Workplace Diesel Exhausts and Gasoline Exposure and Risk of Colorectal Cancer in Four Nordic Countries

Background: Evidence on associations between occupational diesel exhaust and gasoline exposure and colorectal cancer is limited. We aimed to assess the effect of workplace exposure to diesel exhaust and gasoline on the risk of colorectal cancer. Methods: This case-control study included 181,709 colon cancer and 109,227 rectal cancer cases diagnosed between 1961 and 2005 in Finland, Iceland, Norway, and Sweden. Cases and controls were identified from the Nordic Occupational Cancer Study cohort and matched for country, birth year, and sex. Diesel exhaust and gasoline exposure values were assigned by country-specific job-exposure matrices. Odds ratios and 95% confidence intervals were calculated by using conditional logistic regression models. The results were adjusted for physical strain at work and occupational exposure to benzene, formaldehyde, ionizing radiation, chlorinated hydrocarbons, chromium, and wood dust. Results: Diesel exhaust exposure was associated with a small increase in the risk of rectal cancer (odds ratio = 1.05, 95% confidence interval 1.02-1.08). Gasoline exposure was not associated with colorectal cancer risk. Conclusion: This study showed a small risk increase for rectal cancer after workplace diesel exhaust exposure. However, this finding could be due to chance, given the limitations of the study. (C) 2019 Occupational Safety and Health Research Institute, Published by Elsevier Korea LLC.Peer reviewe

Hormone replacement therapy and women's health: umbrella review of interventional and observational studies.

This review aims to undertake an umbrella review of systematic reviews and meta-analyses of observational and interventional studies investigating the role of hormone replacement therapy in the primary and secondary prevention of multiple health and disease outcomes in menopausal women

Menopausal hormone therapy and women's health:An umbrella review

Background: There remains uncertainty about the impact of menopausal hormone therapy (MHT) on women’s health. A systematic, comprehensive assessment of the effects on multiple outcomes is lacking. We conducted an umbrella review to comprehensively summarize evidence on the benefits and harms of MHT across diverse health outcomes. Methods and findings: We searched MEDLINE, EMBASE, and 10 other databases from inception to November 26, 2017, updated on December 17, 2020, to identify systematic reviews or meta-analyses of randomized controlled trials (RCTs) and observational studies investigating effects of MHT, including estrogen-alone therapy (ET) and estrogen plus progestin therapy (EPT), in perimenopausal or postmenopausal women in all countries and settings. All health outcomes in previous systematic reviews were included, including menopausal symptoms, surrogate endpoints, biomarkers, various morbidity outcomes, and mortality. Two investigators independently extracted data and assessed methodological quality of systematic reviews using the updated 16-item AMSTAR 2 instrument. Random-effects robust variance estimation was used to combine effect estimates, and 95% prediction intervals (PIs) were calculated whenever possible. We used the term MHT to encompass ET and EPT, and results are presented for MHT for each outcome, unless otherwise indicated. Sixty systematic reviews were included, involving 102 meta-analyses of RCTs and 38 of observational studies, with 102 unique outcomes. The overall quality of included systematic reviews was moderate to poor. In meta-analyses of RCTs, MHT was beneficial for vasomotor symptoms (frequency: 9 trials, 1,104 women, risk ratio [RR] 0.43, 95% CI 0.33 to 0.57, p [less than] 0.001; severity: 7 trials, 503 women, RR 0.29, 95% CI 0.17 to 0.50, p = 0.002) and all fracture (30 trials, 43,188 women, RR 0.72, 95% CI 0.62 to 0.84, p = 0.002, 95% PI 0.58 to 0.87), as well as vaginal atrophy (intravaginal ET), sexual function, vertebral and nonvertebral fracture, diabetes mellitus, cardiovascular mortality (ET), and colorectal cancer (EPT), but harmful for stroke (17 trials, 37,272 women, RR 1.17, 95% CI 1.05 to 1.29, p = 0.027) and venous thromboembolism (23 trials, 42,292 women, RR 1.60, 95% CI 0.99 to 2.58, p = 0.052, 95% PI 1.03 to 2.99), as well as cardiovascular disease incidence and recurrence, cerebrovascular disease, nonfatal stroke, deep vein thrombosis, gallbladder disease requiring surgery, and lung cancer mortality (EPT). In meta-analyses of observational studies, MHT was associated with decreased risks of cataract, glioma, and esophageal, gastric, and colorectal cancer, but increased risks of pulmonary embolism, cholelithiasis, asthma, meningioma, and thyroid, breast, and ovarian cancer. ET and EPT had opposite effects for endometrial cancer, endometrial hyperplasia, and Alzheimer disease. The major limitations include the inability to address the varying effects of MHT by type, dose, formulation, duration of use, route of administration, and age of initiation and to take into account the quality of individual studies included in the systematic reviews. The study protocol is publicly available on PROSPERO (CRD42017083412). Conclusions: MHT has a complex balance of benefits and harms on multiple health outcomes. Some effects differ qualitatively between ET and EPT. The quality of available evidence is only moderate to poor

