Damon Chaky | Pratt Institute (original) (raw)

Papers by Damon Chaky

Research paper thumbnail of Combined application of δ 13C and molecular ratios in sediment cores for PAH source apportionment in the New York/New Jersey harbor complex

Org Geochem, 2006

Sub-basins within the New York/New Jersey (NY/NJ) Harbor host variable amounts and sources of pol... more Sub-basins within the New York/New Jersey (NY/NJ) Harbor host variable amounts and sources of polycyclic aromatic hydrocarbons (PAHs). Analyses of radionuclides 137Cs and 7Be were used to assign approximate dates to individual sections of sediment cores collected from four major sub-basins of the harbor complex. Sampling sites range from heavily contaminated Newark Bay and Passaic River to less contaminated Raritan Bay and Jamaica Bay. PAHs were identified with GC–MS and quantified by GC respectively. Gas chromatography–isotope ratio mass spectrometry (GC/IRMS) was applied to determine δ13C values of pyrene (δ13CPy), a principal 4 ring parent PAH. Two end-member PAH source components, petroleum-related PAHs (PRPAH) and combustion-related PAHs (CRPAH), were calculated from a carbon isotopic mass balance equation based on assumptions that petroleum-related δ13CPy is −29‰, and that combustion-derived δ13CPy is −24‰. Temporal trends of PRPAH in these cores are similar to those of the petroleum-derived unresolved complex mixture (UCM), whereas CRPAH resembled trends of “Total” PAH (TPAH). Three molecular ratios, fluoranthene to fluoranthene plus pyrene (Fl/(Fl + Py)), high molecular weight 4–6 ring PAH to total PAH (Ring456/TPAH) and parent to total (Par/(Par + Alkyl)), correlate strongly with each other, and show a moderate to strong positive correlation with δ13CPy. In contrast, the ratios of anthracene to phenanthrene plus anthracene (A/(Pa + A)), benzo[a]anthracene to benzo[a]anthracene plus chrysene (BaA/(BaA+Chy)), and indeno[1,2,3-cd]pyrene to indeno[1,2,3-cd]pyrene plus benzo[ghi]perylene (IP/(IP + Bghi)) show no, weak, or even negative correlation with the four well correlated ratios (δ13CPy, Par/(Par + Alkyl), Fl/(Fl + Py), and Ring456/TPAH). Combined application of the four well correlated molecular indicators suggests that PAH contribution from combustion became more important in most areas of the NY/NJ Harbor during the last three decades of the 20th century.

Research paper thumbnail of SI(NYC-BCPaper)

Research paper thumbnail of Membrane processes move toward broad use

Research paper thumbnail of UNION CARBIDE REPORTS first full-year's production of BUTADIENE for the Government's Synthetic Rubber Program

Research paper thumbnail of World Trade Center Environmental Contaminant Database: A Publicly Available Air Quality Dataset for the New York City Area

ACS Symposium Series, 2005

Page 1. Chapter 13 World Trade Center Environmental Contaminant Database: A Publicly Available Ai... more Page 1. Chapter 13 World Trade Center Environmental Contaminant Database: A Publicly Available Air Quality Dataset for the New York City Area Steven N. Chillrud1, Alison S. Geyh2, Diane K. Levy3, Elsie M. Chettiar3, and Damon A. Chaky1 ...

Research paper thumbnail of Combined application of δ13C and molecular ratios in sediment cores for PAH source apportionment in the New York/New Jersey harbor complex

