Airborne transmission pathway for coastal water pollution

Each year, over one hundred million people become ill and tens of thousands die from exposure to viruses and bacteria from sewage transported to the ocean by rivers, estuaries, stormwater, and other coastal discharges. Water activities and seafood consumption have been emphasized as the major exposure pathways to coastal water pollution. In contrast, relatively little is known about the potential for airborne exposure to pollutants and pathogens from contaminated seawater. The Cross Surfzone/Inner-shelf Dye Exchange (CSIDE) study was a large-scale experiment designed to investigate the transport pathways of water pollution along the coast by releasing dye into the surfzone in Imperial Beach, CA. Additionally, we leveraged this ocean-focused study to investigate potential airborne transmission of coastal water pollution by collecting complementary air samples along the coast and inland. Aerial measurements tracked sea surface dye concentrations along 5+ km of coast at 2 m × 2 m resolution. Dye was detected in the air over land for the first 2 days during two of the three dye releases, as far as 668 m inland and 720 m downwind of the ocean. These coordinated water/air measurements, comparing dye concentrations in the air and upwind source waters, provide insights into the factors that lead to the water-to-air transfer of pollutants. These findings show that coastal water pollution can reach people through an airborne pathway and this needs to be taken into account when assessing the full impact of coastal ocean pollution on public health. This study sets the stage for further studies to determine the details and importance of airborne exposure to sewage-based pathogens and toxins in order to fully assess the impact of coastal pollution on public health

Varying Relative Degradation Rates of Oil in Different Forms and Environments Revealed by Ramped Pyrolysis

Degradation of oil contamination yields stabilized products by removing and transforming reactive and volatile compounds. In contaminated coastal environments, the processes of degradation are influenced by shoreline energy, which increases the surface area of the oil as well as exchange between oil, water, sediments, microbes, oxygen, and nutrients. Here, a ramped pyrolysis carbon isotope technique is employed to investigate thermochemical and isotopic changes in organic material from coastal environments contaminated with oil from the 2010 BP Deepwater Horizon oil spill. Oiled beach sediment, tar ball, and marsh samples were collected from a barrier island and a brackish marsh in southeast Louisiana over a period of 881 days. Stable carbon (13C) and radiocarbon (14C) isotopic data demonstrate a predominance of oil-derived carbon in the organic material. Ramped pyrolysis profiles indicate that the organic material was transformed into more stable forms. Our data indicate relative rates of stabilization in the following order, from fastest to slowest: high energy beach sediments \u3e low energy beach sediments \u3e marsh \u3e tar balls. Oil was transformed most rapidly where shoreline energy and the rates of oil dispersion and exchange with water, sediments, microbes, oxygen, and nutrients were greatest. Still, isotope data reveal persistence of oil

Agronomic and silage quality traits of winter cereals

Agronomic and silage quality traits were examined for 12 winter cereals harvested at two stages of maturity. Forage dry matter (DM) yields were higher at the mid-dough than the early-heading stage. Post 90 barley had the highest whole-plant DM yield at the early-heading stage, and Presto triticale had the highest yield at the mid-dough stage. Newton wheat had the lowest whole-plant DM yield at both stages of maturity. The first cutting of all varieties originally was intended to be at the late-boot stage, but harvest was delayed by frequent rainfall and wet soils in May, and field-wilting conditions were less than ideal. The range in heads emerge d was 23 to 87%, and the range in the silage DM content at early-heading stage was 19.2 to 46.4%. Both crude protein (CP) and ash contents were higher for the early-heading cereals than the mid-dough. All 24 silages were of relatively low forage quality, as evidenced by high neutral detergent fiber (NDF) and acid detergent fiber (ADF) percentages. Only five silages, the early-heading stage Tomahawk wheat; mid-dough stage Presto triticale; and the mid-dough stage Kanby, Post, and Post 90 barleys, had less than 60% NDF and 40% ADF. Extensive lodging occurred in virtually all cereals before the mid-dough stage harvest

Varying Relative Degradation Rates of Oil in Different Forms and Environments Revealed by Ramped Pyrolysis

