Indoor Air Quality (IAQ) emerged as a science from the 1970s onwards with the energy crisis and the subsequent construction of sealed buildings (without natural ventilation). This mainly occurred in developed countries and it soon came to public attention that lower levels of air exchange in these environments was the main culprit for the increase in concentration of indoor air pollutants. It is common knowledge that ventilation is one of the principal factors that interfere with air quality in indoor environments and that the occupants contribute to the pollution of these environments with their activities. Furthermore, poor indoor air quality is associated with some diseases (cough, rhinitis, allergy, etc.) and with Sick Building Syndrome (SBS). For sampling of the indoor contaminants there are several methodologies, available including passive monitoring systems, active and automatic systems. To ensure a healthy indoor environment, the application of specific legislation needs to be reconciled with research and fostering awareness among the occupants of such buildings. This survey seeks to identify the different contaminants found in internal environments, their effects on human health and the methodologies available for sampling them.