Emission Factors Of Polycyclic Aromatic Hydrocarbons Research Articles

Increase in polycyclic aromatic hydrocarbon (PAH) emissions due to briquetting: A challenge to the coal briquetting policy

Both China and UNEP recommend replacing raw coal chunks with coal briquettes in household sector as clean coal technology (CCT), which has been confirmed by the decreased emissions of particulate matter and black carbon. However, the clean effect has never been systematically checked by other pollutants like polycyclic aromatic hydrocarbons (PAHs). In this study, 5 coals with different geological maturities were processed as both chunks and briquettes and burned in 3 typical coal stoves for the measurement of emission factors (EFs) of particle-bound PAHs. It was found that the EFs of 16 parent PAHs, 26 nitrated PAHs, 6 oxygenated PAHs, and 8 alkylated PAHs for coal briquettes were 6.90 ± 7.89, 0.04 ± 0.03, 0.65 ± 0.40, and 72.78 ± 18.23 mg/kg, respectively, which were approximately 3.1, 3.7, 1.9, and 171 times those for coal chunks, respectively. Such significant increases in PAH emissions increased human health risk and challenged the policy of CCT.

Elements and polycyclic aromatic hydrocarbons in exhaust particles emitted by light-duty vehicles.

The main purpose of this work was to evaluate the chemical composition of particulate matter (PM) emitted by eight different light-duty vehicles. Exhaust samples from petrol and diesel cars (Euro 3 to Euro 5) were collected in a chassis dynamometer facility. To simulate the real-world driving conditions, three ARTEMIS cycles were followed: road, to simulate a fluid traffic flow and urban with hot and cold starts, to simulate driving conditions in cities. Samples were analysed for the water-soluble ions, for the elemental composition and for polycyclic aromatic hydrocarbons (PAHs), respectively, by ion chromatography, inductively coupled plasma atomic emission spectroscopy (ICP-AES), inductively coupled plasma mass spectrometry (ICP-MS) and gas chromatography-mass spectrometry (GC-MS). Nitrate and phosphate were the major water-soluble ions in the exhaust particles emitted from diesel and petrol vehicles, respectively. The amount of material emitted is affected by the vehicle age. For vehicles ≥Euro 4, most elements were below the detection limits. Sodium, with emission factors in the ranges 23.5-62.4 and 78.2-227μg km(-1), for petrol and diesel Euro 3 vehicles, respectively, was the major element. The emission factors of metallic elements indicated that diesel vehicles release three to five times more than petrol automobiles. Element emissions under urban cycles are higher than those found for on-road driving, being three or four times higher, for petrol vehicles, and two or three times, for diesel vehicles. The difference between cycles is mainly due to the high emissions for the urban cycle with hot start-up. As registered for elements, most of the PAH emissions for vehicles ≥Euro 4 were also below the detection limits. Regardless of the vehicle models or driving cycles, the two- to four-ring PAHs were always dominant. Naphthalene, with emission factors up to 925 μg km(-1), was always the most abundant PAH. The relative cancer risk associated with naphthalene was estimated to be up to several orders of magnitude higher than any of the chemical species found in the PM phase. The highest PAH emission factors were registered for diesel-powered vehicles. The condition of the vehicle can exert a decisive influence on both element and PAH emissions.

Emissions from southeastern U.S. Grasslands and pine savannas: Comparison of aerial and ground field measurements with laboratory burns

Emissions from prescribed burns of a managed longleaf pine (Pinus palustris) forest and grass/savanna fields in western Florida were measured by simultaneous aerial and ground sampling. Results were compared with measurements made in an open burn laboratory test facility using biomass gathered from the same stands. Measurements included polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs), particulate matter (PM2.5), elemental carbon (EC), organic carbon (OC), black carbon (BC), brown carbon (BrC), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs). The flaming phase (high modified combustion efficiency) was characterized by high levels of BC and BrC yet low levels of VOCs. In general, ground-based measurements of PM2.5, BC, and BrC reported marginally higher emission factors than those measured in the plume by aerostat (balloon)-lofted instruments. The optically-determined BC emission factor was approximately ten times higher than many previously reported results. Simultaneous BC and EC measurements showed that EC values were, on average, 42% lower than the BC values, lending uncertainty to the common use of EC measurements as a BC surrogate. PAH emission factors were indistinguishable across the sampling scenarios, while PCDDs/PCDFs saw a significant decline in the laboratory testing. Limited distinctions in particle-related emissions between aerial and ground measurements suggest sampling bias between these methods. Emission factor distinctions between laboratory burn simulations and field tests appear primarily related to lower combustion efficiencies in the latter, perhaps due to higher biomass moisture or surface wetness.

