Cancer morbidity in nitrate fertilizer workers

Summary A cohort of 2,131 male nitrate fertilizer workers was evaluated for cancer morbidity from 1963 to 1986. No significant increase in total cancer, stomach cancer (5 actual vs 6.7 expected cases), or lung cancer (13 vs 13 expected) was found. On the other hand, 26 actual cases of prostate cancer were observed vs 16 expected cases (standardized morbidity ratio, SMR = 161; 95%, confidence interval, CI = 107–239). This risk increase however, was, not enhanced by applying at least a 10-year latency period. In a cohort of 1,148 male fertilizer workers who had never been exposed to nitrate, there was an increased incidence of lung cancer (SMR = 151,95% CI = 103–220) but not of stomach cancer or prostate cancer. There was no association between airborne nitrate exposure dose and total cancer, stomach cancer, lung cancer or prostate cancer, respectively.     

Adverse birth outcomes associated with open dumpsites in Alaska Native Villages

This retrospective cohort study evaluated adverse birth outcomes in infants whose birth records indicated maternal residence in villages containing dumpsites potentially hazardous to health and environment. Birth records from 1997 to 2001 identified 10,073 eligible infants born to mothers in 197 Alaska Native villages. Outcomes included low or very low birth weight, preterm birth, and intrauterine growth retardation. Infants from mothers in villages with intermediate (odds ratio (OR) = 1.73, 95% confidence interval (CI): 1.06, 2.84) and high (OR = 2.06, 95% CI: 1.28, 3.32) hazard dumpsites had a higher proportion of low birth weight infants than did infants from mothers in the referent category. More infants born to mothers from intermediate (OR = 4.38, 95% CI: 2.20, 8.77) and high (OR = 3.98, 95% CI: 1.93, 8.21) hazard villages suffered from intrauterine growth retardation. On average, infants weighed 36 g less (95% CI: -71.2, -0.8) and 55.4 g less (95% CI: -95.3, -15.6) when born to highly exposed mothers than did infants in the intermediate and low exposure groups, respectively, an effect even larger in births to Alaska Native mothers only. No differences in incidence were detected across exposure levels for other outcomes. This is the first study to evaluate adverse pregnancy outcomes associated with open dumpsites in Alaska Native villages.     

Cancer in Alaskan Indians, Eskimos, and Aleuts, 1969-83: implications for etiology and control

The authors collected and analyzed cancer incidence data for Alaska Natives (Indians, Eskimos, and Aleuts) for the 15-year period 1969-83 by ethnic and linguistic groups. Compared with U.S. whites, observed-to-expected ratios are high in more than one ethnic group for cancer of the nasopharynx, salivary gland, liver, gallbladder, and cervix. Low ratios were found for cancer of the breast, uterus, bladder, and melanoma. In Alaska, Eskimos have the highest risk for cancer of the esophagus and liver and the lowest risk for breast and prostate cancer. Risk for multiple myeloma in Indian men in Alaska exceeds not only those of other Native groups in Alaska but that in U.S. whites as well. Despite the short period studied, increases in cancer incidence over time can be documented for lung cancer in Eskimo men and women combined, and for cervical cancer, especially in Indian women.     

Mortality and cancer incidence in a Swedish art glassworks—an updated cohort study

Aim: To study mortality and cancer incidence, in a Swedish art glassworks producing both heavy and semi-crystal glassware, in an extended cohort of workers over a long time period during which some preventive actions had taken place.Methods: In the updated study, 1,229 men and women were eligible as cohort members during the period 1964–1997. The observed number of cases was compared with expected numbers, as calculated from cause-, age-, gender- and calendar year-specific national rates for mortality and cancer incidence.Results: Among men only, a significant risk was seen for cancer incidence in the colon and rectum [standardised incidence ratio (SIR) 1.92, 95% confidence interval (CI) 1.05–3.23; 14 cases] and increased, but statistically non-significant, risks were also seen for male cases of tumours in the liver/bile ducts and brain. Among women, statistically non-significant risks were seen for tumours in the liver/bile ducts and in the lymphatic and haematopoietic systems. No increased risk for cancer of the lung was found in this updated study. The risk for cancer in the colon/rectum was slightly increased in all work categories, and the increase was statistically significant among male and female unspecified glassworkers (SIR 3.13, 95% CI 1.35–6.16; five male and three female cases). A statistically significantly increased risk for cancer in the liver/bile ducts was seen among refinement workers (SIR 3.96, 95% CI 1.07–10.14; two male and two female cases).Conclusion: Most of the causes of death associated with an elevated standardised mortality ratio (SMR) in the 1985 cohort resulted in lower SMRs in this updated cohort, maybe as a consequence of preventive actions taken at the glassworks. On the other hand, the risk for cancers in the digestive system seems to remain, perhaps due to past asbestos exposure or inhalation/digestion of larger particles in the ambient air.     

