ABSTRACT
Many different things affect IAQ. Hazardous pollutants come from external air pollution and from a wide range of items introduced into buildings, such as cleaning materials, perfumes, air fresheners and so on. Also a major hazard in buildings is due to the natural environment. Radon gas emanates from the ground beneath buildings and unless proper measures are taken, it can accumulate in highly dangerous concentrations causing a high risk of cancer. Some buildings can also be affected by other underground gases such as methane and emissions from old pollutants on brownfield sites where remediation has not been properly carried out. Electromagnetic fields (EMFs) can also be a serious risk to health.
