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Objective: To determine whether there is an ongoing risk of developing bladder cancer in a previously studied cohort of workers exposed to both benzidine and dichlorobenzidine or dichlorobenzidine only in the last benzidine manufacturing plant in the USA., Methods: Workers (n=488) were identified from the quarterly 941 forms the employer was required to submit to the Social Security Administration from 1960 to 1977. Exposures were assigned based on dates worked and known benzidine/dichlorobenzidine production schedules. Incidence, vital status and cause of death were determined through 2014. Analyses were restricted to white men., Results: Bladder cancer incidence and mortality were significantly increased (25 incident cases, standardised incidence ratio (SIR) 2.19, 95% CI 1.42 to 3.23, and 5 deaths, standardised mortality ratio (SMR) 3.79, 95% CI 1.23 to 8.84). There were significant increases in incidence and mortality in those exposed to both benzidine and dichlorobenzidine (SIR 3.11, 95% CI 1.97 to 4.67, SMR 4.10, 95% CI 1.12 to 10.50), but not among workers exposed to dichlorobenzidine only (two incident cases, SIR 0.89, 95% CI 0.11 to 3.23 and one death, SMR 2.90, 95% CI 0.07 to 16.15). Bladder cancer incidence and mortality were increased in individuals with > 20 years since last exposure with > 5 years worked (six observed, SIR 5.94, 95% CI 2.18 to 12.92 and two deaths, SMR 7.93, 95% CI 0.96 to 28.65)., Conclusions: Incidence and mortality due to bladder cancer increased among workers exposed to benzidine but not among workers exposed only to dichlorobenzidine. The risk of incidence and death from bladder cancer remain elevated more than 20 years after last exposure to benzidine in those who worked > 5 years., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Objectives: To evaluate total and cause-specific mortality among hardmetal production workers with emphasis on lung cancer., Methods: Subjects were 7304 workers ever employed in one of eight US plants from 1952 to 2008. Vital status through 2012 was determined for 97% of subjects and cause of death for 98.3% of 1087 deaths. We computed standardized mortality ratios (SMRs) and evaluated exposure-response via relative risk regression analysis., Results: We observed overall deficits in deaths for total mortality, all cancers, and lung cancer and found no evidence of any exposure-response relationships for lung cancer., Conclusions: We found no evidence that exposure to tungsten, cobalt, or nickel, at levels experienced by the workers examined, increases lung cancer mortality risks. We also found no evidence that work in the US hardmetal industry increases mortality risks from any other causes of death.

Objective: This study retrospectively investigates causes of death among workers of a hardmetal plant in Austria., Methods: A retrospective cohort was formed of 1965 workers still employed in or after 1970. Follow-up was until end of 2014 based on national databases. Cobalt exposure was assessed through industrial hygiene data and urine analyses. Cox proportional hazards models were calculated for selected causes of death., Results: During 45,598 years of observation in total 177 deaths were observed. Forty-nine workers died from any cancer, 10 from lung cancer, and three from chronic obstructive pulmonary disease. Only the latter showed a significant association with cumulative exposure., Conclusions: Although this is a young study population with little power to detect subtle effects, at least it does not indicate a pronounced cancer risk among tungsten carbide workers due to cobalt.

Objective: The aim of this study was to investigate a cohort in German hardmetal industry, especially relationship between exposures to cobalt, with and without tungsten, and risks of total and cause-specific mortality., Methods: The cohort comprises blue-collar workers at three German plants who were employed in hardmetal processing. Individual cumulative exposures and long-term average concentrations were estimated for cobalt, nickel, tungsten, respirable, and inhalable dust. Standardized mortality ratios (SMRs) were calculated for external comparisons. Time-dependent multivariable Cox models were performed for internal analyses., Results: Elevated SMRs were found for all-cause, heart diseases, and nonmalignant respiratory diseases mortality, but not for lung cancer. Internal analyses did not show increased risks for any endpoints, and no exposure-response relationship was indicated., Conclusions: This study does not provide evidence for elevated lung cancer risks. Methodologic limitations, incomplete ascertainment of death causes in particular, impede conclusions about exposure effects.

Objectives: to study mortality rates among workers in companies manufacturing thermoplastic and rubber articles (excluding tyres)., Design: cohort study., Setting and Participants: the cohort includes 4,543 workers employed up to 2000 in 131 companies in the Province of Bologna (Emilia-Romagna Region, Northern Italy) exposed to emissions from hot processing of plastics (3,937) and rubber (606)., Main Outcome Measures: general- and cause-specific Standardized Mortality Rates (SMR), with 95% confidence intervals; entire reference population resides in the Emilia-Romagna Region., Results: excess mortality for all causes (116 Obs; SMR: 1.20; 95%CI 1.00-1.44) and for lung cancer (18 Obs; SMR: 1.67; 95%CI 1.05-2.65) in men of the rubber factories. Increased mortality rates for oesophageal cancers in women (3 Obs; SMR: 5.41; 95%CI 1.74-16.8) and in men (6 Obs; SMR: 2.16; 95%CI 0.97-4.81), for malignant tumours of pancreas (16 Obs; SMR: 1.65; 95%CI 1.01- 2.70), rectum (11 Obs; SMR: 2.17; 95%CI 1.20-3.92) and kidney (11 Obs; SMR: 1.98; 95%CI 1.10-3.58) in men occupied in plastic processing., Conclusion: in this study, we observed an excess of mortality rates for lung cancer in men of rubber factories and for malignant tumours of the digestive tract, pancreas, and kidney in workers employed in the production of plastic articles. Nevertheless, these results must be interpreted with caution, because exposures to non-occupational risk factors, like tobacco smoke or other occupational exposures outside the companies concerned, are not known. The results suggest to continue epidemiological surveillance.

Background: Mortality among 4,545 toluene diisocyante (TDI)-exposed workers was updated through 2011. The primary outcome of interest was lung cancer., Methods: Life table analyses, including internal analyses by exposure duration and cumulative TDI exposure, were conducted., Results: Compared with the US population, all cause and all cancer mortality was increased. Lung cancer mortality was increased but was not associated with exposure duration or cumulative TDI exposure. In post hoc analyses, lung cancer mortality was associated with employment duration in finishing jobs, but not in finishing jobs involving cutting polyurethane foam., Conclusions: Dermal exposure, in contrast to inhalational exposure, to TDI is expected to be greater in finishing jobs and may play a role in the observed increase in lung cancer mortality. Limitations include the lack of smoking data, uncertainty in the exposure estimates, and exposure estimates that reflected inhalational exposure only. Am. J. Ind. Med. 59:630-643, 2016. Published 2016. This article is a U.S. Government work and is in the public domain in the USA., (Published 2016. This article is a U.S. Government work and is in the public domain in the USA.)

