humidity, and ventilation rate. For most materials, the relationship between emission rate and these variables is not available. Describes research with the use of small test chambers aimed at developing data on emission rates from several building materials.

A study was made of the time dependence of the emission of organic compounds from a polyamide floor covering with styrene-butadiene-rubber backing in three climate chambers at 23 deg. C and 45% relative humidity. Volatile compounds such as toluene reach a maximum concentration of the gas phase in one hour, decreasing to less than 2% in 60 hours, while less volatile compounds decrease slowly over several months. Observed concentration do not depend on the chamber size, the wall material and air velocity provided the chamber is well mixed and a defined chamber loading is maintained.