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PubMed2001

Ultrafine particles in alveolar macrophages from normal children.

BACKGROUND: Increased ambient levels of particulate matter <10 microm (PM(10)) from fossil fuel combustion are associated with an increased prevalence of respiratory symptoms in children. However, it is unknown whether, and to what extent, pollutant particles penetrate the paediatric lower airway. The capacity of alveolar macrophages (AM) to phagocytose inhaled material was used to directly assess exposure of normal children to particles. METHODS: AM from 22 children aged 3 months to 16 years with no respiratory symptoms were obtained by non-bronchoscopic bronchoalveolar lavage prior to elective surgery. In each child the size and composition of environmental particles within single sections from 100 separate AM was determined by electron microscopy and microanalysis. RESULTS: Single and clusters of particles were seen in AM from all children. The percentage of particle-containing AM ranged from 1% to 16% per child. Particles consisted of a carbonaceous core and all were ultrafine (<0.1 microm). Other elements such as metals and silicon were not detected. The percentage of particle-containing AM did not change with age, but was increased in children whose parents lived on a main road compared with those living on a quiet residential road (median 10% v 3%, p = 0.014). CONCLUSIONS: All children had AM containing ultrafine carbonaceous particles. The predominant source of these particles is most likely to be from the combustion of fossil fuels.

Adolescent↗

PubMed1982

Dietary energy requirements of broilers reared in low and moderate environmental temperatures. 1. Adjusting dietary energy to compensate for abnormal environmental temperatures.

Four trials were conducted to determine the feasibility of replacing fossil fuel energy with dietary energy to meet the 23- to 48-day-old broiler chicken's energy requirements during abnormal cold exposure. Sexed broilers were fed 3250 or 3500 kcal metabolizable energy (ME)/kg in a 21.1 C environment (a normal management situation), and 3250 or 3125 kal ME/kg in a 26.7 C environment. Body weights and feed utilizations increased when broilers were exposed to a 15.6 C environmental temperature and fed 3375 kcal ME/kg dietary energy as compared to feeding a 3250 kcal ME/kg dietary energy in the same environment. When broilers were reared in a 10.0 C environment, maximum body weights were not obtained by increasing the dietary energy from 3250 to 3500 kcal/kg dietary energy. Broiler males, fed 3250 kcal ME/kg and reared in either a 21.1 or a 26.7 C environment, were larger than males reared in 10.0 C environment. No significant differences were found in broiler female weights reared in a 10.0, 15.6, or 21.1 C environment and fed 3250 kcal ME/kg in each temperature regimen. Feed utilizations were the same broilers were reared in a 15.6 C environment and fed 3375 kcal ME/kg compared to broilers reared in a 21.1 C environment and fed 3250 kcal ME/kg. These results indicate that maximum performance of 23- to 48-day-old broilers may be achieved in a 15.6 C environment by feeding a high energy diet (3375 kcal/kg). Results also showed that dietary energy may replace fossil fuel energy that would normally be supplied in a 21.1 C environment.

Adipose Tissue↗

PubMed1998

Mutagenic and cytotoxic effects of exhaust particulate matter of biodiesel compared to fossil diesel fuel.

The mutagenic and cytotoxic effects of diesel engine exhaust (DEE) from a modern passenger car using rapeseed oil methyl esters (RME, biodiesel) as fuel were directly compared to DEE of diesel fuel (DF) derived from petroleum. Combustion particulate matter was collected on glass fiber filters coated with polytetrafluoroethylene (PTFE) from an exhaust dilution tunnel using three different engine test cycles on a chassis dynamometer. Filters were extracted with dichloromethane in a soxhlet apparatus for 12 h. The mutagenicity of the extracts was tested in the Salmonella typhimurium/mammalian microsome plate-incorporation assay using strains TA97a, TA98, TA100, and TA102. The toxicity to the established cell line L929 (mouse lung fibroblasts) was investigated in the neutral red assay. In the tester strains TA98 and TA100 a significant increase of mutations resulted for the particle extracts of both fuels, but for DF the revertants were significantly higher compared to RME. The highest levels of revertants were observed in tests including a cold start phase. This was probably due to incomplete combustion in the cold engine and a lower conversion rate of the cold catalytic converter. Testing with activated liver S9 fraction induced a slightly lower increase of revertants in most experiments. TA97a and TA102 showed no significant enhancement of spontaneous mutations. In the FTP-75 test cycle RME extracts showed slightly higher toxic effects to the L929 cells than DF, whereas in the other tests no significant differences were observable. These results indicate a higher mutagenic potency of DEE of DF compared to RME. This is probably due to the lower content of polycyclic aromatic compounds (PAC) in RME exhaust, although the emitted masses of RME were higher in most test procedures applied in this study.