Breast cancer survival of American Indian/Alaska Native women, 1973-1996

Summary. Objective: To assess breast cancer mortality rates among American Indian/Alaska Native women compared with non-Hispanic White women in the five years after diagnosis.Methods: Surveillance, Epidemiology, and End Results data from 1973–1996 were used to compare survival in the two races, controlling for age, marital status, stage, and therapy.Results: The adjusted relative hazard of death was 58% higher for American Indian/Alaska Native women than for non-Hispanic White women (HR = 1.58, 95% CI 1.26–2.00). The survival disparity persisted even when limited to women who received definitive therapy, i.e. mastectomy with axillary node dissection or breast-conserving surgery with axillary node dissection and radiation treatment (HR = 1.88, 95% CI 1.40–2.52).Conclusions: American Indian/Alaska Native women were at greater risk for breast cancer mortality than non-Hispanic White women, even when restricted to women who received definitive breast cancer therapy.

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Zusammenfassung. Überlebensraten nach Brustkrebs bei amerikanischen Frauen indianischen Ursprungs und aus Alaska, 1973–1996Fragestellung: Vergleichen der Brustkrebsmortalitätsraten von amerikanischen Frauen indianischen Ursprungs und aus Alaska mit weissen, nicht-lateinamerikanischen Frauen fünf Jahre nach der Diagnose.Methode: Die Surveillance-, epidemiologischen und die Endergebnisse der zwischen 1973 und 1996 erhobenen Daten wurden gebraucht, um das Überleben zwischen den zwei ethni schen Gruppen zu vergleichen, die Daten wurden für Alter, Zivilstand, Entwicklungsstand und Therapie des Krebses kontrolliertErgebnisse: Das angepasste relative Risiko war 58% höher für amerikanischen Frauen indianischen Ursprungs und aus Alaska als für weisse, nicht-lateinamerikanische Frauen (OR = 1,58; 95%-KI 1,26–2,00). Dieser Unterschied bleibt auch dann noch bestehen, wenn nur noch für Frauen mit chirurgischer Therapie, d.h. Brustamputation und Entnahme der Lymphknoten der Achselhöhle oder brusterhaltende Operation mit Entnahme der Lymphknoten der Achselhöhle und Strahlentherapie, gerechnet wurde (OR =1,95%-KI 1,40–2,52).Schlussfolgerung: Amerikanische Frauen indianischen Ursprungs und aus Alaska haben ein grösseres Risiko für Brustkrebsmortalität als weisse, nicht-lateinamerikanische Frauen, sogar wenn der Vergleich nur für Frauen mit einer chirurgischen Therapie gemacht wurde.

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Résumé. Survie post cancer du sein chez les femmes américaines d’origine indienne ou d’Alaska, 1973–1996Objectifs: Comparer les taux de mortalité par cancer du sein cinq ans après le diagnostic chez les femmes américaines d’origine indienne ou d’Alaska et chez les femmes blanches non-hispaniques.Méthodes: Les résultats (surveillance, épidémiologie et issues) enregistrés entre 1973 et 1996 ont été utilisés pour comparer la survie entre les deux groupes ethniques ; ils ont été contrôlés pour l’âge, l’état civil, le stade de développement du cancer et le traitement.Résultats: Le risque relatif ajusté était de 58% supérieur pour les femmes américaines d’origine indienne ou d’Alaska comparé aux femmes blanches non-hispaniques (OR = 1.58, 95% CI 1.26–2.00). La différence de survie restait présente lorsque la comparaison se limitait aux femmes ayant subi des traitements, c’est-à-dire soit une mastectomie avec ablation des nodules axillaires, soit une chirurgie conservatrice du sein avec radiothérapie (OR =1.88, 95% CI 1.40–2.52).Conclusions: Les femmes américaines d’origine indienne ou d’Alaska avaient un plus grand risque de mourir d’un cancer du sein que les femmes blanches non-hispaniques, même lorsque la comparaison était limitée aux femmes ayant bénéficié d’un traitement définitif du cancer de sein.