Organic Geochemistry, 2006

Sub-basins within the New York/New Jersey (NY/NJ) Harbor host variable amounts and sources of pol... more Sub-basins within the New York/New Jersey (NY/NJ) Harbor host variable amounts and sources of polycyclic aromatic hydrocarbons (PAHs). Analyses of radionuclides 137 Cs and 7 Be were used to assign approximate dates to individual sections of sediment cores collected from four major sub-basins of the harbor complex. Sampling sites range from heavily contaminated Newark Bay and Passaic River to less contaminated Raritan Bay and Jamaica Bay. PAHs were identified with GC-MS and quantified by GC respectively. Gas chromatography-isotope ratio mass spectrometry (GC/IRMS) was applied to determine d 13 C values of pyrene (d 13 C Py ), a principal 4 ring parent PAH. Two end-member PAH source components, petroleum-related PAHs (PRPAH) and combustion-related PAHs (CRPAH), were calculated from a carbon isotopic mass balance equation based on assumptions that petroleum-related d 13 C Py is À29&, and that combustion-derived d 13 C Py is À24&. Temporal trends of PRPAH in these cores are similar to those of the petroleum-derived unresolved complex mixture (UCM), whereas CRPAH resembled trends of ''Total'' PAH (TPAH). Three molecular ratios, fluoranthene to fluoranthene plus pyrene (Fl/(Fl + Py)), high molecular weight 4-6 ring PAH to total PAH (Ring456/TPAH) and parent to total (Par/(Par + Alkyl)), correlate strongly with each other, and show a moderate to strong positive correlation with d 13 C Py . In contrast, the ratios of anthracene to phenanthrene plus anthracene (A/(Pa + A)), benzo[a]anthracene to benzo[a]anthracene plus chrysene (BaA/(BaA+Chy)), and indeno[1,2,3-cd]pyrene to indeno[1,2,3-cd]pyrene plus benzo[ghi]perylene (IP/(IP + Bghi)) show no, weak, or even negative correlation with the four well correlated ratios (d 13 C Py, Par/(Par + Alkyl), Fl/(Fl + Py), and Ring456/TPAH). Combined application of the four well correlated molecular indicators suggests that PAH contribution from combustion became more important in most areas of the NY/NJ Harbor during the last three decades of the 20th century.

Research paper thumbnail of Major Ion Geochemistry and Drinking Water Supply Issues in the Hudson River Basin

The Hudson River Estuary, 2006

... Data from each of these five monitoring stations were compiled and pruned here to eliminatesa... more ... Data from each of these five monitoring stations were compiled and pruned here to eliminatesam-ples for which relatively complete major element ... The ratio of mean Q/P based on another compilation of water budget parameters (Table 7.5; Darmer, 1987) is 56 percent, due to ...

Research paper thumbnail of Radiogenic Lead Isotopes and Time Stratigraphy in the Hudson River, New York

Water, Air, & Soil Pollution: Focus, 2000

Radionuclide, radiogenic lead isotope and trace metal analyses on fine-grained sediment cores col... more Radionuclide, radiogenic lead isotope and trace metal analyses on fine-grained sediment cores collected along 160 km of the upper and tidal Hudson River were used to examine temporal trends of contaminant loadings and to develop radiogenic lead isotopes both as a stratigraphic tool and as tracers for resolving decadal particle transport fluxes. Very large inputs of Cd, Sb, Pb, and Cr are evident in the sediment record, potentially from a single manufacturing facility. The total range in radiogenic lead isotope ratios observed in well-dated cores collected about 24 km downstream of the plant is large (e.g., maximum difference in 206 Pb/ 207 Pb is 10%), characterized by four major shifts occurring in the 1950s, 1960s, 1970s and 1980s. The upper Hudson signals in Cd and radiogenic lead isotopes were still evident in sediments collected 160 km downstream in the tidal Hudson. The large magnitude and abrupt shifts in radiogenic lead isotope ratios as a function of depth provide sensitive temporal constraints that complement information derived from radionuclide analyses to significantly improve the precision of dating assignments. Application of a simple dilution model to data from paired cores suggests much larger sediment inputs in one section of the river than previously reported, suggesting particle influxes to the Hudson have been underestimated.