Animals↗

PubMed2006

[Carbon balance analysis of corn fuel ethanol life cycle].

The quantity of greenhouse gas emissions (net carbon emissions) of corn-based fuel ethanol, which is known as an alternative for fossil fuel is an important criteria for evaluating its sustainability. The methodology of carbon balance analysis for fuel ethanol from corn was developed based on principles of life cycle analysis. For the production state of fuel ethanol from summer corn in China, carbon budgets in overall life cycle of the ethanol were evaluated and its main influence factors were identified. It presents that corn-based fuel ethanol has no obvious reduction of carbon emissions than gasoline, and potential improvement in carbon emission of the life cycle of corn ethanol could be achieved by reducing the nitrogen fertilizer and irrigation electricity used in the corn farming and energy consumption in the ethanol conversion process.

Carbon↗

PubMedDate not supplied

Hydrocarbon emissions and health risks from cookstoves in developing countries.

The nonmethane hydrocarbon emissions from several types of cookstoves commonly used in developing countries were measured in a pilot study conducted in Manila, the Philippines. Four types of fuel, i.e., wood, charcoal, kerosene, and liquefied petroleum gas (LPG), were tested. Because kerosene was burned in three different types of stoves, there were six fuel/stove combinations tested. Fifty-nine nonmethane hydrocarbons were identified frequently in emissions of these cookstoves, with emission ratios to CO2 up to 5.3 x 10(-3). The emissions were quantitated with emission factors on both a mass basis (emissions/kg fuel) and a task basis (emissions/cooking task). On a task basis, combustion of biomass fuels (wood and charcoal) generally produced higher emission factors than combustion of fossil fuels (kerosene and LPG). One type of kerosene stove (wick stove), however, still generated the greatest emissions of some individual and classes of hydrocarbons, indicating that emissions were dependent on not only fuel types but also combustion devices. Some hydrocarbons, e.g., benzene, 1,3-butadiene, styrene, and xylenes, were of concern because of their carcinogenic properties. The lifetime risk from exposures to these compounds emitted from cookstoves was tentatively estimated by using a simple exposure model and published cancer potencies.

Air Pollutants↗

PubMed2004

Cogeneration from thermal treatment of selected municipal solid wastes. A stoichiometric model building for the case study on Palermo.

This paper aims to calculate the energetic and environmental effects of an integrated solid waste management system in Palermo, Italy. In particular, the thermal treatment of Municipal Solid Waste (MSW) with energy recovery is assessed. The current characterization at the local scale is taken into account. Two different options of collection are taken into account: (1) unselected wastes; and (2) sorted collection, according to the current Italian regulation. Combustion process is analyzed and the following features are calculated: (1) stoichiometric content of air and air excess; and (2) temperature and enthalpy of flue gases. Energy recovery is performed in the hypothesis of Hirn cycle both with steam condensation to produce only power, and with bleeding cycle for the combined production of power and thermal energy. Total electric efficiency is assumed as representative index of the technological level of the assessed plant. Results show that the thermal treatment of selected MSW, associated with a cogenerative recovery of energy, represents a relevant sustainable strategy of waste valorization as an alternative to fossil fuels.

Conservation of Energy Resources↗

PubMed2006

Potential of carbon accumulation in no-till soils with intensive use and cover crops in southern Brazil.

The area under no-till (NT) in Brazil reached 22 million ha in 2004-2005, of which approximately 45% was located in the southern states. From the 1970s to the mid-1980s, this region was a source of carbon dioxide to the atmosphere due to decrease of soil carbon (C) stocks and high consumption of fuel by intensive tillage. Since then, NT has partially restored the soil C lost and reduced the consumption of fossil fuels. To assess the potential of C accumulation in NT soils, four long-term experiments (7-19 yr) in subtropical soils (Paleudult, Paleudalf, and Hapludox) varying in soil texture (87-760 g kg(-1) of clay) in agroecologic southern Brazil zones (central region, northwest basaltic plateau in Rio Grande Sul, and west basaltic plateau in Santa Catarina) and with different cropping systems (soybean and maize) were investigated. The lability of soil organic matter (SOM) was calculated as the ratio of total organic carbon (TOC) to particulate organic carbon (POC), and the role of physical protection on stability of SOM was evaluated. In general, TOC and POC stocks in native grass correlated closely with clay content. Conversely, there was no clear effect of soil texture on C accumulation rates in NT soils, which ranged from 0.12 to 0.59 Mg ha(-1) yr(-1). The C accumulation was higher in NT than in conventional-till (CT) soils. The legume cover crops pigeon pea [Cajanus cajan (L.) Millsp] and velvet beans (Stizolobium cinereum Piper & Tracy) in NT maize cropping systems had the highest C accumulation rates (0.38-0.59 Mg ha(-1) yr(-1)). The intensive cropping systems also were effective in increasing the C accumulation rates in NT soils (0.25-0.34 Mg ha(-1) yr(-1)) when compared to the double-crop system used by farmers. These results stress the role of N fixation in improving the tropical and subtropical cropping systems. The physical protection of SOM within soil aggregates was an important mechanism of C accumulation in the sandy clay loam Paleudult under NT. The cropping system and NT effects on C stocks were attributed to an increase in the lability of SOM, as evidenced by the higher POC to TOC ratio, which is very important to C and energy flux through the soil.

Agriculture↗

PubMed1994

Leukaemia clusters in childhood: geographical analysis in Britain.

STUDY OBJECTIVE: To validate previously demonstrated spatial clustering of childhood leukaemias by showing relative proximities of selected map features to cluster locations, compared with control locations. If clusters are real, then they are likely to be close to a determining hazard. DESIGN: Cluster postcode loci and partially matched control postcodes were compared in terms of distances to railways, main roads, churches, surface water, woodland areas, and railside industrial installations. Further supporting comparisons between non-clustered cases and random postcode controls with those map features representable as single grid points were made. SETTING: England, Wales, and Scotland 1966-83. SUBJECTS: Grid referenced registrations of 9406 childhood leukaemias and non-Hodgkin's lymphomas, including 264 pairs (or more) separated by < 150 m, and grid references of random postcodes in equal numbers. MAIN RESULTS: The 264 clusters showed relative proximities (or the inverse) to several map features, of which the most powerful was an association with railways. The non-railway associations seemed to be statistically indirect. Some railside industrial installations, identified from a railway atlas, also showed relative proximities to leukaemia clusters, as well as to non-clustered cases, but did not "explain" the railway effect. These installations, with seemingly independent geographical associations, included oil refineries, petrochemical plants, oil storage and oil distribution depots, power stations, and steelworks. CONCLUSIONS: The previously shown childhood leukaemia clusters are confirmed to be non-random through their systematic associations with certain map features when compared with the control locations. The common patterns of close association of clustered and non-clustered cases imply a common aetiological component arising from a common environmental hazard--namely the use of fossil fuels, especially petroleum.

Adolescent↗

PubMed2005

Life cycle assessment of EPS and CPB inserts: design considerations and end of life scenarios.

Expanded polystyrene (EPS) and corrugated paperboard (CPB) are used in many industrial applications, such as containers, shock absorbers or simply as inserts. Both materials pose two different types of environmental problems. The first is the pollution and resource consumption that occur during the production of these materials; the second is the growing landfills that arise out of the excessive disposal of these packaging materials. Life cycle assessment or LCA will be introduced in this paper as a useful tool to compare the environmental performance of both EPS and CPB throughout their life cycle stages. This paper is divided into two main parts. The first part investigates the environmental impacts of the production of EPS and CPB from 'cradle-to-gate', comparing two inserts--both the original and proposed new designs. In the second part, LCA is applied to investigate various end-of-life cases for the same materials. The study will evaluate the environmental impacts of the present waste management practices in Singapore. Several 'what-if' cases are also discussed, including various percentages of landfilling and incineration. The SimaPro LCA Version 5.0 software's Eco-indicator 99 method is used to investigate the following five environmental impact categories: climate change, acidification/eutrophication, ecotoxicity, fossil fuels and respiratory inorganics.

Environmental Monitoring↗

PubMed2004

Hybrid cars now, fuel cell cars later.

We compare the energy efficiency of hybrid and fuel cell vehicles as well as conventional internal combustion engines. Our analysis indicates that fuel cell vehicles using hydrogen from fossil fuels offer no significant energy efficiency advantage over hybrid vehicles operating in an urban drive cycle. We conclude that priority should be placed on hybrid vehicles by industry and government.

Journal Article↗

PubMed2004

Effect of pH on cellulase production of Trichoderma reesei RUT C30.