Parental occupational exposure to low-frequency magnetic fields and risk of leukaemia in the offspring : findings from the Childhood Leukaemia International Consortium (CLIC)

OBJECTIVES: Previously published studies on parental occupational exposure to extremely low-frequency magnetic fields (ELF-MF) and risk of acute lymphoblastic leukaemia (ALL) and acute myeloid leukaemia (AML) in their offspring were inconsistent. We therefore evaluated this question within the Childhood Leukemia International Consortium. METHODS: We pooled 11 case-control studies including 9723 childhood leukaemia cases and 17 099 controls. Parental occupational ELF-MF exposure was estimated by linking jobs to an ELF-MF job-exposure matrix (JEM). Logistic regression models were used to estimate ORs and 95% CIs in pooled analyses and meta-analyses. RESULTS: ORs from pooled analyses for paternal ELF-MF exposure >0.2 microtesla (µT) at conception were 1.04 (95% CI 0.95 to 1.13) for ALL and 1.06 (95% CI 0.87 to 1.29) for AML, compared with ≤0.2 µT. Corresponding ORs for maternal ELF-MF exposure during pregnancy were 1.00 (95% CI 0.89 to 1.12) for ALL and 0.85 (95% CI 0.61 to 1.16) for AML. No trends of increasing ORs with increasing exposure level were evident. Furthermore, no associations were observed in the meta-analyses. CONCLUSIONS: In this large international dataset applying a comprehensive quantitative JEM, we did not find any associations between parental occupational ELF-MF exposure and childhood leukaemia

