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1.
The concentrations of criteria air pollutants such as CO, NOx (NO + NO2), SO2 and PM were measured in the period of May 2001 and April 2003 in the city of Bursa, Turkey. The average concentrations for
this period were 1115±1600 μg/m3, 29±50 μg/m3, 51±24 μg/m3, 79±65 μg/m3, 40±35 μg/m3, 98±220 μg/m3, for CO, NO, NO2, NOx, SO2 and PM, respectively. Temporal changes in concentrations were analyzed using meteorological factors. Correlations among pollutant
concentrations and meteorological parameters showed weak relations nearly in all data. Lower concentrations were observed
in the summer months while higher concentrations were measured in the winter months. The increase in winter concentrations
was probably due to residential heating. Pollutants were associated with each other in order to have information about their
origin. NOx/SO2 ratio was also examined to bring out the source origin contributing on air pollution (i.e., traffic or stationary). 相似文献
2.
Surface coal mining creates more air pollution problems with respect to dust than underground mining . An investigation was
conducted to evaluate the characteristics of the airborne dust created by surface coal mining in the Jharia Coalfield. Work
zone air quality monitoring was conducted at six locations, and ambient air quality monitoring was conducted at five locations,
for a period of 1 year. Total suspended particulate matter (TSP) concentration was found to be as high as 3,723 μg/m3, respirable particulate matter (PM10) 780 μg/m3, and benzene soluble matter was up to 32% in TSP in work zone air. In ambient air, the average maximum level of TSP was 837 μg/m3, PM10 170 μg/m3 and benzene soluble matter was up to 30%. Particle size analysis of TSP revealed that they were more respirable in nature
and the median diameter was around 20 μm. Work zone air was found to have higher levels of TSP, PM10 and benzene soluble materials
than ambient air. Variations in weight percentages for different size particles are discussed on the basis of mining activities.
Anionic concentration in TSP was also determined. This paper concludes that more stringent air quality standards should be
adopted for coal mining areas and due consideration should be given on particle size distribution of the air-borne dust while
designing control equipment. 相似文献
3.
Aerosol samples for dry deposition and total suspend particulates (TSP) were collected from August to November of 2003 in central Taiwan. Ion chromatography was used to analyze the related water-soluble ionic species (Cl−, NO3
−, SO4
2−, Na+, NH4
+, K+, Mg2+ and Ca2+). The results obtained in this study indicated that the ambient air particulate mass concentrations in the daytime period (averaged 975.4 μg m−3) were higher than the nighttime period (averaged 542.1 μg m−3). And the daytime dry deposition fluxes (averaged 58.12 μg m−2 sec−1) were about 2.2 times as that of nighttime dry deposition fluxes (averaged 26.54 μg m−2 sec−1) of the downward dry deposition. The average values downward and upward of dry deposition fluxes for the weekend period were almost higher than the weekday period for either daytime or nighttime period. Furthermore, the average daytime dry deposition fluxes (averaged 26.37 μg m−2 sec−1) were also about 2.3 times as that of nighttime dry deposition fluxes (averaged 11.52 μg m−2 sec−1). Moreover, the results also indicate that SO4
2− and Ca2+ have higher average composition for total suspended particulates in the daytime period while Ca2+, SO4
2−, and Na+ have the higher average composition for total suspends particulates in the nighttime period. 相似文献
4.
This research paper aims at establishing baseline PM10 and PM2.5 concentration levels, which could be effectively used to develop and upgrade the standards in air pollution in developing countries. The relative contribution of fine fractions (PM2.5) and coarser fractions (PM10-2.5) to PM10 fractions were investigates in a megacity which is overcrowded and congested due to lack of road network and deteriorated air quality because of vehicular pollution. The present study was carried out during the winter of 2002. The average 24h PM10 concentration was 304 μg/m3, which is 3 times more than the Indian National Ambient Air Quality Standards (NAAQS) and higher PM10 concentration was due to fine fraction (PM2.5) released by vehicular exhaust. The 24h average PM2.5 concentration was found 179 μg/m3, which is exceeded USEPA and EU standards of 65 and 50 μg/m3 respectively for the winter. India does not have any PM2.5 standards. The 24 h average PM10-2.5 concentrations were found 126 μg/m3. The PM2.5 constituted more than 59% of PM10 and whereas PM10-PM2.5 fractions constituted 41% of PM10. The correlation between PM10 and PM2.5 was found higher as PM2.5 comprised major proportion of PM10 fractions contributed by vehicular emissions. 相似文献
5.