Objectives: In this study, we address the healthy worker hire effect that arises when people with greater than average health are recruited to work in industrial jobs., Methods: Epidemiologists have used both general and working population reference rates to gauge influence of healthy worker hire effect on the standardized mortality ratio. We propose a Bayesian procedure that uses information derived from general and working population reference rates to calculate standardized mortality ratio., Results: The procedure is illustrated in the context of heart disease and lung cancer mortality analyses of a cohort of workers from a fluoropolymer production facility., Conclusions: Application of our method should allow for fuller discussions of the healthy worker effect when one of its components, the healthy worker hire effect, is evaluated quantitatively. Our method can be utilized to improve risk estimates for a cohort with occupational exposure.

Introduction: The study investigated the geographic variation of mortality risk for hematological malignancies (HMs) in order to identify potential high-risk areas near an Italian petrochemical refinery., Material and Methods: A population-based case-control study was conducted and residential histories for 171 cases and 338 sex- and age-matched controls were collected. Confounding factors were obtained from interviews with consenting relatives for 109 HM deaths and 267 controls. To produce risk mortality maps, two different approaches were applied and compared. We mapped (1) adaptive kernel density relative risk estimation for case-control studies which estimates a spatial relative risk function using the ratio between cases and controls' densities, and (2) estimated odds ratios for case-control study data using Generalized Additive Models (GAMs) to smooth the effect of location, a proxy for exposure, while adjusting for confounding variables., Results: No high-risk areas for HM mortality were identified among all subjects (men and women combined), by applying both approaches. Using the adaptive KDE approach, we found a significant increase in death risk only among women in a large area 2-6 km southeast of the refinery and the application of GAMs also identified a similarly-located significant high-risk area among women only (global p-value<0.025). Potential confounding risk factors we considered in the GAM did not alter the results., Conclusion: Both approaches identified a high-risk area close to the refinery among women only. Those spatial methods are useful tools for public policy management to determine priority areas for intervention. Our findings suggest several directions for further research in order to identify other potential environmental exposures that may be assessed in forthcoming studies based on detailed exposure modeling., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Objectives: To update a cohort study of chemical workers and reevaluate lung cancer mortality in relation to acrylonitrile (AN) exposure., Methods: Subjects were 2096 workers employed during 1955 to 2011. We identified 474 deaths through 2011, and quantitatively estimated worker exposures to AN. Analyses included national and county-based standardized mortality ratios and relative risk regression of internal cohort rates., Results: We found no statistically significant excess mortality risks associated with Lima employment for any cause of death category, including lung cancer and other cancer sites implicated in previous studies., Conclusions: This update provides no evidence that exposure to AN at levels experienced by Lima workers is associated with an increased risk of lung cancer mortality, as suggested in original study. Earlier reported bladder cancer risks decreased to a much lower, not statistically significant level.

Objectives: To evaluate the extent to which lung cancer mortality risk estimates in relation to acrylonitrile (AN) exposure may have been confounded by smoking in the presence of misclassified smoking data., Methods: Subjects were 992 white men employed for three or more months between 1960 and 1996 at a chemical plant in Lima, Ohio. We used Monte Carlo-based sensitivity analysis to address possible confounding by smoking., Results: In Monte Carlo simulations that accounted for the relationship between smoking and AN exposure, mean relative risks for lung cancer mortality in relation to AN exposure decreased and we observed somewhat less evidence of an exposure-response relationship., Conclusions: Our simulations suggest that the relationship between AN exposure and lung cancer mortality was positively confounded by smoking in the original Lima cohort study.

The International Agency for Research on Cancer controversially has classified formaldehyde as causing nasopharyngeal carcinoma and myeloid leukemia. To provide further information on this question, we extended follow-up of a cohort of 14,008 chemical workers at 6 factories in England and Wales, covering the period 1941-2012. Mortality was compared with national death rates for England and Wales, and associations with incident upper airway cancer and leukemia were explored in nested case-control analyses. We observed excess deaths from cancers of the esophagus (100 observed vs. 93.1 expected), stomach (182 vs. 141.4), rectum (107 vs. 86.8), liver (35 vs. 26.9), and lung (813 vs. 645.8), but none of these tumors exhibited a clear exposure-response relationship. Nested case-control analyses of 115 men with upper airway cancer (including 1 nasopharyngeal cancer), 92 men with leukemia, and 45 men with myeloid leukemia indicated no elevations of risk in the highest exposure category (high exposure for ≥1 year). When the 2 highest exposure categories were combined, the odds ratio for myeloid leukemia was 1.26 (95% confidence interval: 0.39, 4.08). Our results provide no support for an increased hazard of myeloid leukemia, nasopharyngeal carcinoma, or other upper airway tumors from formaldehyde exposure. These results indicate that any excess risk of these cancers, even from relatively high exposures, is at most small., (© The Author 2014. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: We updated through 2007 the mortality experience of 1,874 workers employed at a New York State chemical manufacturing plant between 1946 and 2006., Methods: Reassessed exposures to vinyl chloride, carbon disulfide, and shift work and categories of o-toluidine exposure were based on year, department and job title. Standardized mortality ratios (SMR) compared mortality to that of the US population. Internal comparisons used directly standardized rate ratios., Results: Hepatobiliary cancer mortality was elevated among workers ever exposed to vinyl chloride (SMR = 3.80, 95% confidence interval 1.89-6.80); directly standardized rates increased with increasing vinyl chloride exposure duration. No increase in non-Hodgkin lymphoma mortality was observed with vinyl chloride and shift work exposures. Internal comparisons showed increased coronary artery disease mortality among long-term workers exposed to carbon disulfide and shift work for 4 years or more., Conclusions: Excess coronary artery disease mortality confirms earlier results; further investigation is needed to understand risk factors., (© 2014 Wiley Periodicals, Inc.)

Background: The resident population of Gela (Sicily Region, Southern Italy) has shown excess mortality and morbidity risks probably related to the emissions from the local petrochemical plant. We present the methodology and main results of the occupational cohort studies of Gela petrochemical workers., Methods: Standardized Mortality Ratios (SMRs) for specific causes were calculated using mortality rates of the Sicily Region as the reference. Internal analyses on mortality and morbidity (hospitalization) risks were also conducted by job and residence subcohorts., Results: Observed deaths were less than expected for most causes of death. Internal analyses showed an increase in mortality from lung cancer, and an increase in the hospitalization for respiratory and genitourinary diseases among the blue collar subcohort and the Gela resident subcohort., Conclusion: The results of the internal analyses of mortality and morbidity suggest the need of indepth investigations into the occupational and environmental sources of exposure in the area.

