Determination of 2-nitrofluoranthene and 2-nitropyrene in ambient particulate organic matter: Evidence for atmospheric reactions

We have identified and quantified 2-nitrofluoranthene (2-NO₂-FL) and 2-nitropyrene (2-NO₂-PY), both strong, direct mutagens in paniculate organic matter (POM) samples collected in polluted ambient air in southern California. Samples were collected during four consecutive 6-h periods on 18–19 September 1984, during which the ambient concentrations of gaseous co-pollutants were characterized by long pathlength spectroscopic techniques and conventional analyzers. Concentrations ranged up to 0.3 ng m⁻³ for 2-NO₂-FL and 0.02 ng m⁻³ for 2-NO₂-PY. The 2-nitro isomers of fluoranthene and pyrene have not been observed in direct emissions of POM (e.g. diesel exhaust and wood smoke). However, we recently observed these isomers from laboratory reactions involving N₂O₅ or OH radicals and the parent compounds. Thus the identification of 2-NO₂-FL and 2-NO₂-PY in ambient POM suggests that chemical transformations of fluoranthene and pyrene may take place in polluted atmospheres.     

Presence of alkyllead in rural and urban air: Evaluation of some sources of alkyllead pollution of the atmosphere in Norway

Concentrations of alkyllead in ambient air were measured, as well as in car exhaust and in gasoline vapours. In Oslo the concentration in air ranged from 0.010 to 0.100 μg Pb m⁻³, and these values were compared to the concentrations (< 0.001 μg Pb m⁻³) measured in a low traffic rural area of Norway. The amount of alkyllead in car exhaust varied between 0.1 and 15 μg Pb m⁻³, which was between 0.01 and 0.5% of the amount of inorganic lead in exhaust. Evaporation of alkyllead from parked cars was estimated at 0.5 mg Pb per day per car. The concentrations of alkyllead in saturated gasoline vapour were found to be 10–20 mg Pb m⁻³ at ambient air temperatures.     

The continuous field measurements of soluble aerosol compositions at the Taipei Aerosol Supersite,Taiwan

The characteristics of ambient aerosols, affected by solar radiation, relative humidity, wind speed, wind direction, and gas–aerosol interaction, changed rapidly at different spatial and temporal scales. In Taipei Basin, dense traffic emissions and sufficient solar radiation for typical summer days favored the formation of secondary aerosols. In winter, the air quality in Taipei Basin was usually affected by the Asian continental outflows due to the long-range transport of pollutants carried by the winter monsoon. The conventional filter-based method needs a long time for collecting aerosols and analyzing compositions, which cannot provide high time-resolution data to investigate aerosol sources, atmospheric transformation processes, and health effects. In this work, the in situ ion chromatograph (IC) system was developed to provide 15-min time-resolution data of nine soluble inorganic species (Cl⁻, NO₂⁻, NO₃⁻, SO₄²⁻, Na⁺, NH₄⁺, K⁺, Mg²⁺ and Ca²⁺). Over 89% of all particles larger than approximately 0.056 μm were collected by the in situ IC system. The in situ IC system is estimated to have a limit of detection lower than 0.3 μg m⁻³ for the various ambient ionic components. Depending on the hourly measurements, the pollutant events with high aerosol concentrations in Taipei Basin were associated with the local traffic emission in rush hour, the accumulation of pollutants in the stagnant atmosphere, the emission of industrial pollutants from the nearby factories, the photochemical secondary aerosol formation, and the long-range transport of pollutants from Asian outflows.     

