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Elizabeth Delzell - One of the best experts on this subject based on the ideXlab platform.

  • mortality among men and women in the north american Synthetic Rubber industry 1943 to 2009
    Journal of Occupational and Environmental Medicine, 2019
    Co-Authors: Nalini Sathiakumar, Ilene Brill, Meghan Tipre, Mark Leader, Elizabeth Delzell
    Abstract:

    OBJECTIVE To evaluate 1943 to 2009 mortality among 22,785 Synthetic Rubber industry employees. METHODS Standardized mortality ratio (SMR) and internal Cox regression analyses. RESULTS Among hourly employees with more than or equal to 10 years worked and more than or equal to 20 years since hire, SMRs were elevated for leukemia (SMR = 139, 95% confidence interval [CI] = 106 to 179), non-Hodgkin lymphoma (NHL) (SMR = 136, CI = 102 to 177), bladder cancer (SMR = 148, CI = 110 to 195) and, for women only, lung cancer (SMR = 225, CI = 103 to 427). Butadiene and styrene exposure-response trends were positive for leukemia and bladder cancer but not for NHL or for lung cancer among women. CONCLUSIONS Results support a causal relationship between butadiene and leukemia. Interpretation of results for lung cancer among women and for bladder cancer is uncertain because of inability to control for smoking and inadequate or inconsistent support from other studies for an association between butadiene or styrene and the latter cancers.

  • 1 3 butadiene styrene and lymphohematopoietic cancer among male Synthetic Rubber industry workers preliminary exposure response analyses
    Chemico-Biological Interactions, 2015
    Co-Authors: Nalini Sathiakumar, Ilene Brill, Mark Leader, Elizabeth Delzell
    Abstract:

    We updated the mortality experience of North American Synthetic Rubber industry workers to include follow-up from 1944 through 2009, adding 11 years of mortality data to previous investigations. The present analysis used Cox regression to examine the exposure-response relationship between 1,3-butadiene (BD) and styrene (STY) parts per million (ppm)-years and leukemia (N = 114 deaths), non-Hodgkin lymphoma (NHL) (N = 89) and multiple myeloma (MM) (N = 48). A pattern of largely monotonically increasing rate ratios across deciles of BD ppm-years and a positive, statistically significant exposure-response trend were observed for BD ppm-years and leukemia. Using continuous, untransformed BD ppm-years the regression coefficient (β) adjusted only for age was 2.6 × 10(-4) (p < 0.01); the regression coefficient adjusted for age, year of birth, race and plant was 2.9 × 10(-4) (p < 0.01). STY ppm-years also displayed a positive exposure-response association with leukemia. STY and BD were strongly correlated, and the separate effects of these two agents could not be estimated. For NHL, a pattern of approximately monotonically increasing rate ratios across deciles of exposure was seen for STY but not for BD; the test of trend was statistically significant in one of five models that used different STY exposure metrics and adjusted for age and other covariates. BD ppm-years and STY ppm-years were not associated with MM. The present analyses indicated a positive exposure-response relationship between BD cumulative exposure and leukemia. This result along with other research and biological information support an interpretation that BD causes leukemia in humans. STY exposure also was positively associated with leukemia, but its independent effect could not be delineated because of its strong correlation with BD, and there is no external support for a STY-leukemia association. STY, but not BD, was associated positively with NHL. The interpretation of this result is uncertain because the exposure-response data were statistically imprecise and because consistent support for causality from other studies is lacking. The current study provides no support for an association between BD or STY and MM.

  • 1 3 butadiene styrene and lung cancer among Synthetic Rubber industry workers
    Journal of Occupational and Environmental Medicine, 2009
    Co-Authors: Nalini Sathiakumar, Ilene Brill, Elizabeth Delzell
    Abstract:

    Objective:To evaluate the association between cumulative exposure to 1,3-butadiene (BD) or styrene (STY) and lung cancer among Synthetic Rubber industry workers.Methods:Internal Cox regression analyses were performed both with and without natural logarithm transformation of exposure variables and bo

  • a follow up study of mortality among women in the north american Synthetic Rubber industry
    Journal of Occupational and Environmental Medicine, 2009
    Co-Authors: Nalini Sathiakumar, Elizabeth Delzell
    Abstract:

    Objective To evaluate mortality from cancer and other diseases among 4863 women employed at eight North American styrene-butadiene Rubber plants. Cancers of the lymphohematopoietic tissues, breast, and ovary were of strongest a priori interest. Methods Cause-specific standardized mortality ratios (SMRs) and 95% confidence intervals (CIs) were estimated. Results The observed number of deaths was approximately equal to that expected for leukemia (10 observed/13 expected), Hodgkin lymphoma (1/1.6), multiple myeloma (7/7.9), non-Hodgkin lymphoma (15/14), and cancers of the breast (72/74) and ovary (21/22). Ever-hourly women had more than expected deaths from lung (47/30, SMR = 159, CI = 117 to 211) and bladder (6/1.8, SMR = 332, CI = 122 to 723) cancers. Exposure-response analysis, done only for lung cancer, indicated no trend for butadiene or styrene. Conclusions The observed excesses of lung and bladder cancers may be attributable to nonoccupational factors rather than to workplace exposures.