Background: Formaldehyde, a widely used chemical, is considered a human carcinogen., Methods: We extended follow-up of the largest industrial cohort of workers in formaldehyde industries (n = 25,619) by 10 years through 2004. Standardized mortality ratios (SMRs) and rate ratios (RRs) were calculated for deaths from solid tumors using quantitative formaldehyde exposure estimates., Results: During 998,239 person-years, 13,951 deaths occurred. With one additional death, previously observed excesses for nasopharyngeal cancer (n = 10) persisted for peak, average intensity and cumulative exposure; RRs in the highest exposure categories were 7.66 (95% CI: 0.94, 62.34), P-trend = 0.005, 11.54 (95% CI: 1.38, 96.81), P-trend = 0.09, and 2.94 (95% CI: 0.65, 13.28), P-trend = 0.06, respectively. For all cancer, solid tumors and lung cancer, SMRs among exposed workers were elevated, but internal analyses revealed no positive associations with formaldehyde exposure., Conclusions: Consistent with previous analyses of this cohort, this update continues to suggest a link between formaldehyde exposure and nasopharyngeal cancer., (Copyright © 2013 Wiley Periodicals, Inc.)

Tetrafluoroethylene (TFE), a compound used for the production of fluorinated polymers including polytetrafluoroethylene, increases the incidence of liver and kidney cancers and leukemia in rats and mice. This is the first time the cancer risk in humans has been explored comprehensively in a cohort mortality study (1950-2008) that included all polytetrafluoroethylene production sites in Europe and North America at the time it was initiated. A job-exposure matrix (1950-2002) was developed for TFE and ammonium perfluoro-octanoate, a chemical used in the polymerization process. National reference rates were used to calculate standardized mortality ratios (SMRs) and 95% confidence intervals. Among 4,773 workers ever exposed to TFE, we found a lower rate of death from most causes, as well as increased risks for cancer of the liver (SMR = 1.27; 95% confidence interval: 0.55, 2.51; 8 deaths) and kidney (SMR = 1.44; 95% confidence interval: 0.69, 2.65; 10 deaths) and for leukemia (SMR = 1.48; 95% confidence interval: 0.77, 2.59; 12 deaths). A nonsignificant upward trend (P = 0.24) by cumulative exposure to TFE was observed for liver cancer. TFE and ammonium perfluoro-octanoate exposures were highly correlated, and therefore their separate effects could not be disentangled. This pattern of findings narrows the range of uncertainty on potential TFE carcinogenicity but cannot conclusively confirm or refute the hypothesis that TFE is carcinogenic to humans.

Objective: We extended follow-up of a cohort of German rubber industry workers (active or retired in 1981) by 9 years (1992 to 2000) to reassess previously observed cancer mortality risks., Methods: We calculated standardized mortality ratios and stratified results by work area, duration of employment, and year of hire., Results: The cohort includes 11,632 men and 1863 women from five tire or general rubber goods producing factories. Among men we observed significantly elevated standardized mortality ratios for cancers of the lung and the pleura in the full cohort and in specific strata. Among women we observed a significantly elevated standardized mortality ratio for cancer of the lung., Conclusions: We observed excess risk for several cancer sites among men and women. Further cancer risk analysis of workers in the rubber industry should focus on differences in work areas and associated exposures.

Background: Workers employed at the Oak Ridge National Laboratory (ORNL) were potentially exposed to a range of chemical and physical hazards, many of which are poorly characterized. We compared the observed deaths among workers to expectations based upon US mortality rates., Methods: The cohort included 22,831 workers hired between January 1, 1943 and December 31, 1984. Vital status and cause of death information were ascertained through December 31, 2008. Standardized mortality ratios (SMRs) were computed separately for males and females using US and Tennessee mortality rates; SMRs for men were tabulated separately for monthly-, weekly-, and hourly-paid workers., Results: Hourly-paid males had more deaths due to cancer of the pleura (SMR = 12.09, 95% CI: 4.44, 26.32), cancer of the bladder (SMR = 1.89, 95% CI: 1.26, 2.71), and leukemia (SMR = 1.33, 95% CI: 0.87, 1.93) than expected based on US mortality rates. Female workers also had more deaths than expected from cancer of the bladder (SMR = 2.20, 95% CI: 1.20, 3.69) and leukemia (SMR = 1.64, 95% CI: 1.09, 2.36). The pleural cancer excess has only appeared since the 1980s, approximately 40 years after the start of operations. The bladder cancer excess was larger among workers who also had worked at other Oak Ridge nuclear weapons facilities, while the leukemia excess was among people who had not worked at other DOE facilities., Conclusions: Occupational hazards including asbestos and ionizing radiation may contribute to these excesses., (Copyright © 2013 Wiley Periodicals, Inc.)

Background: A cohort of 3,607 workers employed in three DuPont titanium dioxide production facilities was followed from 1935 through 2006., Methods: Combined and plant-specific cohort mortality was compared with the overall US population and other DuPont employees. The relationships between selected causes of death and annual cumulative exposures to titanium dioxide and chloride were investigated using Poisson regression methods to examine trends with increasing exposure., Results: Among the 833 deaths, no causes of deaths were statistically significantly elevated either overall or plant-specific when compared to the US population. Compared to DuPont workers, statistically significantly elevated SMRs for all causes, all cancers, and lung cancers were found driven by the workers at the oldest plant. Comparing increasing exposure groups to the lowest group, disease risk did not increase with exposure., Conclusions: There was no indication of a positive association between occupational exposure and death from all causes, all cancers, lung cancers, non-malignant respiratory disease, or all heart disease., (Copyright © 2012 Wiley Periodicals, Inc.)

