A Method for Rapid Calculation of Merchant Vessel Combustion Emission

A simple method for calculating long term (1 year average) combustion emissions from cargo vessels is presented. The method uses emission factors for the five EPA criteria pollutants based on the amount and type of cargo carried by these vessels. Separate emission factors are derived for the underway and docking operations based on current fuel consumption to transport or load/unload cargo. Fuel consumption is then converted to emission factors in the form of tons of pollutant per million ton miles of cargo transported or tons of pollutant per million tons of cargo loaded/unloaded. The emission calculations can be performed on a desk calculator using data published in a federal document. The annual emissions of the Port of Houston are estimated as a sample calculation. The report also Includes a method of determining the spatial distributions of the emissions and a listing of stack parameters.     

PSII activity and pigment dynamics of Symbiodinium in two Indo-Pacific corals exposed to short-term high-light stress

This study examined the capacity for photoprotection and repair of photo-inactivated photosystem II in the same Symbiodinium clade associated with two coexisting coral species during high-light stress in order to test for the modulation of the symbiont’s photobiological response by the coral host. After 4 days exposure to in situ irradiance, symbionts of the bleaching-sensitive Pocillopora damicornis showed rapid synthesis of photoprotective pigments (by 44 %) and strongly enhanced rates of xanthophyll cycling (by 446 %) while being insufficient to prevent photoinhibition (sustained loss in F _v/F _m at night) and loss of symbionts after 4 days. By contrast, Pavona decussata showed no significant changes in F _v/F _m, symbiont density or xanthophyll cycling. Given the association with the same Symbiodinium clade in both coral species, our findings suggest that symbionts in the two species examined may experience different in hospite light conditions as a result of different biometric properties of the coral host.     

Delineating landfill leachate discharge to an arsenic contaminated waterway

Discharge of contaminated ground water may serve as a primary and on-going source of contamination to surface water. A field investigation was conducted at a Superfund site in Massachusetts, USA to define the locus of contaminant flux and support source identification for arsenic contamination in a pond abutting a closed landfill. Subsurface hydrology and ground-water chemistry were evaluated in the aquifer between the landfill and the pond during the period 2005-2009 employing a network of wells to delineate the spatial and temporal variability in subsurface conditions. These observations were compared with concurrent measures of ground-water seepage and surface water chemistry within a shallow cove that had a historical visual record of hydrous ferric oxide precipitation along with elevated arsenic concentrations in shallow sediments. Barium, presumably derived from materials disposed in the landfill, served as an indicator of leachate-impacted ground water discharging into the cove. Evaluation of the spatial distributions of seepage flux and the concentrations of barium, calcium, and ammonium-nitrogen indicated that the identified plume primarily discharged into the central portion of the cove. Comparison of the spatial distribution of chemical signatures at depth within the water column demonstrated that direct discharge of leachate-impacted ground water was the source of highest arsenic concentrations observed within the cove. These observations demonstrate that restoration of the impacted surface water body will necessitate control of leachate-impacted ground water that continues to discharge into the cove.     

Statute and legislative history of the federal insecticide,fungicide, and rodenticide act and its impact on agriculture

Abstract

This report discusses the responsibilities of government for the legislation of pesticides, and describes the impact of various statutes on the use of pesticides in agriculture. Governmental responsibilities for management of the economy, education, and enactment of laws and regulations are discussed, and the history of U.S. legislation of pesticides and related substances is presented. Finally, the impact of pesticide regulation on international trade is considered.     

"Novel" brominated flame retardants in Belgian and UK indoor dust: implications for human exposure

Concentrations of several “novel” brominated flame retardants (NBFRs) are reported in indoor dust samples from Belgian houses (n = 39) and offices (n = 6) and from day-care centers and schools in the West Midlands of the UK (n = 36). Using a GC-ECNI/MS method, the following NBFRs were quantified: decabromodiphenyl ethane (DBDPE) (range <20-2470 ng g⁻¹), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) (range <0.5-1740 ng g⁻¹), tetrabromobisphenol A-bis(2,3-dibromopropylether) (TBBPA-DBPE) (range <20-9960 ng g⁻¹), 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB) (range <2-436 ng g⁻¹) and bis(2-ethylhexyl)-3,4,5,6-tetrabromophthalate (TBPH) (range <2-6175 ng g⁻¹). Hexachlorocyclopentadienyl-dibromocyclooctane (HCDBCO), another NBFR, was below the detection limit of 2 ng g⁻¹ dust in all dust samples. No correlation was detected between concentrations of NBFRs and PBDEs. The ratio of TBB:TBPH in the dust samples ranged from 0.01 to 4.77 (average 0.42), compared to the ratio present in the commercial flame retardant product FM 550 (TBB:TBPH = 4:1). Furthermore, no correlation was detected between concentrations in dust of TBB and TBPH. This may suggest different sources of these NBFRs, or similar sources but compound-specific differences in their indoor fate and transport. Exposure via dust ingestion was estimated for both adults and toddlers under low-end (5th percentile), typical (median), and high-end (95th percentile concentrations) scenarios. These were calculated assuming 100% absorption of intake dust and using mean dust ingestion (adults = 20 mg d⁻¹; for toddlers = 50 mg d⁻¹) and high dust ingestion (adults = 50 mg d⁻¹; for toddlers = 200 mg d⁻¹). Typical exposure with high dust ingestion estimates for adults were 0.01, 0.2, 0.01, 0.02 and 0.08 ng kg⁻¹ bw d⁻¹ and for toddlers 0.05, 1.9, 0.08, 0.4 and 1.12 ng kg⁻¹ bw d⁻¹ for BTBPE, DBDPE, TBB, TBPH and TBBPA-DBPE, respectively. Our results showed that, similar to PBDEs, toddlers have higher exposure to NBFRs than adults. This study documents the presence of NBFRs in indoor environments, and emphasizes the need to evaluate the health implications of exposure to such chemicals.     