     

Occupational exposure and lung cancer risk in a coastal area of Northeastern Italy

Summary A case-control study of lung cancer and occupational exposure was conducted in a coastal area of Northeastern Italy where metallurgical and mechanical industries, docks and shipyards are located. Cases comprised 756 men who died of primary lung cancer in a 5-year period. Controls comprised 756 male subjects dying from other causes during the same period. Occupational exposures to lung carcinogens were assessed according to a job title-based approach, using two separate lists of industries/occupations recognized as being causally associated (list A) or suspected of being causally associated (list B) with lung cancer in humans. Exposure to asbestos was classified as absent, possible, or definite. After adjustment for cigarette smoking and place of residence, a significant association was found between lung cancer and occupations in both list A [relative risk (RR) = 2.25, 95% confidence interval (CI) = 1.68–3.03] and list B (RR = 1.33, 95% CI = 1.03–1.71). A significant excess risk was found for workers with definite exposure to asbestos as compared to those with no exposure to lung carcinogens (RR = 1.98, 95% CI = 1.42–2.75). Among occupations with recognized exposure to lung carcinogens other than asbestos, a significant excess risk for lung cancer was observed in iron and metalware workers. In occupational groups with definite exposure to asbestos, elevated risk estimates were found for shipyard workers, dockworkers, carpenters, and electricians. The combined effect of smoking and asbestos was found to be compatible with that expected under a multiplicative model. The overall population-attributable risk (ARp) for cigarette smoking was found to be 87.5%. The ARp estimate for occupations in list A was 16.0%. The estimate increased to 25.3% (95% CI = 16.2–34.4) when occupations in list B were included. The ARp estimate for possible or definite exposure to asbestos was 20.0% (95% CI = 11.5–28.5). With regard to the histologic types of lung cancer, significant associations were found between definite exposure to asbestos and squamous cell carcinoma (RR = 2.00, 95% CI = 1.28-–3.11), small cell carcinoma (RR = 2.11, 95% CI = 1.31–3.39), and adenocarcinoma (RR = 2.16, 95% CI = 1.32–3.53).     

Hepatitis B testing in the families and villages of five young eskimos with primary hepatocellular carcinoma

A 15-year-old female Eskimo and a 22-year-old male Eskimo from a southwestern Alaskan village (population 540) were diagnosed as having primary hepatocellular carcinoma (PHC) in December, 1977. The fathers of both patients also died of PHC. Three additional cases of PHC affecting young Alaskan Eskimos had been diagnosed since 1972, all from neighboring villages. Four of the five young patients were positive for hepatitis B surface antigen (HBsAg), and the family members of three patients were all positive for HBsAg or antibody to this antigen (anti-HBs). The other two families had no members positive for HBsAg. The prevalence of HBsAg in the villages of these patients ranged from 0--5%, and the prevalence of anti-HBs ranged from 3--25%. This part of Alaska has a high rate of infection with hepatitis B virus and an increased incidence of PHC. However, other Alaskan villages of similar ethnic background have considerably higher rates of hepatitis B infection than the four villages described and to date they have no PHC. This suggests that genetic and/or environmental factors in addition to hepatitis B infection may have a role in the etiology of PHC in Alaska.     

