Concentrations Of Anthropogenic Species Research Articles

Chemical Composition Change in TSP Due to Dust Storm at Gosan, Korea: Do the Concentrations of Anthropogenic Species Increase Due to Dust Storm?

Aerosol composition change between dust storm and non-dust storm periods in spring is studied using the total suspended particle data measured at Gosan, a background area in Korea. The concentrations of eight inorganic ions and 12 elements were analyzed for the TSP samples collected from March 1992 to May 2006. Two-step statistical analyses were carried out for the data: F test and t test. The concentrations of anthropogenic ionic species showed increasing trend since 2003. The absolute concentrations of most anthropogenic species such as sulfate or nitrate increased (from 7.33 to 9.25 µg m−3 and from 2.04 to 4.84 µg m−3, respectively) during the dust storm period. However, the enrichment factors or normalized concentrations based on Al of most anthropogenic species decreased during dust storm period (factor of 0.1–0.5). It suggests that, in general, relative importance of anthropogenic species during dust storm would be not high.

Wet and Dry Deposition Fluxes of Inorganic Chemical Species at a Rural Site in Northern Jordan

Wet and dry deposition samples were collected in a rural region in northern Jordan during the period of December 1998 to April 2000. Concentrations of 20 chemical species (Na, K, Ca, H(+), Mg, NH(4)(+), Cl(-), NO(3)(-), SO(4)(2-), Pb, Cd, Zn, Cu, Al, Fe, Mn, Mo, Ni, Sb, and V) were determined in collected samples. Most of the Al, Fe, Mn, Mo, Sb, and V were not soluble, whereas major ions (Na, K, Ca, H(+), Mg, NH(4)(+), Cl(-), NO(3)(-), and SO(4)(2-) ) and some trace elements (Cd, Cu, and Zn) were wet deposited mostly in the soluble form. Concentration of the soil-related elements and/or highly soluble species were washed out at the early stages of a precipitation event, and their concentrations were mostly controlled by dilution, whereas concentrations of anthropogenic species were controlled by other factors. Annual fluxes of the soil-related elements and ions were significantly higher than the primarily anthropogenic elements. This was attributed to the arid nature of the region and to the frequent input of the Saharan dust pulses.

Trace gas measurements over the northwest Pacific during the 2002 IOC cruise

The R/V Melville cruised from Osaka (Japan) on 1 May and reached Hawaii on 5 June on a project for the Intergovernmental Oceanographic Commission (IOC) in 2002. During this cruise, the concentrations of atmospheric trace gases (O3, CO, DMS, hydrocarbons, and halocarbons) were measured. Air at high latitudes and low latitudes exhibited starkly different characteristics regarding their chemical composition. The concentrations of anthropogenic species clearly decreased from high latitude to low latitude. On the other hand, biogenic species such as DMS and alkenes were highly abundant at lower latitudes. Backward air trajectories show that the northwestern continental air mass was dominant at higher latitudes and the eastern marine air mass was dominant at lower latitudes. However, the long‐range transport of pollutants to clean regions near Hawaii was also observed. The ratios of ethane to CO decreased from high latitude to low latitude. On the basis of a VOC ratio analysis, the benzene concentration is relatively higher at low latitudes. DMS concentrations and wind speed at low latitudes have good correlation. This indicates that at low latitudes, the DMS concentration at the ocean surface is roughly uniform.

Characterization of chemical species in PM 2.5 and PM 10 aerosols in Hong Kong

Aerosol samples for PM 10 and PM 2.5 were collected in wintertime from November 2000 to February 2001 at three different sampling locations in Hong Kong. PM 10 and PM 2.5 were collected by high-volume (hi-vol.) samplers and the concentrations of major elements, ions, organic and elemental carbons were quantified. The ratios of PM 2.5/PM 10 were 0.61 and 0.78 at the PolyU campus and Kwun Tong (KT), respectively. These results indicated that the concentrations of PM 2.5 contribute the majority of the PM 10 fraction. The concentrations of anthropogenic species (e.g. Pb and Cu) in PM 10 and PM 2.5measured at urban areas were generally higher than at an urban background site (Hok Tsui, HT). The major fractions of sulfate at three monitoring sites are non-sea-salts (nss) sulfates. Although HT is located in coastal areas, the contribution of sea salts to sulfate in fine particles was small, indicating a substantial anthropogenic origin. The OC/EC ratios were less than 2 in PolyU and KT monitoring stations for PM 10 and PM 2.5. However, the OC/EC ratios were over 3 at HT for both PM 10 and PM 2.5. This indicates the presence of secondary organic aerosols. Correlations between OC and EC as well as OC and sulfate in HT during both seasons were used to prove that atmospheric transport and transformation of anthropogenic organic species from northeastern area was the dominant source in winter. The chemical composition of the samples was reconstructed from the observed elemental composition. The contribution of the seven components, namely crustal matter, sea salt, ammonium, sulfate, nitrate, elemental carbon and organic matter accounted for 77–84% of the PM 10 and PM 2.5 mass in the urban area (PolyU and KT) and 74% for Hok Tsui (HT). Sulfate, organic matter and elemental carbon are the major constituents in particles especially in PM 2.5 collected at PolyU and KT. The major constituents of PM 10 in HT are sea salt and sulfate.

Fine particle measurements at two background sites in Korea between 1996 and 1997

Five intensive field measurements were carried out at two background sites in Korea; Kosan and Kangwha during spring, fall, and winters of 1996 and 1997 to investigate the characteristics of long-range transport of air pollutants in northeastern Asia. Fine particles (PM 2.5) were collected by low-volume samplers and the concentrations of major ions, organic and elemental carbons, and nitric acid were quantified. The concentrations of anthropogenic species in PM 2.5 measured at both sites were generally higher than those at other background areas, Nagano, Japan and San Nicolas Is., USA due to continental outflow of air pollutants, but lower than those at an urban background site, Qingdao, China. The major components of PM 2.5 were sulfate, organic carbon (OC), and ammonium for Kosan and sulfate, OC, ammonium, and nitrate for Kangwha. The major fractions of sulfate at both sites are non-sea-salts (nss) sulfate. Based on the relationship among major anthropogenic species, analysis of the nss sulfate to total nitrate molar ratios, and backward air parcel trajectories, it was found that fine particles measured at both sites during the measurement periods are mainly coming from China. At Kosan, the concentrations of anthropogenic species were higher when air parcels were coming from southern China than when air parcels were from northern China. At Kangwha, however, the differences of the concentrations were not statistically significant since most air parcels were from northern China and local effects are prominent.