  • 1 3 butadiene and leukemia among Synthetic Rubber industry workers exposure response relationships
    Chemico-Biological Interactions, 2007
    Co-Authors: Hong Cheng, Nalini Sathiakumar, John J Graff, Robert Matthews, Elizabeth Delzell
    Abstract:

    Abstract Previous research updated the mortality experience of North American Synthetic Rubber industry workers during the period 1944–1998, determined if leukemia and other cancers were associated with several employment factors and carried out Poisson regression analysis to examine exposure–response associations between estimated exposure to 1,3-butadiene (BD) or other chemicals and cancer. The present study used Cox regression procedures to examine further the exposure–response relationship between several unlagged and lagged, continuous, time-dependent BD exposure indices (BD parts per million (ppm)-years, the total number of exposures to BD concentrations >100 ppm (“peaks”) and average intensity of BD) and leukemia, lymphoid neoplasms and myeloid neoplasms. All three BD exposure indices were associated positively with leukemia. Using continuous, untransformed BD ppm-years the regression coefficient (β) from an analysis that controlled only for age was 2.9 × 10−4 (p

Nalini Sathiakumar - One of the best experts on this subject based on the ideXlab platform.

  • mortality among men and women in the north american Synthetic Rubber industry 1943 to 2009
    Journal of Occupational and Environmental Medicine, 2019
    Co-Authors: Nalini Sathiakumar, Ilene Brill, Meghan Tipre, Mark Leader, Elizabeth Delzell
    Abstract:

    OBJECTIVE To evaluate 1943 to 2009 mortality among 22,785 Synthetic Rubber industry employees. METHODS Standardized mortality ratio (SMR) and internal Cox regression analyses. RESULTS Among hourly employees with more than or equal to 10 years worked and more than or equal to 20 years since hire, SMRs were elevated for leukemia (SMR = 139, 95% confidence interval [CI] = 106 to 179), non-Hodgkin lymphoma (NHL) (SMR = 136, CI = 102 to 177), bladder cancer (SMR = 148, CI = 110 to 195) and, for women only, lung cancer (SMR = 225, CI = 103 to 427). Butadiene and styrene exposure-response trends were positive for leukemia and bladder cancer but not for NHL or for lung cancer among women. CONCLUSIONS Results support a causal relationship between butadiene and leukemia. Interpretation of results for lung cancer among women and for bladder cancer is uncertain because of inability to control for smoking and inadequate or inconsistent support from other studies for an association between butadiene or styrene and the latter cancers.

  • 1 3 butadiene styrene and lymphohematopoietic cancer among male Synthetic Rubber industry workers preliminary exposure response analyses
    Chemico-Biological Interactions, 2015
    Co-Authors: Nalini Sathiakumar, Ilene Brill, Mark Leader, Elizabeth Delzell
    Abstract:

    We updated the mortality experience of North American Synthetic Rubber industry workers to include follow-up from 1944 through 2009, adding 11 years of mortality data to previous investigations. The present analysis used Cox regression to examine the exposure-response relationship between 1,3-butadiene (BD) and styrene (STY) parts per million (ppm)-years and leukemia (N = 114 deaths), non-Hodgkin lymphoma (NHL) (N = 89) and multiple myeloma (MM) (N = 48). A pattern of largely monotonically increasing rate ratios across deciles of BD ppm-years and a positive, statistically significant exposure-response trend were observed for BD ppm-years and leukemia. Using continuous, untransformed BD ppm-years the regression coefficient (β) adjusted only for age was 2.6 × 10(-4) (p < 0.01); the regression coefficient adjusted for age, year of birth, race and plant was 2.9 × 10(-4) (p < 0.01). STY ppm-years also displayed a positive exposure-response association with leukemia. STY and BD were strongly correlated, and the separate effects of these two agents could not be estimated. For NHL, a pattern of approximately monotonically increasing rate ratios across deciles of exposure was seen for STY but not for BD; the test of trend was statistically significant in one of five models that used different STY exposure metrics and adjusted for age and other covariates. BD ppm-years and STY ppm-years were not associated with MM. The present analyses indicated a positive exposure-response relationship between BD cumulative exposure and leukemia. This result along with other research and biological information support an interpretation that BD causes leukemia in humans. STY exposure also was positively associated with leukemia, but its independent effect could not be delineated because of its strong correlation with BD, and there is no external support for a STY-leukemia association. STY, but not BD, was associated positively with NHL. The interpretation of this result is uncertain because the exposure-response data were statistically imprecise and because consistent support for causality from other studies is lacking. The current study provides no support for an association between BD or STY and MM.