Zabalza J Ogulei D Elustondo D Santamaría JM Alastuey A Querol X Hopke PK 《Environmental monitoring and assessment》2007,134(1-3):137-151
An ambient air quality study was undertaken in two cities (Pamplona and Alsasua) of the Province of Navarre in northern Spain
from July 2001 to June 2004. The data were obtained from two urban monitoring sites. At both monitoring sites, ambient levels
of ozone, NOx, and SO2 were measured. Simultaneously with levels of PM10 measured at Alsasua (using a laser particle counter), PM10 levels were also determined at Pamplona (using a beta attenuation monitor). Mean annual PM10 concentrations in Pamplona and Alsasua reached 30 and 28 μg m−3, respectively. These concentrations are typical for urban background sites in Northern Spain. By using meteorological information
and back trajectories, it was found that the number of exceedances of the daily PM10 limit as well as the PM10 temporal variation was highly influenced by air masses from North Africa. Although North African transport was observed on
only 9% of the days, it contributed the highest observed PM10 levels. Transport from the Atlantic Ocean was observed on 68% of the days; transport from Europe on 13%; low transport and
local influences on 7%; and transport from the Mediterranean region on 3% of the days. The mean O3 concentrations were 45 and 55 μg m−3 in Pamplona and Alsasua, respectively, which were above the values reported for the main Spanish cities. The mean NO and
NO2 levels were very similar in both sites (12 and 26 μg m−3, respectively). Mean SO2 levels were 8 μg m−3 in Pamplona and 5 μg m−3 in Alsasua. Hourly levels of PM10, NO and NO2 showed similar variations with the typically two coincident maximums during traffic rush hours demonstrating a major anthropogenic
origin of PM10, in spite of the sporadic dust outbreaks. 相似文献
6.
An air quality sampling program was designed and implemented to collect the baseline concentrations of respirable suspended
particulates (RSP = PM10), non-respirable suspended particulates (NRSP) and fine suspended particulates (FSP = PM2.5). Over a three-week period, a 24-h average concentrations were calculated from the samples collected at an industrial site
in Southern Delhi and compared to datasets collected in Satna by Envirotech Limited, Okhla, Delhi in order to establish the
characteristic difference in emission patterns. PM2.5, PM10, and total suspended particulates (TSP) concentrations at Satna were 20.5 ± 6.0, 102.1 ± 41.1, and 387.6 ± 222.4 μg m−3 and at Delhi were 126.7 ± 28.6, 268.6 ± 39.1, and 687.7 ± 117.4 μg m−3. Values at Delhi were well above the standard limit for 24-h PM2.5 United States National Ambient Air Quality Standards (USNAAQS; 65 μg m−3), while values at Satna were under the standard limit. Results were compared with various worldwide studies. These comparisons
suggest an immediate need for the promulgation of new PM2.5 standards. The position of PM10 in Delhi is drastic and needs an immediate attention. PM10 levels at Delhi were also well above the standard limit for 24-h PM10 National Ambient Air Quality Standards (NAAQS; 150 μg m−3), while levels at Satna remained under the standard limit. PM2.5/PM10 values were also calculated to determine PM2.5 contribution. At Satna, PM2.5 contribution to PM10 was only 20% compared to 47% in Delhi. TSP values at Delhi were well above, while TSP values at Satna were under, the standard
limit for 24-h TSP NAAQS (500 μg m−3). At Satna, the PM10 contribution to TSP was only 26% compared to 39% in Delhi. The correlation between PM10, PM2.5, and TSP were also calculated in order to gain an insight to their sources. Both in Satna and in Delhi, none of the sources
was dominant a varied pattern of emissions was obtained, showing the presence of heterogeneous emission density and that nonrespirable
suspended particulate (NRSP) formed the greatest part of the particulate load. 相似文献
7.