Effect of oxygenated fuels on physicochemical and toxicological characteristics of diesel particulate emissions.

A systematic study was conducted to make a comparative evaluation of the effects of blending five different oxygenates (diglyme (DGM), palm oil methyl ester (PME), dimethyl carbonate (DMC), diethyl adipate (DEA), and butanol (Bu)) with ultralow sulfur diesel (ULSD) at 2% and 4% oxygen levels on physicochemical and toxicological characteristics of particulate emissions from a nonroad diesel engine. All blended fuels led to an overall decrease in the particulate mass concentration and elemental carbon (EC) emissions, which was strongly associated with the oxygen content in fuels and the specific type of fuels used. In general, the proportion of particulate-bound organic carbon (OC) and water-soluble organic carbon (WSOC) increased while using oxygenated fuel blends. Compared to ULSD, all fuel blends showed different emission factors of particle-phase PAHs and n-alkanes, slight alterations in soot nanostructure, lower soot ignition temperature, and lower activation energy. The total counts of particles (≤ 560 nm diameter) emitted decreased gradually for ULSD blended with DMC, DEA, and Bu, while they increased significantly for other fuel blends. The in vitro toxicity of particulates significantly increased with ULSD blended with DMC and DEA, while it decreased when ULSD was blended with PME, DGM, and Bu.

Characterization of polycyclic aromatic hydrocarbon emissions in the particulate and gas phase from smoldering mosquito coils containing various atomic hydrogen/carbon ratios

The polycyclic aromatic hydrocarbon emissions in particulate and gas phases generated from smoldering mosquito coils containing various atomic H/C ratios were examined. Five types of mosquito coils were burned in a test chamber with a total airflow rate of 8.0L/min at a constant relative humidity and temperature. The concentrations of individual PAHs were determined using the GC/MS technique. Among the used mosquito coils, the atomic H/C ratio ranged from 1.23 to 1.57, yielding total mass, gaseous, and particulate PAH emission factors of 28.17–78.72mg/g, 26,139.80–35,932.98 and 5735.22–13,431.51ng/g, respectively. The various partitions of PAHs in the gaseous and particulate phases were in the ranges, 70.26–83.70% and 16.30–29.74% for the utilized mosquito coils. The carcinogenic potency of PAH emissions in the particulate phase (203.82–797.76ng/g) was approximately 6.92–25.08 times higher than that of the gaseous phase (26.27–36.07ng/g). Based on the analyses of PAH emissions, mosquito coils containing the lowest H/C ratio, a low oxygen level, and additional additives (i.e., CaCO3) are recommended for minimizing the production of total PAH emission factors and carcinogenic potency.

Gaseous and particulate emission profiles during controlled rice straw burning

Burning of rice straw can emit considerable amounts of atmospheric pollutants. We evaluated the effect of rice straw moisture content (5%, 10%, and 20%) on the emission of carbon dioxide (CO2) and on the organic and inorganic constituents of released particulate matter (PM): dioxins, heavy metals, and polycyclic aromatic hydrocarbons (PAHs). Four burning tests were conducted per moisture treatment using the open chamber method. Additionally, combustion characteristics, including burning stages, durations, temperature, and relative humidity, were recorded. Burning tests showed flaming and smoldering stages were significantly longer in 20% moisture treatment (P < 0.05) compared with the rest. The amount of burned straw and ashes decreased with increasing straw moisture content (P < 0.001). Carbon dioxide was the main product obtained during combustion with emission values ranging from 692 g CO2 kg dry straw−1 (10% moisture content) to 835 g CO2 kg dry straw−1 (20% moisture content). Emission factors for PM were the highest in 20% moisture treatment (P < 0.005). Fine PM (PM2.5) accounted for more than 60% of total PM mass. Emission factors for dioxins increased with straw moisture content, being the highest in 20% moisture treatment, although showing a wide variability among burning tests (P > 0.05). Emissions factors for heavy metals were low and similar among moisture treatments (P > 0.05). Emission factors for individual PAHs were generally higher in 20% moisture treatment. Overall, emission factors of atmospheric pollutants measured in our study were higher in the 20% moisture content. This difference could be attributed to the incomplete combustion at higher levels of rice straw moisture content. According to our results, rice straw burning should be done after straw drying and under minimal moisture conditions to lower pollutant emission levels.

