The Experts below are selected from a list of 3489 Experts worldwide ranked by ideXlab platform
Francine Laden - One of the best experts on this subject based on the ideXlab platform.
-
historical estimation of Diesel exhaust exposure in a cohort study of u s railroad workers and lung cancer
Cancer Causes & Control, 2006Co-Authors: Thomas J Smith, Francine Laden, Jaime E Hart, Alan Eschenroeder, Eric GarshickAbstract:We have previously shown an elevated risk of lung cancer mortality in Diesel exhaust exposed railroad workers. To reduce exposure misclassification, we obtained extensive historical information on Diesel Locomotives used by each railroad. Starting in 1945, we calculated the rate each railroad converted from steam to Diesel, creating annual railroad-specific weighting factors for the probability of Diesel exposure. We also estimated the average annual exposure intensity based on emission factors. The U.S. Railroad Retirement Board provided railroad assignment and work histories for 52,812 workers hired between 1939–1949, for whom we ascertained mortality from 1959–1996. Among workers hired after 1945, as Diesel Locomotives were introduced, the relative risk of lung cancer for any exposure was 1.77 (95% CI = 1.50–2.09), and there was evidence of an exposure–response relationship with exposure duration. Exposed workers hired before 1945 had a relative risk of 1.30 (95% CI = 1.19–1.43) for any exposure and there was no evidence of a dose response with duration. There was no evidence of increasing risk using estimated measures of intensity although the overall lung cancer risk remained elevated. In conclusion, although precise historical estimates of exposure are not available, weighting factors helped better define the exposure–response relationship of Diesel exhaust with lung cancer mortality.
-
lung cancer in railroad workers exposed to Diesel exhaust
Environmental Health Perspectives, 2004Co-Authors: Eric Garshick, Thomas J Smith, Francine Laden, Jaime E Hart, Bernard Rosner, Douglas W Dockery, Frank E SpeizerAbstract:Diesel exhaust has been suspected to be a lung carcinogen. The assessment of this lung cancer risk has been limited by lack of studies of exposed workers followed for many years. In this study, we assessed lung cancer mortality in 54,973 U.S. railroad workers between 1959 and 1996 (38 years). By 1959, the U.S. railroad industry had largely converted from coal-fired to Diesel-powered Locomotives. We obtained work histories from the U.S. Railroad Retirement Board, and ascertained mortality using Railroad Retirement Board, Social Security, and Health Care Financing Administration records. Cause of death was obtained from the National Death Index and death certificates. There were 43,593 total deaths including 4,351 lung cancer deaths. Adjusting for a healthy worker survivor effect and age, railroad workers in jobs associated with operating trains had a relative risk of lung cancer mortality of 1.40 (95% confidence interval, 1.30–1.51). Lung cancer mortality did not increase with increasing years of work in these jobs. Lung cancer mortality was elevated in jobs associated with work on trains powered by Diesel Locomotives. Although a contribution from exposure to coal combustion products before 1959 cannot be excluded, these results suggest that exposure to Diesel exhaust contributed to lung cancer mortality in this cohort.
Jaime E Hart - One of the best experts on this subject based on the ideXlab platform.
-
historical estimation of Diesel exhaust exposure in a cohort study of u s railroad workers and lung cancer
Cancer Causes & Control, 2006Co-Authors: Thomas J Smith, Francine Laden, Jaime E Hart, Alan Eschenroeder, Eric GarshickAbstract:We have previously shown an elevated risk of lung cancer mortality in Diesel exhaust exposed railroad workers. To reduce exposure misclassification, we obtained extensive historical information on Diesel Locomotives used by each railroad. Starting in 1945, we calculated the rate each railroad converted from steam to Diesel, creating annual railroad-specific weighting factors for the probability of Diesel exposure. We also estimated the average annual exposure intensity based on emission factors. The U.S. Railroad Retirement Board provided railroad assignment and work histories for 52,812 workers hired between 1939–1949, for whom we ascertained mortality from 1959–1996. Among workers hired after 1945, as Diesel Locomotives were introduced, the relative risk of lung cancer for any exposure was 1.77 (95% CI = 1.50–2.09), and there was evidence of an exposure–response relationship with exposure duration. Exposed workers hired before 1945 had a relative risk of 1.30 (95% CI = 1.19–1.43) for any exposure and there was no evidence of a dose response with duration. There was no evidence of increasing risk using estimated measures of intensity although the overall lung cancer risk remained elevated. In conclusion, although precise historical estimates of exposure are not available, weighting factors helped better define the exposure–response relationship of Diesel exhaust with lung cancer mortality.