Benzene, a known carcinogen, can be generated as a by-product during the use of petroleum-based raw materials in chemical manufacturing. The aim of this study was to analyze a large data set of benzene air concentration measurements collected over nearly 40 years during routine employee exposure monitoring at a petrochemical manufacturing facility. The facility used ethane, propane, and natural gas as raw materials in the production of common commercial materials such as polyethylene, polypropylene, waxes, adhesives, alcohols, and aldehydes. In total, 3607 benzene air samples were collected at the facility from 1962 to 1999. Of these, in total 2359 long-term (>1 h) personal exposure samples for benzene were collected during routine operations at the facility between 1974 and 1999. These samples were analyzed by division, department, and job title to establish employee benzene exposures in different areas of the facility over time. Sampling data were also analyzed by key events over time, including changes in the occupational exposure limits (OELs) for benzene and key equipment process changes at the facility. Although mean benzene concentrations varied according to operation, in nearly all cases measured benzene quantities were below the OEL in place at the time for benzene (10 ppm for 1974-1986 and 1 ppm for 1987-1999). Decreases in mean benzene air concentrations were also found when data were evaluated according to 7- to 10-yr periods following key equipment process changes. Further, an evaluation of mortality rates for a retrospective employee cohort (n = 3938) demonstrated that the average personal benzene exposures at this facility (0.89 ppm for the period 1974-1986 and 0.125 ppm for the period 1987-1999) did not result in increased standardized mortality ratio (SMRs) for diseases or malignancies of the lymphatic system. The robust nature of this data set provides comprehensive exposure information that may be useful for assessing human benzene exposures at similar facilities. The data also provide a basis for comparable measured exposure levels and the potential for adverse health effects. These data may also prove beneficial for comparing relative exposure potential for production versus nonproduction operations and the relationship between area and personal breathing zone samples.

ABSTRACT This study evaluated unique exposures and their relationship to brain cancer mortality in employees of a specialty chemical research facility. Following an exposure assessment that concerned compounds distinct to this facility, the authors conducted a cohort mortality study of 5,284 workers to assess mortality in reference to the general population and a nested case-control study to evaluate brain cancer risk associated with specific jobs and unique chemical exposures. Four hundred eighty-six deaths, including 14 brain cancer deaths, were identified. Overall mortality was lower than expected. Brain cancer mortality was elevated (standardized mortality ratio [SMR] = 2.02, 95% confidence interval [CI] = 1.11-3.40). Exposures to 5 specific chemical categories were assessed. Exploration of work history and the specific chemical exposures did not explain the brain cancer cases. No clear occupational etiology was identified.

Objectives: To examine the long-term effects of dioxin-exposure, particularly with regard to cancer mortality, in a follow-up 23 years after closure of the chemical plant (Hamburg, Germany)., Methods: The study comprised all persons (1191 men/398 women) employed in the plant on a full-time basis for a minimum of 3 months between 1952 and 1984 when the plant was closed down. Mortality follow-up was performed for the period from 1952 up to the reference date of 31 December 2007. Subjects entered the cohort at the date of their first employment in the plant. We calculated standardised mortality ratios (SMRs) using the population of Hamburg as reference., Results: The vital status could be determined for 96.5% of the study group (1145 men and 389 women). For men, there was an increase in overall mortality (ICD-9 1-999) (SMR=1.14, 95% CI 1.06 to 1.23), all-cancer mortality (SMR=1.37, 95% CI 1.21 to 1.56) and specific mortality from respiratory cancer (ICD-9 161, 162, 163) (SMR=1.64, 95% CI 1.32 to 2.03), oesophageal cancer (ICD-9 150) (SMR=2.56, 95% CI 1.27 to 4.57), rectum cancer (ICD-9 154) (SMR=1.96, 95% CI 0.98 to 3.51), as well as diseases of the circulatory system (ICD-9 390-459) (SMR=1.16, 95% CI 1.02 to 1.31). For women, there was an increase in breast cancer mortality (ICD-9 174) (SMR=1.86, 95% CI 1.12 to 2.91)., Conclusions: The results of this extended follow-up are consistent with those of previous analyses of the cohort and with those of other cohorts. Our findings support the carcinogenic effect of dioxin compounds.

Background: The area of Gela was included among the 57 Italian polluted sites of national interest for environmental remediation because of its widespread contamination from a petrochemical complex. The present study investigates mortality and morbidity of the cohort of Gela petrochemical workers with the aim of disentangling occupational from residential risk., Methods: Mortality was assessed for 5,627 men hired from 1960, year of the plant start-up, to 1993; it was followed up for vital status in the period 1960-2002. Morbidity was analysed for 5,431 workers neither dead nor lost to follow-up from 1960 to 2001 and was based on Hospital Discharge Records in the period 2001-2006. The work experience was classified in terms of job categories such as blue collars, white collars, and both--workers who shifted from blue to white collar (95%) or vice versa. An ad hoc mobility model was applied to define qualitative categories of residence in Gela, as residents and commuters. Standardized Mortality Ratios (SMRs) and Mortality Rate Ratios (MRRs) were computed, the latter by using a Poisson regression model. Morbidity was analyzed in terms of Hospital Discharge Odds Ratios (HDORs) through a logistic regression model. While performing the internal comparisons, white collars was the reference category for the job analysis, and commuters was the reference category for the residential analysis., Results: In the light of epidemiological evidence about health risk from petrochemical industries in both occupational and environmental settings, and/or on the basis of information about occupational and residential contamination and health risk in the area of Gela, noteworthy results are shown for lung cancer [MRR: 2.11 (CI 90%; 0.96-4.63) in blue collars; 1.71 (1.09-2.69) in residents], respiratory diseases [HDOR: 2.0 (1.0-3.0) in blue collars; 1.4 (0.96-2.06) in residents] and genitourinary diseases [HDOR: 1.34 (1.06-1.68) in blue collars; 1.23 (1.04-1.45) in residents]., Conclusions: The results support a role of the exposures in the occupational and residential settings, the latter due to the local ascertained contamination, in affecting the workers' health. These results underline the urgent need of water, soil, air and food-chain monitoring programs, to discover active sources of exposure and consequently define public health interventions.

Purpose: To update the mortality experience of employees of a factory that produced cellulose triacetate film base at Brantham in the United Kingdom and generate information on the effects of exposure to methylene chloride, in particular, mortality from cardiovascular disease and cancers of the lung, liver and biliary tract, pancreas and brain., Methods: All 1,785 male employees with a record of employment at the film factory in 1946-1988 were followed through 2006, including 1,473 subjects exposed to methylene chloride on average for 9 years at a concentration of 19 ppm (8 h time-weighted average)., Results: A total of 559 deaths occurred during the follow-up period. In the subcohort of workers exposed to methylene chloride, substantially reduced mortalities compared with national and local rates were found for all causes, all cancers, and all the principal cancer sites of interest except for brain cancer. There was a small excess of brain cancer deaths (8 observed and 4.4 expected), but no evidence of an association with exposure to methylene chloride. Lung cancer mortality was significantly reduced in exposed workers, even compared to the low mortality rate in the local population (SMR 55). In contrast, mortality from ischaemic heart disease in exposed workers was slightly increased compared with local rates (SMR 102), but was lower in active employees (SMR 94; local rates), where a direct effect of exposure to methylene chloride should be concentrated., Conclusions: The study provided no indication that employment at the plant, or exposure to methylene chloride, had adversely affected the mortalities of workers.