Research paper thumbnail of An approach to interpreting contaminant deposition fluxes from dated sediment cores

Research paper thumbnail of Mineralogical Variations within the S-Type Asteroid Class

Research paper thumbnail of Elemental and Molecular Evidence of Soot- and Char-Derived Black Carbon Inputs to New York City's Atmosphere during the 20th Century

Environmental Science & Technology, 2007

Research paper thumbnail of Twentieth Century Atmospheric Metal Fluxes into Central Park Lake, New York City

Environmental Science & Technology, 1999

Research paper thumbnail of Molecular Tracers of Saturated and Polycyclic Aromatic Hydrocarbon Inputs into Central Park Lake, New York City

Environmental Science & Technology, 2005

Saturated hydrocarbons (SH) and polycyclic aromatic hydrocarbons (PAHs) have been quantified in a... more Saturated hydrocarbons (SH) and polycyclic aromatic hydrocarbons (PAHs) have been quantified in a sediment core obtained from Central Park Lake, New York City. Radionuclides 210 Pb and 137 Cs were used to assign approximate dates to each individual section in the core. The dating profile based on 210 Pb matches very well with the time constraints provided by 137 Cs. Radionuclide-derived depositional dates are consistent with temporal information from the petroleum-indicator ratio U/R [the ratio of unresolved complex mixture (UCM) to saturated hydrocarbons in the aliphatic fraction] and the history of fuel use in the NYC area. Ratios of 1,7dimethylphenanthrane (DMP) to 1,7-DMP plus 2,6-DMP [1,7/(1,7 + 2,6)-DMP], retene to retene plus chrysene [Ret/(Ret + Chy)], and fluoranthene to fluoranthene plus pyrene [Fl/(Fl + Py)] provide additional source discrimination throughout the core. Results show that the ratio U/R is sensitive to petroleum inputs and Ret/(Ret + Chy) is responsive to contributions from softwood combustion, whereas both Fl/(Fl + Py) and 1,7/(1,7 + 2,6)-DMP can be used to discriminate among wood, coal, and petroleum combustion sources. Combined use of these ratios suggests that in New York City, wood combustion dominated 100 years ago, with a shift to coal combustion occurring from the 1900s to the 1950s. Petroleum use began around the 1920s and has dominated since the 1940s.

Research paper thumbnail of Stable lead isotopes, contaminant metals and radionuclides in upper Hudson River sediment cores: implications for improved time stratigraphy and transport processes

Chemical Geology, 2003

Radionuclide, stable lead isotope and trace metal analyses on fine-grained sediment cores collect... more Radionuclide, stable lead isotope and trace metal analyses on fine-grained sediment cores collected along a 24-mile reach of the upper Hudson River were used to establish temporal trends of contaminant loadings, to establish stable lead isotopes as an additional stratigraphic tool, and as tracers for resolving particle transport fluxes over periods of decades. Very large contaminant inputs of Cd, Sb, Pb and Cr were evident in the sediment record. One potential large source for these metals was from a pigment manufacturing facility in Glens Falls, NY. The total range in stable lead isotope ratios observed in well-dated cores from about 15 miles downstream of the potential metal inputs was large (e.g., maximum difference in 206 Pb/ 207 Pb is 10%) and characterized by four major shifts occurring in the 1950s, 1960s, 1970s and 1980s. The temporal trend in 206 Pb/ 207 Pb has been used to establish precise dating of a sediment core from 24 miles further downstream. The large magnitude and abrupt shifts in stable lead isotope ratios preserved in upper Hudson sediment cores provide a way to significantly improve dating models, based only on radionuclide analyses. Cadmium, lead and antimony were identified as quite sensitive tracers of upper Hudson sediments due to the magnitude of contamination and the lack of significant additional downstream sources of these contaminant metals. Metal measurements in a pair of sediment cores located 24 miles apart were used to constrain relative fluxes of sediment entering the river between the two coring locations, with sediment sections deposited between the early 1960s and the late 1970s in these two cores suggesting that 3 -4 times more sediment entered the river between the two coring sites than was transported from upstream. These dilution factors agree very well with estimates based on suspended sediment measurements during a flood event in April 1994 and with estimates based on mechanistic model of suspended sediment transport between 1977 and 1992. D