Estimation and characterization of polycyclic aromatic hydrocarbons from magnesium metallurgy facilities in China.

Field monitoring was conducted to develop a polycyclic aromatic hydrocarbon (PAH) emission inventory for the magnesium (Mg) metallurgy industry in China. PAH emissions in stack gas and fly/bottom ash samples from different smelting units of a typical Mg smelter were measured and compared. Large variations of concentrations, congener patterns, and emission factors of PAHs during the oxidation and reduction stages in the Mg smelter were observed. The measured average emission factor (166,487 μg/t Mg) was significantly higher than those of other industrial sources. Annual emission from Mg metallurgy in 2012 in China was estimated at 116 kg (514 g BaPeq) for PAHs. The results of this study suggest that PAH emission from Mg industries should be considered by local government agencies. These data may be helpful for understanding PAH levels produced by the Mg industry and in developing a PAH inventory.

Uncharted sources of particle bound polycyclic aromatic hydrocarbons from South Asia: Religious/ritual burning practices

This paper deals with the real–world emissions of particle bound polycyclic aromatic hydrocarbons (PAHs) emitted from different religious and ritual burning practices in India. The emission factors (EFs) of various PAHs were characterized over integrated stages of burning practices including pyrolysis, flaming and smoldering. Sampling was carried out in selected five different types of religious and ritual places: Hindu Temples (HT), Muslim Holy shrines (MG), Buddhist Temples (BT), Hindu Marriage Places (MP) and Cremation Centers (Hindu Funeral Pyre) (CC); where burning practices mostly include natural and synthetic biomaterials in different proportions. Seventy PAHs were analyzed and grouped in light PAHs (LPAHs=25) and heavy PAHs (HPAHs=45) according to number of benzene rings present and respective molecular weights. The average EF of total PAHs (TPAHs) from MP, MG, BT, HT and CC is estimated as 77.04±5.39, 99.09±6.02, 90.35±6.76, 22.78±1.57, and 77.15±6.16mg kg−1, respectively. Country level emission budget of particulate bound TPAHs from religious and ritual burning practices has also been evaluated to 0.47Gg yr−1; contributed ~23% of the 2.07Gg yr−1 – Indian emission budget of PAHs from unknown sources reported earlier.

자동차 도장시설에서 발생하는 유해대기오염물질 및 미세먼지의 배출특성에 관한 연구

This study is about emission characteristics of HAPs and particulate matters emitted by spray of paint and organic solvent usually used in vehicle paint facilities. To analyze emission characteristics of HAPs and particulate matters emitted from vehicle paint facilities are calculated based on the measuring emission quantity of pollutants based on the amount of paint used (kg) and unit area () by paint manufacturers (J company, K company, and R company). In cases of paint manufacturers (J, K, and R), average emission factors of VOCs, carbonyl compound, particulate matter, and PAHs per 1 kg of paint were 327.81 g/kg, 5.98 g/kg, 336.70 g/kg, and 0.0078 g/kg respectively. The average emission factors of VOCs, carbonyl compounds, particulate matters, and PAHs by unit area were , , , and respectively.