Characteristics of mercury exchange flux between soil and air in the heavily air-polluted area,eastern Guizhou,China

To investigate the characteristics of mercury exchange between soil and air in the heavily air-polluted area, total gaseous mercury (TGM) concentration in air and Hg exchange flux were measured in Wanshan Hg mining area (WMMA) in November, 2002 and July–August, 2004. The results showed that the average TGM concentrations in the ambient air (17.8–1101.8 ng m⁻³), average Hg emission flux (162–27827 ng m⁻² h⁻¹) and average Hg dry deposition flux (0–9434 ng m⁻² h⁻¹) in WMMA were 1–4 orders of magnitude higher than those in the background area. It is said that mercury-enriched soil is a significant Hg source of the atmosphere in WMMA. It was also found that widely distributed roasted cinnabar banks are net Hg sources of the atmosphere in WMMA. Relationships between mercury exchange flux and environmental parameters were investigated. The results indicated that the rate of mercury emission from soil could be accelerated by high total soil mercury concentration and solar irradiation. Whereas, highly elevated TGM concentrations in the ambient air can restrain Hg emission from soil and even lead to strongly atmospheric Hg deposition to soil surface. A great amount of gaseous mercury in the heavily polluted atmosphere may cycle between soil and air quickly and locally. Vegetation can inhibit mercury emission from soil and are important sinks of atmospheric mercury in heavily air-polluted area.     

Urban-Center CO Air Quality Projections

The distribution of mutagenic activity and nitroaromatic components of polycyclic organic matter (POM) in ambient air at industrial, urban, suburban, rural, and remote sites was studied using organic extracts from high volume aerosol samples. Direct-acting mutagens including 1-nitropyrene (1-NP), dinitropyrenes (DNP), and hydroxynitropyrenes (HNP) were measured by high performance liquid chromatography while the mutagenicity was determined in the Salmonella bioassay with strain TA-98. Benzo(a)pyrene (BaP), one of the possible precursors of nitroaromatic compounds in POM, was also measured. In comparing samples from a range of sites, TSP and the concentration of BaP per mass of particulate matter decreased, as expected, at greater distances from urban and industrial combustion sources. However, the concentrations of polar nitroaromatic POM compounds per mass of particles were higher at a remote site than in nonindustrial urban and suburban areas. The mutagenicity in particulate matter extracts from the remote area was predominantly (>90 percent) in the very polar fractions. There were also high atmospheric levels of nitroaromatic compounds and mutagenicity in heavily industrialized areas. These observations may reflect the influences of source emissions, atmospheric transformations of POM compounds, and ther atmospheric processes on the composition of ambient suspended particulate matter.     

Organic matter of the troposphere—II. Natural background of biogenic lipid matter in aerosols over the rural western united states

Higher plant waxes are the predominant natural components in the lipid fractions (> C₁₅) of aerosols sampled over rural and oceanic regions. Hydrocarbon, fatty acid, ketone and fatty alcohol fractions of the lipids were characterized in terms of their contents of homologous compound series and specific biogenic molecular markers. Paniculate samples from the rural western United States have been analyzed and compared with samples from urban Los Angeles and remote areas over the Atlantic Ocean. The samples from rural sites contained predominantly vascular plant wax and lesser amounts of higher plant sterols and resin residues. Urban samples and, to varying degrees, some rural samples contained primarily higher weight residues of petroleum products. The loadings of hydrocarbons derived from higher plant waxes ranged approximately from 10 to 160 ng m⁻³ of air (for fatty acids, 10–100 ng m⁻³ and for fatty alcohols, 10–200 ng m⁻³). Higher molecular weight lipids (i.e. plant epicuticular wax, terpenes, etc.) from flora comprise a significant component of the organic carbon in rural aerosols. Primary biogenic residues are major components of aerosols in all areas and they are important components in the global cycling of organic carbon.     