Degradation of oil contamination yields stabilized products by removing and transforming reactive and volatile compounds. In contaminated coastal environments, the processes of degradation are influenced by shoreline energy, which increases the surface area of the oil as well as exchange between oil, water, sediments, microbes, oxygen, and nutrients. Here, a ramped pyrolysis carbon isotope technique is employed to investigate thermochemical and isotopic changes in organic material from coastal environments contaminated with oil from the 2010 BP Deepwater Horizon oil spill. Oiled beach sediment, tar ball, and marsh samples were collected from a barrier island and a brackish marsh in southeast Louisiana over a period of 881 days. Stable carbon (¹³C) and radiocarbon (¹⁴C) isotopic data demonstrate a predominance of oil-derived carbon in the organic material. Ramped pyrolysis profiles indicate that the organic material was transformed into more stable forms. Our data indicate relative rates of stabilization in the following order, from fastest to slowest: high energy beach sediments > low energy beach sediments > marsh > tar balls. Oil was transformed most rapidly where shoreline energy and the rates of oil dispersion and exchange with water, sediments, microbes, oxygen, and nutrients were greatest. Still, isotope data reveal persistence of oil

Effect of bacterial inoculants on the fermentation and preservation efficiencies and nutritive value of alfalfa silage for growing steers

Two silage bacterial inoculants from Pioneer Hi-Bred International, Inc. were evaluated using second-cutting alfalfa. The Pioneer brand 1174® inoculant and a Pioneer experimental inoculant each increased the rate and efficiency of the ensiling process in both farm-scale and laboratory-scale silos. The two inoculants increase d the DM recovery in the farm-scale silos compared to the untreated silage. Steers fed the experimental inoculant-treated silage gained faster (P<. 10) (2.56 vs. 2.37 lb per day), had a 4.0% higher DM intake, and were 4.3% more efficient than steers fed the untreated silage. The 1174-treated silage supported a numerically but not statistically better steer performance than the control silage. When the DM recovery results were combined with the feed per gain results, the silages with 1174 and experimental inoculant produced 5.3 and 10.5 lb more steer gain per ton of crop ensiled, respectively, than the control silage

Linking Ramped Pyrolysis Isotope Data To oil Content through PAH Analysis

Ramped pyrolysis isotope (13C and 14C) analysis coupled with polycyclic aromatic hydrocarbon (PAH) analysis demonstrates the utility of ramped pyrolysis in screening for oil content in sediments. Here, sediments from Barataria Bay, Louisiana, USA that were contaminated by oil from the 2010 BP Deepwater Horizon spill display relationships between oil contamination, pyrolysis profiles, and isotopic composition. Sediment samples with low PAH concentrations are thermochemically stable until higher temperatures, while samples containing high concentrations of PAHs pyrolyze at low temperatures. High PAH samples are also depleted in radiocarbon (14C), especially in the fractions that pyrolyze at low temperatures. This lack of radiocarbon in low temperature pyrolyzates is indicative of thermochemically unstable, 14C-free oil content. This study presents a proof of concept that oil contamination can be identified by changes in thermochemical stability in organic material and corroborated by isotope analysis of individual pyrolyzates, thereby providing a basis for application of ramped pyrolysis isotope analysis to samples deposited in different environments for different lengths of time

Blank Corrections for Ramped Pyrolysis Radiocarbon Dating of Sedimentary and Soil Organic Carbon

Ramped pyrolysis (RP) targets distinct components of soil and sedimentary organic carbon based on their thermochemical stabilities and allows the determination of the full spectrum of radiocarbon (14C) ages present in a soil or sediment sample. Extending the method into realms where more precise ages are needed or where smaller samples need to be measured involves better understanding of the blank contamination associated with the method. Here, we use a compiled data set of RP measurements of samples of known age to evaluate the mass of the carbon blank and its associated 14C signature, and to assess the performance of the RP system. We estimate blank contamination during RP using two methods, the modern-dead and the isotope dilution method. Our results indicate that during one complete RP run samples are contaminated by 8.8 ± 4.4 μg (time-dependent) of modern carbon (MC, fM ∼ 1) and 4.1 ± 5.5 μg (time-independent) of dead carbon (DC, fM ∼ 0). We find that the modern-dead method provides more accurate estimates of uncertainties in blank contamination; therefore, the isotope dilution method should be used with caution when the variability of the blank is high. Additionally, we show that RP can routinely produce accurate 14C dates with precisions ∼100 14C years for materials deposited in the last 10 000 years and ∼300 14C years for carbon with 14C ages of up to 20 000 years