health

Heatwaves are often responsible for many deaths due to high temperature indoors. Energy savings is a key element in building design and refurbishment works to reduce the impact of climate change. Natural ventilation is often promoted as an indoor space cooling solution thanks to its energy saving potential.
The paper deals with prediction of heat-related health risks situations in naturally ventilated dwellings.

This guide, released by the Building Research Association of New Zealand (BRANZ), is a literature review of recent research on indoor air quality that is relevant to New Zealand’s indoor environments (residential houses, schools, preschools and age care facilities). The document looks at the health effects, the pollutants and the building characteristics. Where possible, New Zealand research is presented. Emphasis is placed on gaps in the knowledge in order to identify future research in New Zealand.

Indoor environmental quality (IEQ) is generally taken to encompass four main factors: indoor air quality (IAQ), thermal conditions, visual quality, and acoustical quality. Although there is an implicit concern for safety, the predominant metrics all four in standards for design of buildings are based on perceived quality or comfort.

The long term exposure to fine particulate matter with a diameter of ≤2.5 μm (PM2.5) is linked to numerous health problems, including chronic respiratory and cardiovascular diseases, and cancer. In dwellings, a primary emission source of PM2.5 is cooking, an activity conducted several times per day in most households. People spend over 90% of their time indoors and more time in their homes than any other type of building. Therefore, they are at risk of exposure to elevated levels of PM2.5 emitted by cooking if these particles are not removed at source.

People in industrialised countries spend about 90% of their time indoors. Hence, a good indoor climate is essential for health and well-being. Ventilation of buildings plays an important role concerning health aspects of the occupants and inadequate ventilation may cause health costs that may have been avoidable if ventilation would have been adequate. Additionally, good or bad ventilation has impacts on the quality of the building, e.g. in very tight buildings, the risk of mould and dampness is higher if air change is insufficient.

It is estimated that people in the developed world spend more than 85-90% of their time indoors. Of this, most is spent in homes. To minimize health risks from pollutants occurring in homes, exposures should be controlled. The most effective way to achieve this is to control sources of pollutants and to reduce emissions. Often, especially in existing buildings, this strategy is difficult to implement, in which case exposures are controlled by providing sufficient, presumably clean, outdoor ventilation air to dilute and remove the contaminants.

This report is concerned with the strategy and methodology for investigating four major categories of biological particles in the indoor air of private houses, non-industrial workplaces and public buildings (excluding hospitals). These particles are mites and their faeces; dander from pets and other furred animals; fungi, including moulds and yeasts; and bacteria, including actinomycetes.

These Guidelines recommend the ventilation required to obtain a desired indoor air quality in a space. The first step is to decide the air quality aimed for in the ventilated space. A certain air quality is prescribed to avoid adverse health effects while a decision is required on the level of perceived air quality aimed for in the ventilated space. Three different comfort levels are suggested. The next step is to determine the pollution load on the air caused by pollution sources in the space.

The report contains a summary discussion of human health effects linked to indoor air pollution (IAP) in homes and other non-industrial indoor environments. Rather than discussing the health effects of the main different pollutants which can be found in indoor air, the approach has been to group broad categories of adverse health effects in separate chapters, and describe the relevant indoor exposures which may give rise to these health effects.