Mortality study among workers producing chromate pigments in France

In a follow-up study of 294 men who had worked for at least 6 months in a chromate-producing factory in France between 1958 and 1987, only 16 were lost to follow-up and the number of person-years in the study was 5207. Occupational data were provided by the administration of the plant. The causes of deaths were ascertained from hospital and general practitioners' records. The observed numbers of deaths were compared with the expected numbers based on local rates with adjustment for age, sex and calendar time (standardized mortality ratio, SMR). The overall mortality did not differ significantly from that expected (SMR = 1.20, 95% CI = 0.98–1.47), whereas mortality due to lung cancer was in significant excess (SMR = 3.60, 95% CI = 2.13–5.68). Significantly higher lung cancer SMRs were found for workers whose duration of employment was more than 10 years. A non-significant excess was observed for all forms of digestive tract cancer (SMR = 1.30, 95% CI = 0.60–2.47). There were two cases of brain cancer when 0.24 was expected (SMR = 8.44, 95% CI = 1.02–30.49). No previous report has mentioned an association of brain cancer with chromate pigments; however, because of the small numbers involved, a chance excess should be considered.     

Cancer-Preventive Effects of Drinking Green Tea among a Japanese Population

Background.Laboratory studies have revealed the cancer preventive effects of green tea, so the association between green tea consumption and cancer was examined in a human population.Methods.The association between green tea consumption and cancer incidence was studied in our prospective cohort study of a Japanese population. We surveyed 8,552 individuals over 40 years of age living in a town in Saitama prefecture on their living habits, including daily consumption of green tea. During the 9 years of follow-up study (71,248.5 person-years), we identified a total of 384 cases of cancer in all sites.Results.We found a negative association between green tea consumption and cancer incidence, especially among females drinking more than 10 cups a day. The slowdown in increase of cancer incidence with age observed among females who consumed more than 10 cups a day is consistent with the finding that increased consumption of green tea is associated with later onset of cancer. Age-standardized average annual incidence rate was significantly lower among females who consumed large amounts of green tea. Relative risk (RR) of cancer incidence was also lower among both females (RR = 0.57, 95% CI = 0.33–0.98) and males (RR = 0.68, 95% CI = 0.39–1.21) in groups with the highest consumption, although the preventive effects did not achieve statistical significance among males, even when stratified by smoking and adjusted for alcohol and dietary variables.Conclusion.Our epidemiological study showed that green tea has a potentially preventive effect against cancer among humans.     

The effect of physical activity on breast cancer risk: A cohort study of 30,548 women

Background: In epidemiological studies abundant physical activity has been related to decreased breast cancer risk, though the results have been inconsistent. The purpose of this paper was to study the association of physical activity at leisure and commuting to work and incidence of breast cancer. Methods: The study cohort consisted of 30,548 female participants of the Finnish adult health behaviour survey, based on annual random samples of Finns aged 15–64, collected in 1978–1993. By the end of 1995, 332 breast cancer cases had been diagnosed in the cohort. Relative risks of breast cancer were adjusted for age at survey, body mass index (BMI), education, length of follow-up, parity and age at first birth using Poisson regression models. Results: Compared to women exercising less than once a week, the adjusted relative risk of breast cancer for women exercising once a week was 0.80 (95% confidence interval (CI): 0.58–1.10), for women exercising 2–3 times per week 0.92 (95% CI: 0.78–1.22) and for women exercising daily 1.01 (95% CI: 0.72–1.42). Women who reported commuting, walking or bicycling to work 30 min or more daily had slightly lower adjusted risk of breast cancer (RR: 0.87, 95% CI: 0.62–1.24) than women working at home, being unemployed or driving a car to working place. Conclusion: Although a small protective effect of regular physical activity for breast cancer incidence was found in physical activity when commuting to work, the role of the physical activity in breast cancer prevention is still an open question.     

An updated cohort mortality study of workers at a northeastern United States petroleum refinery

