Levels of formaldehyde in residential indoor air of Gonabad, Iran

Abstract

Human health has been identified to be affected more significantly by indoor air quality. Among numerous pollutants present in indoor air, formaldehyde (FA) is of great concern because of its highly hazardous nature. The concentrations of FA were determined from 20 newly decorated homes in the city of Gonabad, Iran during 2015. It was found that the indoor air levels of FA in all the sampled houses were exceptionally high in the range of 21 to 360 mu g/m(3) (mean of 149.3 mu g/m(3)). If the 24-h average concentrations of FA measured from those sites were concerned, nearly 40% of them were seen to exceed the WHO guideline values (i.e., 100 mu g/m(3)). One of the important reasons for the high concentrations could be low air exchange rates in those houses (e.g., from 0.18 to 0.37 h(-1)), high levels of humidity in the newly decorating houses and stronger sources in the indoor environment. Furthermore, its pollution in homes with natural ventilation was seen to be much higher than those of mechanical ventilation. Due to high levels of indoor FA, more effective control procedures should be developed and employed to reduce the risk associated with formaldehyde exposure.