-
lung cancer in railroad workers exposed to Diesel exhaust
Environmental Health Perspectives, 2004Co-Authors: Eric Garshick, Thomas J Smith, Francine Laden, Jaime E Hart, Bernard Rosner, Douglas W Dockery, Frank E SpeizerAbstract:Diesel exhaust has been suspected to be a lung carcinogen. The assessment of this lung cancer risk has been limited by lack of studies of exposed workers followed for many years. In this study, we assessed lung cancer mortality in 54,973 U.S. railroad workers between 1959 and 1996 (38 years). By 1959, the U.S. railroad industry had largely converted from coal-fired to Diesel-powered Locomotives. We obtained work histories from the U.S. Railroad Retirement Board, and ascertained mortality using Railroad Retirement Board, Social Security, and Health Care Financing Administration records. Cause of death was obtained from the National Death Index and death certificates. There were 43,593 total deaths including 4,351 lung cancer deaths. Adjusting for a healthy worker survivor effect and age, railroad workers in jobs associated with operating trains had a relative risk of lung cancer mortality of 1.40 (95% confidence interval, 1.30–1.51). Lung cancer mortality did not increase with increasing years of work in these jobs. Lung cancer mortality was elevated in jobs associated with work on trains powered by Diesel Locomotives. Although a contribution from exposure to coal combustion products before 1959 cannot be excluded, these results suggest that exposure to Diesel exhaust contributed to lung cancer mortality in this cohort.
Eric Garshick - One of the best experts on this subject based on the ideXlab platform.
-
historical estimation of Diesel exhaust exposure in a cohort study of u s railroad workers and lung cancer
Cancer Causes & Control, 2006Co-Authors: Thomas J Smith, Francine Laden, Jaime E Hart, Alan Eschenroeder, Eric GarshickAbstract:We have previously shown an elevated risk of lung cancer mortality in Diesel exhaust exposed railroad workers. To reduce exposure misclassification, we obtained extensive historical information on Diesel Locomotives used by each railroad. Starting in 1945, we calculated the rate each railroad converted from steam to Diesel, creating annual railroad-specific weighting factors for the probability of Diesel exposure. We also estimated the average annual exposure intensity based on emission factors. The U.S. Railroad Retirement Board provided railroad assignment and work histories for 52,812 workers hired between 1939–1949, for whom we ascertained mortality from 1959–1996. Among workers hired after 1945, as Diesel Locomotives were introduced, the relative risk of lung cancer for any exposure was 1.77 (95% CI = 1.50–2.09), and there was evidence of an exposure–response relationship with exposure duration. Exposed workers hired before 1945 had a relative risk of 1.30 (95% CI = 1.19–1.43) for any exposure and there was no evidence of a dose response with duration. There was no evidence of increasing risk using estimated measures of intensity although the overall lung cancer risk remained elevated. In conclusion, although precise historical estimates of exposure are not available, weighting factors helped better define the exposure–response relationship of Diesel exhaust with lung cancer mortality.
-
lung cancer in railroad workers exposed to Diesel exhaust
Environmental Health Perspectives, 2004Co-Authors: Eric Garshick, Thomas J Smith, Francine Laden, Jaime E Hart, Bernard Rosner, Douglas W Dockery, Frank E SpeizerAbstract:Diesel exhaust has been suspected to be a lung carcinogen. The assessment of this lung cancer risk has been limited by lack of studies of exposed workers followed for many years. In this study, we assessed lung cancer mortality in 54,973 U.S. railroad workers between 1959 and 1996 (38 years). By 1959, the U.S. railroad industry had largely converted from coal-fired to Diesel-powered Locomotives. We obtained work histories from the U.S. Railroad Retirement Board, and ascertained mortality using Railroad Retirement Board, Social Security, and Health Care Financing Administration records. Cause of death was obtained from the National Death Index and death certificates. There were 43,593 total deaths including 4,351 lung cancer deaths. Adjusting for a healthy worker survivor effect and age, railroad workers in jobs associated with operating trains had a relative risk of lung cancer mortality of 1.40 (95% confidence interval, 1.30–1.51). Lung cancer mortality did not increase with increasing years of work in these jobs. Lung cancer mortality was elevated in jobs associated with work on trains powered by Diesel Locomotives. Although a contribution from exposure to coal combustion products before 1959 cannot be excluded, these results suggest that exposure to Diesel exhaust contributed to lung cancer mortality in this cohort.
Atul Dhar - One of the best experts on this subject based on the ideXlab platform.
-
Exhaust Heat Recovery Options for Diesel Locomotives
Locomotives and Rail Road Transportation, 2017Co-Authors: Gaurav Tripathi, Atul DharAbstract:Even by conservative estimates more than 20% fuel energy from internal combustion engines is wasted as exhaust heat. Currently organic Rankine cycles and thermoelectric generators are most widely investigated options for automobile exhaust heat recovery. Use of thermoelectric generators for recovery of exhaust heat in automobiles at concept level started few decades ago. Major advantages of this technology over Rankine cycles are little noise and vibration, high durability, environmental friendliness, and low maintenance cost for converting low quality thermal energy directly into high quality electrical energy. Major challenges are lower efficiency (~8%), drop in efficiency at lower temperatures, performance optimization in synchronization with multiple constraints of after-treatment devices, silencer, back pressure reduction, turbo-charging etc. Larger size of Diesel Locomotives compared with space available for automobile engine’s mounting on vehicles makes the installation of exhaust heat recovery system in Diesel Locomotives more practical. In this paper, feasibility and suitability of various exhaust heat energy recovery methods for Diesel Locomotives has been discussed.
