Particle associated polycyclic aromatic hydrocarbons in urban air of Agra

Abstract

<smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="City" downloadurl="http://www.5iamas-microsoft-com:office:smarttags"><smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="place" downloadurl="http://www.5iantlavalamp.com/"><smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="country-region" downloadurl="http://www.5iantlavalamp.com/"> Total suspended particulate matter (TSPM) samples were collected at Nunhai, Agra from May 2006 to September 2006. Since polycyclic aromatic hydrocarbons (PAHs) are known carcinogenic and mutagenic, concentrations of 16 PAHs in aerosols were quantified in the present paper. The dominating PAHs in TSPM include high molecular weight Benzo(ghi)Perylene, dibenzo(b)anthracene, indeno(123cd) pyrene, benzo(a)pyrene. Naphthalene and acenapthylene being more volatile were not detected in any of the samples. The sum of 14 PAHs ranged 150 - 480 ng m^-3with a mean value of 269 ± 121 ng m^-3. The results indicate that PAH concentrations are higher than other industrial sites but are comparable to those measured in several urban Chinese cities, however, less than the industrial locations of China. Higher PAH concentrations are attributed to higher rates of emissions as well as greater scavenging and adsorption of vapor phase PAH on available TSPM. The potential sources of PAHs in aerosols were identified using the diagnostic ratios between PAHs. The vehicular emissions were the main contributors of particulate-associated PAHs and stationary combustion sources also contribute to the particulate PAHs. PAHs in aerosols were predominantly from gasoline and diesel engines. </smarttagtype></smarttagtype></smarttagtype>