Min Li, et al. (2006). "Seasonal abundance of organic molecular markers in urban particulate matter". Atmospheric Environment, 40 (2006):
2260–2273, accessed September 24, 2015, doi:10.1016/j.atmosenv.2005.10.025.
Abstract:
The organic components of the particulate matter (PM10) present in the city of Philadelphia were measured. Samples were studied from 2 week measurements from each season. 52 forms of organic markers were found. Gas chromatography was used as the method of measurement. The results were parallel to previous studies in LA, CA and Atlanta Georgia. Findings revealed a difference in organic molecular markers between seasons.
Where do the authors work, and what are their areas of expertise? Note any other publications by the authors with relevance to the 6Cities project.
Min Li
Department of Civil & Environmental Engineering, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
Department of Civil & Environmental Engineering and Center for Advanced Infrastructure and Transportation, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
What are the main findings or arguments presented in the article or report?
As seasons vary, the molecular marker compounds found in the PM10 (particulate matter that is 10 micrometers or less in diameter) vary, in source and form.
Over 50 organic compounds were registered in samples of PM10 in Philadelphia, PA.
n-Alkanes
From "vegetative detritus"
Concentration was highest in fall, lowest in spring
PAH
Products of transportation pollution, from engine combustion.
In particle form mostly throughout the year
Concentration was highest in winter, lowest in summer
hopanes
Products of transportation pollution, from engine combustion.
"in crude oil and source rocks"
"fall>summer>spring>winter"
n-Alkanoic acids
from cooking, burning gas, "biogenic processes"
low weight: max in summer
high weight: max in fall
"Comprising 64% of the total yield of organic compounds identified in this study, n-alkanoic acids ranging from C10 to C30 are the most abundant organic molecular source marker group in the urban aerosol of Philadelphia"
Describe at least three ways that the argument is supported.
Charts containing concentrations of samples of PM10 measured by air pollution monitors describe explicitly what was found in the PM10 during each season's sampling session.
Graphs display the concentrations of molecular markers (PAH, hopanes, n-alkanes, dicarboxylic acids, and n-alkanoic acids) during the different seasonal periods in which sampling occurred.
Each category of marker is analyzed on its own.
Where they come from
What season they were most and least abundant
What three (or more) quotes capture the message of the article or report?
"Understanding the composition and sources of particulate matter in the urban Northeast is important for assessing its effects and developing air pollution control strategies"
States why they chose what they are studying
"Seasonal and day-to-day variations between the different classes of compounds are consistent with important contributions from petroleum related emissions, especially in winter"
"Summer concentration patterns are consistent with an important secondary organic aerosol contribution that could be local in nature".
"n-Alkane distributions indicate a considerable biogenic contribution in the fall"
Proposed reasons for why each component was more prevalent during each season.
"More than 50 individual organic compounds were identified in the PM10 samples collected in Philadelphia, PA, including 9 n-alkanes, 5 PAHs, 9 hopanes, 21 n-alkanoic acids and 8 dicarboxylic acids"
What were the methods, tools and/or data used to produce the claims or arguments made in the article or report?
Sampled from the North Broad Street monitoring cite
71 samples across the seasons (Jan.-Nov.) came from Anderson PM10 sampler
specific pretreatment, storage, and transportation requirements for fabric filters that took the samples
Very complicated extraction method for the material from the sample filters
See technical description below from the methodology of the report.