The objective of the study is to investigate seasonal and spatial variations of PM10 (particulate matter with aerodynamic diameter less than or equal to 10 μm) and TSP (total suspended particulate matter) of
an Indian Metropolis with high pollution and population density from November 2003 to November 2004. Ambient concentration
measurements of PM10 and TSP were carried out at two monitoring sites of an urban region of Kolkata. Monitoring sites have been selected based
on the dominant activities of the area. Meteorological parameters such as wind speed, wind direction, rainfall, temperature
and relative humidity were also collected simultaneously during the sampling period from Indian Meteorological Department,
Kolkata. The 24 h average concentrations of PM10 and TSP were found in the range 68.2–280.6 μg/m3 and 139.3–580.3 μg/m3 for residential (Kasba) area, while 62.4–401.2 μg/m3 and 125.7–732.1 μg/m3 for industrial (Cossipore) area, respectively. Winter concentrations of particulate pollutants were higher than other seasons,
irrespective of the monitoring sites. It indicates a longer residence time of particulates in the atmosphere during winter
due to low winds and low mixing height. Spread of air pollution sources and non-uniform mixing conditions in an urban area
often result in spatial variation of pollutant concentrations. The higher particulate pollution at industrial area may be
attributed due to resuspension of road dust, soil dust, automobile traffic and nearby industrial emissions. Particle size
analysis result shows that PM10 is about 52% of TSP at residential area and 54% at industrial area. 相似文献
8.
Spyros P. Karakitsios Pavlos A. Kassomenos Dimosthenis A. Sarigiannis Georgios A. Pilidis 《Environmental Modeling and Assessment》2010,15(4):283-294
The objective of the present study is the exploitation of active sampling personal exposure data in assessing the factors
that affect exposure to benzene in combination with the widely accepted scheme of passive sampling—time microenvironment–activity
diaries (TMAD). The campaign included personal exposure measurements with both passive and active sampling in several microenvironments,
evaluation of TMAD kept by the volunteers, and a variety of environmental data (ambient air benzene determination, traffic
and meteorological observations). Due to the relatively elevated benzene traffic emissions, average personal exposure was
determined to be equal to 8.9 μg/m3, ranging between 5 and 20 μg/m3, which is a value highly related to the average urban concentration (9.2 μg/m3). The information gained from TMAD was embedded (in terms of spatial and temporal distribution) into three zones respectively,
in order to draw statistically significant conclusions about the exposure levels and the activity patterns. The contribution
of the activities to the overall amount of exposure was further quantified and refined by active sampling measurements. These
data revealed that driving in a traffic-congested road was the main activity leading to elevated exposure levels (up to 70 μg/m3), followed by walking on the roadside of a congested road (up to 35 μg/m3). Indoor exposure to benzene was in general lower than outdoor (indicating that traffic is the dominant source of benzene
emissions in the wider area), and it was significantly affected by the presence of environmental tobacco smoke. The higher
significance of the regression coefficients obtained by statistical analysis of the active sampling data was fundamental for
the development of a regression-based prediction exposure model. The model was evaluated through comparison with the passive
sampling data, which were considered as an unknown but realistic data exposure pattern. The model performed very well in terms
of expressing the variance of the exposure data with an average score of R
2 equal to 0.935. All of the above indicate that active sampling is a necessary albeit more laborious tool that needs to be
used as a complement to passive sampling for precise quantification of the factors determining personal exposure patterns. 相似文献
9.
Development of baseline (air quality) data in Pakistan 总被引:1,自引:0,他引:1
During 2003–2004, SUPARCO, the Pakistan Space and Upper Atmosphere Research Commission has conducted a year long baseline
air quality study in country’s major urban areas (Karachi, Lahore, Quetta, Rawalpindi, Islamabad and Peshawar). The objective
of this study was to establish baseline levels and behavior of airborne pollutants in urban centers with temporal and spatial
parameters. This study reveals that the highest concentrations of CO were observed at Quetta (14 ppm) while other pollutants
like SO2 (52.5 ppb), NO
x
(60.75 ppb) and O3 (50 ppb) were higher at Lahore compared to other urban centers like Karachi, Peshawar etc. The maximum particulate (TSP)
and PM10 levels were observed at Lahore (996 ug/m3 and 368 ug/m3 respectively), Quetta (778 ug/m3, 298 ug/m3) and in Karachi (410 ug/m3, 302 ug/m3). In all major cities the highest levels were recorded at major intersections and variations were directly correlated with
traffic density. These pollutants showed highest levels in summer and spring while lowest were observed in winter and monsoon.