Redox activity and PAH content in size-classified nanoparticles emitted by a diesel engine fuelled with biodiesel and diesel blends

Diesel and biodiesel emissions are important sources of ambient air pollution. Therefore, the influence of using different blending percentages of biodiesel to diesel as fuel on redox activity, particulate matter (PM) and polycyclic aromatic hydrocarbons (PAH) emission profiles, and the corresponding carcinogenicity index (BaPE) size distributions are not well known. In this way, the present work aims to investigate the effect of diesel/biodiesel blends on the physical, chemical, and toxicological properties of diesel engine exhaust at low condition, through the study of the changes in size-distribution and emission factors of PAH associated to PM, corresponding carcinogenicity index (BaPE) size distributions and PM redox activity. For that, particle emissions from commercial petroleum-based diesel with 4% of soy biodiesel (B4), a biodiesel blend of 25% and 50% (B25 and B50) and also pure biodiesel (B100) were measured on a steady-state dynamometer in a test using a diesel engine at low load. Size-fractionated PM samples were collected by using the NanoMOUDI impactor and analyzed for the 16 priority PAH by HPLC–fluorescence detector. In addition, PM2.5 samples were collected and analyzed for redox activity by DTT assay. PM was distributed in all sizes, while PAH size distribution was found in higher levels in the accumulation mode (30nm<Dp<2.5μm). Total PAH emission factors (ng kgfuel-1) for B4, B25, B50 and B100 were: 237,111,182 and 319ng kgfuel-1, respectively. Individual PAH emission factors showed that PAH containing four or more rings (MW>202) such as BBF, BAA, PYR and BGP were the main PAH emitted by the four studied fuels. The percentage reductions of individual PAH emission factors for the blend fuels in comparison with B4 were 37% and 22% for B25 and B50, respectively, and an increase around 31% for B100. On the other hand it was observed increase in redox activity for B25, B50 and B100 when compared to B4. In general, the results from our study suggest that emissions from pure waste cooking biodiesel may not be the better fuel choice in terms of PM, PAH and BaPE particle size distribution and emission factors as well as redox activity. However, B25 and B50 blends presented some improvements in terms of PM, HPA, BaPE size distribution and redox activity of engine exhaust in comparison to B4. This suggests that addition of low percentages of biodiesel to diesel promotes benefices in both environmental and human health concerns.

PAHs Emission Characteristics and Assessment from the Coal Combustion Process in the Large Capacity Power Plant Boilers

Many studies have demonstrated an association between exposure to ambient Polycyclic Aromatic Hydrocarbons (PAHs) and some serious diseases, such as cancer, malformation and mutation. PAHs is thought as a carcinogenic and mutagenic compound to human health. Coal-fired power plant industry plays an important role in the observed PAHs emission process. However, the PAHs emission characteristic and environment impact in coal-fired power plant is still not fully clarified. In this study, the PAHs distribution characteristic of the flue gas and fly ash emitted from electrostatic precipitator in two coal-fired power plant boilers with the steam capacity 1000t/h and 2000t/h have been studied in China based on USEPA method 0023(sampling part). PAHs concentrations and PAHs emission factors were determined. And the correlation between PAHs emission and the steam capacity of the power plant boiler was discussed. In addition, the PAHs removal effects of air pollution control devices were also included. According to the measured PAHs emission data and the report of China statistical year book, the PAHs emission assessment from the coal combustion process in the large capacity co-fired power plant boilers have been done. Though the PAHs emission value in the large capacity power plant were present within recommended emission limits of energy production, the problem of PAHs emission in large capacity coal-fired power plant shouldnt be ignored due to the huge amounts and long-range transport in soil, water and ambient air.

Global Atmospheric Emissions of Polycyclic Aromatic Hydrocarbons from 1960 to 2008 and Future Predictions

Global atmospheric emissions of 16 polycyclic aromatic hydrocarbons (PAHs) from 69 major sources were estimated for a period from 1960 to 2030. Regression models and a technology split method were used to estimate country and time specific emission factors, resulting in a new estimate of PAH emission factor variation among different countries and over time. PAH emissions in 2007 were spatially resolved to 0.1° × 0.1° grids based on a newly developed global high-resolution fuel combustion inventory (PKU-FUEL-2007). The global total annual atmospheric emission of 16 PAHs in 2007 was 504 Gg (331-818 Gg, as interquartile range), with residential/commercial biomass burning (60.5%), open-field biomass burning (agricultural waste burning, deforestation, and wildfire, 13.6%), and petroleum consumption by on-road motor vehicles (12.8%) as the major sources. South (87 Gg), East (111 Gg), and Southeast Asia (52 Gg) were the regions with the highest PAH emission densities, contributing half of the global total PAH emissions. Among the global total PAH emissions, 6.19% of the emissions were in the form of high molecular weight carcinogenic compounds and the percentage of the carcinogenic PAHs was higher in developing countries (6.22%) than in developed countries (5.73%), due to the differences in energy structures and the disparities of technology. The potential health impact of the PAH emissions was greatest in the parts of the world with high anthropogenic PAH emissions, because of the overlap of the high emissions and high population densities. Global total PAH emissions peaked at 592 Gg in 1995 and declined gradually to 499 Gg in 2008. Total PAH emissions from developed countries peaked at 122 Gg in the early 1970s and decreased to 38 Gg in 2008. Simulation of PAH emissions from 2009 to 2030 revealed that PAH emissions in developed and developing countries would decrease by 46-71% and 48-64%, respectively, based on the six IPCC SRES scenarios.