Dissipation, half-lives, and mass spectrometric identification of endosulfan isomers and the sulfate metabolite on three field-grown vegetables

Endosulfan 3 EC, a mixture of α- and β-stereo isomers, was sprayed on field-grown pepper, melon, and sweet potato plants at the recommended rate of 0.44 kg A.I. acre(-1). Plant tissue samples (leaves, fruits, or edible roots) were collected 1 h to 30 days following spraying and analyzed for endosulfan isomers (α- and β-isomers). Analysis of samples was accomplished using a gas chromatograph (GC) equipped with a mass detector in total ion mode. The results indicated the formation of endosulfan sulfate as the major metabolite of endosulfan sulfite and the relatively higher persistence of the β-isomers as compared to the α-isomer. The initial total residues (α- and β-isomers plus endosulfan sulfate) were higher on leaves than on fruits. On pepper and melon fruits, the α-isomer, which is the more toxic to mammals, dissipated faster (T(1/2) = 1.22 and 0.95 d, respectively) than the less toxic β-isomer (T(1/2) = 3.0 and 2.5 d, respectively). These results confirm the greater loss of the α-isomer compared to the β-isomer, which can ultimately impact endosulfan dissipation in the environment. Additionally, the higher initial residues of endosulfan on pepper and sweet potato leaves should be considered of great importance for timing field operations and the safe entry of harvesters due to the high mammalian toxicity of endosulfan.     

PFOS or PreFOS? Are perfluorooctane sulfonate precursors (PreFOS) important determinants of human and environmental perfluorooctane sulfonate (PFOS) exposure?

The extent to which perfluorooctanesulfonate precursors (PreFOS) play a role in human or environmental exposure to perfluorooctanesulfonate (PFOS) is not well characterized. The diversity of manufactured PreFOS and its degradation products (e.g. C(8)F(17)SO(2)R and C(8)F(17)SO(2)NR'R', where R is H or F, and R' and R' are various) has made it difficult to track their fate. Temporal trends of PFOS in both humans and wildlife are discrepant, thus it is difficult to predict future exposure, and hypotheses about the role of PreFOS have been raised. Although abiotic degradation of commercially important PreFOS materials requires further research, current data suggest that the yield of PFOS is negligible or minor. On the other hand, in vivo biotransformation of PreFOS yields PFOS as the major metabolite, and >32% yields have been observed. In Canadians, exposure to PreFOS was equivalent or greater than direct PFOS exposure prior to 2002. In most ocean water, PFOS is dominant to PreFOS, but in the oceans east of Greenland there may be more PreFOS than PFOS, consistent with the fact that whales and humans in this region also show evidence of substantial PreFOS exposure. Quantitative assessments of PFOS body-burdens coming from PreFOS are complicated by the fact that PreFOS partitions to the cellular fraction of blood, thus biomonitoring in serum under predicts PreFOS relative to PFOS. Many unknowns exist that prevent accurate modelling, thus analytical methods that can distinguish directly manufactured PFOS, from PFOS that has been biotransformed from PreFOS, should be applied in future human and environmental monitoring. Two new source tracking principles are presented and applied to human serum.     

Alkyl nitrate photochemistry during the tropospheric organic chemistry experiment

Alkyl nitrates (C₁–C₅) were measured at two sites (near urban and rural) in southeast England during the Tropospheric Organic Chemistry Experiment (TORCH). Methyl nitrate was the dominant species during both campaigns accounting for on average about one third of the total measured alkyl nitrates. High mixing ratios (>50 pptv) and variability of methyl nitrate were observed at the near urban site (TORCH1) that were not seen at the rural site (TORCH2) and which could not be explained by local photochemical production or direct emissions. The diurnal variation of methyl nitrate during TORCH1 showed a morning maximum that would be consistent with nighttime chemistry followed by transport to the surface by boundary layer dynamics. Similarly, elevated morning mixing ratios were also observed during TORCH2 although the magnitudes were much smaller. As a result, methyl nitrate could represent a tracer for nighttime chemistry seen at the ground the following day. At both campaigns, the dominant source of short chain alkyl nitrates and carbonyl precursor radicals (≤C₄) were from decomposition of larger compounds. The magnitude of the source increased with decreasing carbon number consistent with increasing total precursor abundance. Non-photochemical emissions of acetaldehyde and acetone could not be accounted for by automobile exhaust emissions alone and indicated that other direct sources are likely important in this environment.     

Industrial Pollution Prevention

The 1992 A&WMA Critical Review was authored by Harry Freeman and members of his staff at the Pollution Prevention Research Branch, Risk Reduction Engineering Laboratory, U.S. Environmental Protection Agency in Cincinnati, Ohio. Mr. Freeman presented the paper "Industrial Pollution Prevention," at the Critical Review session held during the 85th Air & Waste Management Association Annual Meeting in Kansas City, Missouri. Prepared discussions and invited comments presented during the session are published here, as well as closing remarks by Mr. Freeman.