A cohort of 2122 US pentachlorophenol (PCP) production workers from four plants in the National Institute for Occupational Safety and Health Dioxin Registry was exposed to PCP and to polychlorinated dibenzo-p-dioxin and dibenzofuran contaminants of PCP production. A subcohort of 720 was also exposed to 2,3,7,8-tetrachlorodibenzodioxin, a contaminant of trichlorophenol (TCP) while using TCP or a TCP derivative. PCP and several production contaminants have been implicated as animal carcinogens. A priori hypotheses were that the cohort would have elevated standardized mortality ratios (SMRs) for aplastic anemia, soft-tissue sarcoma, and non-Hodgkin lymphoma, as suggested by human studies, and for leukemia and liver, adrenal, thyroid, and parathyroid cancer, as suggested by animal studies. From 1940 to 2005 1165 deaths occurred with an overall SMR of 1.01 [95% confidence limits (CI), 0.95-1.07]. Overall cancer mortality (326 deaths, SMR 1.17, CI 1.05-1.31) was in statistically significant excess. There were excess deaths for trachea, bronchus and lung cancers (126 deaths, SMR 1.36, CI 1.13-1.62), non-Hodgkin lymphoma (17 deaths, SMR 1.77, CI 1.03-2.84), chronic obstructive pulmonary disease (63 deaths, SMR 1.38, CI 1.06-1.77), and medical complications (5 deaths, SMR 3.52, CI 1.14-8.22). In race- and sex-specific analyses, white males had increased non-Hodgkin lymphoma mortality (17 deaths, SMR 1.98, CI 1.15-3.17) and males of other races had increased leukemia mortality (four deaths, SMR 4.57, CI 1.25-11.7). The excess of cancers of a priori interest, non-Hodgkin lymphoma and leukemia, provide some support for the carcinogenicity of PCP, however, further studies with more detailed exposure assessment are needed., (Published by Elsevier Ltd.)

Background: Occupational studies typically observe a 20% deficit in overall mortality, broadly characterized as the healthy worker effect (HWE). Components of the HWE may be addressed by various analytical approaches., Aims: To explore the HWE in a modern industrial cohort., Methods: Standardized mortality ratios (SMRs) were calculated for 114,683 US chemical industry employees, who worked at least 3 days between 1960 and 2005., Results: SMRs were 79 (95% confidence interval 78-80) for all causes, 81 (95% confidence interval 79-82) for heart disease, 70 (95% confidence interval 67-73) for non-malignant respiratory disease, 83 (95% confidence interval 81-85) for smoking-related cancers (buccal, cervix, oesophagus, stomach, pancreas, lung, larynx, bladder and kidney) combined and 97 (95% confidence interval 95-100) for other cancers., Conclusions: The low SMRs observed in this study are likely due to differential smoking between the cohort and the background population. Future considerations to control for the HWE should take this into account.

Objective: The municipality of Pace del Mela, together with Milazzo and San Filippo del Mela, has been recognized as a contaminated site of national concern. The purpose of the present study is to evaluate the health status of subjects resident in the Gabbia district, which is close to the industrial areas of both, Pace del Mela and Milazzo., Setting and Participants: All streets and addresses of the area of interest have been identified, taking into account their changes in name over time. The cohort of subjects who lived in the area for any period of time from September 1st, 1984, through December 31st, 2007 has been reconstructed by manual consultation of the Registrar Office files. Standardized mortality ratios, specific for cause, age class, gender and calendar period, have been computed using as reference the Sicilian population. Standardised incidence ratios, based on regional hospital discharge files, have been computed for the years 2001-2007. The cohort is constituted by 457 subjects, 230 men and 227 women. Ascertainment of vital status has not been possible for 39 subjects, corresponding to 8.5% of the cohort., Results: Observed mortality for all causes and for all cancers is consistent with expected figures (62 observed vs 63 expected and 14 observed vs 15 expected, respectively). Observed cancer morbidity is inferior to the corresponding expected figure (SIR=0.49, CI 95%: 0.31-0.79)., Conclusion: The health profile of the Gabbia district population, as estimated from mortality and hospital discharge records, does not show major departures from expected figures.

Objectives: The potential health effects of the manufacture and use of crop protection chemicals were investigated through systematic review and meta-analysis of studies of cohorts of workers in the crop protection product manufacturing industry., Methods: Several computerised literature databases were searched from inception until December 2003, with references listed in identified articles checked for further relevant articles. Random effects meta-analyses of log standardised mortality ratios (SMRs) were carried out. Heterogeneity was explored through subgroup analyses and meta-regression; sensitivity analyses of different approaches for zero events were performed., Results: 21 references reporting information on 37 separate cohorts for mortality were identified. The meta-SMR for all cause mortality was 0.94 (95% CI 0.88 to 1.00) (37 cohorts). Significantly raised mortality was found for cancers of the buccal cavity and pharynx, oesophagus, rectum, larynx, lung, and lymphatic and haematopoietic system with little heterogeneity being observed. Excluding studies with zero events identified additional excesses., Conclusions: Evidence of multiple excesses, particularly in subgroups exposed to phenoxy herbicides contaminated with dioxins, substantiates previous findings. The importance of careful treatment of zero cases was highlighted. Future systematic reviews and meta-analyses would benefit from availability of results for a standard list of causes of disease.

Objectives: To evaluate the mortality experience of workers at a major chemical manufacturing site and to examine brain and liver cancers excesses reported at this site in previous studies., Methods: This study included 9,730 employees at the Texas City location who worked between 1940 and 2001. Standardized mortality ratios and confidence intervals were calculated., Results: There was less than expected deaths due to all cause mortality and no increase in all cancer mortality. Brain tumor mortality, which did exceed expected rates in past years, was at expected levels in recent years. Liver cancer mortality was greater than expected., Conclusion: Brain tumor mortality was either due to chance in the early years or the cause of the brain tumors has been eliminated. Mortality due to liver cancer is higher than expected but only among men hired before 1950.

