pollutant

Briefly reviews sources and types of air contaminants common in tight houses. Covers four indoor pollutants - carbon-monoxide and nitrogen dioxide from gas stoves, particleboard plywood and urea-formaldehyde from insulation, and radon from various building materials.Suggests ways of lowering pollutant levels without compromising energy conservation considerations.

Describes work sponsored by the Electric Power Research Institute (EPRI) to investigate indoor air quality in 10 single-family houses and 2 office buildings in Boston. The point was to compare indoor and outdoor pollutant levels, and find reasons for the differences. Found particulate levels were higher indoors, and houses with gas facilities showed higher concentrations of carbon monoxide and nitrogen oxides.

Numerically predicts air quality and thermal comfort in 2-dimensional ventilated air spaces of several geometries when conditions on the various room surfaces are taken to be either adiabatic or constant temperature. 

Investigations in Denmark show that there are as many as 75 different compounds in indoor air in tight houses including toluene, xylene, and radon. The dust in homes contains a large number of allergically active ingredients, the most important being the dust mite, which occurs in bed clothes.< States that good air quality is therefore difficult to maintain with natural ventilation in new tight houses. If the hygienic demands of this decade increase the need for ventilation, mechanical ventilation seems to stand a good chance.

In dwellings and similar spaces with limited volume, dilution of indoor air contaminants may be insufficient. The concentration of contaminants in the inside air depends partly on the rate of emission into the room, partly on the ventilation and the concentration of impurities in the outside air. Sulphur dioxide, hydrocarbons, ozone and lead compounds occur in higher concentrations in the outside air, whereas nitrogen oxides, carbon monoxide, benzpyrene (from tobacco smoke), formaldehyde and dust have higher concentrations indoors.

During the period 1973-76, measurements in housing where particle board is used as a building material have revealed a reduction in the formaldehyde content of the indoor atmosphere from 0.64 to 0.40 mg/cu.m. under standard indoor climatic conditions. A corresponding although slighter reduction in therelease of formaldehyde from particle board was found under controlled conditions in climatic chambers. Suggests these improvements in the quality of particle board will suffice to fulfill the proposed limit of 0.40 mg/cu.m.

Elucidates many different aspects of formaldehyde occurrence, such as, comparable indoor air pollutants, complaints and investigations, coherence with ventilation rate and construction, chipboard types, qualities and prices, differing European directives on board composition, chipboard in cold and warm types of flat roofs.

Indoor concentrations of pollutants often equal or exceed outdoor concentrations, and since most people spend 90% of their time indoors this constitutes a health threat much greater than that posed by outdoor pollution, which has received most of the attention in the U.S.A. The problem has been made worse by energy conservation measures which reduce ventilation. Thisarticle reviews recent research findings and their implications for pollution control programmes, and considers the further research that is needed.

Reports investigation of the air quality in a sound-insulated dwelling house. Measurements of ventilation rate and concentrations of CO, CO2, and NO2 were measured in a tight sound-insulated dining-kitchen, with and without the operation of a gas range, instantaneous hot-water heater and ventilation fan. Finds that natural ventilation was inadequate when the gas appliances were operating and recommends that an instantaneous gas hot-water heater should be provided with an exclusive air exhauster.

Reviews the source and nature of pollutants occurring in indoor air. Discusses two research projects at the Institute of Hygiene and Work Physiology of the Swiss Federal Institute of Technology in Zurich; one studying the air pollution caused by men; theother concentrates on pollution caused by materials. Outlines methods of investigating odours. Concludes that control measures to reduce emissions are necessary. Recommends that guidelines for a minimum ventilation rate should be drawn.