Thomas J Smith - One of the best experts on this subject based on the ideXlab platform.
-
historical estimation of Diesel exhaust exposure in a cohort study of u s railroad workers and lung cancer
Cancer Causes & Control, 2006Co-Authors: Thomas J Smith, Francine Laden, Jaime E Hart, Alan Eschenroeder, Eric GarshickAbstract:We have previously shown an elevated risk of lung cancer mortality in Diesel exhaust exposed railroad workers. To reduce exposure misclassification, we obtained extensive historical information on Diesel Locomotives used by each railroad. Starting in 1945, we calculated the rate each railroad converted from steam to Diesel, creating annual railroad-specific weighting factors for the probability of Diesel exposure. We also estimated the average annual exposure intensity based on emission factors. The U.S. Railroad Retirement Board provided railroad assignment and work histories for 52,812 workers hired between 1939–1949, for whom we ascertained mortality from 1959–1996. Among workers hired after 1945, as Diesel Locomotives were introduced, the relative risk of lung cancer for any exposure was 1.77 (95% CI = 1.50–2.09), and there was evidence of an exposure–response relationship with exposure duration. Exposed workers hired before 1945 had a relative risk of 1.30 (95% CI = 1.19–1.43) for any exposure and there was no evidence of a dose response with duration. There was no evidence of increasing risk using estimated measures of intensity although the overall lung cancer risk remained elevated. In conclusion, although precise historical estimates of exposure are not available, weighting factors helped better define the exposure–response relationship of Diesel exhaust with lung cancer mortality.
-
lung cancer in railroad workers exposed to Diesel exhaust
Environmental Health Perspectives, 2004Co-Authors: Eric Garshick, Thomas J Smith, Francine Laden, Jaime E Hart, Bernard Rosner, Douglas W Dockery, Frank E SpeizerAbstract:Diesel exhaust has been suspected to be a lung carcinogen. The assessment of this lung cancer risk has been limited by lack of studies of exposed workers followed for many years. In this study, we assessed lung cancer mortality in 54,973 U.S. railroad workers between 1959 and 1996 (38 years). By 1959, the U.S. railroad industry had largely converted from coal-fired to Diesel-powered Locomotives. We obtained work histories from the U.S. Railroad Retirement Board, and ascertained mortality using Railroad Retirement Board, Social Security, and Health Care Financing Administration records. Cause of death was obtained from the National Death Index and death certificates. There were 43,593 total deaths including 4,351 lung cancer deaths. Adjusting for a healthy worker survivor effect and age, railroad workers in jobs associated with operating trains had a relative risk of lung cancer mortality of 1.40 (95% confidence interval, 1.30–1.51). Lung cancer mortality did not increase with increasing years of work in these jobs. Lung cancer mortality was elevated in jobs associated with work on trains powered by Diesel Locomotives. Although a contribution from exposure to coal combustion products before 1959 cannot be excluded, these results suggest that exposure to Diesel exhaust contributed to lung cancer mortality in this cohort.
-
Urinary mutagenic activity in workers exposed to Diesel exhaust.
Environmental Research, 1992Co-Authors: Marc B Schenker, Steven J. Samuels, Susan R Woskie, S. K. Hammond, Norman Y. Kado, Thomas J SmithAbstract:We measured postshift urinary mutagenicity (mutu; n = 306 samples) on a population of railroad workers (n = 87) with a range of Diesel exhaust exposures. Postshift urinary mutagenicity was determined by a sensitive microsuspension procedure using Salmonella strain TA 98 ± S9. Number of cigarettes smoked on the study day and urinary cotinine were highly correlated with postshift urinary mutagenicity. Diesel exhaust exposure was measured over the work shift by constant-flow personal sampling pumps. Respirable particle concentrations were adjusted for the contribution of environmental tobacco smoke, as estimated from nicotine concentration on treated filters. The relative ranking of jobs by this adjusted respirable particle concentration (ARP) was correlated with relative contact the job groups have with operating Diesel Locomotives. After adjustment for cigarette smoking (active and passive) in multiple regressions, there was no independent association of Diesel exhaust exposure, as estimated by ARP, with postshift urinary mutagenicity among smokers or nonsmokers. An important finding is the detection of “baseline” mutagenicity in most of the nonsmoking workers. Despite the use of individual measurements of Diesel exhaust exposure, the absence of a significant association in this study may be due to the low levels of Diesel exposure, the lack of a specific marker for Diesel exhaust exposure, and/or urinary mutagenicity levels from Diesel exposure below the limit of sensitivity for the mutagenicity assay.