Emissions of Polycyclic Aromatic Hydrocarbons, Polychlorinated Dibenzo-p-Dioxins, and Dibenzofurans from Incineration of Nanomaterials

Disposal of some nanomaterial-laden waste through incineration is inevitable, and nanomaterials' influence on combustion byproduct formation under high-temperature, oxidative conditions is not well understood. This work reports the formation of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated-dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) from incineration of paper and plastic waste containing various nanomaterials, including titania, nickel oxide, silver, ceria, iron oxide, quantum dots, and C60-fullerene, in a laboratory-scale furnace. The presence of nanomaterials in the waste stream resulted in higher emissions of some PAH species and lower emissions of others, depending on the type of waste. The major PAH species formed were phenanthrene and anthracene, and emissions were sensitive to the amount of nanomaterials in the waste. Generally, there were no significant differences in emission factors for the larger PAH species when nanomaterials were added to the waste. The total PAH emission factors were on average ~6 times higher for waste spiked with nanomaterials v. their bulk counterparts. Emissions of chlorinated dioxins from poly(vinyl chloride) (PVC) waste were not detected; however, chlorinated furans were formed at elevated concentrations with wastes containing silver and titania nanomaterials, and toxicity was attributable mainly to 2,3,4,7,8-pentachlorodibenzofuran. The combination of high specific surface area and catalytic, including electrocatalytic, properties of nanomaterials might be responsible for affecting the formation of toxic pollutants during incineration.

Investigation of gaseous and particulate emissions from various marine vessel types measured on the banks of the Elbe in Northern Germany

Abstract. Measurements of the ambient aerosol, various trace gases and meteorological quantities using a mobile laboratory (MoLa) were performed on the banks of the Lower Elbe in an emission control area (ECA) which is passed by numerous private and commercial marine vessels reaching and leaving the port of Hamburg, Germany. From 25–29 April 2011 a total of 178 vessels were probed at a distance of about 0.8–1.2 km with high temporal resolution. 139 ship emission plumes were of sufficient quality to be analyzed further and to determine emission factors (EFs). Concentrations of aerosol number and mass as well as polycyclic aromatic hydrocarbons (PAH) and black carbon were measured in PM1 and size distribution instruments covered the diameter range from 6 nm up to 32 μm. The chemical composition of the non-refractory submicron aerosol was measured by means of an Aerosol Mass Spectrometer (Aerodyne HR-ToF-AMS). Gas phase species analyzers monitored various trace gases (O3, SO2, NO, NO2, CO2) in the air and a weather station provided wind, precipitation, solar radiation data and other quantities. Together with ship information for each vessel obtained from Automatic Identification System (AIS) broadcasts a detailed characterization of the individual ship types and of features affecting gas and particulate emissions is provided. Particle number EFs (average 2.6e+16 # kg−1) and PM1 mass EFs (average 2.4 g kg−1) tend to increase with the fuel sulfur content. Observed PM1 composition of the vessel emissions was dominated by organic matter (72%), sulfate (22%) and black carbon (6%) while PAHs only account for 0.2% of the submicron aerosol mass. Measurements of gaseous components showed an increase of SO2 (average EF: 7.7 g kg−1) and NOx (average EF: 53 g kg−1) while O3 decreased when a ship plume reached the sampling site. The particle number size distributions of the vessels are generally characterized by a bimodal size distribution, with the nucleation mode in the 10–20 nm diameter range and a combustion aerosol mode centered at about 35 nm while particles \\textgreater 1 μm were not found. "High particle number emitters" are characterized by a dominant nucleation mode. By contrast, increased particle concentrations around 150 nm primarily occurred for "high black carbon emitters". Classifying the vessels according to their gross tonnage shows a decrease of the number, black carbon and PAH EFs while EFs of SO2, NO, NO2, NOx, AMS species (particulate organics, sulfate) and PM1 mass concentration increase with increasing gross tonnages.