An update of a cohort study of 4855 employees at a Paulsboro, New Jersey refinery was conducted to further examine mortality patterns. The earlier study investigated refinery workers employed for a minimum of 1 year between 1 January 1946 and 1 January 1979. The vital status of these workers was ascertained through 1979. The update extended enrollment in the study and vital status follow-up for an additional 8 years (1980–1987). As in the previous study, mortality from all causes [standardized mortality ratio (SMR) = 87; 95% confidence interval (95% CI): 83–91] was significantly lower than expected compared with the general population. Total cancer mortality was also lower than expected (SMR = 96; 95% CI: 86–106). A borderline significant mortality increase in prostatic cancer was found (SMR = 144; 95% CI: 106–190). This increase was similar to the nonsignificant increase reported in the original study (SMR = 135; 95% CI: 90–196). The excess was of comparable magnitude among white males and nonwhite males, although it was not significant for the latter. Detailed analysis indicated that the prostatic cancer was not likely to be related to employment at the refinery. Mortality from lymphatic and hematopoietic cancers was similar to the expected mortality. Mortality from overall leukemia was as expected and detailed analyses by specific cell type showed no increase. An increase in mortality occurred from non-Hodgkin's lymphoma among male workers (SMR = 132; 95% CI: 74–217). The increase was not statistically significant and unlikely to be associated with refinery employment. Mortality from multiple myeloma among male employees was lower than expected (SMR = 74; 95% CI: 20–190). Mortality from asbestos-related diseases (pulmonary fibrosis, lung cancer, malignant mesothelioma) was also lower than expected among male workers. No cause-specific mortality was found to be associated with duration of employment at the refinery, including several causes which have been reported to be elevated in previous studies. The findings of this updated study indicate, as in the previous report, the generally favorable mortality experience of Paulsboro refinery workers.The work for this study was performed at Mobil Corporate Medical Department     

Bladder cancer and black tobacco cigarette smoking

A retrospective study was planned in the Hérault (Mediterranean) region of France where bladder cancer mortality and incidence rates are high. In the present paper, variations in bladder cancer risk according to various smoking-related variables, in particular time of exposure and type of tobacco, are examined. This case-control study with 219 male incident cases and 794 male population controls randomized from electoral rolls was carried out in 1987–89. Trained interviewers obtained information on demographics, dietary habits (coffee, alcohol, artificial sweeteners, vegetables, spices, etc.), occupational exposures and detailed history of tobacco smoking (average number of cigarettes per day, number of years of smoking, age at which they began and/or quitted smoking, use of filter-tip and type of tobacco). The odds ratio (OR) for cigarette smokers versus non-smokers was greater than 5. Results for number of cigarettes daily, duration of smoking and lifetime smoking showed a highly significant dose-response relationship, which was confirmed when these variables were treated as continuous in a logistic regression model. Eighty-eight percent of the smokers used black tobacco. Quitting smoking did not result in a significant reduction in bladder cancer risk. Higher risks were associated with starting to smoke at an early age (OR before age 13 versus after age 21=3.42; 95% CI 1.07–10.9) and with black tobacco smoking (OR black versus blond =1.63; 95% CI 0.73–3.64). Results suggest that black tobacco may be more harmful than blond tobacco and may have an early non-reversible role in bladder carcinogenesis.     

Postmenopausal Estrogen Use and Invasive versus in situ Breast Cancer Risk

To examine the effect of cancer histopathology on the relationship between estrogen-replacement therapy (ERT) use and breast cancer risk, we performed a case-control study of 109 postmenopausal women 45 years or older with in situ or invasive breast cancer matched to 545 controls. When in situ and invasive tumors were combined, the overall odds ratio (OR) describing the association between ERT use and breast cancer risk was not statistically significantly elevated (adjusted OR = 1.48, 95% confidence interval [CI] = 0.89–2.47). When the analyses were confined to women with invasive disease, risk estimates were uniformly higher (adjusted OR = 1.85, 95% CI = 1.00–3.45). In contrast, the overall estimate for the relationship between ERT use and in situ breast cancer was close to 1 (adjusted OR = 1.08, 95% CI = 0.42–2.77). The positive association between ERT use and invasive breast cancer we observed, and the lack of association in women with in situ disease, may represent a distinct biological difference or may be related to the small sample size of our study.     

