Characteristics of Carbonaceous Aerosols Emitted from Peatland Fire in Riau, Sumatra, Indonesia

Biomass burning is a significant source of fine particulate matter (PM 2.5). Forest, bush, and peat fires in Kalimantan and Sumatra, Indonesia are major sources of transboundary haze pollution in Southeast Asia. However, limited data exist regarding the chemical characteristics of aerosols at sources. We conducted intensive field studies in Riau Province, Sumatra, Indonesia, during the peatland fire and non-burning seasons Ni 2012. We characterized PM carbonaceous aerosols emitted from peatland fire based on ground-based source-dominated sampling. PM 2.5 aerosols were collected with two mini-volume samplers using Teflon and quartz fiber filters. Background aerosols were also sampled during the transition period between the non-burning and fire seasons. We analyzed the carbonaceous content (organis carbon (OC) and elemental carbon (EC)) by a thermal optical reflectance utilizing the IMPROVE_A protokol and the major organic components of the aerosols by a gas chromatography/mass spectrometry. PM 2.5 aerosols emitted from peatland fire were observed in high concentrations of 7120 _ 3620 mgm and were primarily composed of OC (71.0 _ 5.11% of PM mass). Levoglucosan exhibited the highest total ion current and was present at concentrations of 464 _ 183 µg m-3. The OC/EC ratios (36.4 _ 9.08), abundances of eight thermally-derived carbon fractions, OC/Levoglucosan ratios (10.6 _ 1.96), and Levoglucosan/Mannosan ratios (10.6 _ 2.03) represent a signature profile that is inherent in peatland fire. These data will be useful in identifying contributions from single bor multiple species in atmospheric aerosol samples collected from peatland fires

Occupational Exposure to Gaseous and Aerosolized Volatile Organic Compounds in Flight Line Crews Using Different Types of Jet Fuel

We conducted a study to characterize the occupational chemical exposure to JP-8 ［a kerosene-based jet fuel used widely for both military and commercial aircraft） and JP-4 （a naphtha – and kerosene-based jet fuel that is used by the Japan Air Self-Defense Force （JASDF）］. The study population included 90 volunteer subjects from JASDF and United States Air Force bases in Japan. The individual exposure to 48 volatile organic compounds （VOCs） was measured in C-130 （a cargo aircraft） flight line crews and non-exposed control subjects （workers in the Yokota and Kadena hospitals）. The individual air samples were collected during a typical work shift using a compact battery-operated personal air sampler with activated charcoal for gaseous VOCs and with a cascade impactor for aerosolized VOCs （diameter:＜6.6µm）. Each collected sample was analyzed by gas chromatography. Subjects in the JP-4 group were mainly exposed to gaseous aromatics and shorter straight-chain alkanes including carcinogenic benzene and neurotoxic hexane, while the subjects in the JP-8 group were exposed to aerosolized alkanes with a longer straight chain such as tridecane. In conclusion, this study revealed the characteristics of chemical exposure according to the fuel type in the flight line environment. The results suggest the health risks associated with each fuel type and the protective measures that should be employed. Aerosolized tridecane or aerosol containing tridecane might be causing the complaints from workers using kerosene-based fuel. None of the subjects were exposed to VOCs at levels exceeding recommended exposure limits

Substrate Specificity of an Aminopropyltransferase and the Biosynthesis Pathway of Polyamines in the Hyperthermophilic Crenarchaeon Pyrobaculum calidifontis