Development of a modified factor analysis/multiple regression model to apportion suspended particulate matter in a complex urban airshed

A modified factor analysis/multiple regression (FA/MR) receptor-oriented source apportionment model has been developed which permits application of FA/MR statistical methods when some of the tracers are not unique to an individual source type. The new method uses factor and regression analyses to apportion non-unique tracer ambient concentrations in situations where there are unique tracers for all sources contributing to the non-unique tracer except one, and ascribes the residual concentration to that source. This value is then used as the source tracer in the final FA/MR apportionment model for ambient paniculate matter. In addition, factor analyses results are complemented with examination of regression residuals in order to optimize the number of identifiable sources.The new method has been applied to identify and apportion the sources of inhalable particulate matter (IPM; D₅₀15 μm), Pb and Fe at a site in Newark, NJ. The model indicated that sulfate/secondary aerosol contributed an average of 25.8 μ⁻³ (48%) to IPM concentrations, followed by soil resuspension (8.2 μ⁻³ or 15%), paint spraying/paint pigment (6.7/gmm⁻³or 13%), fuel oil burning/space heating (4.3 μ⁻³ or 8 %), industrial emissions (3.6 μm⁻³ or 7 %) and motor vehicle exhaust (2.7 μ⁻³ or 15 %). Contributions to ambient Pb concentrations were: motor vehicle exhaust (0.16μm⁻³or 36%), soil resuspension (0.10μm⁻³ or 24%), fuel oil burning/space heating (0.08μm⁻³or 18%), industrial emissions (0.07 μ⁻³ or 17 %), paint spraying/paint pigment (0.036 μm⁻³or 9 %) and zinc related sources (0.022 μ⁻³ or 5 %). Contributions to ambient Fe concentrations were: soil resuspension (0.43μ⁻³or 51%), paint spraying/paint pigment (0.28 μm⁻³or 33 %) and industrial emissions (0.15 μ⁻³or 18 %). The models were validated by comparing partial source profiles calculated from modeling results with the corresponding published source emissions composition.     

Conditions in which power stations contribute to high ground level SO2 concentrations in the U.K.

Weather and topographical situations where different types of emission sources give their highest ground level concentrations have been tabulated during a CORECH study. To see what daily average concentrations actually occur in an area where there are a large number of power stations, low level and other industrial sources but no topographical complications, occasions when one or more of the 10 SO₂ recorders in the Drax monitoring network exceeded 200 μm⁻³ during the 10-year period preceding the termination of sampling were noted. There were 44 such occasions. On 17 of them, the principal contribution to the peak value appeared to come from low level sources associated with smoke emissions and on nine it appeared to come from industrial sources in the Doncaster (including Doncaster and Thorpe Marsh power stations), Scunthorpe (including Keadby power station) or Humberside (no power station) areas. The source areas containing the most modern 2000 MW power stations. South Yorkshire (13 times) and Trent Valley (five times), appeared to pre-dominale on other occasions. In these latter cases, with only one exception, the weather situation was either a persistent slow moving anti-cyclone with the free stream wind speed falling to 2.5 ms⁻¹ or less or a day with a very steady free stream wind direction, associated with a col in the surface pressure distribution. In both of these situations, upward vertical mixing was limited by a subsidence and/or advection temperature inversion aloft.     

Continuous measurement of particulate and sulfur dioxide concentrations in Junk Bay,Hong Kong

As part of an environmental impact assessment for building a new town in Junk Bay, continuous measurement of SO₂ and particulate concentrations was carried out from October 1981 to June 1982 at three sites in Junk Bay to study the air quality in the area. Flame photometric SO₂ analyzers were used to measure ambient SO₂ level, whereas tape monitors were used to measure the ambient suspended particulate level (in terms of soiling index, or coefficient of haze per 1000 feet). It was found that the mean SO₂ concentrations at the three monitoring sites ranged from 5μg m⁻³ to 35μg m⁻³. Maximum daily values up to about 250 μg m⁻³ and hourly values up to 800 μg m ⁻³ had been recorded on occasion. Comparison of the hourly meteorological data and the hourly SO₂ concentrations in four high-SO₂-level days suggested that the ‘sulfur dioxide episodes’ were all associated with very light wind speeds and local sources. The mean coefficient of haze level in Junk Bay was less than one, which corresponded to very slight particulate pollution.     