A data bank has been generated for future planning and air pollution impact studies. 相似文献
10.
Sharma KK Rao CS Dubey JK Patyal SK Parihar NS Battu RS Sharma V Gupta P Kumar A Kalpana Jaya M Singh B Sharma ID Nath A Gour TB 《Environmental monitoring and assessment》2007,132(1-3):25-31
In a field study carried out at three different locations, the dissipation of spiromesifen on cotton and chili was studied
and its DT50, and DT99 were estimated at each location. Spiromesifen was sprayed on chili at 96 and 192 g a.i. ha−1 and cotton at 120 and 240 g a.i. ha−1. Samples of chili fruits were drawn at 0, 1, 3, 5, 7, 10, 15, 21, 30 days after treatment and that of cotton seed and lint
at first picking and harvest. Soil samples were drawn 30 days after treatment from 0 to 15 and 15 to 30 cm layer. Quantification
of residues was done on GC–MS in Selected Ion Monitoring (SIM) mode in mass range 271–274 m/z. The LOQ of this method was
found 0.033 μg g−1, LOD being 0.01 μg g−1. The DT50 of spiromesifen when applied at recommended doses in chili fruits was found to be 2.18–2.40 days. Ninety-nine percent degradation
was found to occur within 14.5–16.3 days after application. Residues of spiromesifen were not detected in cotton seed and
lint samples at the first picking. In soil, no residues of spiromesifen were detectable 15 days after treatment. 相似文献
11.
Delhi is an instructive location for studying the impact of air pollution since it is a rapidly expanding centre of government,
trade commerce and industry. We have made an attempt to (1) determine the association between environmental pollution and
respiratory morbidity in Delhi for the period 1998–2004, (2) assess the impact on hospital admission of the implementation
of recent governmental regulations and (3) calculate the relative risk of hospitalization due to respiratory ailments caused
by air pollutants. Seven hospitals from different parts of Delhi were selected. The pollution profiles of these areas were
assessed and subsequently Poisson regression model was performed for the patient population. There was a remarkable decrease
in monthly average concentration of sulphur dioxide (from 17.9 to 11.1 μg m−3) and increase in monthly average concentration of nitrogen dioxide (from 34.2 to 49.1 μg m−3) after the newly introduced regulations. Particulates were observed to have marginal fall in their concentration but still
remained above the permissible limits. Gaseous pollutants, in spite of being at a level lower than the permissible level,
showed more consistent significant association with respiratory admissions. The relative risks of hospitalization due to respiratory
diseases were in the range of 1.07–2.82 in residential cum commercial areas. Comparative study of pre and post new stringent
governmental regulation showed significant positive association of NO2 with respiratory disorders in southern (RR: 1.10; CI: 1.09–1.12) and northern regions (RR: 1.33; CI: 1.27–1.39), both mixed
use areas. In spite of the improvement in the air quality, the associated health effects were found to be substantial. 相似文献
12.
