Preliminary Study Of Aldehydes And Other Volatile Organic Compounds In The Atmospheric Environment Of Guangzhou

Organic pollutants are among the most important factors influencing ambient air quality. Volatile organic compounds (VOCs),including some carbonyls,are major organic components both in indoor and outdoor air. Carbonyls,which are both primary (directly emitted) and secondary (formed in the atmosphere) atmospheric species,play a key role in atmospheric photochemistry;they are precursors of free radical,ozone,carboxylic acid and peroxyacetyl nitrates (PAN). Carbonyls particularly aldehydes are toxic chemicals,and formaldehyde and acrolein are suspected cancer agents. For their importance in atmospheric chemistry and their health impacts,carbonyls has been receiving worldwide concern,and many studies have been conducted,but there lack related studies in China especially in outdoor air.In this paper,we present a method of DNPH cartridge sampling followed by HPLC-UV detection and quantification. This method was used for measuring carbonyls in ambient air near a highway in Guangzhou.This paper also includes preliminary studies of formaldehyde in newly erected and decorated houses and VOCs in a shopping mall in Guangzhou.Upon those studies,we concluded:1. The method we developed is suitable for simultaneously measuring Cl -CIO carbonyls in atmosphere. The method detected limits of these carbonyls were 0.05 -0.15 ug/m3. It is a precise and reliable method for monitoring low levels of C1 - C10 carbonyls in indoor and outdoor air.2. The air is seriously polluted along the highway. Average concentration of CO2,CO,PM2.5,and carbonyls were 1143ppm,3ppm,0.292 mg/m3,53.89ng/m3 respectively. The most abundant carbonyls were formaldehyde (14.8ng/m3),acetone (14.5ng/m3) and acetaldehyde (8.6g/m3),and these three compounds account for 69% of total carbonyls. Motor vehicular were the major source of carbonyls.3. In the newly erected and decorated houses,most of indoor formaldehyde levels exceeded the guideline level of 0.080mg/m3 in China. Studies indicated the new wood furniture were the major sources of formaldehyde.4. In the shopping mall,CO2 levels exceeded the guideline level,also PMio level near or beyond the guideline level (daily). The high CO2 levels indicated the needs of better ventilation,but enhanced ventilation would haveno effects on indoor PMio levels for the high PMio level in outdoor air. 5. In the shopping mall air was lightly polluted considering the high VOCs level. Apart from a common source from ventilation air heavily influenced by traffic emission,the sources of VOCs varied with sampling sites due to emission of shopping goods or indoor activities (like cooking). There were also some unclear sources of VOCs.