Objective: This study evaluates the mortality experience of 6,157 chemical laboratory workers employed at United States Department of Energy facilities., Methods: All cause, all cancer and cause-specific standardized mortality ratios were calculated. Cox regression analyses were conducted to further evaluate the relation between chemical exposure and mortality risk due to selected cancers., Results: The mortality due to all causes combined and all cancers combined were below expectation for the cohort. There were no statistically significant elevations reported among males for any specific cancer or non-cancer outcome. There no statistically significant elevations among females for any specific non-cancer and most specific cancers; however, multiple myeloma deaths were significantly elevated (SMR = 3.56; 95% CI = 1.43-7.33; number of observed deaths, n = 7). Statistically significant elevations were seen among workers employed 20+ years for leukemia using both 2- and 5-year lag periods. Also, a statistically significant positive trend of elevated lung cancer mortality with increasing employment duration was seen using both 5- and 10-year lags. A similar trend was seen for smoking related cancers among men., Conclusion: While lymphatic and hematopoietic cancer mortality was below expectation, a significant elevation of multiple myeloma deaths among females and an elevation of leukemia among workers employed 20+ years (possibly due to radiation and benzene exposure) were observed. A NIOSH case-control study is underway to examine more closely the relation between multiple myeloma and a variety of chemical exposures among workers employed at the Oak Ridge K-25 facility., (Published 2008 Wiley-Liss, Inc.)

Medico-dosimetric register is an optimal model of epidemiological studies on evaluation of ionizing radiation effects. Regional medico-dosimetric register (RMDR) is a system of interrelating information blocks including data on Siberian Group of Chemical Enterprises (SGCE) personnel. At present SGCE personnel and Seversk residents RMDR database includes information on 138496 persons, 65538 of which are SGCE workers. SGCE personnel and Seversk residents RMDR is a scientific base for researches with the aim of evaluating long-term ionizing radiation effects in a "low" dose range. Information on mortality and morbidity rate as well as "thematic" registers of the main diseases potentiates in evaluating the spectrum of somatic stochastic effects and radiogenic risks in SGCE workers and Seversk residents as well as their offsprings. A practical significance of RMDR database is the formation of the main diseases "risk" groups depending on definite risk factors in certain groups that provides targeted diagnostic and preventive therapy both among high-dose establishments' workers and residents living near-by.

Background: The production of vinyl chloride (VC) and polyvinyl chloride (PVC) involves the use of various chemicals, some known to be toxic and potentially or definitely carcinogenic. The related potential risk often has not been properly investigated. Updated cancer mortality among different subgroups of workers employed in a VC-PVC production plant located in Porto Marghera (Italy) was re-analyzed using an internal reference group of workers with low (or null) exposure to VC., Methods: Mortality of 1658 male workers was analyzed by Poisson regression. Relative risks (RRs) and 95% confidence intervals (CIs) for blue collar workers and their specific subgroups of PVC baggers, PVC compound, autoclave and other blue collar workers were calculated using technicians and clerks as an internal reference group. The follow-up covered the period 1972-1999., Results: Significantly increased mortality rates were observed for all causes of death among the whole blue collar workforce (RR = 1.55; 95% CI = 1.03-2.35; 229 deaths), PVC baggers (1.72; 95% CI = 1.04-2.83; 49 deaths) and PVC compound workers (1.71; 95% CI = 1.09-2.67; 72 deaths). Liver cancer, including angiosarcoma, was increased among autoclave workers (9.57; 95% CI = 3.71-24.68; 7 deaths) and cardiovascular diseases among PVC baggers (2.25; 95% CI = 1.08-4.70; 12 deaths). Hemolymphopoietic system tumors, leukemias and lymphomas prevalently, were found only among exposed workers, with 4, 4 and 6 deaths observed among PVC baggers, PVC compound and other blue collar workers, respectively. An excess of lung cancer was found among PVC baggers., Conclusion: This cohort analysis, based on internal comparison, confirmed previously reported specific risk excesses for liver tumors and liver cirrhosis among autoclave workers and for lung cancer among PVC baggers, and revealed PVC compound workers as a possible new at risk group for all causes, all tumors and for liver and lung tumors. In conclusion, RRs for all causes of death and all tumors were increased among all blue collar workers.

Purpose: Based on previous reports of increased serum lipid levels in workers at a U.S. polymer manufacturing facility, the study objective was to investigate ischemic heart disease (IHD) mortality as well as a broad range of mortality causes for an occupational cohort at the facility., Methods: The cohort comprised 6,027 men and women who had worked at the facility between 1948 and 2002; these years delimit the mortality follow-up period. Standardized mortality ratios (SMR) were estimated to compare observed numbers of deaths to expected numbers derived from mortality rates for 3 reference populations: the U.S. population, the West Virginia state population, and an 8-state regional employee population from the same company., Results: Most SMR estimates based on U.S. and state populations were below 100. Comparison to the employee population also resulted in many SMR estimates at or near a no-effect level. Relative to the regional worker population, a nonsignificant elevation for IHD mortality was observed (SMR = 109, 95% confidence interval [CI]: 96, 124). Mortality associated with diabetes was significantly increased compared to the regional worker population (SMR = 197, 95% CI: 123, 298). A corresponding increase in the SMR for IHD and diabetes mortality was not detected for comparisons with the two general populations., Conclusions: The results reported herein show little evidence of increased cause-specific mortality risks for workers at the plant. This study demonstrates the utility of comparing occupational cohorts with a similar worker reference population in order to reduce bias associated with the healthy worker effect.

Aim: To monitor the occurrence of cancer in a recently defined cohort of UK rubber workers., Methods: A cohort of 8651 male and female workers from 41 UK rubber factories has been enumerated. All employees had a minimum of 12 months employment and were first employed at one of the participating factories in the period 1982-91. Mortality and cancer incidence data for the period 1983-2004 were compared with expected values based on appropriate national rates., Results: Mortality from lung cancer was close to expectation for males [observed 22, standardized mortality ratio (SMR) 93] and females (observed 2, SMR 70). Mortality from stomach cancer was also unexceptional in males (observed 4, SMR 86) and females (observed 0, SMR 0). Although based on small numbers, significantly elevated mortality was shown for multiple myeloma in males (observed 5, SMR 385) and females (observed 2, SMR 952). All seven of these latter deaths occurred in workers from the general rubber goods (GRG) sector., Conclusions: The findings should be treated with caution as they relate to a relatively early period of follow-up. Nevertheless, they hold out the prospect that the elevated SMRs for stomach and lung cancers reported for historical cohorts of UK rubber workers will not be present in more recent cohorts. The elevated occurrence of multiple myeloma may represent no more than a chance finding. Alternatively, these findings may reflect the presence of an unrecognized occupational cancer hazard in parts of the GRG sector of the UK rubber industry.