Currently, the high market price of cellulases prohibits commercialization of the lignocellulosics-to-fuel ethanol process, which utilizes enzymes for saccharification of cellulose. For this reason research aimed at understanding and improving cellulase production is still a hot topic in cellulase research. Trichoderma reesei RUT C30 is known to be one of the best hyper producing cellulolytic fungi, which makes it an ideal test organism for research. New findings could be adopted for industrial strains in the hope of improving enzyme yields, which in turn may result in lower market price of cellulases, thus making fuel ethanol more cost competitive with fossil fuels. Being one of the factors affecting the growth and cellulase production of T. reesei, the pH of cultivation is of major interest. In the present work, numerous pH-controlling strategies were compared both in shake-flask cultures and in a fermentor. Application of various buffer systems in shake-flask experiments was also tested. Although application of buffers resulted in slightly lower cellulase activity than that obtained in non-buffered medium, beta-glucosidase production was increased greatly.

Biotechnology↗

PubMed2002

A pilot study to assess ground-level ambient air concentrations of fine particles and carbon monoxide in urban Guatemala.

Ambient concentrations and the elemental composition of particles less than 2.5 microm in diameter (PM2.5), as well as carbon monoxide (CO) concentrations, were measured at ground-level in three Guatemalan cities in summer 1997: Guatemala City, Quetzaltenango, and Antigua. This pilot study also included quantitative and qualitative characterizations of microenvironment conditions, e.g., local meteorology, reported elsewhere. The nondestructive X-ray fluorescence elemental analysis (XRF) of Teflon filters was conducted. The highest integrated average PM2.5. concentrations in an area (zona) of Guatemala City and Quetzaltenango were 150 microg m(-3) (zona 12) and 120 microg m(-3) (zona 2), respectively. The reported integrated average PM2.5 concentration for Antigua was 5 microg m(-3). The highest observed half-hour and monitoring period average CO concentrations in Guatemala City were 10.9 ppm (zona 8) and 7.2 ppm (zonas 8 and 10), respectively. The average monitoring period CO concentration in Antigua was 2.6 ppm. Lead and bromine concentrations were negligible, indicative of the transition to unleaded fuel use in cars and motorcycles. The XRF results suggested sources of air pollution in Guatemala, where relative rankings varied by city and by zonas within each city, were fossil fuel combustion emitting hydrocarbons, combustion of sulfurous conventional fuels, soil/roadway dust, farm/agricultural dust, and vehicles (evaportion of gas, parts' wear).

Agriculture↗

PubMedDate not supplied

Medical aspects of power generation, present and future.

It can be seen that the radiation emissions of nuclear power plants are small indeed, compared to natural background radiation and other man-made sources of radiation. For example, the poulation is exposed to 100 times more radiation from television sets than from nuclear power reactors. The assumed risks to the people in this country from nuclear power reactors are also small compared to the normal risks which are tolerated in this society. The complete elimination of all hazards is a most difficult if not impossible task. If we need and desire a certain level of electrical energy, if we must choose between alternative sourves of the energy, then it is apparent that the total impact on our health from nuclear power generation of electricity, under normal operations and in consideration of catastrophic accident probabilities, is significantly less than that of continuing or increasing use of fossil fuels to generate electricity.

Abnormalities, Radiation-Induced↗

PubMed2004

Distribution and sources of polynuclear aromatic hydrocarbons in Mangrove surficial sediments of Deep Bay, China.

Twelve sediment samples collected from three transects of mangrove swamp of Deep Bay, Shenzhen, China, were determined for polynuclear aromatic hydrocarbons (PAHs). The total PAHs concentrations ranged from 237 to 726 ng g(-1) dry weight, and showed strong correlation with total organic carbon (TOC), clay content and Pb concentrations. The highest PAHs concentrations were found in the samples from mangrove sediments. Overall, PAHs in Deep Bay sediment were lower than those in other developed areas. The biological effect due to PAHs alone in Deep Bay is expected to be low, based on the comparisons of individual and total PAHs concentrations determined in the sediment with those in USEPA sediment quality guidelines. Four and five-ring compounds dominated the PAHs composition pattern profiles. Principal component analysis (PCA) was applied to further investigate the source of PAHs. The PAH sources of Deep Bay mangrove swamp were suggested to be primarily combustion of fossil fuel, especially leaded-gasoline exhaust.

China↗

PubMed2006

Is cumulative fossil energy demand a useful indicator for the environmental performance of products?