Monitored Asbestos Concentrations in Connecticut

An air asbestos survey was conducted between late 1974 and early 1977 to define the magnitude of the health hazard posed by airborne asbestos fibers in Connecticut prior to the promulgation of the State's proposed asbestos air quality standard (i.e., 30 ?g/m³ or 30,000 total asbestos fibers/m³, 30-day average). A newly developed low volume particulate sampler, which operates continuously for 30 days at an air sampling flow rate of 4 cfm, equipped with special membrane filters was used to collect ambient TSP samples for subsequent chrysotile asbestos electron microscopic determination by the Bat-telle-Columbus Laboratories and Walter C. McCrone Associates.

Approximately 40 monitoring sites were selected; ambient locations included "typical" urban sites removed from known stationary sources of asbestos emissions, rural-background sites, stations contiguous to 4 industrial users of asbestos (i.e., manufacturers of friction products, insulated wire and cable, ammunition and molding compounds), 3 toll plazas situated at various points along Interstate 95 and indoors at a swimming pool at the University of Connecticut (the ceiling over the pool was sprayed with an asbestos-containing insulating material). Ambient chrysotile asbestos levels removed from asbestos emission sources in both urban and rural locations were below 10 ?g/m³. However, asbestos concentrations above 30 ?g/m³ were measured near each of the industrial users of asbestos. Furthermore, asbestos levels adjacent to the toll plazas were also elevated (in the 10 ?g/m³ to 25 ?g/m³ range), implicating asbestos emissions from vehicle braking lining decomposition as a significant source of airborne asbestos fibers. Indoor air asbestos levels were below 1 ?g/m³ suggesting that the risk to public health associated with the deterioration of asbestos surface coatings applied indoors may not be as severe as previously thought.     

Factors controlling benzo(a)pyrene concentration in aerosols in the urbanized coastal zone. A case study: Gdynia, Poland (Southern Baltic Sea)

Annual study on the benzo(a)pyrene (BaP) concentration in aerosols in the coastal zone of the Gulf of Gdansk (southern Baltic) has been performed at Gdynia station. Combustion processes, especially domestic heating of both local and regional origin, were identified as the main sources of benzo(a)pyrene in this area. Concentrations observed during the heating season (mean 2.18 ng?m^?3) were significantly higher than these recorded in the non-heating season (mean 0.05 ng?m^?3). High benzo(a)pyrene concentrations were associated with low temperature and high humidity. Whereas high levels of precipitation usually decreased the BaP concentration in aerosols. The concentration of this factor in the studied area depended also on the wind direction and air masses trajectories. During heating season, continental air masses (coming from S, SE, SW) seemed to increase benzo(a)pyrene concentration, while maritime air masses (from N, NE, NW) caused its decrease. The differences in the BaP concentration resulting from potentially different emission levels of this compound during working and non-working days were not clearly pronounced.     

Long-term monitoring and modeling of polychlorinated dibenzo-p-dioxins and dibenzofurans from municipal solid waste incinerators and surrounding area in northern Taiwan

Municipal solid waste incinerators (MSWIs) have long been the major contributors of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) to ambient air in Taiwan. After stringent MSWI emission standards were introduced in 2001, the long-term continuous monitoring of flue gas and ambient air quality became necessary to ensure the effectiveness of the related control strategies. Three MSWIs and the surrounding ambient air were investigated in the current study for PCDD/F characteristics during 2006 to 2011. The average concentrations in the flue gas ranged from 0.008?~?0.0488 ng I-TEQ/Nm³, which is much less than the emission standard in Taiwan (0.1 ng I-TEQ/Nm³) (I-TEQ is the abbreviation of International Toxic Equivalent). This led to extremely low levels in the ambient air, 0.0255 pg I-TEQ/Nm³, much less than the levels seen in most urban areas around the world. Additionally, the results obtained using the Industrial Source Complex Short-Term Dispersion Model (ISCST3) indicate that the PCDD/F contributions from the three MSWIs to the ambient air were only in the range from 0.164?~?0.723 %. Principal component analysis (PCA) showed that the PCDD/Fs in the air samples had very similar characteristics to those from mobile sources. The results thus show that stringent regulations have been an effective control strategy, especially for urban areas, such as Taipei City.     