This investigation presents the assessment of ambient air quality with respect to suspended particulate matter (SPM), sulphur dioxide (SO2) and oxides of nitrogen (NOX) at four sites (RGC, SRS, BBC and BCC) in the Raniganj-Asansol area in West Bengal, India. Ambient air was monitored with a sampling frequency of twenty four hours (3 × 8 hours) at each site on every alternate day (3 days a week) covering a period of one year. A total of 429 samples were collected from RGC, 429 from SRS and 435 each from the BBC and BCC sites. Meteorological parameters such as temperature, relative humidity, wind-speed and wind-direction were also recorded simultaneously during the sampling period. Monthly and seasonal variation of these pollutants have been observed and recorded. The annual average and range values have also been calculated. Results of the investigation indicates that the 95th percentile values of SPM levels exceed the limits (200 g m-3) at RGC, SRS and BBC sites and is within the limit of 500 g m-3 at the BCC sites. The 95th percentile values of SO2 levels did not exceed the reference level at any of the monitoring stations. The 95th percentile values of NOX are found to be exceeding the limit (80 g m-3) at RGC, SRS and BBC sites but is within the prescribed limit of 120 g m-3 at the BCC site. Further, it has been observed that the concentrations of the pollutants are high in winter in comparison to the summer or the monsoon seasons. Results of the investigation indicates that industrial activities, indiscriminate open air burning of coal by the local inhabitants for cooking as well as coking purposes, vehicular traffic, etc. are responsible for the high concentration of pollutants in this area. 相似文献
13.
Throughout August and September, 2003, wildfires burned in close proximity to Missoula, Montana, with smoke emanating from the fires impacting the valley for much of the summer. This presented the perfect opportunity to measure the levels of polychlorinated dibenzodioxins and dibenzofurans (PCDD/F) comprising ambient forest fire smoke particles impacting the Missoula Valley. An air sampler at the Montana Department of Environmental Quality's (DEQ) compliance site in Missoula measured hourly averages of PM10 throughout the fire season. Three collocated PM2.5 cyclones collected 24-h smoke samples using quartz filters and Polyurethane Foam (PUF) sorbent cartridges. From the quartz filters, concentrations of Organic and Elemental Carbon (OC/EC) were measured, while PCDD/F were measured from one set of a filter (particle phase) and PUF (vapor phase) aggregate of samples in an attempt to also investigate the different phases of PCDD/F in forest fire smoke impaired communities.Hourly PM10 concentrations peaked at 302.9 μg m−3 on August 15. The highest OC concentration (115.6 μg m−3) was measured between August 21–22, and the highest EC concentration of 10.5 μg m−3 was measured August 20–21. Measurable concentrations of PM2.5 associated PCDD/Fs were not detected from a representative aggregate sample, with the exception of small amounts of 1,2,3,4,6,7,8-heptachlorodibenzodioxin and octachlorodibenzodioxin. PM2.5 samples collected during the smoke events were composed of approximately 65% OC. However, the OC fraction of the particles collected in the smoke impaired Missoula valley was not composed of significant amounts of PCDD/F. 相似文献
14.
Jackson MM 《Environmental monitoring and assessment》2005,104(1-3):385-407
This study used manual air sampling method to assess the contribution of road traffic to air pollution level in Dar-es-Salaam City, Tanzania. Samples were collected from 11 different sites. Parameters measured were: sulphur dioxide using pararosaniline method, nitrogen dioxide using saltzman method, particulate matter and particulate lead using filtration method and atomic absorption spectrometric method, respectively. Results showed that hourly average sulphur dioxide concentration range from 127 to 1385 g/m3. The measured values of sulphur dioxide were above the recommended WHO guidelines with an hourly objective value of 350 g/m3 at 87% of the sampling sites. The hourly average nitrogen dioxide concentration ranged from 18 to 53 g/m3. The maximum hourly nitrogen dioxide concentration at 53 g/m3 was below the WHO guideline value of 200 g/m3. The hourly average suspended particulate matter (SPM) ranged from 98 to 1161 g/m3, exceeding the recommended value of 230 g/m3 by WHO at 87% of the sampling sites. The hourly average lead concentration was found to range from 0.60 to 25.6 g/m3, exceeding again the WHO guideline value of 1.5 g/m3at 83% of the sampling sites. Results predicted by Gaussian model when compared with the measured values were found to have a correlation coefficient of 0.8, signifying a good correlation. The risk assessment was undertaken considering the people who spend a significant portion of their time near the roads, such as the Uhuru primary school pupils and the adult population who reside by the roadside. The unit risk realised was 18.2 × 10–6 for adult population and 2.2 × 10–6 for pupils, both scenarios showing risk higher than the United Sates of America Environmental Protection Agency (USEPA) acceptable limit of 1× 10–6. Considering the magnitude of the problem at hand, this study recommends an introduction of mandatory emission tests of SPM, lead and sulphur dioxide (SO2). The study further recommends the introduction of continuous and/or regular air quality monitoring and the use non-leaded petrol in Tanzania. 相似文献
15.
Srijan Lal Shrestha 《Environmental Modeling and Assessment》2007,12(3):239-251
The distributed lag effects of ambient particulate air pollution exposure on respiratory hospital admissions in Kathmandu
Valley are modelled using daily time series data. The extended exposure to PM10 is accounted for by assigning weights to daily average PM10 which decline geometrically as the lag period increases in days. Results show that the percent increase in chronic obstructive
pulmonary disease (COPD) hospital admissions and respiratory admissions including COPD, asthma, pneumonia, and bronchitis
per 10 μg/m3 rise in PM10 are found to be 4.85% for 30 days lag effect, about 15.9% higher than that observed for same-day lag effect and 3.52% for
40 days lag effect, about 28.9% higher than the observed value for same-day lag effect, respectively. 相似文献
16.
Seasonal variation of the concentrations of trace metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn) were measured by ICP-AES
in the water and sediment from the Saricay Stream, Geyik Dam and Ortakoy Well in the same basin. Comparisons between trace
metal concentrations in water and sediment in three sources (Stream, Dam and Well) were made. The concentrations of a large
number of trace metals in the water and sediment were generally higher in the Stream than in the Well and Dam, particularly
in summer. Trace metal concentration ranges in sediments of the Saricay Stream and its sources showed very wide ranges (as
mass ratio): Co: 5–476 μg g−1, Cr: 15–1308 μg g−1, Cu: 7–128 μg g−1, Fe: 1120–13210 μg g−1, Mn: 150–2613 μg g−1, Ni: 102–390 μg g−1, Pb: 0.7–31.3 μg g−1 and Zn: 18–304 μg g−1, whereas Cd was not detected. Trace metal concentration ranges found in waters were: Co: 9.5–20.7 μg L−1, Cr: 20.3–284 μg L−1, Cu: 170–840 μg L−1, Fe: 176–1830 μg L−1, Mn: 29.3–387 μg L−1, and Ni: 4.3–21.9 μg L−1. Among the trace metals studied, Cd and Zn in two seasons and Pb in winter were usually not detected or in the recommended
levels. In addition, Cd was not detected in the sediment during the winter season. The analysis of variance (one-way ANOVA)
and correlation matrix was employed for the sediment and water samples of the two field surveys (summer and winter) comparison.
The three sources showed differences in metal contents. The metal levels in sediments displayed marked seasonal and regional
variations, which were attributed to anthropogenic influences and natural processes. In the Saricay Stream, high values of
metals during the dry season showed an anthropological effect from small industry firms, e.g.: an olive mill and a dairy farm
or water dilution during summer seasons. Finally, the pollution in this basin probably originated from small industrial, low
quality coal-burned thermal power plants, and particularly agricultural and domestic waste discharges. 相似文献
17.
In this study, SO2 dispersion over İzmit Gulf is simulated by California Puff (CALPUFF) model for three air pollution cases, which occurred
on January 28, February 12, and February 26, 1997. These days are generally characterized by dominant high-pressure systems
– pressure values reaching 1032 mb, low wind speeds and sometimes calm conditions, and low temperatures with a minimum of
0°C. Hourly simulations during those critical cases were carried out and results revealed very high concentrations of SO2 transported to the downwind regions of Tüpraş and Gebze, and values sometimes exceeded 1,000 μg/m3. Nighttime and morning simulations associated with inversion produced considerably higher values of SO2 than the afternoon simulations associated with breeze. Model verification was conducted by comparing the measured daily average
values of eight stations with the model predicted values at the same receptor points. Results showed that the model well predicted
the values at station Gebze in all three cases. The model sometimes underestimated and sometimes overestimated the concentrations
at other receptor stations. 相似文献
18.