자동차에서 배출되는 가스상 유해대기오염물질 (HAPs) 배출량 추정

Hazardous Air Pollutants (HAPs) are difficult to measure, analyze and assess for risk because of low ambient concentrations and varieties. Types of HAPs are Volatile organic compounds (VOCs), Polycyclic aromatic hydrocarbon (PAHs) and Aldehydes. HAP emissions from vehicles are a contributor to serious adverse health effects in urban areas. In this study, hazardous air pollutant emissions from road transport vehicles by Non-methane volatile organic compounds (NMVOC) weight fraction and PAHs emission factors are estimated in 2008. The top-five-most hazardous air pollutant emissions were estimated to toluene 864.3 ton/yr, acrolein 690.6 ton/yr, acetaldehyde 554.5 ton/yr, formaldehyde 498.7 ton/yr, propionaldehyde 421.6 ton/yr in 2008. The results for a cancer and non-cancer risk assessment of HAPs emissions show that the major cancer driver is formaldehyde and the non-cancer driver is acrolein.

Effect of Relative Humidity on Polycyclic Aromatic Hydrocarbon Emissions from Smoldering Incense

Incense was burned in a controlled environment, in order to understand the effect of relative humidity on polycyclic aromatic hydrocarbons (PAHs) emissions from smoldering incense. The concentrations of individual PAHs were determined using the GC/MS analysis method. Incense was burned in a test chamber with a total airflow rate of 6.0 L/min, with relative humidity of 21.3 ± 1.0, 51.0 ± 0.2 and 90.5 ± 0.5%, at a constant temperature (28.9 ± 0.4°C). The results show that the rate at which the incense burns decreases linearly as the relative humidity increases, at the tested airflow rate. The sums of the total PAH and toxic equivalency emission factors for particulate and gas phases were 47467.39–50218.87 and 325.21–358.85 ng/g, for the incense used in this study, and these values also decrease as the relative humidity increases. The carcinogenic potency of PAHs emissions in the particulate phase is approximately 6 times higher than those of the gaseous phase, at the relative humidity tested.

Release of Harmful Air Pollutants from Open Burning of Domestic Municipal Solid Wastes in a Metropolitan Area of Korea

Open burning of solid wastes, a potential nonpoint emission source, has recently become a topic of interests, particularly in the metropolitan area of Seoul, Korea. To estimate the effects of irregular open burning on local air quality, we evaluated the emission levels of harmful substances from test combustion of individual types of domestic municipal solid waste (MSW), including paper, wood, and plastics. The emission factors of PM10, PM2.5, PAHs, and heavy metals obtained from laboratory tests differed depending on the combustion material. A brief survey of residents and local government officials showed that more than 10.6% of homes in the metropolitan area have eliminated waste by irregular burning. Based on the public survey in the test area, the average annual emissions of hazardous materials from frequent open burning was estimated to be 71 tons for PM10, 46.6 tons for PM2.5, 914 kg for heavy metals, and 67 kg for PAHs. Open burning creates nearly 0.44% of regional air pollution from PM10.

Emissions estimates of PAH from biomass fuels used in rural sector of Indo-Gangetic Plains of India

