Mortality in Florida professional firefighters, 1972 to 1999

BACKGROUND: Exposure to occupational hazards among firefighters may lead to increased mortality from cancer, lung, or heart disease. METHODS: Age- and gender-adjusted mortality rates of 34,796 male and 2,017 female Florida professional firefighters between 1972 and 1999 were compared with the Florida general population. RESULTS: One thousand four hundred eleven male and 38 female firefighter deaths with known causes were identified. In male firefighters, mortality due to all causes and most non-malignant diseases was significantly less than expected. There was no excess overall mortality from cancer, but excesses existed for male breast cancer [standardized mortality ratio (SMR = 7.41; 95% confidence interval (CI): 1.99-18.96) and thyroid cancer (SMR = 4.82; 95% CI: 1.30-12.34)]. Mortality from bladder cancer was increased and approached statistical significance (SMR = 1.79; 95% CI: 0.98-3.00). Firefighters certified between 1972 and 1976 had excess mortality from bladder cancer (SMR = 1.95; 95% CI: 1.04-3.33). Female firefighters had similar morality patterns to Florida women except for atherosclerotic heart disease (SMR = 3.85; 95% CI: 1.66-7.58). CONCLUSIONS: Excess mortality risk from bladder cancer may be related to occupational exposure during firefighting. The thyroid cancer and breast cancer risk in males, as well as the excess risk of cardiovascular disease mortality noted in females warrant further investigation.     

Cohort mortality study among French asphalt workers

BACKGROUND: In conjunction with the European cohort study among asphalt workers coordinated by the International Agency for Research on Cancer (IARC), we studied the mortality of 15,011 French men who were followed for 17 years for a total of 175,062 persons-years. This group contained 2,506 subjects who had ever been employed as asphalt workers: they contributed 30,692 person-years of risk. A reference group was composed of 6,675 subjects (i.e., 61,856 persons-years) who had been employed only in building or ground construction. METHODS: Mortality ratios standardized for age and period were computed with their 95% confidence intervals (CI) from the age and period mortality rates of all French men for the years covered by the study (1979-1996). We also compared the mortality of exposed workers and the reference group with Poisson regression models after adjustment for age, calendar period, and either duration of employment or length of follow-up. RESULTS: Mortality from lung cancer was equivalent to the expected rate [SMR = 1.01 95% CI (0.6-1.6)], but was 40% greater than among the non-exposed reference group [RR = 1.4 95% CI (0.7-2.8)]. We also found an excess of gastrointestinal cancers, especially of the esophagus [SMR = 1.94, 95% CI (0.9-3.6)] and stomach [SMR = 2.2, 95% CI (0.8-4.7)]. Comparison with the internal reference group confirmed these findings, especially for stomach cancer [RR = 2.8, 95% CI (0.7-11.4)]. CONCLUSIONS: Although our results are not statistically significant, they suggest that road-paving workers may have a slightly higher rate of lung cancer and a moderately higher rate of stomach cancer than their non-exposed counterparts. The excess of lung cancer may be due to potential confounding factors, including the occupational risk factor of coal tar exposure and the lifestyle risk factor of smoking. A nested case-control study is under way that will make it possible to control for smoking and other potential carcinogenic exposures; this is necessary before any definitive conclusions can be drawn.     