Background: The health of UK petroleum industry workers has been monitored for many years., Aim: To identify any long-term adverse health outcomes from occupational exposures in this industry., Methods: The mortality (1951-2003) and cancer morbidity (1971-2003) experienced by cohorts of 28,555 oil refinery workers and 16,477 petroleum distribution workers has been investigated. Study subjects were all those males first employed in the period 1946-74 at one of eight UK oil refineries or 476 UK petroleum distribution centres; all subjects had a minimum of 12 months employment with some employment after 1 January 1951. Observed numbers of cause-specific deaths and site-specific cancer registrations were compared with expectations based on national mortality and cancer incidence rates., Results: Standardized mortality ratios (SMRs) were significantly <100 for all causes both in oil refinery workers (Obs 11,156, SMR 89) and in petroleum distribution workers (Obs 7320, SMR 96). Significantly elevated SMRs were shown in oil refinery workers for cancer of the pleura (mesothelioma) (Obs 64, SMR 261) and melanoma (Obs 48, SMR 168). Significantly elevated SMRs were not found in petroleum distribution workers for any site of cancer. Significantly elevated standardized registration ratios (SRRs) were only shown in oil refinery workers and for cancer of the pleura (mesothelioma) (Obs 115, SMR 274), melanoma (Obs 85, SMR 129) and other skin cancer (Obs 983, SRR 117)., Conclusions: The only findings that showed clear evidence of an occupational cancer hazard were those for mesothelioma in oil refinery workers.

Objective: The objective of this study was to update the mortality experience of a cohort of workers with and without potential exposure to acrylamide (AMD) at three U.S. plants (n = 8508) and one plant in The Netherlands (n = 344)., Methods: We computed standardized mortality ratios (SMRs) using national and local rates and modeled internal cohort rates to assess site-specific cancer risks by demographic and work history factors and several exposure indicators for AMD., Results: For the 1925-2002 study period, we observed both deficit and excess overall mortality risks among the U.S. cohort for cancer sites implicated in experimental animal studies: brain and other central nervous system (SMR = 0.67, confidence interval [CI] = 0.40-1.05), thyroid gland (SMR = 1.38, CI = 0.28-4.02), testis and other male genital organs (SMR = 0.64, CI = 0.08-2.30); and for sites selected in earlier exploratory analyses of this cohort: respiratory system cancer (RSC) (SMR = 1.17, CI = 1.06-1.27), esophagus (SMR = 1.20, CI = 0.86-1.63), rectum (SMR = 1.25, CI = 0.84-1.78), pancreas (SMR = 0.94, CI = 0.70-1.22), and kidney (SMR = 1.01, CI = 0.66-1.46). Except for RSC, attributed earlier to muriatic acid exposure, none of the mortality excesses was statistically significant. In the Dutch cohort, we observed deficits in deaths for all sites of a priori interest. An updated analysis of our previous exploratory findings for pancreatic cancer in the U.S. cohort revealed much less evidence of a possible exposure-response relationship with AMD., Conclusion: AMD exposure at the levels present in our study sites was not associated with elevated cancer mortality risks.

Objective: To study mortality of male workers employed in the petrochemical plant located in Gela, Sicily, Italy., Design: A cohort of 6458 workers employed in the period 1960-1993 was enumerated from company payrolls, follow-up was between November 1, 1960 and December 31, 2002. Ascertainment of vital status was completed through Registrar's office at the place of residence/birth and linkage to the Internal Revenue Service database. Causes of death were retrieved from Registrar's office at the place of death and the National Death Index and coded using the ICD Revision at the time of death. The cause specific expected mortality was computed relative to Sicily Region, specific for gender, 5-year age groups and calendar year., Setting: Petrochemical plant in Gela, Italy., Main Outcome Measures: Cause specific Standardized Mortality Ratios (SMRs) and 90% confidence interval (CI)., Results: Observed mortality was below expected for all causes (662 cases, SMR 0.70 90% CI 0.66-0.74) and all malignant tumours (210 cases, SMR 0.71 90% CI 0.63-0.79). For the cancer sites of a priori interest in the petrochemical industry (skin, lymphatyic and hematopoietic tissues, lung, bladder, kidney liver, brain, pleura) the lower confidence interval of the SMR is never upper than unity., Conclusions: In the cohort the Healthy Worker Effect, the lack of information on exposure and the high percentage of missing causes of deaths (7.6%) can result in an underestimation of mortality specifically for rare diseases as the ones of a priori interest. Information and classification of exposure over time are envisaged developments to better describe the mortality pattern of the Gela cohort.

To expand a cohort of chemical workers in the Kanawha Valley, we conducted a study of 33,225 workers who were employed at three locations between 1940 and 1999. We observed no increase in overall cancer mortality. Higher risk estimates were observed for lymphosarcoma and reticulosarcoma among hourly employees who worked at the Institute or South Charleston locations. This finding was limited to men hired before 1960. We observed no new cases of angiosarcoma of the liver, a cause of death previously reported in association with vinyl chloride production at the South Charleston location. Specific risk factors for lymphosarcoma and reticulosarcoma have not been identified in previous targeted studies of this population and it is unlikely that additional cause-specific research will elucidate the etiology. Updates of the entire cohort will continue and can be used as a comparison population for chemical specific studies within these three plants.

Objectives: We conducted a mortality study of two German chromate production facilities and evaluated possible dose-response relationships between hexavalent chromium exposure and lung cancer., Methods: Mortality was followed-up through 1998 and limited to those employed since each plant converted to a no-lime production process. More than 12,000 urinalysis results of chromium levels were available, as was smoking information., Results: All-cause mortality indicated a healthy worker effect (standardized mortality ratio [SMR] = 0.80, 95% confidence interval [CI] = 0.67-0.96); however, lung cancers appeared to be increased (SMR = 1.48, 95% CI = 0.93-2.25). No clear dose-response was found in stratified analyses by duration of employment and time since hire. On the basis of urinary chromium data, lung cancer risk was elevated only in the highest exposure group (SMR = 2.09, 95% CI = 1.08-3.65)., Conclusions: These data suggest a possible threshold effect of occupational hexavalent chromium exposure on lung cancer.

