Biogenic Sulfur Gas Emissions from Soils in Eastern and Southeastern United States

Data are presented for the first systematic measurements of biogenic sulfur gas flux from the major soil orders within the eastern and southeastern United States. Sulfur flux samples were collected and analyzed on-site during the fall of 1977, spring and summer of 1978 and summer of 1979. A total of 27 sampling locales in 17 states were examined. Eight additional sites were visited in 1980.

At some locales, two to four soils were examined, providing an even broader sampling of the soil orders. Three of the locales were revisited two or three times during the course of the study to establish the influence of seasonal climatology upon the measured emission rates and chemical composition of the sulfur flux mixtures.

The sulfur gas enhancement of sulfur-free sweep air passing through dynamic emission flux chambers placed over selected sampling areas was determined by combined cryogenic enrichment sampling and wall-coated, open tubular, capillary column, cryogenic gas chromatography (WCOT/GC) using a sulfur selective, flame photometric detector (FPD).

Sulfur gas mixtures varied with soil order, ambient temperature, insolation, soil moisture, cultivation, and vegetative cover. Statistical analyses indicated strong temperature and soil order relationships for sulfur emissions from soils.

Fluxes ranged from 0.001 g to 1940 g of total sulfur as S/m²/yr. The calculated mean annual sulfur flux, weighted by soil order, was 0.03 g S/m²/yr for the study land area, or 110,872 metric tons (mT). The estimated annual average sulfur flux increased from 65 mT per 6400 km² for the land grids in the northernmost east-west grid tier to an average 1800 mT for the land grids in the southern Florida grid tiers.

This systematic sampling of major soils provides a much broader data base for estimating biogenic sulfur flux than previously reported for isolated intertidal sites, and presents the first sulfur flux estimates for inland soils which make up approximately 93% of the land of the eastern United States.     

A comparison of results from two test methods for assessing the toxicity of aminotriazole to Selenastrum capricornutum

Two different test methods for assessing the toxicity of aminotriazole to Selenastrum capricornutum are compared. Growth medium composition is demonstrated to have a significant effect on the toxicity of aminotriazole.     

Annual migrations,diving behavior,and thermal biology of Atlantic bluefin tuna, <Emphasis Type="Italic">Thunnus thynnus</Emphasis>, on their Gulf of Mexico breeding grounds

Electronic tags were used to examine the biology of Atlantic bluefin tuna (Thunnus thynnus L.) on their breeding grounds in the Gulf of Mexico (GOM). The hypothesis that movement patterns, diving behavior, and thermal biology change during different stages of the breeding migration was tested. Mature Atlantic bluefin tuna tagged in the western Atlantic and the GOM, were on their breeding grounds from February to June for an average of 39 ± 11 days. The bluefin tuna experienced significantly warmer mean sea surface temperatures (SSTs) within the GOM (26.4 ± 1.6°C) than outside the GOM (20.2 ± 1.9°C). As the bluefin tuna entered and exited the GOM, the fish dove to daily maximum depths of 568 ± 50 and 580 ± 144 m, respectively, and exhibited directed movement paths to and from the localized breeding areas. During the putative breeding phase, the bluefin tuna had significantly shallower daily maximum depths (203 ± 76 m), and exhibited shallow oscillatory dives during the night. The movement paths of the bluefin tuna during the breeding phase were significantly more residential and sinuous. The heat transfer coefficients (K) were calculated for a bluefin tuna in the GOM using the recorded ambient and body temperatures. The K for this fish increased rapidly at the high ambient temperatures encountered in the GOM, and was significantly higher at night in the breeding phase when the fish was exhibiting shallow oscillatory dives. This suggests that the fish were behaviorally and physiologically thermoregulating in the Gulf of Mexico. This study demonstrates that the movement patterns, diving behavior, and thermal biology of Atlantic bluefin tuna change significantly at different stages of the breeding migration and can be used to define spawning location and timing. Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users.     

Survey of Airborne 2,4-D in South-Central Washington

The extensive application of 2,4-D herbicides to wheat and other agricultural crops in the states of Washington and Oregon can produce "off-target" damage when the 2,4-D formulations are transported by the atmosphere to sensitive crops, such as grapes. During May-June of 1973 and April-June of 1974, a 2,4-D monitoring network in south-central Washington collected samples for subsequent herbicide analysis. The daily, 24 hr field samples were collected with differential Impactor-impinger air samplers and were routinely analyzed in the analytical laboratory by electron-capture gas chromatography. In addition, gas chromatography/mass spec-trometry was employed for positive identification of the 2,4-D esters and for comparative quantitative analysis. The complete sampling and analytical methodology, the 2,4-D concentration data for 1973 and 1974, the agricultural 2,4-D application records and crop Injury reports, and the concomitant meteorological data are described in this paper.     