  • 1 3 butadiene styrene and lung cancer among Synthetic Rubber industry workers
    Journal of Occupational and Environmental Medicine, 2009
    Co-Authors: Nalini Sathiakumar, Ilene Brill, Elizabeth Delzell
    Abstract:

    Objective:To evaluate the association between cumulative exposure to 1,3-butadiene (BD) or styrene (STY) and lung cancer among Synthetic Rubber industry workers.Methods:Internal Cox regression analyses were performed both with and without natural logarithm transformation of exposure variables and bo

  • a follow up study of mortality among women in the north american Synthetic Rubber industry
    Journal of Occupational and Environmental Medicine, 2009
    Co-Authors: Nalini Sathiakumar, Elizabeth Delzell
    Abstract:

    Objective To evaluate mortality from cancer and other diseases among 4863 women employed at eight North American styrene-butadiene Rubber plants. Cancers of the lymphohematopoietic tissues, breast, and ovary were of strongest a priori interest. Methods Cause-specific standardized mortality ratios (SMRs) and 95% confidence intervals (CIs) were estimated. Results The observed number of deaths was approximately equal to that expected for leukemia (10 observed/13 expected), Hodgkin lymphoma (1/1.6), multiple myeloma (7/7.9), non-Hodgkin lymphoma (15/14), and cancers of the breast (72/74) and ovary (21/22). Ever-hourly women had more than expected deaths from lung (47/30, SMR = 159, CI = 117 to 211) and bladder (6/1.8, SMR = 332, CI = 122 to 723) cancers. Exposure-response analysis, done only for lung cancer, indicated no trend for butadiene or styrene. Conclusions The observed excesses of lung and bladder cancers may be attributable to nonoccupational factors rather than to workplace exposures.

  • 1 3 butadiene and leukemia among Synthetic Rubber industry workers exposure response relationships
    Chemico-Biological Interactions, 2007
    Co-Authors: Hong Cheng, Nalini Sathiakumar, John J Graff, Robert Matthews, Elizabeth Delzell
    Abstract:

    Abstract Previous research updated the mortality experience of North American Synthetic Rubber industry workers during the period 1944–1998, determined if leukemia and other cancers were associated with several employment factors and carried out Poisson regression analysis to examine exposure–response associations between estimated exposure to 1,3-butadiene (BD) or other chemicals and cancer. The present study used Cox regression procedures to examine further the exposure–response relationship between several unlagged and lagged, continuous, time-dependent BD exposure indices (BD parts per million (ppm)-years, the total number of exposures to BD concentrations >100 ppm (“peaks”) and average intensity of BD) and leukemia, lymphoid neoplasms and myeloid neoplasms. All three BD exposure indices were associated positively with leukemia. Using continuous, untransformed BD ppm-years the regression coefficient (β) from an analysis that controlled only for age was 2.9 × 10−4 (p

Robert Matthews - One of the best experts on this subject based on the ideXlab platform.

  • 1 3 butadiene and leukemia among Synthetic Rubber industry workers exposure response relationships
    Chemico-Biological Interactions, 2007
    Co-Authors: Hong Cheng, Nalini Sathiakumar, John J Graff, Robert Matthews, Elizabeth Delzell
    Abstract:

    Abstract Previous research updated the mortality experience of North American Synthetic Rubber industry workers during the period 1944–1998, determined if leukemia and other cancers were associated with several employment factors and carried out Poisson regression analysis to examine exposure–response associations between estimated exposure to 1,3-butadiene (BD) or other chemicals and cancer. The present study used Cox regression procedures to examine further the exposure–response relationship between several unlagged and lagged, continuous, time-dependent BD exposure indices (BD parts per million (ppm)-years, the total number of exposures to BD concentrations >100 ppm (“peaks”) and average intensity of BD) and leukemia, lymphoid neoplasms and myeloid neoplasms. All three BD exposure indices were associated positively with leukemia. Using continuous, untransformed BD ppm-years the regression coefficient (β) from an analysis that controlled only for age was 2.9 × 10−4 (p