Research paper thumbnail of Source apportionment of polycyclic aromatic hydrocarbons (PAHs) into Central Park Lake, New York city, over a century of deposition

Environmental Toxicology and Chemistry, 2014

Relative contributions of polycyclic aromatic hydrocarbons (PAHs) from combustion sources of wood... more Relative contributions of polycyclic aromatic hydrocarbons (PAHs) from combustion sources of wood, petroleum, and coal were computed in sediments from Central Park Lake in New York City (NY, USA) by chemical mass balance based on several reliable source indicators. These indicators are the ratio of retene to the sum of retene and chrysene, the ratio of 1,7-dimethylphenanthrene (DMP) to 1,7-DMP and 2,6-DMP, and the ratio of fluroanthene to fluroanthene and pyrene. The authors found that petroleum combustion-derived PAH fluxes generally followed the historical consumption data of New York State. Coal combustion-derived PAH flux peaked approximately in the late 1910s, remained at a relatively high level over the next 3 decades, then rapidly declined from the 1950s to the 1960s; according to historical New York State coal consumption data, however, there was a 2-peak trend, with peaks around the early 1920s and the mid-1940s. The 1940s peak was not observed in Central Park Lake, most likely because of the well-documented shift from coal to oil as the major residential heating fuel in New York City during the late 1930s. It was widely believed that the decreased PAH concentrations and fluxes in global sediments during the last century resulted from a major energy shift from coal to petroleum. The data, however, show that this shift occurred from 1945 through the 1960s and did not result in an obvious decline. The sharpest decrease, which occurred in the 1970s was not predominantly related to coal usage but rather was the result of multiple factors, including a decline in petroleum usage largely, the introduction of low sulfur-content fuel in New York City, and the introduction of emission-control technologies.

Research paper thumbnail of Combined application of δ 13C and molecular ratios in sediment cores for PAH source apportionment in the New York/New Jersey harbor complex

Org Geochem, 2006

Sub-basins within the New York/New Jersey (NY/NJ) Harbor host variable amounts and sources of pol... more Sub-basins within the New York/New Jersey (NY/NJ) Harbor host variable amounts and sources of polycyclic aromatic hydrocarbons (PAHs). Analyses of radionuclides 137Cs and 7Be were used to assign approximate dates to individual sections of sediment cores collected from four major sub-basins of the harbor complex. Sampling sites range from heavily contaminated Newark Bay and Passaic River to less contaminated Raritan Bay and Jamaica Bay. PAHs were identified with GC–MS and quantified by GC respectively. Gas chromatography–isotope ratio mass spectrometry (GC/IRMS) was applied to determine δ13C values of pyrene (δ13CPy), a principal 4 ring parent PAH. Two end-member PAH source components, petroleum-related PAHs (PRPAH) and combustion-related PAHs (CRPAH), were calculated from a carbon isotopic mass balance equation based on assumptions that petroleum-related δ13CPy is −29‰, and that combustion-derived δ13CPy is −24‰. Temporal trends of PRPAH in these cores are similar to those of the petroleum-derived unresolved complex mixture (UCM), whereas CRPAH resembled trends of “Total” PAH (TPAH). Three molecular ratios, fluoranthene to fluoranthene plus pyrene (Fl/(Fl + Py)), high molecular weight 4–6 ring PAH to total PAH (Ring456/TPAH) and parent to total (Par/(Par + Alkyl)), correlate strongly with each other, and show a moderate to strong positive correlation with δ13CPy. In contrast, the ratios of anthracene to phenanthrene plus anthracene (A/(Pa + A)), benzo[a]anthracene to benzo[a]anthracene plus chrysene (BaA/(BaA+Chy)), and indeno[1,2,3-cd]pyrene to indeno[1,2,3-cd]pyrene plus benzo[ghi]perylene (IP/(IP + Bghi)) show no, weak, or even negative correlation with the four well correlated ratios (δ13CPy, Par/(Par + Alkyl), Fl/(Fl + Py), and Ring456/TPAH). Combined application of the four well correlated molecular indicators suggests that PAH contribution from combustion became more important in most areas of the NY/NJ Harbor during the last three decades of the 20th century.