Preliminary Measurements of Biogenic Sulfur-Containing Gas Emissions From Soils

Emission factors for particulate matter and carbon monoxide have been measured for wood, anthracite coal, and bituminous coal burned in residential heaters operated at less than 15 kW (50,000 Btu/hr). In these studies the stove effluent is mixed with about four volumes of outside air and samples are collected about two minutes after mixing. The main purpose of using this sampling method is to simulate atmospheric conditions more closely. Particulate samples are collected on 20 × 25 cm filters after cyclone preseparation of particles larger than 4 μm. Carbon monoxide concentrations are measured with Draeger tubes.

Particulate emission factors for wood ranged from 1.6 to 6.4 g/kg (fuel) and were found to depend on the fuel load and the firing rate, as indicated by earlier studies. These values are substantially less than the values obtained previously for stoves operated under similar conditions. The average particulate emission factors for bituminous and anthracite coal are 10.4 and 0.50 g/kg, respectively. Carbon monoxide emission factors for wood, bituminous, and anthracite coal are 100,116, and 21 g/kg, respectively.     

Performance Characterization and Optimization of the AgNO3-Filter/FMA Fluorimetric Method for Atmospheric H2S Measurements

This sensitive, albeit precarious, method for measuring ppb-ppt (V/V) concentrations of H₂S was examined for various sources of potential error within the procedure. Filter preparation, filter storage, filter extraction, fluorimetric reagent stabilities, matrix differences between standards and samples, and possible interferences from other sulfur-containing compounds were separately studied for their effects on the analytical performance of the method. The overall method showed no Interference from SO₂, CS₂, COS, CH₃SH, CH₃SCH₃, and SO₄ ^-2. To minimize bias and obtain a reliable estimate of precision, the method should be calibrated with H₂S standards rather than liquid bisulfide standards. The measurement precision is a function of the quantity of H₂S collected as Ag₂S and/or AgSH on the impregnated filters. Because of the method’s linear dynamic range, sufficient air should be sampled to achieve filter loadings of 15 to 35 ng S/filter. A quality control method based on fluorescein mercuric acetate (FMA) is presented that ensures data quality while reducing the otherwise frequent need for fluori-metric calibration.     

Tolerance of transgenic canola plants (Brassica napus) amended with plant growth-promoting bacteria to flooding stress at a metal-contaminated field site

The growth of transgenic canola (Brassica napus) expressing a gene for the enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase was compared to non-transformed canola exposed to flooding and elevated soil Ni concentration, in situ. In addition, the ability of the plant growth-promoting bacterium Pseudomonas putida UW4, which also expresses ACC deaminase, to facilitate the growth of non-transformed and transgenic canola under the above mentioned conditions was examined. Transgenic canola and/or canola treated with P. putida UW4 had greater shoot biomass compared to non-transformed canola under low flood-stress conditions. Under high flood-stress conditions, shoot biomass was reduced and Ni accumulation was increased in all instances relative to low flood-stress conditions. This is the first field study to document the increase in plant tolerance utilizing transgenic plants and plant growth-promoting bacteria exposed to multiple stressors.     

Octachlorodibenzo-p-dioxin in wood treatment materials and treated wood

The octachlorodibenzo-p-dioxin (OCDD) concentrations have been determined in aged samples of commercial pentachlorophenol (PCP), in wood protection formulations containing PCP and in wood treated with PCP as a preservative or as an anti-sapstain treatment. The concentrations of OCDD found in the various samples are within the range expected from the amount of commercial PCP initially present in the samples. In view of the known stability of OCDD the results are interpreted as indicating that the formulation, treatment and ageing processes have not led to any substantial conversion of PCP to OCDD; although one result indicates that outdoor exposure of treated samples increased the OCDD concentration by a factor of approximately 2 after $\text{3}\text{1}\text{2}$ years. Analysis of aged samples of treated wood indicate that OCDD is lost much less rapidly from the wood than PCP.