  • an updated study of mortality among north american Synthetic Rubber industry workers
    Research report (Health Effects Institute), 2006
    Co-Authors: Elizabeth Delzell, Nalini Sathiakumar, Maurizio Macaluso, John J Graff, George Maldonado, Robert Matthews
    Abstract:

    This study evaluated mortality rates from leukemia and other diseases during the time period 1944 through 1998 among 17,924 men employed in the Synthetic Rubber industry. In this group, there were 6237 deaths, which is 14% fewer than the 7242 deaths expected based on general population rates. Numbers of observed versus expected deaths (shown hereafter as observed/expected) were 1608/1741 for all cancers combined, including 71/61 for leukemia, 53/53 for non-Hodgkin lymphoma (NHL*), and 26/27 for multiple myeloma. The higher than expected number of deaths from leukemia (16% increase) was concentrated in workers paid hourly who had started work 20 to 29 years earlier, had worked 10 or more years in the industry, and had worked in subgroups employed in polymerization, coagulation, maintenance labor, and laboratory operations. The overall higher leukemia mortality rate, as well as the higher rate in the subgroup of hourly workers who had 20 or more years since hire and 10 or more years worked, was not limited to a particular form of leukemia. Cumulative exposure to 1,3-butadiene (BD) was associated positively with all leukemias, with chronic myelogenous leukemia and, to a lesser extent, with chronic lymphocytic leukemia (CLL). Exposure to styrene or to dimethyldithiocarbamate (DMDTC) also was associated positively with leukemia. Exposures to these two agents were correlated with exposure to BD; data were limited on the independent effects of each of the three chemicals on leukemia. After controlling for the effects of BD, we found no consistent exposure-response relation between either styrene or DMDTC and all leukemias, chronic myelogenous leukemia, or CLL. However, a positive association between any exposure to DMDTC and leukemia persisted. The data from this study indicate that employment in the Synthetic Rubber industry is related causally to leukemia. Uncertainty remains about the specific agent or agents responsible for the association. The carcinogenic mechanisms through which BD, styrene, or DMDTC could cause leukemia in humans have not been established, and epidemiologic support for a leukemogenic role is limited for these agents. Styrene and DMDTC were associated positively with NHL. External support for this relation has not been reported from other epidemiologic studies. The study did not find any clear relation between exposure to BD, styrene, or DMDTC and multiple myeloma. Some subgroups of subjects had more than the expected number deaths from colorectal cancer, prostate cancer, and other diseases. These increases did not appear to be related to occupational exposure in the industry.

  • an updated study of mortality among north american Synthetic Rubber industry workers
    Occupational and Environmental Medicine, 2005
    Co-Authors: Nalini Sathiakumar, Maurizio Macaluso, John J Graff, George Maldonado, Robert Matthews, Elizabeth Delzell
    Abstract:

    Aim: This study evaluated the mortality experience of workers from the styrene-butadiene industry. Methods: The authors added seven years of follow up to a previous investigation of mortality among 17 924 men employed in the North American Synthetic Rubber industry. Analyses used the standardised mortality ratios (SMRs) to compare styrene-butadiene Rubber workers’ cause specific mortality (1943–98) with those of the United States and the Ontario general populations. Results: Overall, the observed/expected numbers of deaths were 6237/7242 for all causes (SMR = 86, 95% CI 84 to 88) and 1608/1741 for all cancers combined (SMR = 92, 95% CI 88 to 97), 71/61 for leukaemia, 53/53 for non-Hodgkin’s lymphoma, and 26/27 for multiple myeloma. The 16% leukaemia increase was concentrated in hourly paid subjects with 20–29 years since hire and 10 or more years of employment in the industry (19/7.4, SMR = 258, 95% CI 156 to 403) and in subjects employed in polymerisation (18/8.8, SMR = 204, 95% CI 121 to 322), maintenance labour (15/7.4, SMR = 326, 95% CI 178 to 456), and laboratory operations (14/4.3, SMR = 326, 95% CI 178–546). Conclusion: The study found that some subgroups of Synthetic Rubber workers had an excess of mortality from leukaemia that was not limited to a particular form of leukaemia. Uncertainty remains about the specific agent(s) that might be responsible for the observed excesses and about the role of unidentified confounding factors. The study did not find any clear relation between employment in the industry and other forms of lymphohaematopoietic cancer. Some subgroups of subjects had more than expected deaths from colorectal and prostate cancers. These increases did not appear to be related to occupational exposure in the industry.