Työperäisen altistumisen yhteys leukemian riskiin aikuisilla

Leukemia veren valkosolujen syöpä. Sen neljä yleisintä muotoa ovat akuutti myelooinen leukemia (engl. lyhenne AML), akuutti lymfaattinen leukemia (ALL), krooninen myelooinen leukemia (CML) ja krooninen lymfaattinen leukemia (CLL). Vaikka monilla geneettisillä ja elintapoihin ja –ympäristöön liittyvillä tekijöillä on arvioitu olevan yhteyttä leukemian riskiin, useimmissa tapauksissa näyttö on epäyhtenäistä. Tutkimukseni tavoitteena oli arvioida eräiden ammattialtistusten yhteyttä aikuisten leukemiariskiin. Tutkimus pohjautuu pohjoismaisen ammattisyöpätutkimussarjan (Nordic Occupational Cancer Studies, NOCCA) yhteensä 14,9 miljoonan pohjoismaisen henkilön aineistoon. Näiden henkilöiden ammattitiedot 30-64 vuoden iässä ja tieto syöpään sairastumisesta vuoteen 2003-2005 asti saatiin kansallisista rekistereistä. Tutkimuksessa I verrattiin 53 ammattiluokan leukemiariskiä yleisen väestön leukemiariskiin (AML-tapaukset (n=18 811), CLL-tapaukset (n=20 462) ja muut leukemiatapaukset (n=15 570)). Tutkimuksessa II arvioitiin liuottimille altistumisen ja AML-riskin välistä yhteyttä ( 15 332 AML-tapausta ja 76 660 verrokkia) ja tutkimuksessa III erittäin matalataajuuksisen magneettikenttäaltistuksen ja sähköaltistuspiikkien määräarvioiden yhteyttä AML-riskiin (13 435 AML-tapausta ja 67 175 verrokkia). Tutkimuksessa IV verrattiin ryhmätason (NOCCA-JEM-niminen ammattialtistumatriisi) kosmiselle säteilylle altistumisen arvioita yksilökohtaisiin säteilymittaustietoihin, joita oli saatavissa Säteilyturvakeskuksesta (STUK) (1 535 lentäjää ja 3 487 matkustamohenkilökunnan jäsentä). Tutkimus osoitti leukemian ilmaantuvuuden olevan hieman väestökeskiarvoa suurempi eräissä ammattiluokissa. AML:n riski oli koholla autonkuljettajilla ja elintarviketyöntekijöillä ja CLL:n riski maanviljelijöillä ja konttorityöntekijöillä. Muiden leukemiatyyppien riski oli suurentunut merimiehillä, kemian prosessityöntekijöillä ja myyntiedustajilla. Metsureilla AML:n riski, merimiehillä AML:n ja CLL:n riskit, sekä kalastajilla muiden leukemiatyyppien riski, olivat tilastollisesti merkitsevästi tavanomaista pienempiä. AML:n riski ei liittynyt liuotinaltistuksiin eikä magneettikenttä- tai sähköaltistuksiin. Tutkimus osoitti myös, että kosmisen säteilyn altistusestimaatit poikkeavat toisistaan riippuen siitä, onko arvion lähteenä NOCCA-JEM (ryhmätason ammattialtistumatriisi) vai Säteilyturvakeskuksen mittausaineisto (yksilökohtaiset säteilymittaustiedot). Tutkimuksessa havaitut vaihtelut ammattialakohtaisessa leukemiailmaantuvuudessa olivat melko pieniä ja voisivat johtua työhön liittyvistä kemikaali- tai muista altistuksista. Havaintojemme mukaan ilmiön selittäjiä eivät ole liuotinaltistukset, magneettikentät eivätkä sähköaltistukset. Arvioitaessa lentohenkilökunnan altistumista kosmiselle säteilylle altistusarvioissa havaittiin selviä eroja NOCCA-JEM:n ja yksilöllisiin mittaustietoihin perustuvien arvioiden välillä.Leukemia is a cancer of blood. Its four major types are acute myeloid leukemia (AML), acute lymphocytic leukemia (ALL), chronic myeloid leukemia (CML) and chronic lymphocytic leukemia (CLL). While a number of genetic, life-style, therapeutic and environmental factors have been linked to an increased risk of leukemia, the evidence to date is inconsistent on majority of these factors. The aim of this study was to evaluate associations between various occupational agents and adult leukemia. The study was based on the Nordic Occupational Cancer Studies (NOCCA), which includes 14.9 million persons from the Nordic countries. Occupational information and cancer cases were identified from national cancer registries. In Study I, leukemia incidences (18 811 AML, 20 462 CLL and 15 570 other non-specified leukemia) in 53 occupational categories were compared to corresponding incidences in general population. In Study II, risk of AML associated with occupational exposure to solvents was assessed in a matched case-control study based on 15 332 AML cases and 76 660 controls. In Study III, risk of AML following occupational exposure to low-frequency magnetic fields (ELF-MF) and electrical shocks was evaluated in a matched case-control setting consisting of 13 435 AML cases and 67 175 controls. In Study IV, reliability of NOCCA job-exposure matrix (NOCCA-JEM) was assessed by comparing NOCCA-JEM based cosmic radiation dose estimates to individual dose estimates from Radiation and Nuclear Safety Authority, Finland (STUK) among 5 022 Finnish airline workers (1 535 cockpit and 3 487 cabin crew members). Study I showed that AML incidence among drivers and food workers, CLL incidence among farmers and clerical workers, and incidence of other non-specified leukemia among seamen, other health workers, chemical process workers, and sales agents was slightly elevated. On the other hand, AML incidence among forestry workers and seamen, CLL incidence among seamen, and incidence of other non-specified leukemia among fishermen was significantly reduced compared to general population. Study IV demonstrated large disagreement between NOCCA-JEM and individual dose estimates. In conclusion, observed small leukemia excess in some occupational categories maybe associated with exposure to specific occupational agents. However, studies on solvent, ELF-MF and electrical shocks exposures did not demonstrate any association with adult leukemia. A large disagreement between NOCCA-JEM and individual dose estimates from STUK suggested that NOCCA-JEM can lead to cosmic radiation exposure misclassification in NOCCA studies

Night-shift work and hematological cancers: a population based case–control study in three Nordic countries