Three Maternal Risk Factors Associated with Elevated Risk of Postneonatal Mortality Among Alaska Native Population

Objective Compared to non-Natives in Alaska, the Alaska Native population has a postneonatal mortality rate 2.3 times higher (95% CI 1.9, 2.7). The objective of the study was to identify variables that account for this elevated risk. Methods The dataset used included birth and death certificate records for all Alaska-resident live births and infant deaths occurring during 1992–2004. Race was defined as Alaska Native or non-Native. The association between race and postneonatal mortality was examined using univariate, stratified and regression analyses. Variables were considered confounding if they resulted in a change of at least 10% in the odds ratio between race and postneonatal mortality when added to a bivariate model, or when removed from a multivariate model. Results In stratified analysis, race remained associated with postneonatal mortality within most categories of marital status, maternal education, maternal age, prenatal tobacco or alcohol use, prenatal care utilization, parity and residence. The odds ratio between race and postneonatal mortality was reduced to 1.3 (95% CI 1.0, 1.6) by controlling for education, a composite variable of marital status and the presence of father’s name on the birth certificate, and prenatal tobacco or alcohol use. Conclusions A small number of potentially modifiable factors explain most of the postneonatal mortality disparity between Alaska Natives and non-Natives, leaving a relatively small increase in risk. These findings suggest that by targeting Alaska Native women who display these characteristics, the postneonatal mortality gap may be reduced.     

Risk factors for laryngeal cancer

This case-control study comprised 100 histologically verified laryngeal cancer patients and 100 hospital controls matched with cases by sex, age and place of residence. The following variables were tested for their association with cancer of the larynx: marital status, educational level, hard liquor consumption, cigarette smoking, unfavorable working conditions, sudden and frequent temperature changes at work, cold housing, loud speech at work, frequent hoarseness, frequent and persistent cough, persistently swollen neck glands, tonsillectomy and laryngeal surgery. According to conditional logistic regression analysis, significant association with laryngeal cancer was found for unfavourable working conditions for more than 10 years (OR=4.36; 95% CI=1.92–9.91), hard liquor consumption for more than 5 years (OR=2.59; 95% CI=1.14–5.87), cigarette smoking for more than 10 years (OR=7.29; 95% CI=2.41–22.09), tonsillectomy (OR=4.80; 95% CI=1.61–14.30) and frequent and persistent cough prior to disease (OR=8.17; 95% CI=1.72–38.76).     

Updated Trends in Cancer in Japan: Incidence in 1985–2015 and Mortality in 1958–2018—A Sign of Decrease in Cancer Incidence

BackgroundUnlike many North American and European countries, Japan has observed a continuous increase in cancer incidence over the last few decades. We examined the most recent trends in population-based cancer incidence and mortality in Japan.MethodsNational cancer mortality data between 1958 and 2018 were obtained from published vital statistics. Cancer incidence data between 1985 and 2015 were obtained from high-quality population-based cancer registries maintained by three prefectures (Yamagata, Fukui, and Nagasaki). Trends in age-standardized rates (ASR) were examined using Joinpoint regression analysis.ResultsFor males, all-cancer incidence increased between 1985 and 1996 (annual percent change [APC] +1.1%; 95% confidence interval [CI], 0.7–1.5%), increased again in 2000–2010 (+1.3%; 95% CI, 0.9–1.8%), and then decreased until 2015 (−1.4%; 95% CI, −2.5 to −0.3%). For females, all-cancer incidence increased until 2010 (+0.8%; 95% CI, 0.6–0.9% in 1985–2004 and +2.4%; 95% CI, 1.3–3.4% in 2004–2010), and stabilized thereafter until 2015. The post-2000 increase was mainly attributable to prostate in males and breast in females, which slowed or levelled during the first decade of the 2000s. After a sustained increase, all-cancer mortality for males decreased in 1996–2013 (−1.6%; 95% CI, −1.6 to −1.5%) and accelerated thereafter until 2018 (−2.5%; 95% CI, −2.9 to −2.0%). All-cancer mortality for females decreased intermittently throughout the observation period, with the most recent APC of −1.0% (95% CI, −1.1 to −0.9%) in 2003–2018. The recent decreases in mortality in both sexes, and in incidence in males, were mainly attributable to stomach, liver, and male lung cancers.ConclusionThe ASR of all-cancer incidence began decreasing significantly in males and levelled off in females in 2010.Key words: incidence, mortality, neoplasms, population surveillance, vital statistics     