  • chemical exposures in the Synthetic Rubber industry and lymphohematopoietic cancer mortality
    Journal of Occupational and Environmental Medicine, 2005
    Co-Authors: Nalini Sathiakumar, Maurizio Macaluso, John J Graff, George Maldonado, Robert Matthews, Elizabeth Delzell
    Abstract:

    Objective: This study evaluated the association between exposure to several chemicals and mortality from lymphohematopoietic cancer (LHC) among 16,579 Synthetic Rubber industry workers who were followed up from 1943 to 1998. Methods: Poisson regression analyses examined LHC rates in relation to butadiene, styrene, and DMDTC exposure. Models provided maximum likelihood estimates of the relative rate for the contrast between categories of one agent, adjusting for other agents and for additional potential confounders. Results: Cumulative exposure to 1,3-butadiene was associated positively with all leukemia (relative rates of 1.0, 1.4, 1.2, 2.9, and 3.7, respectively, for exposures of 0, >0 to <33.7, 33.7 to < 184.7, 184.7 to < 425.0, and 425.0+ ppm-years), chronic myelogenous leukemia and to a lesser extent with chronic lymphocjtic leukemia. Adjusting for styrene and DMDTC attenuated these associations. After controlling for butadiene, neither styrene nor DMDTC displayed a consistent exposure-response trend with all leukemia, chronic myelogenous leukemia, or chronic lymphocytic leukemia. Conclusions: This study found a positive association between butadiene and leukemia that was not explained by exposure to other agents examined.

  • leukemia and exposure to 1 3 butadiene styrene and dimethyldithiocarbamate among workers in the Synthetic Rubber industry
    Chemico-Biological Interactions, 2001
    Co-Authors: Elizabeth Delzell, Nalini Sathiakumar, Maurizio Macaluso, Robert Matthews
    Abstract:

    Abstract This study evaluated relations between exposure to 1,3-butadiene (BD), styrene (STY) and dimethyldithiocarbamate (DMDTC) and mortality from leukemia among Synthetic Rubber industry workers. Subjects were 13 130 men employed for at least 1 year during 1943–1991 at any of six plants that manufactured Synthetic Rubber. Death certificates and medical records identified workers with leukemia. Cumulative exposure estimates were based on plant- and time period-specific process and task characteristics, linked to subjects’ work histories. Poisson regression estimated relative rates (RRs) for workers exposed to each agent compared to unexposed workers. Leukemia (N=59) was positively associated with BD ppm-years (RRs of 1.0, 1.2, 2.0 and 3.8, for exposures of 0, >0– 0– 0– 100 ppm than for ppm-years due to lower concentrations. BD and DMDTC, but not STY, were positively associated with leukemia in multivariable analyses. The independent effect of each agent was difficult to evaluate because of correlations with other agents and imprecision.

John J Graff - One of the best experts on this subject based on the ideXlab platform.

  • 1 3 butadiene and leukemia among Synthetic Rubber industry workers exposure response relationships
    Chemico-Biological Interactions, 2007
    Co-Authors: Hong Cheng, Nalini Sathiakumar, John J Graff, Robert Matthews, Elizabeth Delzell
    Abstract:

    Abstract Previous research updated the mortality experience of North American Synthetic Rubber industry workers during the period 1944–1998, determined if leukemia and other cancers were associated with several employment factors and carried out Poisson regression analysis to examine exposure–response associations between estimated exposure to 1,3-butadiene (BD) or other chemicals and cancer. The present study used Cox regression procedures to examine further the exposure–response relationship between several unlagged and lagged, continuous, time-dependent BD exposure indices (BD parts per million (ppm)-years, the total number of exposures to BD concentrations >100 ppm (“peaks”) and average intensity of BD) and leukemia, lymphoid neoplasms and myeloid neoplasms. All three BD exposure indices were associated positively with leukemia. Using continuous, untransformed BD ppm-years the regression coefficient (β) from an analysis that controlled only for age was 2.9 × 10−4 (p

  • an updated study of mortality among north american Synthetic Rubber industry workers
    Research report (Health Effects Institute), 2006
    Co-Authors: Elizabeth Delzell, Nalini Sathiakumar, Maurizio Macaluso, John J Graff, George Maldonado, Robert Matthews
    Abstract:

    This study evaluated mortality rates from leukemia and other diseases during the time period 1944 through 1998 among 17,924 men employed in the Synthetic Rubber industry. In this group, there were 6237 deaths, which is 14% fewer than the 7242 deaths expected based on general population rates. Numbers of observed versus expected deaths (shown hereafter as observed/expected) were 1608/1741 for all cancers combined, including 71/61 for leukemia, 53/53 for non-Hodgkin lymphoma (NHL*), and 26/27 for multiple myeloma. The higher than expected number of deaths from leukemia (16% increase) was concentrated in workers paid hourly who had started work 20 to 29 years earlier, had worked 10 or more years in the industry, and had worked in subgroups employed in polymerization, coagulation, maintenance labor, and laboratory operations. The overall higher leukemia mortality rate, as well as the higher rate in the subgroup of hourly workers who had 20 or more years since hire and 10 or more years worked, was not limited to a particular form of leukemia. Cumulative exposure to 1,3-butadiene (BD) was associated positively with all leukemias, with chronic myelogenous leukemia and, to a lesser extent, with chronic lymphocytic leukemia (CLL). Exposure to styrene or to dimethyldithiocarbamate (DMDTC) also was associated positively with leukemia. Exposures to these two agents were correlated with exposure to BD; data were limited on the independent effects of each of the three chemicals on leukemia. After controlling for the effects of BD, we found no consistent exposure-response relation between either styrene or DMDTC and all leukemias, chronic myelogenous leukemia, or CLL. However, a positive association between any exposure to DMDTC and leukemia persisted. The data from this study indicate that employment in the Synthetic Rubber industry is related causally to leukemia. Uncertainty remains about the specific agent or agents responsible for the association. The carcinogenic mechanisms through which BD, styrene, or DMDTC could cause leukemia in humans have not been established, and epidemiologic support for a leukemogenic role is limited for these agents. Styrene and DMDTC were associated positively with NHL. External support for this relation has not been reported from other epidemiologic studies. The study did not find any clear relation between exposure to BD, styrene, or DMDTC and multiple myeloma. Some subgroups of subjects had more than the expected number deaths from colorectal cancer, prostate cancer, and other diseases. These increases did not appear to be related to occupational exposure in the industry.

  • an updated study of mortality among north american Synthetic Rubber industry workers
    Occupational and Environmental Medicine, 2005
    Co-Authors: Nalini Sathiakumar, Maurizio Macaluso, John J Graff, George Maldonado, Robert Matthews, Elizabeth Delzell
    Abstract:

    Aim: This study evaluated the mortality experience of workers from the styrene-butadiene industry. Methods: The authors added seven years of follow up to a previous investigation of mortality among 17 924 men employed in the North American Synthetic Rubber industry. Analyses used the standardised mortality ratios (SMRs) to compare styrene-butadiene Rubber workers’ cause specific mortality (1943–98) with those of the United States and the Ontario general populations. Results: Overall, the observed/expected numbers of deaths were 6237/7242 for all causes (SMR = 86, 95% CI 84 to 88) and 1608/1741 for all cancers combined (SMR = 92, 95% CI 88 to 97), 71/61 for leukaemia, 53/53 for non-Hodgkin’s lymphoma, and 26/27 for multiple myeloma. The 16% leukaemia increase was concentrated in hourly paid subjects with 20–29 years since hire and 10 or more years of employment in the industry (19/7.4, SMR = 258, 95% CI 156 to 403) and in subjects employed in polymerisation (18/8.8, SMR = 204, 95% CI 121 to 322), maintenance labour (15/7.4, SMR = 326, 95% CI 178 to 456), and laboratory operations (14/4.3, SMR = 326, 95% CI 178–546). Conclusion: The study found that some subgroups of Synthetic Rubber workers had an excess of mortality from leukaemia that was not limited to a particular form of leukaemia. Uncertainty remains about the specific agent(s) that might be responsible for the observed excesses and about the role of unidentified confounding factors. The study did not find any clear relation between employment in the industry and other forms of lymphohaematopoietic cancer. Some subgroups of subjects had more than expected deaths from colorectal and prostate cancers. These increases did not appear to be related to occupational exposure in the industry.

  • chemical exposures in the Synthetic Rubber industry and lymphohematopoietic cancer mortality
    Journal of Occupational and Environmental Medicine, 2005
    Co-Authors: Nalini Sathiakumar, Maurizio Macaluso, John J Graff, George Maldonado, Robert Matthews, Elizabeth Delzell
    Abstract:

    Objective: This study evaluated the association between exposure to several chemicals and mortality from lymphohematopoietic cancer (LHC) among 16,579 Synthetic Rubber industry workers who were followed up from 1943 to 1998. Methods: Poisson regression analyses examined LHC rates in relation to butadiene, styrene, and DMDTC exposure. Models provided maximum likelihood estimates of the relative rate for the contrast between categories of one agent, adjusting for other agents and for additional potential confounders. Results: Cumulative exposure to 1,3-butadiene was associated positively with all leukemia (relative rates of 1.0, 1.4, 1.2, 2.9, and 3.7, respectively, for exposures of 0, >0 to <33.7, 33.7 to < 184.7, 184.7 to < 425.0, and 425.0+ ppm-years), chronic myelogenous leukemia and to a lesser extent with chronic lymphocjtic leukemia. Adjusting for styrene and DMDTC attenuated these associations. After controlling for butadiene, neither styrene nor DMDTC displayed a consistent exposure-response trend with all leukemia, chronic myelogenous leukemia, or chronic lymphocytic leukemia. Conclusions: This study found a positive association between butadiene and leukemia that was not explained by exposure to other agents examined.