Research paper thumbnail of SI(NYC-BCPaper)

Research paper thumbnail of Membrane processes move toward broad use

Research paper thumbnail of UNION CARBIDE REPORTS first full-year's production of BUTADIENE for the Government's Synthetic Rubber Program

Research paper thumbnail of World Trade Center Environmental Contaminant Database: A Publicly Available Air Quality Dataset for the New York City Area

ACS Symposium Series, 2005

Page 1. Chapter 13 World Trade Center Environmental Contaminant Database: A Publicly Available Ai... more Page 1. Chapter 13 World Trade Center Environmental Contaminant Database: A Publicly Available Air Quality Dataset for the New York City Area Steven N. Chillrud1, Alison S. Geyh2, Diane K. Levy3, Elsie M. Chettiar3, and Damon A. Chaky1 ...

Research paper thumbnail of Combined application of δ13C and molecular ratios in sediment cores for PAH source apportionment in the New York/New Jersey harbor complex

Organic Geochemistry, 2006

Sub-basins within the New York/New Jersey (NY/NJ) Harbor host variable amounts and sources of pol... more Sub-basins within the New York/New Jersey (NY/NJ) Harbor host variable amounts and sources of polycyclic aromatic hydrocarbons (PAHs). Analyses of radionuclides 137 Cs and 7 Be were used to assign approximate dates to individual sections of sediment cores collected from four major sub-basins of the harbor complex. Sampling sites range from heavily contaminated Newark Bay and Passaic River to less contaminated Raritan Bay and Jamaica Bay. PAHs were identified with GC-MS and quantified by GC respectively. Gas chromatography-isotope ratio mass spectrometry (GC/IRMS) was applied to determine d 13 C values of pyrene (d 13 C Py ), a principal 4 ring parent PAH. Two end-member PAH source components, petroleum-related PAHs (PRPAH) and combustion-related PAHs (CRPAH), were calculated from a carbon isotopic mass balance equation based on assumptions that petroleum-related d 13 C Py is À29&, and that combustion-derived d 13 C Py is À24&. Temporal trends of PRPAH in these cores are similar to those of the petroleum-derived unresolved complex mixture (UCM), whereas CRPAH resembled trends of ''Total'' PAH (TPAH). Three molecular ratios, fluoranthene to fluoranthene plus pyrene (Fl/(Fl + Py)), high molecular weight 4-6 ring PAH to total PAH (Ring456/TPAH) and parent to total (Par/(Par + Alkyl)), correlate strongly with each other, and show a moderate to strong positive correlation with d 13 C Py . In contrast, the ratios of anthracene to phenanthrene plus anthracene (A/(Pa + A)), benzo[a]anthracene to benzo[a]anthracene plus chrysene (BaA/(BaA+Chy)), and indeno[1,2,3-cd]pyrene to indeno[1,2,3-cd]pyrene plus benzo[ghi]perylene (IP/(IP + Bghi)) show no, weak, or even negative correlation with the four well correlated ratios (d 13 C Py, Par/(Par + Alkyl), Fl/(Fl + Py), and Ring456/TPAH). Combined application of the four well correlated molecular indicators suggests that PAH contribution from combustion became more important in most areas of the NY/NJ Harbor during the last three decades of the 20th century.