Aliphatic and aromatic hydrocarbons in different sized aerosols over the Mediterranean Sea: Occurrence and origin

Marine aerosols were collected using a five-stage cascade impactor during the PHYCEMED II cruise in the Western Mediterranean Sea (October 1983). Their composition in aliphatic and aromatic hydrocarbons (HCs) was analyzed, representing the first time that concentrations of polynuclear aromatic HCs (PAH) are reported in relation to particle size for aerosols of remote marine areas. The HC concentrations were found to be dependent on the origin of the air masses. They were higher for air coming from North European countries than for air originating in the Atlantic and the South of Spain. The concentrations range between 7 and 14 ng m⁻³for n-alkanes and between 0.2 and 0.4 ng m⁻³for total PAH. Based on molecular criteria, several sources for these HCs have been identified: continental higher plant waxes, petroleum and pyrolysis (namely coal combustion and vehicular exhausts). Mass medium equivalent diameters (MMED) for the naturally derived n-alkanes are in the 1.79-2.53 μm range, indicating an origin related with the emission of large particles from higher plant waxes or from soil dusts. In contrast, MMED for the anthropogenic HCs, both aliphatic and aromatic, are smaller than the micron, suggesting initial emission of PAH through pyrolytic processes in the vapor phase followed by condensation onto larger sub-μm particles.     

The Berlin smog project—Description and summary of results

The composition of ambient air pollution, emphasising the ambient particulate matter, has been investigated for 14 wintertime smog periods (SO₂ and/or suspended particulate concentrations exceeding 400 μg m⁻³) in Berlin (West). The total aerosol mass concentration, the SO₂, CO, NO and NO₂ and pertinent meteorological parameters were measured. For chemical characterization the aerosol was collected by hi-volume, low-volume samplers and cascade impactors. The samples were analysed for the metals Pb, Cd, Mn, Ni; the water soluble ions: NH₄⁺, SO₄²⁻, NO₃⁻; and the PAH's: Fl, Py, Per, BaP, BghiP and Cor. The aerosol size distribution (0,01 < d_p < 20 μm) was measured by a combination of electrical and optical analysers with a time resolution of 10 min.The smog periods lasted from 6 to 100 h and occured during anticyclonic conditions with restricted vertical mixing and low to moderate wind velocities. The smog producing pollutants originated either in the city of Berlin or in the industrial regions 100–200 km away.Ambient air quality standards were exceeded by SO₂ (highest 24-h concentration: 760 μg m⁻³), NO_x (320), TSP (930) and SO₄²⁻ (190). BaP levels of up to 92 μg m⁻³ were measured. The total sulfate level increases with the SO₂ concentration and exceeds 100 μg m⁻³ for SO₂ levels above 600 μg m⁻³. In 40% of all cases the aerosol sulfate seems to be more acidic than (NH₄)HSO₄. The secondary aerosol fraction, i.e. the sum of SO₄²⁻, NH₄⁺ and NO₂⁻ ranges from 23 up to 65% of TSP and is related to the age of the pollutants.The composition of the pollutants reflects the different emission patterns of the various source regions and chemical conversions during the trip from the sources to the measuring station. Therefore, the patterns of the composition of the pollutants provide a means to apportion the pollutants among contributing source regions. Thus, it seems possible to develop a scheme to determine during an ongoing smog condition the major contributing source region on the basis of real time measurements of selected physical and chemical parameters of ambient pollutants.     

