Guidelines and Regulations for Indoor Environmental Quality

This chapter summarizes the guidelines and regulations for indoor environmental quality. It consists of four sections: the characteristics of indoor environmental pollution, the guidelines related to indoor environmental quality developed by the World Health Organization (WHO), multiroute exposure to phthalates in indoor environments and policy recommendations to reduce the health effects of the phthalates, as well as a recent strategic approach to reduce the health effects of combined or multiple exposures to health stressors in indoor environments. To protect public health in indoor environments, guideline values for specific indoor air pollutants have been developed by the WHO and collaborating countries. This has been the conventional approach to reduce health risks due to indoor air pollutants. However, health effects due to semivolatile organic compounds, particularly phthalates, have been reported over the past decade. There are multiple mediums that humans come in contact with that contain phthalates, including indoor air, indoor dust, and certain foods, with three exposure pathways (inhalation, ingestion, and dermal exposure) that can affect human health. An integrated multipollutant and multicompartment approach to those pathways appears essential in order to determine the extent of the threat to public health posed by phthalates. In addition, source control is required for various products that contain phthalates and that have exposure pathways to humans. Furthermore, combined exposure to multiple low-level pollutants occurs in indoor environments. Although health risk assessment based on measurements of air concentrations has been applied to represent the health risk in the environment, the types and concentrations of indoor air pollutants have not been consistent over time and have changed with alterations in lifestyle and the development of novel products used in indoor environments. Thus, a novel approach to health risk assessment using environmental biomarkers to evaluate biological or health effects that directly represent environment-derived health stress will be needed, in place of the existing health risk assessment, which is based on air-concentration measurements of specific pollutants. This approach will prevent health effects from the combined exposure to multiple low-level pollutants or exposure to alternative chemicals that potentially risk harming human health.