Research paper thumbnail of Major Ion Geochemistry and Drinking Water Supply Issues in the Hudson River Basin

The Hudson River Estuary, 2006

... Data from each of these five monitoring stations were compiled and pruned here to eliminatesa... more ... Data from each of these five monitoring stations were compiled and pruned here to eliminatesam-ples for which relatively complete major element ... The ratio of mean Q/P based on another compilation of water budget parameters (Table 7.5; Darmer, 1987) is 56 percent, due to ...

Research paper thumbnail of Radiogenic Lead Isotopes and Time Stratigraphy in the Hudson River, New York

Water, Air, & Soil Pollution: Focus, 2000

Radionuclide, radiogenic lead isotope and trace metal analyses on fine-grained sediment cores col... more Radionuclide, radiogenic lead isotope and trace metal analyses on fine-grained sediment cores collected along 160 km of the upper and tidal Hudson River were used to examine temporal trends of contaminant loadings and to develop radiogenic lead isotopes both as a stratigraphic tool and as tracers for resolving decadal particle transport fluxes. Very large inputs of Cd, Sb, Pb, and Cr are evident in the sediment record, potentially from a single manufacturing facility. The total range in radiogenic lead isotope ratios observed in well-dated cores collected about 24 km downstream of the plant is large (e.g., maximum difference in 206 Pb/ 207 Pb is 10%), characterized by four major shifts occurring in the 1950s, 1960s, 1970s and 1980s. The upper Hudson signals in Cd and radiogenic lead isotopes were still evident in sediments collected 160 km downstream in the tidal Hudson. The large magnitude and abrupt shifts in radiogenic lead isotope ratios as a function of depth provide sensitive temporal constraints that complement information derived from radionuclide analyses to significantly improve the precision of dating assignments. Application of a simple dilution model to data from paired cores suggests much larger sediment inputs in one section of the river than previously reported, suggesting particle influxes to the Hudson have been underestimated.

Research paper thumbnail of An approach to interpreting contaminant deposition fluxes from dated sediment cores

Research paper thumbnail of Mineralogical Variations within the S-Type Asteroid Class

Research paper thumbnail of Elemental and Molecular Evidence of Soot- and Char-Derived Black Carbon Inputs to New York City's Atmosphere during the 20th Century

Environmental Science & Technology, 2007

Research paper thumbnail of Twentieth Century Atmospheric Metal Fluxes into Central Park Lake, New York City

Environmental Science & Technology, 1999

Research paper thumbnail of Molecular Tracers of Saturated and Polycyclic Aromatic Hydrocarbon Inputs into Central Park Lake, New York City

Environmental Science & Technology, 2005

Saturated hydrocarbons (SH) and polycyclic aromatic hydrocarbons (PAHs) have been quantified in a... more Saturated hydrocarbons (SH) and polycyclic aromatic hydrocarbons (PAHs) have been quantified in a sediment core obtained from Central Park Lake, New York City. Radionuclides 210 Pb and 137 Cs were used to assign approximate dates to each individual section in the core. The dating profile based on 210 Pb matches very well with the time constraints provided by 137 Cs. Radionuclide-derived depositional dates are consistent with temporal information from the petroleum-indicator ratio U/R [the ratio of unresolved complex mixture (UCM) to saturated hydrocarbons in the aliphatic fraction] and the history of fuel use in the NYC area. Ratios of 1,7dimethylphenanthrane (DMP) to 1,7-DMP plus 2,6-DMP [1,7/(1,7 + 2,6)-DMP], retene to retene plus chrysene [Ret/(Ret + Chy)], and fluoranthene to fluoranthene plus pyrene [Fl/(Fl + Py)] provide additional source discrimination throughout the core. Results show that the ratio U/R is sensitive to petroleum inputs and Ret/(Ret + Chy) is responsive to contributions from softwood combustion, whereas both Fl/(Fl + Py) and 1,7/(1,7 + 2,6)-DMP can be used to discriminate among wood, coal, and petroleum combustion sources. Combined use of these ratios suggests that in New York City, wood combustion dominated 100 years ago, with a shift to coal combustion occurring from the 1900s to the 1950s. Petroleum use began around the 1920s and has dominated since the 1940s.