A cohort mortality study of construction workers

This report presents a mortality study among the 17,344 members of the Construction Workers' Health Insurance Society of Mie Prefecture in Japan. The study period was between 1973 and 1993. During this period, 480 members died. Age-specific mortality rates of Mie Prefecture were used as comparison standards. Significantly elevated standardized mortality ratio (SMR) and proportionate mortality ratio (PMR) were observed for “accidents and adverse effects.” In addition, the PMRs of all cancers and “cancers of trachea, bronchus and lung” were also significantly elevated. The job classifications were reorganized into three groups, according to the frequency of asbestos exposure the workers experienced on the construction sites. The asbestos exposure was based on job classifications among 7,411 workers who had completed a self-administered survey questionnaire. In the frequent-exposure group, the PMR was significantly elevated for all cancers. In the medium-exposure group, the SMRs were significantly elevated for all cancers and “cancer of trachea, bronchus and lung.” The PMR was significantly elevated for “cancer of trachea, bronchus and lung.” In the less-exposure group, the PMR was significantly elevated for “accidents and adverse effects.” This study provided support for the hypothesis that working in the construction industry might be associated with high risks for asbestos-associated cancers and accidental deaths. Am. J. Ind. Med. 32:35-41, 1997. © 1997 Wiley-Liss, Inc.     

Surveillance of cancer risks for firefighters,police, and armed forces among men in a Canadian census cohort

Background

Firefighters, police, and armed services may be exposed to hazards such as combustion by‐products and shift work.

Methods

The CanCHEC cohort linked 1991 census data to the Canadian cancer registry for follow up. Cox proportional hazards modeling was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) to estimate risks for firefighter, police, or armed forces compared to workers in other occupations.

Results

The cohort of 1 108 410 men included 4535 firefighters, 10 055 police, and 9165 armed forces. For firefighters, elevated risks were noted for Hodgkin's lymphoma (HR: 2.89, 95%CI: 1.29‐6.46), melanoma (HR: 1.67, 95%CI: 1.17‐2.37), and prostate cancer (HR: 1.18, 95%CI: 1.01‐1.37). Police had elevated risks for melanoma (HR:1.69, 95%CI: 1.32‐2.16) and prostate cancer (HR:1.28, 95%CI: 1.14‐1.42). No significant associations were found for armed forces workers.

Conclusions

Canadian firefighters, police, and armed services, may be at an increased risk of developing certain cancers. Results suggested that a healthy worker effect may influence risk estimates.

     

Cancer incidence in sites potentially related to occupational exposures: 58 years of follow-up of firefighters in the Norwegian Fire Departments Cohort

ObjectivesFirefighters are exposed to a variety of known and suspected carcinogens through their work. However, the association with cancer risk has limited evidence. We examined cancer incidence among firefighters in the newly established Norwegian Fire Departments Cohort restricted to sites with established associations with carcinogens encountered during firefighting. This included sites within the respiratory, urinary, and lympho-hematopoietic systems, and the skin and all sites combined.MethodsMale firefighters (N=3881) in the cohort were linked to the Cancer Registry of Norway for incident cancer cases occurring during the period 1960–2018. We calculated standardized incidence ratios (SIR) with rates for the national male population as reference, and stratified SIR analyses by period of first employment, duration of employment, and time since first employment.ResultsElevated risk was seen for all sites combined (SIR 1.15, 95% confidence interval 1.07–1.23). Elevated risk of urinary tract cancer was observed among firefighters who began working before 1950, and with observation ≥40 years since first employment. Risk of mesothelioma and laryngeal cancer were elevated with ≥40 years since first employment and with ≥30 years employment duration.ConclusionsThe observed associations between firefighting and urinary tract cancer, laryngeal cancer, and mesothelioma have been observed in some studies previously, and our results suggest the observed elevated risks are related to carcinogenic occupational exposures. Differences in risk by period of employment potentially reflect changes in exposures from improved quality and use of personal protective equipment.     