The study objective is to describe cause specific mortality of employees in a plant engaged in production, recovery and refining of catalytic converters located in Rome. Previous epidemiological studies conducted in similar plants are not available. A total of 828 workers (642 males and 186 females) were followed up between 1956 and 31-12-2003. Cause specific standardized mortality ratio (SMR) and 90% confidence intervals (CI) were computed using regional rates for comparison. Among males hired between 1956 and 1993, followed up until 31/12/2003, mortality for all causes (SMR 0,8; 90% CI 0,7-1,0; 85 observed) and all neoplasms (SMR 0,6; 90% CI 0,42-0,87; 20 observed) is below expected; an increase is present for liver cirrhosis (SMR 2,74; 90% CI 1,47-5,1; 7 observed) and brain cancer (SMR 5,24; 90% CI 2,3-11,90; 4 observed). The present investigation complies with the proposed scientific standards for occupational cohort studies. The study was not prompted by well defined a priori hypotheses but it is included in a process intended to typify a potentially polluted site; the absence of a priori hypotheses and of previous epidemiological evidence, prevent from a causal interpretation of the increased mortality from liver cirrhosis and brain cancer. The implementation of cohort studies in industrial sites where industrial activities similar to the one here examined are present, are highly recommended.

Background: Previously, the mortality was reported in a cohort of male workers at an Ontario chemical plant., Aims: To expand the cohort and to investigate the mortality and cancer incidence risk among chemical manufacturing sites., Methods: We followed 5277 men and 1301 women from 1950 to 1999., Results: Employees experienced lower mortality and cancer incidence rates than the general population for several major causes of death, including heart disease, respiratory cancer and many other cancers. There were no cases of angiosarcoma of the liver. We observed a lower mortality rate of prostate cancer [standardized mortality ratio = 0.79, 95% confidence interval (CI) 0.43-1.32], but a higher incidence rate of prostate cancer [standardized incidence ratio (SIR) = 1.22, 95% CI 1.00-1.48]. Among the Sarnia employees, the incidence of pleural neoplasms was increased (5 observed versus 1.48 expected, SIR = 3.37, 95% CI 1.09-7.86). These cancers were included in the 12 deaths with malignant mesothelioma at Sarnia., Conclusion: Consistent with the earlier report, lower mortality rates were observed for the major classifications of disease and malignant neoplasms. The higher incidence rates of prostate cancer are not readily explainable but may reflect increased screening among current employees and recent retirees. Past asbestos exposure prior to 1980 is probably a contributor to the deaths due to malignant mesothelioma but is not reflected in lung cancer mortality. We find little indication of any other increased rates of mortality or cancer within the overall workforce of these chemical plants.

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.

Background: In a previous cohort study of glass fiber manufacturing, we found a significant increase in lung cancer. This study extends the follow-up period., Methods: We conducted a historical prospective study of 2557 men employed in producing glass wool. We obtained work histories, causes and dates of death, and date and site of cancer diagnoses. We computed standardized mortality and incidence ratios (SMR, SIR)., Results: The overall SMR for lung cancer was 163 (95% CI = 118-221). The SMR did not vary consistently by duration of employment and time since first employment. However, plant workers with >20 years' employment and >40 years since first exposure had an SMR for lung cancer of 282 (95% CI = 113-582). The SMR dropped with later date of first exposure, but the trend was non-significant. There was an unexpected overall increase in kidney cancer incidence., Discussion: The increase in lung cancer is greater than in other cohorts of glass fiber workers. Since exposure data are lacking from the early years of the plant, we cannot state if the excess was due to glass fibers, other work exposures or other reasons.

Aims: To evaluate mortality in New Zealand phenoxy herbicide producers and sprayers exposed to dioxins., Methods: Phenoxy herbicide producers (n = 1025) and sprayers (n = 703) were followed up from 1 January 1969 and 1 January 1973 respectively to 31 December 2000. A total of 813 producers and 699 sprayers were classified as exposed to dioxin and phenoxy herbicides. Standardised mortality ratios (SMR) were calculated using national mortality rates., Results: At the end of follow up, 164 producers and 91 sprayers had died. Cancer mortality was reduced for sprayers (SMR = 0.82, 95% CI 0.57 to 1.14) and increased in exposed production workers (SMR = 1.24, 95% CI 0.90 to 1.67), especially for synthesis workers (SMR = 1.69), formulation and lab workers (SMR = 1.64), and maintenance/waste treatment/cleaning workers (SMR = 1.46). Lymphohaematopoietic cancer mortality was increased in exposed production workers (SMR = 1.65, 95% CI 0.53 to 3.85), especially for multiple myeloma (SMR = 5.51, 95% CI 1.14 to 16.1). Among sprayers, colon cancer (SMR = 1.94, 95% CI 0.84 to 3.83) showed increased mortality., Conclusions: Results showed 24% non-significant excess cancer mortality in phenoxy herbicide producers, with a significant excess for multiple myeloma. Associations were stronger for those exposed to multiple agents including dioxin during production. Overall cancer mortality was not increased for producers and sprayers mainly handling final technical products, although they were likely to have been exposed to TCDD levels far higher than those currently in the general New Zealand population.

Background: Alachlor is the active ingredient in pre-emergent herbicide formulations that have been used widely on corn, soybeans, and other crops. It has been found to cause nasal, stomach, and thyroid tumours in rodent feeding studies at levels that are much higher than likely human exposures., Aims: To evaluate mortality rates from 1968 to 1999 and cancer incidence rates from 1969 to 1999 for alachlor manufacturing workers at a plant in Muscatine, Iowa., Methods: Worker mortality and cancer incidence rates were compared to corresponding rates for the Iowa state general population. Analyses addressed potential intensity and duration of exposure., Results: For workers with any period of high alachlor exposure, mortality from all causes combined was lower than expected (42 observed deaths, SMR 64, 95% CI 46 to 86) and cancer mortality was slightly lower than expected (13 observed deaths, SMR 79, 95% CI 42 to 136). Cancer incidence for workers with potential high exposure was similar to that for Iowa residents, both overall (29 observed cases, SIR 123, 95% CI 82 to 177) and for workers exposed for five or more years and with at least 15 years since first exposure (eight observed cases, SIR 113, 95% CI 49 to 224). There were no cases of nasal, stomach, or thyroid cancer., Conclusions: There were no cancers of the types found in toxicology studies and no discernible relation between cancer incidence for any site and years of alachlor exposure or time since first exposure. Despite the small size of this population, the findings are important because these workers had chronic exposure potential during extended manufacturing campaigns, while use in agriculture is typically limited to a few days or weeks each year.