The facultative anaerobic hyperthermophilic crenarchaeon Pyrobaculum calidifontis possesses norspermine (333), norspermidine (33), and spermidine (34) as intracellular polyamines (where the number in parentheses represents the number of methylene CH2 chain units between NH2, or NH). In this study, the polyamine biosynthesis pathway of P. calidifontis was predicted on the basis of the enzymatic properties and crystal structures of an aminopropyltransferase from P. calidifontis (Pc-SpeE). Pc-SpeE shared 75% amino acid identity with the thermospermine synthase from Pyrobaculum aerophilum, and recombinant Pc-SpeE could synthesize both thermospermine (334) and spermine (343) from spermidine and decarboxylated S-adenosyl methionine (dcSAM). Recombinant Pc-SpeE showed high enzymatic activity when aminopropylagmatine and norspermidine were used as substrates. By comparison, Pc-SpeE showed low affinity toward putrescine, and putrescine was not stably bound in its active site. Norspermidine was produced from thermospermine by oxidative degradation using a cell-free extract of P. calidifontis, whereas 1,3-diaminopropane (3) formation was not detected. These results suggest that thermospermine was mainly produced from arginine via agmatine, aminopropylagmatine, and spermidine. Norspermidine was produced from thermospermine by an unknown polyamine oxidase/dehydrogenase followed by norspermine formation by Pc-SpeE

Substrate Specificity of an Aminopropyltransferase and the Biosynthesis Pathway of Polyamines in the Hyperthermophilic Crenarchaeon <i>Pyrobaculum calidifontis</i>

The facultative anaerobic hyperthermophilic crenarchaeon Pyrobaculum calidifontis possesses norspermine (333), norspermidine (33), and spermidine (34) as intracellular polyamines (where the number in parentheses represents the number of methylene CH2 chain units between NH2, or NH). In this study, the polyamine biosynthesis pathway of P. calidifontis was predicted on the basis of the enzymatic properties and crystal structures of an aminopropyltransferase from P. calidifontis (Pc-SpeE). Pc-SpeE shared 75% amino acid identity with the thermospermine synthase from Pyrobaculum aerophilum, and recombinant Pc-SpeE could synthesize both thermospermine (334) and spermine (343) from spermidine and decarboxylated S-adenosyl methionine (dcSAM). Recombinant Pc-SpeE showed high enzymatic activity when aminopropylagmatine and norspermidine were used as substrates. By comparison, Pc-SpeE showed low affinity toward putrescine, and putrescine was not stably bound in its active site. Norspermidine was produced from thermospermine by oxidative degradation using a cell-free extract of P. calidifontis, whereas 1,3-diaminopropane (3) formation was not detected. These results suggest that thermospermine was mainly produced from arginine via agmatine, aminopropylagmatine, and spermidine. Norspermidine was produced from thermospermine by an unknown polyamine oxidase/dehydrogenase followed by norspermine formation by Pc-SpeE

Characteristics of carbonaceous aerosols emitted from peatland fire in Riau, Sumatra, Indonesia

Biomass burning is a significant source of fine particulate matter (PM₂.₅). Forest, bush, and peat fires in Kalimantan and Sumatra, Indonesia are major sources of transboundary haze pollution in Southeast Asia. However, limited data exist regarding the chemical characteristics of aerosols at sources. We conducted intensive field studies in Riau Province, Sumatra, Indonesia, during the peatland fire and non-burning seasons in 2012. We characterized PM₂.₅ carbonaceous aerosols emitted from peatland fire based on ground-based source-dominated sampling. PM₂.₅ aerosols were collected with two mini-volume samplers using Teflon and quartz fiber filters. Background aerosols were also sampled during the transition period between the non-burning and fire seasons. We analyzed the carbonaceous content (organic carbon (OC) and elemental carbon (EC)) by a thermal optical reflectance utilizing the IMPROVE_A protocol and the major organic components of the aerosols by a gas chromatography/mass spectrometry. PM₂.₅ aerosols emitted from peatland fire were observed in high concentrations of 7120 ± 3620 μg m⁻³ and were primarily composed of OC (71.0 ± 5.11% of PM2.5 mass). Levoglucosan exhibited the highest total ion current and was present at concentrations of 464 ± 183 μg m⁻³. The OC/EC ratios (36.4 ± 9.08), abundances of eight thermally-derived carbon fractions, OC/Levoglucosan ratios (10.6 ± 1.96), and Levoglucosan/Mannosan ratios (10.6 ± 2.03) represent a signature profile that is inherent in peatland fire. These data will be useful in identifying contributions from single or multiple species in atmospheric aerosol samples collected from peatland fires