Height and cancer mortality: results from the Glasgow University student cohort

The aim of the study was to examine the association between height and cancer mortality in a socially homogeneous group of subjects. The study was based on a cohort of students, 8397 men and 2329 women, aged 16-30 y, who attended the University of Glasgow between 1948 and 1968. Mean follow-up time was 40 y. Height was measured at a medical examination performed at the student health service. The outcome measures used in the study were all-cause mortality and mortality from: all cancers, smoking and non-smoking related cancers and cancers related to sex hormones. No substantial or statistically significant associations were seen between height and all-cause or all-cancer mortality in either sex. Neither were any significant associations found between height and any of the sub-types of cancer studied (ie those related to smoking, those not related to smoking, and those related to sex hormones). Previous observations which have shown positive associations between height and cancer mortality have generally been based on populations with diverse social origins, among whom the variation in height will reflect variation in health and nutrition in childhood. The relatively low level of such variation in the present study may account for the negative findings. Public Health (2000) 114, 451-455     

Leisure Activities and All-Cause Mortality Among the Chinese Oldest-Old Population: A Prospective Community-Based Cohort Study

ObjectiveTo investigate associations between leisure activities, examining each activity separately and in combination, and all-cause mortality among the Chinese oldest-old (≥80 years) population.DesignProspective cohort study.SettingCommunity-living, the oldest-old from 22 provinces in China.ParticipantsWe included 30,070 Chinese individuals aged ≥80 years (mean age: 92.7 years) from the Chinese Longitudinal Healthy Longevity Survey from 1998 to 2014.MeasurementsCox proportional hazards models were used to estimate relationships between leisure activities and all-cause mortality, adjusting for covariates including sociodemographic and lifestyle factors, self-reported medical history, and other potential confounders.ResultsDuring 110,278 person-years of follow-up, 23,661 deaths were documented. Participants who engaged in watching TV or listening to the radio, playing cards or mah-jong, reading books or newspapers, gardening, keeping domestic animals or pets, or attending religious activities “almost every day” had a significantly lower mortality risk (adjusted hazard ratios ranged from 0.82 to 0.89; P < .01 for all) than did participants who “never” engaged in those activities. Furthermore, engagement in multiple leisure activities was associated with a reduced risk of all-cause mortality (P for the trend < .001).Conclusions and implicationsFrequent participation in leisure activities might help decrease the risk of death in the Chinese oldest-old population. This finding has important implications for public health policy and encourages the incorporation of a broad range of leisure activities into the daily lives of oldest-old individuals.     

Overall mortality among patients surviving an episode of peptic ulcer bleeding

STUDY OBJECTIVE: The authors investigated whether patients who have survived an acute episode of peptic ulcer bleeding (PUB) have an excess long term all cause mortality compared with the general population free of PUB. DESIGN: Follow up study of previously identified cohort of patients with a PUB episode and a general population cohort. SETTING: The source population included all people aged 30 to 89 years, registered with general practitioners in the United Kingdom. PATIENTS: All patients alive one month after the PUB episode constituted the cohort of PUB patients (n = 978). A control group of 5000 people was randomly sampled from the source population. The same eligibility criteria as for patients with PUB were applied to the control series. Also, controls had to be free of PUB before start date. MAIN RESULTS: Relative risk of mortality among PUB patients was 2.1, 95% CI: 1.7, 2.6) compared with the general population. This increased mortality risk occurred mainly in the patients less than 60 years old. No difference was observed between men and women. The excess mortality was not only circumscribed to deaths attributable to recurrent gastrointestinal bleed, but also cardiovascular, cancer and other causes. CONCLUSIONS: People who have survived an acute episode of PUB have a reduced long term survival compared with the general population. This reduction was stronger among middle age patients than in the elderly.     

Industry-wide study of mortality of pulp and paper mill workers

A study of pulp and paper mill workers indicated low risks of death from all causes (standardized mortality ratio (SMR) = 0.74) and all cancers (SMR = 0.81) compared with U.S. rates. The leukemia death rate in workers was not higher than the U.S. rate but was higher than the rate in county populations surrounding mills. Workers whose last jobs were in the finishing areas of the mills had an elevated SMR for liver cancer. An internal comparison of occupational characteristics indicated that workers employed in mills using other chemical pulping operations had significantly elevated mortality from all causes, all cancers, heart disease, lymphomas, and brain cancers. Lung cancer mortality was elevated in mills using kraft pulping. The internal comparisons confirmed the association between work in finishing and the risk of liver cancer. This study was designed to investigate whether pulp and paper mill workers have any risks that would indicate the need for studies detailing exposures. Am. J. Ind. Med. 33:354–365, 1998. © 1998 Wiley-Liss, Inc.     