Factors determining the fluctuation of fluoride concentrations in PM10 aerosols in the urbanized coastal area of the Baltic Sea (Gdynia, Poland)

Fluoride concentrations were determined in PM10 samples collected in the urbanized coastal area of the Baltic Sea (Gdynia) in the period between 1 August 2008 and 8 January 2010. F^? concentrations remained within the range of 0.4–36.6 ng?·?m^?3. The economic transformations which have taken place in Poland increasing ecological awareness have had an excellent effect on the levels of fluoride pollution in the air of the studied region. In our measurements, fluoride concentrations increased in wintertime, when air temperature dropped, at low wind speeds (<1 m?·?s^?1) and with low dispersion of pollutants originating from local sources (traffic, industry, domestic heating). At times when wind speed grew to >10 m?·?s^?1, fluorides were related to marine aerosols or else brought from distant sources. Apart from wind speed and air temperature, other significant meteorological parameters which determined the variability of F^? turned out to be air humidity and precipitation volume. Aerosols were washed out effectively, even with small precipitation (h?=?4 mm), and if a dry period lasted for several days, their concentrations grew rapidly to over 30.0 ng?·?m^?3.     

Isocyanatocyclohexane and isothiocyanatocyclohexane levels in urban and industrial areas and possible emission-related activities

Isocyanatocyclohexane and isothiocyanatocyclohexane are becoming relevant compounds in urban and industrial air, as they are used in important amounts in automobile industry and building insulation, as well as in the manufacture of foams, rubber, paints and varnishes. Glass multi-sorbent tubes (Carbotrap, Carbopack, Carboxen) were connected to LCMA-UPC pump samplers for the retention of iso- and isothiocyanatocyclohexanes. The analysis was performed by automatic thermal desorption (ATD) coupled with capillary gas chromatography (GC)/mass spectrometry detector (MSD). TD-GC/MS was chosen as analytical method due to its versatility and the possibility of analysis of a wide range of volatility and polarity VOC in air samples. The method was satisfactory sensitive, selective and reproducible for the studied compounds. The concentrations of iso- and isothioisocyanatocyclohexanes were evaluated in different urban, residential and industrial locations from extensive VOC air quality and odour episode studies in several cities in the Northeastern edge of Spain. Around 200–300 VOC were determined qualitatively in each sample. Higher values of iso- and isothiocyanatocyclohexane were found in industrial areas than in urban or residential locations. The concentrations ranged between n.d.−246 and n.d.−29 μg m⁻³ for isocyanatocyclohexane and isothiocyanatocyclohexane, respectively, for industrial areas. On the other hand, urban and residential locations showed concentrations ranging between n.d.−164 and n.d.−29 μg m⁻³ for isocyanatocyclohexane and isothiocyanatocyclohexane, respectively. The site location (urban or industrial), the kind and nearness of possible iso- and isothiocyanatocyclohexane emission activities (industrial or building construction) and the changes of wind regimes throughout the year have been found the most important factors influencing the concentrations of these compounds in the different places.     

In-stack dilution technique for the sampling of polycyclic organic compounds. Application to effluents of a domestic waste incineration plant

A dilution technique for on-site stack sampling is described. The procedure enables the effluents to be cooled from 250°C to nearly ambient temperature with nitrogen or air and to circumvent the problems resulting from the handling of dirty stack gases providing dry samples of particulate matter collected on filters.The equipment includes devices to trap the vapor phases of polycyclic aromatic hydrocarbons at −80°C. Low vapor pressure 6-ring PAHs are not detected in both vapor and paniculate phases. 4- and 5-ring PAHs from waste incineration plants are released predominantly in the vapor phase and are not captured by electrostatic filters. These observations raise the problem of their removal. As sources of PAHs, the contribution of the waste incineration plants is in the ng m⁻³ effluent level.     