"The PM10 sample filters corresponding to a single analysis day were extracted individually by Soxhlet extraction in 250 ml of a 1:1 methylene chloride: acetone mixture for 4 h following the procedure of Ligocki et al. (1985) developed for soxhlet extraction of a range of organic compoundclasses in atmospheric particulate matter. Extracts were evaporated to 5 ml using a Kuderna–Danish apparatus and concentrated to 1.0 ml by a stream of high-purity nitrogen gas. Each sample extract was divided into two known-volume portions (approx. 50% each) after concentration to about 1.0 ml. One portion was derivatized with diazomethane. Analyses of all underivatized and derivatized sample aliquots were performed with a Varian 3800 capillary column gas chromatograph interfaced to a Saturn 2000 ion trap mass spectrometer (GC/IT MS). Perdeuterated n-tetracosane (nC24D50) was added as the internal standard to all sample filters prior to solvent extraction. Molecular markers were verified by comparing the GC retention times and mass spectra with those produced from analyses of the authentic standards corresponding to each compound listed in Table 1. Linear five-point calibration curves (R240:95) for each compound were used to quantify organic molecular source markers. GC/IT MS analysis precision based on duplicate analysis for every tenth sample ranged from 2.5% for n-octacosane to 8.1% for ntriacontane, and was less than 5.0% for most compounds"
Through these processes, the researchers were able to analyze what molecular markers made up each season's PM10 emissions. Studies of the markers assist in finding the origins of the pollutants.
How (if at all) are health disparities or other equity issues addressed in the article or report?
Health disparities and equity issues are not mentioned in this report.
Where has this article or report been referenced or discussed? (In some journals, you can see this in a sidebar.)
Has been referenced in lots of journals about particulate matter and aerosols
Can you learn anything from the article or report’s bibliography that tells us something about how the article or report was produced?
The bibliography cited many sources that had similar studies of composition of particulate mater from all over the world.
The EPA Air Quality System database was cited
A journal on gas chromatography of fine particles was cited and additional sources assist with methodology.
One article referenced was an article by one of the same authors
There was extensive literature review done before starting this experiment, shown by the large abundance of references. In addition, the bibliography shows that
What three points, details or references from the text did you follow up on to advance your understanding of how air pollution science has been produced and used in governance and education in different settings?
I referred to other sources of information on what molecular markers are to understand more about what they reflect about Philadelphia's air quality.
- Citation:
Min Li, et al. (2006). "Seasonal abundance of organic molecular markers in urban particulate matter". Atmospheric Environment, 40 (2006):2260–2273, accessed September 24, 2015, doi:10.1016/j.atmosenv.2005.10.025.
- Abstract:
The organic components of the particulate matter (PM10) present in the city of Philadelphia were measured. Samples were studied from 2 week measurements from each season. 52 forms of organic markers were found. Gas chromatography was used as the method of measurement. The results were parallel to previous studies in LA, CA and Atlanta Georgia. Findings revealed a difference in organic molecular markers between seasons.Where do the authors work, and what are their areas of expertise? Note any other publications by the authors with relevance to the 6Cities project.
What are the main findings or arguments presented in the article or report?
- As seasons vary, the molecular marker compounds found in the PM10 (particulate matter that is 10 micrometers or less in diameter) vary, in source and form.
- Over 50 organic compounds were registered in samples of PM10 in Philadelphia, PA.
- n-Alkanes
- From "vegetative detritus"
- Concentration was highest in fall, lowest in spring
- PAH
- Products of transportation pollution, from engine combustion.
- In particle form mostly throughout the year
- Concentration was highest in winter, lowest in summer
- hopanes
- Products of transportation pollution, from engine combustion.
- "in crude oil and source rocks"
- "fall>summer>spring>winter"
- n-Alkanoic acids
- from cooking, burning gas, "biogenic processes"
- low weight: max in summer
- high weight: max in fall
- "Comprising 64% of the total yield of organic compounds identified in this study, n-alkanoic acids ranging from C10 to C30 are the most abundant organic molecular source marker group in the urban aerosol of Philadelphia"
- Dicarboxylic acids
- signify photooxidation
- "oxidation under the influence of radiant energy (as light)" (http://www.merriam-webster.com/dictionary/photooxidation)
- specific to urban areas
Describe at least three ways that the argument is supported.- Charts containing concentrations of samples of PM10 measured by air pollution monitors describe explicitly what was found in the PM10 during each season's sampling session.
- Graphs display the concentrations of molecular markers (PAH, hopanes, n-alkanes, dicarboxylic acids, and n-alkanoic acids) during the different seasonal periods in which sampling occurred.
- Each category of marker is analyzed on its own.