The appropriateness of the fossil Cumulative Energy Demand (CED) as an indicator for the environmental performance of products and processes is explored with a regression analysis between the environmental life-cycle impacts and fossil CEDs of 1218 products, divided into the product categories "energy production", "material production", "transport", and "waste treatment". Our results show that, for all product groups but waste treatment, the fossil CED correlates well with most impact categories, such as global warming, resource depletion, acidification, eutrophication, tropospheric ozone formation, ozone depletion, and human toxicity (explained variance between 46% and 100%). We conclude that the use of fossil fuels is an important driver of several environmental impacts and thereby indicative for many environmental problems. It maytherefore serve as a screening indicatorfor environmental performance. However, the usefulness of fossil CED as a stand-alone indicator for environmental impact is limited by the large uncertainty in the product-specific fossil CED-based impact scores (larger than a factor of 10 for the majority of the impact categories; 95% confidence interval). A major reason for this high uncertainty is nonfossil energy related emissions and land use, such as landfill leachates, radionuclide emissions, and land use in agriculture and forestry.

Agriculture↗

PubMed2005

Mortality and greenhouse gas impacts of biomass and petroleum energy futures in Africa.

We analyzed the mortality impacts and greenhouse gas (GHG) emissions produced by household energy use in Africa. Under a business-as-usual (BAU) scenario, household indoor air pollution will cause an estimated 9.8 million premature deaths by the year 2030. Gradual and rapid transitions to charcoal would delay 1.0 million and 2.8 million deaths, respectively; similar transitions to petroleum fuels would delay 1.3 million and 3.7 million deaths. Cumulative BAU GHG emissions will be 6.7 billion tons of carbon by 2050, which is 5.6% of Africa's total emissions. Large shifts to the use of fossil fuels would reduce GHG emissions by 1 to 10%. Charcoal-intensive future scenarios using current practices increase emissions by 140 to 190%; the increase can be reduced to 5 to 36% using currently available technologies for sustainable production or potentially reduced even more with investment in technological innovation.

Adult↗

PubMed2002

Energy recovery from New York City municipal solid wastes.

This work was part of a major study that examined the policy and technology implications of alternatives for managing the municipal solid wastes (MSW) of New York City. At this time, of the 4.1 million metric tons of MSW collected by the City annually, 16.6% are recycled, 12.4% are combusted in Waste-to-Energy (WTE) plants, and the remaining 71% are landfilled. Despite the heterogeneity of organic materials in MSW, the composite molecular structure can be approximated by the organic compound C6H10O4. A formula was derived that allows the prediction of the heating value of MSW as a function of moisture and glass/metal content and compares well with experimentally derived values. The performance of a leading Waste-to-Energy plant that utilises suspension firing of shredded MSW, processes one million tons of MSW per year, and generates a net of 610 kWh/metric ton was examined. The results of this study showed that WTE processing of the MSW reduces fossil fuel consumption and is environmentally superior to landfilling.

Conservation of Natural Resources↗

PubMedDate not supplied

Energy and emission benefits of alternative transportation liquid fuels derived from switchgrass: a fuel life cycle assessment.

We conducted a mobility chains, or well-to-wheels (WTW), analysis to assess the energy and emission benefits of cellulosic biomass for the U.S. transportation sector in the years 2015-2030. We estimated the life-cycle energy consumption and emissions associated with biofuel production and use in light-duty vehicle (LDV) technologies by using the Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model. Analysis of biofuel production was based on ASPEN Plus model simulation of an advanced fermentation process to produce fuel ethanol/protein, a thermochemical process to produce Fischer-Tropsch diesel (FTD) and dimethyl ether (DME), and a combined heat and power plant to co-produce steam and electricity. Our study revealed that cellulosic biofuels as E85 (mixture of 85% ethanol and 15% gasoline by volume), FTD, and DME offer substantial savings in petroleum (66-93%) and fossil energy (65-88%) consumption on a per-mile basis. Decreased fossil fuel use translates to 82-87% reductions in greenhouse gas emissions across all unblended cellulosic biofuels. In urban areas, our study shows net reductions for almost all criteria pollutants, with the exception of carbon monoxide (unchanged), for each of the biofuel production option examined. Conventional and hybrid electric vehicles, when fueled with E85, could reduce total sulfur oxide (SO(x)) emissions to 39-43% of those generated by vehicles fueled with gasoline. By using bio-FTD and bio-DME in place of diesel, SO(x) emissions are reduced to 46-58% of those generated by diesel-fueled vehicles. Six different fuel production options were compared. This study strongly suggests that integrated heat and power co-generation by means of gas turbine combined cycle is a crucial factor in the energy savings and emission reductions.

Air Pollution↗