Cancer incidence among male Norwegian asphalt workers

BACKGROUND: The main objective of the present study was to investigate whether exposure to bitumen fumes could enhance the risk of cancer in asphalt workers. METHODS: A historical prospective cohort study was performed including 8,763 male asphalt workers from all main asphalt companies in Norway. Name, date of birth, and unique personal identification number, address, job type, and start and stop of employment in specific jobs was obtained for the workers. Information was complied from payroll and personnel records in the companies. The cohort was then linked to the Cancer Registry of Norway, which has complete records of individual cases of cancer in the Norwegian population since 1953. Follow-up was from 1 January 1970 to 31 December 1997. The 5-year age and period adjusted general male population in Norway served as reference population. RESULTS: Lung cancer was found elevated with standardized incidence ratio (SIR) = 1.3 (95% confidence intervals (CI) = 1.1, 1.7) in the overall analysis. Lung cancer was found more elevated in workers first exposed in the 1950s and 1960s and in mastic asphalt workers (SIR = 4.2, 95% CI = 1.2, 10, based on four cases) and pavers (SIR = 1.4, 95% CI = 1.0, 1.9). There was a deficiency in the incidence of malignant melanoma with 13 cases versus 26 expected. CONCLUSIONS: Risk of lung cancer was found enhanced among the asphalt workers. Some of the enhanced risk could probably be explained by the smoking habits of the workers. Exposure to coal tar may also have contributed to the enhanced risk.     

Invasive pneumococcal disease epidemiology and effectiveness of 23-valent pneumococcal polysaccharide vaccine in Alaska native adults

Alaska Native persons have age-adjusted invasive pneumococcal disease (IPD) rates two- to three-fold greater than non-Native Alaskans. To characterize IPD epidemiology and 23-valent polysaccharide pneumococcal vaccine (PPV-23) effectiveness in Alaska Native adults we reviewed IPD cases from Alaska-wide, laboratory-based surveillance. Sterile site isolates were serotyped. Vaccine effectiveness (VE) was estimated using the indirect cohort method. 394 cases (44.5 cases/100,000/year) occurred in 374 Alaska Native adults (36.0% aged > or =55 years). Underlying conditions included heavy alcohol use (65.7%), smoking (60.8%) and COPD (25.0%). Overall VE was 75% (95% confidence interval [CI]: 27%, 91%) but declined with increasing age; for persons > or =55 years (VE=<0; 95% CI: <0, 78%; p=0.713). Alaska Native adults experience high rates of IPD. The majority of IPD cases occurred in persons with underlying conditions and behaviors associated with increased risk of IPD in other populations. PPV-23 vaccine effectiveness was confirmed in younger Alaska Native adults but not among adults > or =55 years.     

Cancer morbidity in workers at aluminum foundries and secondary aluminum smelters

In a Swedish cohort of workers (n = 6,454) from seven aluminum foundries and three secondary aluminum (scrap) smelters there was no overall excess risk of cancer among male or female workers less than 85 years of age (males: 325 observed cases, standardized incidence ratio (SIR) 1.02, 95% confidence interval (CI) 0.91–1.13; females: 22 cases, SIR = 0.95, 95% CI = 0.60–1.44). In male workers, however, significantly elevated risk estimates were observed for cancer of the lung (51 cases; SIR = 1.49, 95%CI = 1.11–1.96), anorectal cancer (33 cases; SIR 2.13, 95%CI = 1.47–2.99), and sinonasal cancer (4 cases; SIR = 4.70, 95%CI = 1.28–12.01). There was no increase of urinary bladder or liver cancer. Lung cancer risks were highest in workers with a short duration of employment (<5 years) suggesting determinants of risk related to socioeconomic factors rather than the occupational environment under study, but there were also indications of a lung cancer hazard from sand casting of aluminum for 10 years or more (SIR = 2.10, 95%CI = 1.01–3.87). The increase in anorectal cancer could not be etiologically related to occupational determinants of risk. Sand casting of aluminum aside, the cancer risk in secondary aluminum smelting seems to be lower than in primary aluminum smelting and in iron and steel founding, respectively. Am. J. Ind. Med. 32:467–477, 1997. © 1997 Wiley-Liss, Inc.