- Where they come from
- What season they were most and least abundant
What three (or more) quotes capture the message of the article or report?- "Understanding the composition and sources of particulate matter in the urban Northeast is important for assessing its effects and developing air pollution control strategies"
- States why they chose what they are studying
- "Seasonal and day-to-day variations between the different classes of compounds are consistent with important contributions from petroleum related emissions, especially in winter"
- "Summer concentration patterns are consistent with an important secondary organic aerosol contribution that could be local in nature".
- "n-Alkane distributions indicate a considerable biogenic contribution in the fall"
- Proposed reasons for why each component was more prevalent during each season.
- "More than 50 individual organic compounds were identified in the PM10 samples collected in Philadelphia, PA, including 9 n-alkanes, 5 PAHs, 9 hopanes, 21 n-alkanoic acids and 8 dicarboxylic acids"
What were the methods, tools and/or data used to produce the claims or arguments made in the article or report?- Sampled from the North Broad Street monitoring cite
- 71 samples across the seasons (Jan.-Nov.) came from Anderson PM10 sampler
- specific pretreatment, storage, and transportation requirements for fabric filters that took the samples
- Very complicated extraction method for the material from the sample filters
- See technical description below from the methodology of the report.
- "The PM10 sample filters corresponding to a single analysis day were extracted individually by Soxhlet extraction in 250 ml of a 1:1 methylene chloride: acetone mixture for 4 h following the procedure of Ligocki et al. (1985) developed for soxhlet extraction of a range of organic compoundclasses in atmospheric particulate matter. Extracts were evaporated to 5 ml using a Kuderna–Danish apparatus and concentrated to 1.0 ml by a stream of high-purity nitrogen gas. Each sample extract was divided into two known-volume portions (approx. 50% each) after concentration to about 1.0 ml. One portion was derivatized with diazomethane. Analyses of all underivatized and derivatized sample aliquots were performed with a Varian 3800 capillary column gas chromatograph interfaced to a Saturn 2000 ion trap mass spectrometer (GC/IT MS). Perdeuterated n-tetracosane (nC24D50) was added as the internal standard to all sample filters prior to solvent extraction. Molecular markers were verified by comparing the GC retention times and mass spectra with those produced from analyses of the authentic standards corresponding to each compound listed in Table 1. Linear five-point calibration curves (R240:95) for each compound were used to quantify organic molecular source markers. GC/IT MS analysis precision based on duplicate analysis for every tenth sample ranged from 2.5% for n-octacosane to 8.1% for ntriacontane, and was less than 5.0% for most compounds"
- Through these processes, the researchers were able to analyze what molecular markers made up each season's PM10 emissions. Studies of the markers assist in finding the origins of the pollutants.
How (if at all) are health disparities or other equity issues addressed in the article or report?- Health disparities and equity issues are not mentioned in this report.
Where has this article or report been referenced or discussed? (In some journals, you can see this in a sidebar.)- Has been referenced in lots of journals about particulate matter and aerosols
- India:
- Chemical Speciation and Source Assignment of Particulate (PM10) Phase Molecular Markers in Mumbai
- Composition And Sources Of Organic Tracers In Aerosol Particles Of Industrial Central India
- China:
- Seasonal variations and source identification of selected organic acids associated with PM10 in the coastal area of Southeastern China
- Secondary organic aerosol tracers and malic acid in Hong Kong: seasonal trends and origins
- Korea
- Chemical characteristics of PM2.5 aerosol in Incheon, Korea
Can you learn anything from the article or report’s bibliography that tells us something about how the article or report was produced?- The bibliography cited many sources that had similar studies of composition of particulate mater from all over the world.
- The EPA Air Quality System database was cited
- A journal on gas chromatography of fine particles was cited and additional sources assist with methodology.
- One article referenced was an article by one of the same authors
- There was extensive literature review done before starting this experiment, shown by the large abundance of references. In addition, the bibliography shows that
What three points, details or references from the text did you follow up on to advance your understanding of how air pollution science has been produced and used in governance and education in different settings?