You are here:
BIOGENIC SULFUR COMPOUNDS IN COASTAL ATMOSPHERES OF NORTH CAROLINA
Citation:
Hitchcock, D., L. Spiller, AND W. Wilson. BIOGENIC SULFUR COMPOUNDS IN COASTAL ATMOSPHERES OF NORTH CAROLINA. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/3-78/061 (NTIS PB285059), 1978.
Description:
Atmospheric H2S, SO2, and particulate SO4(-2), Na(+), C1(-), NH4(-), and NO3(-) were measured in two experiments on the North Carolina coast to determine the levels of biogenic sulfur species at marsh and estuarine locations where dissimilatory bacterial sulfate reduction produces H2S in local anoxic muds. The first (summertime) experiment demonstrated the occurrence of variable and high H2S levels--4-h means up to 80 microgram/cu m (57 ppb)--associated with low-tide mud exposure in a Spartine alterniflora marsh. Little or no SO2 was observed here, and little or no SO2 or H2S were observed at a background site 2.4 km distant. Biogenic sulfate in marine air masses ranged from 2 to 13 microgram/cu m, and was strongly associated with the loss of chloride from marine aerosols. Both H2S and SO2 were observed in the second (autumn) experiment at concentrations up to 7 microgram/cu m (5 ppb) (H2S) and 25 microgram/cu m (17 ppb) (SO2) at an estuarine site where anoxic muds are not exposed to low tide, under conditions which implied a biogenic origin, and the rapid conversion of biogenic H2S to SO2. Particulate excess (non-sea salt) sulfate and chloride loss from marine aerosols were observed at this site in continental air masses (marine air masses did not occur).