Microbial pollution is a key element of indoor air pollution. It is caused by hundreds of species of bacteria and fungi, in particular filamentous fungi (mould), growing indoors when sufficient moisture is available. This document provides a comprehensive review of the scientific evidence on health problems associated with building moisture and biological agents. The review concludes that the most important effects are increased prevalences of respiratory symptoms, allergies and asthma as well as perturbation of the immunological system. The document also summarizes the available information on the conditions that determine the presence of mould and measures to control their growth indoors. WHO guidelines for protecting public health are formulated on the basis of the review. The most important means for avoiding adverse health effects is the prevention (or minimization) of persistent dampness and microbial growth on interior surfaces and in building structures. [Ed.]

This book presents WHO guidelines for the protection of public health from risks due to a number of chemicals commonly present in indoor air. The substances considered in this review, i.e. benzene, carbon monoxide, formaldehyde, naphthalene, nitrogen dioxide, polycyclic aromatic hydrocarbons (especially benzo[a]pyrene), radon, trichloroethylene and tetrachloroethylene, have indoor sources, are known in respect of their hazardousness to health and are often found indoors in concentrations of health concern. The guidelines are targeted at public health professionals involved in preventing health risks of environmental exposures, as well as specialists and authorities involved in the design and use of buildings, indoor materials and products. They provide a scientific basis for legally enforceable standards.

The main objective of these updated global guidelines is to offer health-based air quality guideline levels, expressed as long-term or short-term concentrations for six key air pollutants: PM2.5, PM10, ozone, nitrogen dioxide, sulfur dioxide and carbon monoxide. In addition, the guidelines provide interim targets to guide reduction efforts of these pollutants, as well as good practice statements for the management of certain types of PM (i.e., black carbon/elemental carbon, ultrafine particles, particles originating from sand and duststorms). These guidelines are not legally binding standards; however, they provide WHO Member States with an evidence-informed tool, which they can use to inform legislation and policy. Ultimately, the goal of these guidelines is to help reduce levels of air pollutants in order to decrease the enormous health burden resulting from the exposure to air pollution worldwide.

People spend most of their time indoors, and indoor air pollutants can cause both long and short term health effects. Awareness of indoor air pollution as an environmental issue, however, is relatively new. This book has been prepared to offer an up-to-date, comprehensive reference manual on indoor air quality to scientists and professionals active in this area. The intention of the book is to bring together a collection of contributions from specialists in the specific disciplines of indoor air quality, covering all points of view from various angles, from building design and building sciences, to health effects and medical diagnosis, toxicology of indoor air pollutants, and air sampling and analysis. One of the characteristics of this book is the multidisciplinary approach that integrates the expertise of medical doctors, architects, engineers, chemists, biologists, physicists and toxicologists. The resulting product is of great educational value and recommended for consultation as well as teaching purposes. The panel of conrtibuting authors includes top experts on indoor air worldwide, who have participated in international workshops and led the development of indoor air sciences over the recent years.

Built on existing WHO indoor air quality guidelines for specific pollutants, these guidelines bring together the most recent evidence on fuel use, emission and exposure levels, health risks, intervention impacts and policy considerations, to provide practical recommendations to reduce this health burden.