Trends in Concentrations of Benzene Soluble Suspended Particulate Fraction and Benzo(a)pyrene

The bacterial mutagenicity of ambient particulate organic matter (POM) was measured for consecutive 3-hour time intervals over a 27-hour period in March 1983 at two sites on opposite sides of the heavily traveled San Diego Freeway (I-405) in West Los Angeles (WLA), California, the diurnal variations in the direct (not requiring S9 metabolic activation) mutagenic burden of airborne particulates and the magnitude of the mutagen doses observed at these sites were similar to those previously observed at a site just east of downtown Los Angeles (ELA). Highs (～150 rev m^?3) and lows (～35 rev m^?3) in mutagen densities occurred over short time intervals (a few hours) probably due to changes in emissions, mixing heights and wind speeds. Offshore air flows which drained the air basin between midnight and 0600 PST resulted in elevated mutagen density levels at the western edge of the Los Angeles Basjn. The incremental burden of direct mutagens in respirable POM attributable to freeway traffic reached 50 rev m^?3 during this study. Consistent with our results for ELA there was diminished response on the Salmonella typhimurium nitroreductase-deficient strain TA98NR vs. TA98 suggesting that nitroarenes contribute significantly to the direct mutagenicity of POM collected at the WLA sites.     

Airborne lead levels in the Korean peninsula: characterization of temporal and spatial patterns and cancer risk analysis

Introduction

This study collected long-term airborne lead concentrations in the Korean peninsula and analyzed their temporal, spatial, and cancer risk characterization.

Methods

Approximately, 12,000 airborne samples of total suspended particulate (TSP) were collected from 30 ambient air monitoring stations in inland (Daegu, Daejeon, Gwangju, and Seoul) cities and portal cities (Incheon, Busan, and Ulsan) over a period of 7?years (2004?C2010). High volume air samplers were employed to collect daily TSP samples during the second week of the consecutive months throughout the entire study period. The concentrations of Pb extracted from the TSP samples were analyzed using either inductively coupled plasma-atomic emission or flame atomic absorption spectrometry.

Results

The long-term high mean Pb concentrations were observed in the port cities including Incheon (88?±?18?ng/m³), Ulsan (61?±?7?ng/m³), and Busan (58?±?6?ng/m³). In the temporal analysis, seasonal mean Pb levels were relatively higher in winter and spring than those in summer and fall. In the spatial analysis, the mean Pb levels in spring, winter, and fall from Incheon, which showed the highest seasonal concentrations except summer, were 110?±?19, 101?±?18, and 76?±?23?ng/m³, respectively. In summer, the highest seasonal mean Pb level was observed in the largest industrial city and the second port city, Ulsan (78?±?15?ng/m³), followed by Incheon (65?±?13?ng/m³).

Conclusion

The estimated excess cancer risk analysis showed that inhalation of Pb could result in cancer for one or two persons per million of population in the Korean peninsula.     

Ambient levels of particulate organic matter in New York City in winter and summer

Samples of suspended particulate matter were collected during two summer and two winter sampling campaigns. Non-polar, moderately polar and polar fractions of particulate organic matter (POM) were separated by 8h sequential Soxhlet extractions with cyclobexane, dichloromethane and acetone, respectively. Atmospheric concentrations of total POM averaged 13.0 μgm⁻³ for the two summer periods and 16.0 μgm⁻³ for the two winter periods. Extractable organic matter in respirable (D₅₀≤3.5μm aerodynamic diameter) suspended particulate matter was 81% of the TSP organics during January–February 1978, but only 54% of TSP organics in August 1978.Evaluation of dispersion normalized aerosol concentrations of POM indicated that space heating contributed approximately 75% of the total POM in New York City in February 1977 and 51% in January–February 1978. The strong association of POM with the “oil-burning” factor obtained by factor analysis performed on the data was also indicative of a substantial contribution from this source. Use of high-sulfur (1.5–15 %) fuel oil in New York City during the 1976–1977 fuel crisis appears to have had a striking and significant impact on both total emissions and ambient concentrations of POM during February 1977. The cumulative evidence indicates oil-burning for space heating is currently the most significant source of POM although it contributes only 10–20% of the TSP.The atmospheric concentrations of POM and TSP determined in this study were compared to those measured at the same site in 1968 and 1969. Although wintertime TSP levels have declined to almost one-half of the levels of 1968 and 1969, wintertime concentrations of airborne POM do not appear to have declined. The summertime concentrations of POM in 1977 and 1978 were about 40% higher than those determined for similar periods in 1968 and 1969.