Polycyclic aromatic hydrocarbons (PAHs) are of special interest due to their carcinogenicity, and ubiquitous presence in the environment. Emissions of PAH vary with use of biomass fuels. In this study, the experimentally determined emission factors and emission estimates of PAH emitted from biomass fuels (dung cake, fuelwood and crop residue) from rural household of six states (Delhi, Uttar Pradesh, Punjab, Haryana, Uttarakhand and Bihar) over the IGP, India, are presented. The gaseous phase and particulate phase PAHs emissions are simultaneously determined from various biomass fuels. The average emission factors of total PAHs from dung cakes, fuelwood and crop residue over the IGP, India are estimated as 59.5 ± 19.9 mg kg−1, 52.5 ± 19.6 mg kg−1 and 40.9 ± 15.2 mg kg−1 respectively. The emission factor of particulate phase PAHs (56.5 mg kg−1, 45.3 mg kg−1 and 35.8 mg kg−1) was found higher as compared to gaseous phase PAHs (3.1 mg kg−1, 7.2 mg kg−1 and 5.1 mg kg−1) from dung cakes, fuel-wood and crop residue, respectively. Anthracene, fluoranthene, pyrene, benzo[a]anthracene and chrysene are predominant PAHs in all biomass fuels. The emission estimates of PAH over IGP are determined as 2.95 ± 0.98 Gg yr−1, 3.13 ± 1.08 Gg yr−1 and 0.66 ± 0.26 Gg yr−1 from dung cakes, fuelwood and crop residue, respectively.

On-road emission factors of PM pollutants for light-duty vehicles (LDVs) based on urban street driving conditions

An on-road sampling campaign was conducted on two major surface streets (Wilshire and Sunset Boulevards) in Los Angeles, CA, to characterize PM components including metals, trace elements, and organic species for three PM size fractions (PM10–2.5, PM2.5–0.25, and PM0.25). Fuel-based emission factors (mass of pollutant per kg of fuel) were calculated to assess the emissions profile of a light-duty vehicle (LDV) traffic fleet characterized by stop-and-go driving conditions that are reflective of urban street driving. Emission factors for metals and trace elements were highest in PM10–2.5 while emission factors for PAHs and hopanes and steranes were highest in PM0.25. PM2.5 emission factors were also compared to previous freeway, roadway tunnel, and dynamometer studies based on an LDV fleet to determine how various environments and driving conditions may influence concentrations of PM components. The on-road sampling methodology deployed in the current study captured substantially higher levels of metals and trace elements associated with vehicular abrasion (Fe, Ca, Cu, and Ba) and crustal origins (Mg and Al) than previous LDV studies. The semi-volatile nature of PAHs resulted in higher levels of PAHs in the particulate phase for LDV tunnel studies (Phuleria et al., 2006) and lower levels of PAHs in the particulate phase for freeway studies (Ning et al., 2008). With the exception of a few high molecular weight PAHs, the current study's emission factors were in between the LDV tunnel and LDV freeway studies. In contrast, hopane and sterane emission factors were generally comparable between the current study, the LDV tunnel, and LDV freeway, as expected given the greater atmospheric stability of these organic compounds. Overall, the emission factors from the dynamometer studies for metals, trace elements, and organic species are lower than the current study. Lastly, n-alkanes (C19–C40) were quantified and alkane carbon preference indices (CPIs) were determined to be in the range of 1–2, indicating substantial anthropogenic source contribution for surface streets in Los Angeles.

Emissions from open burning of used agricultural pesticide containers

Emissions from simulated open burning of used agricultural pesticide containers were sampled for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/PCDFs), polycyclic aromatic hydrocarbon compounds (PAHs), and particle matter (PM10 and PM2.5). Clean high density polyethylene (HDPE) containers, containers with trace pesticide, and triple-rinsed containers were burned separately in an open combustion facility and their emissions compared. Two common chlorinated pesticides were used: 2,4-dichlorophenoxyacetic acid (2,4-D) and 1-chloro-3-ethylamino-5-isopropylamino-2,4,6-triazine (atrazine). PCDD/PCDF emission factors ranged from 0.1 to 24ng toxic equivalents (TEQ)/kg C burned with a mean and median of 4.9 and 1.9ng TEQ/kgC burned, respectively. In a limited number of trials, the trace 2,4-D in the HDPE container led to a statistically significant increase in PCDD/PCDF formation compare to all other conditions. Residual atrazine did not lead to more PCDD/PCDF than the unrinsed 2,4-D container. Total (16 compounds) PAH emission factors varied from 1.5 to 6.7mg/kgC burned. These limited data suggest that rinsing the 2,4-D container prior to burning reduces both PCDD/PCDF and PAH emissions. Nine PM2.5 emission factors ranged from 9 to 35mg/gC burned and ten PM10 values ranged from 6 to 43mg/gC burned. Neither pesticide appeared to have any effect on PM concentration.