Prospective study of hepatic, renal, and haematological surveillance in hazardous materials firefighters

OBJECTIVES—To evaluate possible health effects related to work with hazardous materials as measured by end organ effect markers in a large cohort over about 2 years, and in a subcohort over 5 years.
METHODS—Hepatic, renal, and haematological variables were analysed from 1996-98 in hazardous materials firefighters including 288 hazardous materials technicians (81%) and 68 support workers (19%). The same end organ effect markers in a subcohort of the technicians were also analysed (n=35) from 1993-98. Support workers were considered as controls because they are also firefighters, but had a low potential exposure to hazardous materials.
RESULTS—During the study period, no serious injuries or exposures were reported. For the end organ effect markers studied, no significant differences were found between technicians and support workers at either year 1 or year 3. After adjustment for a change in laboratory, no significant longitudinal changes were found within groups for any of the markers except for creatinine which decreased for both technicians (p<0.001) and controls (p<0.01).
CONCLUSIONS—Health effects related to work are infrequent among hazardous materials technicians. Haematological, hepatic, and renal testing is not required on an annual basis and has limited use in detecting health effects in hazardous materials technicians.


Keywords: hazardous materials; firefighters; medical surveillance     

Registry-based case-control study of cancer in California firefighters

BACKGROUND: There is no consensus whether firefighters are at increased cancer risk for particular cancers. Previous studies have been small, mostly investigated cancer mortality, and suggested increased risks for brain, bladder, testicular, prostate, thyroid and colo-rectal cancers, leukemia, and melanoma. METHODS: Records of all male cancers registered in California during 1988-2003 were obtained. Firefighters were identified from occupation and industry text fields. Logistic regression analysis used other cancers as controls. RESULTS: Of the 804,000 eligible records, 3,659 had firefighting as their occupation. Firefighting was associated with testicular cancer (odds ratio = 1.54, 95% confidence interval: 1.18-2.02), melanoma (1.50, 1.33-1.70), brain cancer (1.35, 1.06-1.72), esophageal cancer (1.48, 1.14-1.91), and prostate cancer (1.22, 1.12-1.33). CONCLUSIONS: Use of other-cancer controls and lack of an occupational history may have biased relative risks towards the null. However, this study, which contained more firefighter cancers than any previous epidemiologic study, produced evidence supporting some prior hypotheses.     

Risk of nonaccidental and cardiovascular mortality in relation to long-term exposure to low concentrations of fine particulate matter: a Canadian national-level cohort study

Background: Few cohort studies have evaluated the risk of mortality associated with long-term exposure to fine particulate matter [≤ 2.5 μm in aerodynamic diameter (PM_2.5)]. This is the first national-level cohort study to investigate these risks in Canada.Objective: We investigated the association between long-term exposure to ambient PM_2.5 and cardiovascular mortality in nonimmigrant Canadian adults.Methods: We assigned estimates of exposure to ambient PM_2.5 derived from satellite observations to a cohort of 2.1 million Canadian adults who in 1991 were among the 20% of the population mandated to provide detailed census data. We identified deaths occurring between 1991 and 2001 through record linkage. We calculated hazard ratios (HRs) and 95% confidence intervals (CIs) adjusted for available individual-level and contextual covariates using both standard Cox proportional survival models and nested, spatial random-effects survival models.Results: Using standard Cox models, we calculated HRs of 1.15 (95% CI: 1.13, 1.16) from nonaccidental causes and 1.31 (95% CI: 1.27, 1.35) from ischemic heart disease for each 10-μg/m³ increase in concentrations of PM_2.5. Using spatial random-effects models controlling for the same variables, we calculated HRs of 1.10 (95% CI: 1.05, 1.15) and 1.30 (95% CI: 1.18, 1.43), respectively. We found similar associations between nonaccidental mortality and PM_2.5 based on satellite-derived estimates and ground-based measurements in a subanalysis of subjects in 11 cities.Conclusions: In this large national cohort of nonimmigrant Canadians, mortality was associated with long-term exposure to PM_2.5. Associations were observed with exposures to PM_2.5 at concentrations that were predominantly lower (mean, 8.7 μg/m³; interquartile range, 6.2 μg/m³) than those reported previously.     