Research paper thumbnail of Stable lead isotopes, contaminant metals and radionuclides in upper Hudson River sediment cores: implications for improved time stratigraphy and transport processes

Chemical Geology, 2003

Radionuclide, stable lead isotope and trace metal analyses on fine-grained sediment cores collect... more Radionuclide, stable lead isotope and trace metal analyses on fine-grained sediment cores collected along a 24-mile reach of the upper Hudson River were used to establish temporal trends of contaminant loadings, to establish stable lead isotopes as an additional stratigraphic tool, and as tracers for resolving particle transport fluxes over periods of decades. Very large contaminant inputs of Cd, Sb, Pb and Cr were evident in the sediment record. One potential large source for these metals was from a pigment manufacturing facility in Glens Falls, NY. The total range in stable lead isotope ratios observed in well-dated cores from about 15 miles downstream of the potential metal inputs was large (e.g., maximum difference in 206 Pb/ 207 Pb is 10%) and characterized by four major shifts occurring in the 1950s, 1960s, 1970s and 1980s. The temporal trend in 206 Pb/ 207 Pb has been used to establish precise dating of a sediment core from 24 miles further downstream. The large magnitude and abrupt shifts in stable lead isotope ratios preserved in upper Hudson sediment cores provide a way to significantly improve dating models, based only on radionuclide analyses. Cadmium, lead and antimony were identified as quite sensitive tracers of upper Hudson sediments due to the magnitude of contamination and the lack of significant additional downstream sources of these contaminant metals. Metal measurements in a pair of sediment cores located 24 miles apart were used to constrain relative fluxes of sediment entering the river between the two coring locations, with sediment sections deposited between the early 1960s and the late 1970s in these two cores suggesting that 3 -4 times more sediment entered the river between the two coring sites than was transported from upstream. These dilution factors agree very well with estimates based on suspended sediment measurements during a flood event in April 1994 and with estimates based on mechanistic model of suspended sediment transport between 1977 and 1992. D

Research paper thumbnail of Source apportionment of polycyclic aromatic hydrocarbons (PAHs) into Central Park Lake, New York city, over a century of deposition

Environmental Toxicology and Chemistry, 2014

Relative contributions of polycyclic aromatic hydrocarbons (PAHs) from combustion sources of wood... more Relative contributions of polycyclic aromatic hydrocarbons (PAHs) from combustion sources of wood, petroleum, and coal were computed in sediments from Central Park Lake in New York City (NY, USA) by chemical mass balance based on several reliable source indicators. These indicators are the ratio of retene to the sum of retene and chrysene, the ratio of 1,7-dimethylphenanthrene (DMP) to 1,7-DMP and 2,6-DMP, and the ratio of fluroanthene to fluroanthene and pyrene. The authors found that petroleum combustion-derived PAH fluxes generally followed the historical consumption data of New York State. Coal combustion-derived PAH flux peaked approximately in the late 1910s, remained at a relatively high level over the next 3 decades, then rapidly declined from the 1950s to the 1960s; according to historical New York State coal consumption data, however, there was a 2-peak trend, with peaks around the early 1920s and the mid-1940s. The 1940s peak was not observed in Central Park Lake, most likely because of the well-documented shift from coal to oil as the major residential heating fuel in New York City during the late 1930s. It was widely believed that the decreased PAH concentrations and fluxes in global sediments during the last century resulted from a major energy shift from coal to petroleum. The data, however, show that this shift occurred from 1945 through the 1960s and did not result in an obvious decline. The sharpest decrease, which occurred in the 1970s was not predominantly related to coal usage but rather was the result of multiple factors, including a decline in petroleum usage largely, the introduction of low sulfur-content fuel in New York City, and the introduction of emission-control technologies.