Despite long-standing awareness of adverse health effects associated with chronic human exposure to formaldehyde, this hazardous air pollutant remains a challenge to measure in indoor environments. Traditional analytical techniques evaluate formaldehyde concentrations over several hours to several days in a single location in a residence, making it difficult to characterize daily temporal and spatial variation in human exposure to formaldehyde. There is a need for portable, easy-to-use devices that are specific and sensitive to gas-phase formaldehyde over short sampling periods so that dynamic processes governing formaldehyde fate, transport, and potential remediation in indoor environments may be studied more effectively. A recently developed device couples a chemical sensor element with spectrophotometric analysis for detection and quantification of part per billion (ppb v) gas-phase formaldehyde concentrations. This study established the ability of the coupled sensor-spectrophotometric device (CSSD) to report formaldehyde concentrations accurately and continuously on a 30-min sampling cycle at low ppb v concentrations previously untested for this device in a laboratory setting. Determination of the method detection limit (MDL), based on 40 samples each at test concentrations of 5 and 10 ppb v, was found to be 1.9 and 2.0 ppb v, respectively. Performance of the CSSD was compared with the dinitrophenylhydrazine (DNPH) derivatization method for formaldehyde concentrations ranging from 5-50 ppb v, and a linear relationship with a coefficient of determination of 0.983 was found between these two analytical techniques. The CSSD was also used to monitor indoor formaldehyde concentrations in two manufactured homes. During this time, formaldehyde concentrations varied from below detection limit to 65 ppb v and were above the US National Institute for Occupational Safety and Health (NIOSH) recommended exposure limit (REL) of 16 ppb v, which is also the exposure limit value now adopted by the US Federal Emergency Management Agency (FEMA) to procure manufactured housing, 80% and 100% of the time, respectively.
|Original language||English (US)|
|Number of pages||6|
|Journal||Journal of Exposure Science and Environmental Epidemiology|
|State||Published - 2014|
Bibliographical noteFunding Information:
We thank Matrix Analytical Laboratories for their assistance in completing analysis of DNPH samples and the Indoor Air Quality Group at the National Institute of Standards and Technology for loan of equipment. EMC and this work were supported by US Environmental Protection Agency STAR Fellowship program and the American Society of Heating, Refrigerating, and Air-conditioning Engineers Grant-In-Aid. We would also like to thank the community members of Cottonwood Creek for the opportunity to carry out sampling in the field.
- Coupled sensor-spectrophotometric device
- Manufactured housing