Temporal variation in the association between benzene and leukemia mortality

BACKGROUND: Benzene is a human carcinogen. Exposure to benzene occurs in occupational and environmental settings. OBJECTIVE: I evaluated variation in benzene-related leukemia with age at exposure and time since exposure. METHODS: I evaluated data from a cohort of 1,845 rubber hydrochloride workers. Benzene exposure-leukemia mortality trends were estimated by applying proportional hazards regression methods. Temporal variation in the impact of benzene on leukemia rates was assessed via exposure time windows and fitting of a multistage cancer model. RESULTS: The association between leukemia mortality and benzene exposures was of greatest magnitude in the 10 years immediately after exposure [relative rate (RR) at 10 ppm-years = 1.19; 95% confidence interval (CI), 1.10-1.29]; the association was of smaller magnitude in the period 10 to < 20 years after exposure (RR at 10 ppm-years = 1.05; 95% CI, 0.97-1.13); and there was no evidence of association > or = 20 years after exposure. Leukemia was more strongly associated with benzene exposures accrued at > or = 45 years of age (RR at 10 ppm-years = 1.11; 95% CI, 1.04-1.17) than with exposures accrued at younger ages (RR at 10 ppm-years = 1.01; 95% CI, 0.92-1.09). Jointly, these temporal effects can be efficiently modeled as a multistage process in which benzene exposure affects the penultimate stage in disease induction. CONCLUSIONS: Further attention should be given to evaluating the susceptibility of older workers to benzene-induced leukemia.     

Impact of intensive care unit-acquired infection on hospital mortality in Japan: A multicenter cohort study

Objectives To elucidate factors associated with hospital mortality in intensive care unit (ICU) patients and to evaluate the impact of ICU-acquired infection on hospital mortality in the context of the drug resistance of pathogens. Methods By using the Japanese Nosocomial Infection Surveillance (JANIS) database, 7,374 patients who were admitted to the 34 participating ICUs between July 2000 and May 2002, were aged 16 years or older, and who stayed in the ICU for 48 to 1,000 hours, did not transfer to another ICU, and did not become infected within 2 days after ICU admission, were followed up until hospital discharge or to Day 180 after ICU discharge. Adjusted hazard ratios (HRs) with the 95% confidence intervals (CIs) for hospital mortality were calculated using Cox’s proportional hazard model. Results After adjusting for sex, age, and severity-of-illness (APACHE II score), a significantly higher HR for hospital mortality was found in ventilator use, central venous catheter use, and ICU-acquired drug-resistant infection, with a significantly lower HR in elective or urgent operations and urinary catheter use. The impact of ICU-acquired infection on hospital mortality was different between drug-susceptible pathogens (HR 1.11,95% CI:0.94–1.31) and drug-resistant pathogens (HR 1.42,95% CI: 1.15–1.77). Conclusions The use of a ventilator or a central venous catheter, and ICU-acquired drug-resistant infection were associated with a high risk of hospital mortality in ICU patients. The potential impact on hospital mortality emphasizes the importance of preventive measures against ICU-acquired infections, especially those caused by drug-resistant pathogens.     