Maurizio Macaluso - One of the best experts on this subject based on the ideXlab platform.

  • an updated study of mortality among north american Synthetic Rubber industry workers
    Research report (Health Effects Institute), 2006
    Co-Authors: Elizabeth Delzell, Nalini Sathiakumar, Maurizio Macaluso, John J Graff, George Maldonado, Robert Matthews
    Abstract:

    This study evaluated mortality rates from leukemia and other diseases during the time period 1944 through 1998 among 17,924 men employed in the Synthetic Rubber industry. In this group, there were 6237 deaths, which is 14% fewer than the 7242 deaths expected based on general population rates. Numbers of observed versus expected deaths (shown hereafter as observed/expected) were 1608/1741 for all cancers combined, including 71/61 for leukemia, 53/53 for non-Hodgkin lymphoma (NHL*), and 26/27 for multiple myeloma. The higher than expected number of deaths from leukemia (16% increase) was concentrated in workers paid hourly who had started work 20 to 29 years earlier, had worked 10 or more years in the industry, and had worked in subgroups employed in polymerization, coagulation, maintenance labor, and laboratory operations. The overall higher leukemia mortality rate, as well as the higher rate in the subgroup of hourly workers who had 20 or more years since hire and 10 or more years worked, was not limited to a particular form of leukemia. Cumulative exposure to 1,3-butadiene (BD) was associated positively with all leukemias, with chronic myelogenous leukemia and, to a lesser extent, with chronic lymphocytic leukemia (CLL). Exposure to styrene or to dimethyldithiocarbamate (DMDTC) also was associated positively with leukemia. Exposures to these two agents were correlated with exposure to BD; data were limited on the independent effects of each of the three chemicals on leukemia. After controlling for the effects of BD, we found no consistent exposure-response relation between either styrene or DMDTC and all leukemias, chronic myelogenous leukemia, or CLL. However, a positive association between any exposure to DMDTC and leukemia persisted. The data from this study indicate that employment in the Synthetic Rubber industry is related causally to leukemia. Uncertainty remains about the specific agent or agents responsible for the association. The carcinogenic mechanisms through which BD, styrene, or DMDTC could cause leukemia in humans have not been established, and epidemiologic support for a leukemogenic role is limited for these agents. Styrene and DMDTC were associated positively with NHL. External support for this relation has not been reported from other epidemiologic studies. The study did not find any clear relation between exposure to BD, styrene, or DMDTC and multiple myeloma. Some subgroups of subjects had more than the expected number deaths from colorectal cancer, prostate cancer, and other diseases. These increases did not appear to be related to occupational exposure in the industry.

  • an updated study of mortality among north american Synthetic Rubber industry workers
    Occupational and Environmental Medicine, 2005
    Co-Authors: Nalini Sathiakumar, Maurizio Macaluso, John J Graff, George Maldonado, Robert Matthews, Elizabeth Delzell
    Abstract:

    Aim: This study evaluated the mortality experience of workers from the styrene-butadiene industry. Methods: The authors added seven years of follow up to a previous investigation of mortality among 17 924 men employed in the North American Synthetic Rubber industry. Analyses used the standardised mortality ratios (SMRs) to compare styrene-butadiene Rubber workers’ cause specific mortality (1943–98) with those of the United States and the Ontario general populations. Results: Overall, the observed/expected numbers of deaths were 6237/7242 for all causes (SMR = 86, 95% CI 84 to 88) and 1608/1741 for all cancers combined (SMR = 92, 95% CI 88 to 97), 71/61 for leukaemia, 53/53 for non-Hodgkin’s lymphoma, and 26/27 for multiple myeloma. The 16% leukaemia increase was concentrated in hourly paid subjects with 20–29 years since hire and 10 or more years of employment in the industry (19/7.4, SMR = 258, 95% CI 156 to 403) and in subjects employed in polymerisation (18/8.8, SMR = 204, 95% CI 121 to 322), maintenance labour (15/7.4, SMR = 326, 95% CI 178 to 456), and laboratory operations (14/4.3, SMR = 326, 95% CI 178–546). Conclusion: The study found that some subgroups of Synthetic Rubber workers had an excess of mortality from leukaemia that was not limited to a particular form of leukaemia. Uncertainty remains about the specific agent(s) that might be responsible for the observed excesses and about the role of unidentified confounding factors. The study did not find any clear relation between employment in the industry and other forms of lymphohaematopoietic cancer. Some subgroups of subjects had more than expected deaths from colorectal and prostate cancers. These increases did not appear to be related to occupational exposure in the industry.