Agarwal R Jayaraman G Anand S Marimuthu P 《Environmental monitoring and assessment》2006,114(1-3):489-504
The study focuses on assessing the status of respiratory morbidity in Delhi over a four years period from 2000–2003. An attempt was made to investigate the role of important pollutants (SO2, NO2, SPM and RSPM) and various meteorological factors (temperature minimum & maximum, relative humidity at 0830 and 1730 hrs. and wind speed) in being responsible for respiratory admissions on account of COPD, asthma and emphysema. The study showed that winter months had greater exposure risk as pollutants often get trapped in the lower layers of atmosphere resulting in high concentrations. Statistical analysis revealed that two pollutants have significant positive correlation with the number of COPD cases viz., SPM (r = 0.474; p < 0.01) and RSPM (r = 0.353; p < 0.05), while a meteorological factor temperature (minimum) has a significant negative correlation (r = −0.318; p < 0.05) with COPD. Stepwise multiple regression analysis was performed for COPD as dependent variable and R2 value of 0.33 was obtained indicating that SPM and RH(1730) were able to explain 33 percent variability in COPD. The partial correlation of SPM and RH(1730) on COPD was higher than any other combination and therefore they can be regarded as important contributing variables on COPD. 相似文献
19.
The objective of this study is an attempt to conduct an environmentalmonitoring and impact assessment of the On-Nooch solid waste disposal sitein Bangkok, Thailand. Four water and five air sampling stations (2 upwindand 3 downwind directions) were established at the site. Grab water samplesfrom leachate treatment plant and Khlong Song Hong, a nearby stream, werecollected during the rainy and dry seasons. Analytical results of the wastewater discharged by the leachate treatment plant, during dry season showedchemical oxygen demand: 618 mg/l; biochemical oxygen demand: 80 mg/l;suspended solid: 101 mg/l; Total Kjeldahl Nitrogen: 283 mg/l, which werestill higher than standard limit for effluents in Thailand. During the dryseason, results also showed widespread heavy metal pollution from leachate(chromium: 1.03 mg/l; manganese: 1.07 mg/l; mercury: 0.025 mg/l) and werehigher than the allowable level of heavy metals for the Industrial EffluentStandard in Thailand. The direct discharge of untreated leachate into inlandwater will cause considerable water pollution in the study area. Compositeair samples in this study area were collected during the rainy and dryseasons and were analyzed for methane (CH4), carbon dioxide(CO2), carbon monoxide (CO), sulphur dioxide(SO2), nitrogen dioxide (NO2) andsuspended particulate matter (SPM). The average concentration of SPM rangedbetween 0.1–0.36 mg/m3 for 24-hour average, dependingupon the season. The level of CH4 and CO2 inthe ambient air of the study area were found to be 3.48–65.71mg/m3 and 886-1758 mg/m3 respectively which weremuch higher than the normal concentration of CH4 andCO2 in the air (CH4: 2.41 mg/m3;CO2: 585 mg/m3). Hence, adverse health andenvironmental effects could be expected from water and air pollution. 相似文献
20.
Chuaybamroong P Cayse K Wu CY Lundgren DA 《Environmental monitoring and assessment》2007,128(1-3):421-430
Ambient aerosols were collected during 2000–2001 in Gainesville, Florida, using a micro-orifice uniform deposit impactor (MOUDI)
to study mass size distribution and carbon composition. A bimodal mass distribution was found in every sample with major peaks
for aerosols ranging from 0.32 to 0.56 μm, and 3.2 to 5.6 μm in diameter. The two distributions represent the fine mode (<2.5 μm)
and the coarse mode (>2.5 μm) of particle size. Averaged over all sites and seasons, coarse particles consisted of 15% carbon
while fine particles consisted of 22% carbon. Considerable variation was noted between winter and summer seasons. Smoke from
fireplaces in winter appeared to be an important factor for the carbon, especially the elemental carbon contribution. In summer,
organic carbon was more abundant. The maximum secondary organic carbon was also found in this season (7.0 μg m−3), and the concentration is between those observed in urban areas (15–20 μg m−3) and in rural areas (4–5 μg m−3). However, unlike in large cities where photochemical activity of anthropogenic emissions are determinants of carbon composition,
biogenic sources were likely the key factor in Gainesville. Other critical factors that affect the distribution, shape and
concentration were precipitation, brushfire and wind. 相似文献