Measurements of formaldehyde at the US-Mexico border during the Cal-Mex 2010 air quality study Academic Article uri icon


  • Ambient formaldehyde (HCHO), along with other volatile organic compounds (VOCs), was measured using proton-transfer reaction mass spectrometry (PTR-MS) at a ground site along the U.S.-Mexico border during the Cal-Mex 2010 air quality study. During the observation period, the HCHO mixing ratio varied between 1.0 ppbv and 13.7 ppbv. On average, a daily maximum of 6.3 2.6 ppbv occurred around 10 AM and a minimum of 2.8 1.3 ppbv was observed around midnight. The early onset of the HCHO daily maximum (~ 3 h before the solar noon) indicated the presence of primary HCHO sources and a fast photolysis loss of HCHO, consistent with a measured low ratio of HCHO to acetaldehyde of (2.5 0.8). Using the simulated photolysis rates, we estimated the contribution of OH radical production from HCHO photolysis relative to that from O 3 photolysis, with a ratio from 0.8 to 18 and the highest values around traffic rush hours. Hence, our results indicate that HCHO plays a dominant role in regulating the OH radical budget in the area. 2012 Elsevier Ltd.

published proceedings


author list (cited authors)

  • Zheng, J., Zhang, R., Garzon, J. P., Huertas, M. E., Levy, M., Ma, Y., ... Molina, L. T.

citation count

  • 20

complete list of authors

  • Zheng, Jun||Zhang, Renyi||Garzón, Jessica P||Huertas, María E||Levy, Misti||Ma, Yan||Torres-Jardón, Ricardo||Ruiz-Suárez, Luis G||Russell, Lynn||Takahama, Satoshi||Tan, Haobo||Li, Guohui||Molina, LT

publication date

  • May 2013