  • chemical exposures in the Synthetic Rubber industry and lymphohematopoietic cancer mortality
    Journal of Occupational and Environmental Medicine, 2005
    Co-Authors: Nalini Sathiakumar, Maurizio Macaluso, John J Graff, George Maldonado, Robert Matthews, Elizabeth Delzell
    Abstract:

    Objective: This study evaluated the association between exposure to several chemicals and mortality from lymphohematopoietic cancer (LHC) among 16,579 Synthetic Rubber industry workers who were followed up from 1943 to 1998. Methods: Poisson regression analyses examined LHC rates in relation to butadiene, styrene, and DMDTC exposure. Models provided maximum likelihood estimates of the relative rate for the contrast between categories of one agent, adjusting for other agents and for additional potential confounders. Results: Cumulative exposure to 1,3-butadiene was associated positively with all leukemia (relative rates of 1.0, 1.4, 1.2, 2.9, and 3.7, respectively, for exposures of 0, >0 to <33.7, 33.7 to < 184.7, 184.7 to < 425.0, and 425.0+ ppm-years), chronic myelogenous leukemia and to a lesser extent with chronic lymphocjtic leukemia. Adjusting for styrene and DMDTC attenuated these associations. After controlling for butadiene, neither styrene nor DMDTC displayed a consistent exposure-response trend with all leukemia, chronic myelogenous leukemia, or chronic lymphocytic leukemia. Conclusions: This study found a positive association between butadiene and leukemia that was not explained by exposure to other agents examined.

  • leukemia and exposure to 1 3 butadiene styrene and dimethyldithiocarbamate among workers in the Synthetic Rubber industry
    Chemico-Biological Interactions, 2001
    Co-Authors: Elizabeth Delzell, Nalini Sathiakumar, Maurizio Macaluso, Robert Matthews
    Abstract:

    Abstract This study evaluated relations between exposure to 1,3-butadiene (BD), styrene (STY) and dimethyldithiocarbamate (DMDTC) and mortality from leukemia among Synthetic Rubber industry workers. Subjects were 13 130 men employed for at least 1 year during 1943–1991 at any of six plants that manufactured Synthetic Rubber. Death certificates and medical records identified workers with leukemia. Cumulative exposure estimates were based on plant- and time period-specific process and task characteristics, linked to subjects’ work histories. Poisson regression estimated relative rates (RRs) for workers exposed to each agent compared to unexposed workers. Leukemia (N=59) was positively associated with BD ppm-years (RRs of 1.0, 1.2, 2.0 and 3.8, for exposures of 0, >0– 0– 0– 100 ppm than for ppm-years due to lower concentrations. BD and DMDTC, but not STY, were positively associated with leukemia in multivariable analyses. The independent effect of each agent was difficult to evaluate because of correlations with other agents and imprecision.

  • leukemia and cumulative exposure to butadiene styrene and benzene among workers in the Synthetic Rubber industry
    Toxicology, 1996
    Co-Authors: Maurizio Macaluso, Nalini Sathiakumar, Elizabeth Delzell, Rodney R Larson, Mary Hovinga, Jim A Julian, D C F Muir, Philip A Cole
    Abstract:

    Retrospective, quantitative estimates of exposure to 1,3-butadiene, styrene and benzene were developed for a follow-up study of leukemia mortality among 16610 subjects employed at six North American styrene-butadiene Rubber manufacturing plants (418846 person-years, 58 leukemia deaths). The estimation procedure entailed identifying work areas within each manufacturing process, historical changes in exposure potential and specific tasks involving exposure, and using mathematical models to calculate job- and time-period-specific average exposures. The resulting estimates were linked with the subjects' work histories to obtain cumulative exposure estimates, which were employed in stratified and Poisson regression analyses of mortality rates. Mantel-Haenszel rate ratios adjusted by race, age, and cumulative styrene exposure increase with cumulative butadiene exposure from 1 in the nonexposed category to 4.5 in the category of 80 ppm-years or more (P = 0.01). The risk pattern is less clear and statistically nonsignificant for styrene exposure. A trend of increasing risk with butadiene exposure is still present after exclusion of the nonexposed category (P = 0.03). A parsimonious interpretation of the findings presented here, in light of previous epidemiologic studies, is that exposure to butadiene in the Synthetic Rubber industry produces a dose-related increase in the occurrence of leukemia.