Association of Dietary Fiber Intake with All-Cause Mortality and Cardiovascular Disease Mortality: A 10-Year Prospective Cohort Study

Although previous studies have established that dietary fiber (DF) intake reduces the total cardiovascular disease (CVD) mortality in general populations, limited studies have been conducted in individuals with pre-existing chronic conditions, especially in Asian countries. We aimed to investigate the association of DF intake with all-cause and CVD mortality in the general population and in the subpopulation with hypertension, diabetes, and dyslipidemia. We examined the relationship between DF intake and all-cause and CVD mortality using the Korean genome and epidemiology study. Diet was assessed using a food-frequency questionnaire at baseline. Cox proportional hazard models were used to estimate the hazard ratio (HR) and 95% confidence intervals (CIs) after adjusting for confounders. During the mean 10.1 years of follow-up, higher DF intake was significantly associated with a lower risk of all-cause mortality after adjusting for confounders (HR and 95% CIs for Q5 vs. Q1: 0.84 (0.76–0.93); p < 0.001). DF intake was inversely associated with a lower risk of CVD mortality after adjusting for the same confounders (HR and 95% CIs for Q5 vs. Q1: 0.61 (0.47–0.78); p < 0.001). Total DF intake was inversely associated with all-cause and CVD mortality in middle-aged and older adults.     

An update of a mortality study of talc miners and millers in Italy

BACKGROUND: While talc containing asbestiform fibers is considered a human carcinogen, only limited animal and human data are available on non-asbestiform talc. To provide further evaluation on the issue, we updated the analysis of an Italian cohort of talc miners and millers in Val Chisone; talc found here is free from asbestiform fibers. METHODS: The cohort was comprised of 1,795 men who had worked for at least 1 year in the mine and/or in the factory between 1946 and 1995. Vital status and death certificates were obtained from registration offices in the municipality of death or of birth. Employment, termination of employment, and detailed job history were obtained from personnel records at the plant. RESULTS: No excess was found for total cancer mortality, nor mortality for lung cancer. No case of mesothelioma was reported. There was a significant excess mortality from non-neoplastic respiratory diseases (SMR 228.2, 95% CI 190.2-271.5). Mortality excess for non-neoplastic respiratory diseases was mainly due to silicosis. CONCLUSIONS: This study provides additional support for an association between talc in mining and milling and non-neoplastic respiratory diseases, while showing no significant excess risk for lung cancer and mesothelioma. The results also provide additional information of interest to evaluate the potential association between silica and lung cancer.     

The Association between Dietary Purine Intake and Mortality: Evidence from the CHNS Cohort Study

Objectives: To investigate the association between dietary purine intake and mortality among Chinese adults. Methods: Based on data from the 2004–2015 China Health and Nutrition Survey (CHNS) and the corresponding edition of China Food Composition, the average purine intake per day (mg/day) from 2004 to 2011 was calculated, and the surveyed population was divided into five groups by quintiles. The outcome event and timepoint of concern were defined as death and time, respectively, as reported by family members, recorded until the 2015 survey. Cox proportional hazards regression was used to estimate the hazard ratios (HRs) with 95% confidence intervals (CIs) for death. The possibly nonlinear relationship between purine intake and mortality was examined with restricted cubic splines. Results: We included 17,755 subjects, and the average purine intake among them was 355.07 ± 145.32 mg/day. Purine intake was inversely associated with mortality (P_trend < 0.001). Compared with the lowest quintiles of purine intake, the highest quintiles (HR = 0.60; 95% CI: 0.46, 0.77) showed a significant association with lower mortality. The negative association with mortality was mainly found in plant-derived purine (P_trend = 0.001) and, weakly, in animal-derived purine (P_trend = 0.052). In addition, a U-shaped relationship between purine intake and mortality was observed in males; however, there was no statistically significant dose–response relationship in females. Conclusion: Considering the low-purine-intake levels of the Chinese population, we observed a U-shaped relationship between purine intake and mortality in males, but purine intake may not relate to mortality in females. Future studies should investigate the causal relationship between purine intake and disease burden in China.