Objective The aim of this case–control study was to assess the effect of night-shift work on the risk of hematological cancers. Methods The study included 39 371 leukemia, 56 713 non-Hodgkin lymphoma, 9322 Hodgkin lymphoma, and 26 188 multiple myeloma cases diagnosed between 1961 and 2005 in Finland, Sweden, and Iceland. Five controls for each case were selected from the Nordic Occupational Cancer Study (NOCCA) cohort, matched by year of birth, sex and country. Night-shift exposure was assessed by using the NOCCA job-exposure matrix (JEM). Odds ratios (OR) and 95% confidence intervals (95% CI) were calculated from conditional logistic regression models. Results Overall, night work was not associated with a risk of hematological cancers. We observed a small but non-significantly increased risk for leukemia (OR 1.07, 95% CI 0.99–1.16), especially for acute myeloid leukemia (OR 1.15, 95% CI 0.97–1.36) among workers exposed to a high level of cumulative night work exposure. Night work exposure was not associated with lymphatic cancers and multiple myeloma. Conclusion This study did not support associations between night-shift work and hematological cancers

Benzene exposure at workplace and risk of colorectal cancer in four Nordic countries

Objective: The aim of this case-control study was to assess the effect of occupational benzene exposure on the risk of colorectal cancer, including its subtypes. Methods: The study included 181,709 colon cancer and 109,227 rectal cancer cases diagnosed between 1961 and 2005 in Finland, Iceland, Norway and Sweden. Cases were identified from the Nordic Occupational Cancer Study (NOCCA) cohort. Five controls per case were selected from the same cohort, matched for country, birth year, and sex. Occupational benzene exposure for each study participant was estimated by linking their job titles to country specific job-exposure matrices. Odds ratios (OR) and 95% confidence intervals (CI) were calculated by using conditional logistic regression models. The results were adjusted for physical strain at work, formaldehyde, ionizing radiation and wood dust. Results: Increased risk was observed for all colorectal cancer (OR = 1.12, 95% CI 1.05-1.18) for the high decile of cumulative benzene exposure, indicating a statistically significant dose-response relationship. This excess risk was mainly seen in ascending colon (OR = 1.27, 95% CI 1.13-1.43), and transversal colon (OR = 1.21, 95% CI 1.01-1.41). The ORs in the highest exposure category were markedly higher in women than in men in all subsites of colon and rectum. Conclusion: This study showed an association between workplace benzene exposure and colorectal cancer. The risk was restricted to ascending and transversal colon, and was the strongest among women.Peer reviewe

Perceived physical strain at work and incidence of prostate cancer - A case-control study in Sweden and Finland

The evidence that prostate cancer is associated to physical inactivity is inconsistent. We studied the association of perceived physical workload (PPWL) at work and incidence of prostate cancer in a case-control setting. We used data from the Nordic Occupational Cancer study from Finland and Sweden. Five population controls were selected for each prostate cancer patient, matched on age and country. We had 239,835 cases and 1,199,175 controls in our study. For each case and control we estimated cumulative PPWL based on probability, level and duration of PPWL using the NOCCA Job Exposure Matrix. We then stratified individuals as having no exposure (reference category), low physical activity (below 50th percentile of the exposed), moderate exposure (50th-90th percentile) and high exposure (90th percentile and higher). The hazard ratios for prostate cancer from the lowest to highest cumulative PPWL levels were 0.90 (95% confidence interval 0.89-0.91), 0.88 (0.87-0.89) and 0.93 (0.92-0.95). There was no statistically significant dose response effect of PPWL on prostate cancer incidence. Inclusion of socioeconomic status in the model did not substantially change the result. The results were similar before Prostate Specific Antigen (PSA) testing and during the years of PSA testing in these countries. In summary, individuals with physical strain at work had a lower risk of invasive prostate cancer as compared to individuals without physical strain at work

Night-shift work and hematological cancers: A population based case-control study in three Nordic countries

Objective The aim of this case–control study was to assess the effect of night-shift work on the risk of hematological cancers. Methods The study included 39 371 leukemia, 56 713 non-Hodgkin lymphoma, 9322 Hodgkin lymphoma, and 26 188 multiple myeloma cases diagnosed between 1961 and 2005 in Finland, Sweden, and Iceland. Five controls for each case were selected from the Nordic Occupational Cancer Study (NOCCA) cohort, matched by year of birth, sex and country. Night-shift exposure was assessed by using the NOCCA job-exposure matrix (JEM). