Aldehydes are ubiquitous constituents of the atmosphere. Their concentrations are elevated in polluted urban atmospheres. The present study was carried out to characterize three aldehydes of most health concern (formaldehyde, acetaldehyde, and acrolein) in a central Beijing site in the summer and early fall of 2008 (from June to October). Measurements were made before, during, and after the Beijing Olympics to examine whether the air pollution control measures implemented to improve Beijing's air quality during the Olympics had any impact on concentrations of the three aldehydes. Average concentrations of formaldehyde, acetaldehyde and acrolein were 29.34 ± 15.12 μg/m³, 27.09 ± 15.74 μg/m³ and 2.32 ± 0.95 μg/m³, respectively, for the entire period of measurements, all being the highest among the levels measured in cities around the world in photochemical smog seasons. Among the three measured aldehydes, only acetaldehyde had a substantially reduced mean concentration during the Olympic air pollution control period compared to the pre-Olympic period. Formaldehyde and acrolein followed the changing pattern of temperature and were each significantly correlated with ozone (a secondary product of photochemical reactions). In contrast, acetaldehyde was significantly correlated with several pollutants emitted mainly from local emission sources (e.g., NO₂, CO, and PM_2.5). These findings suggest that local direct emissions had a larger impact on acetaldehyde than formaldehyde and acrolein

The atmospheric corrosion behavior of 6061 aluminum alloy exposed in industrial and marine atmosphere environments for 36 months has been investigated by weight loss test, tensile strength test, X‐ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), and optical microscope. The results of weight loss and tensile strength showed that, compared with industrial atmosphere environment, 6061 presented higher corrosion susceptibility in marine atmosphere environment. XPS analysis indicated that the major constituents of corrosion products formed in industrial atmosphere environment were aluminum hydroxide, aluminum oxide, and aluminum sulfate. In marine atmosphere environment, corrosion products mainly contained aluminum chloride, aluminum hydroxide, and aluminum oxide. Surface morphologies analysis revealed that the corrosion products formed in industrial atmosphere environment were agglomerated and uneven. The corrosion products formed in marine atmosphere environment presented polygon shape, and revealed some broad cracks. Cross‐section morphologies analysis manifested that 6061 suffered pitting attack in both types of atmosphere environments, and the intensity of pitting attack in marine atmosphere environment was much more serious than that in industrial atmosphere environment.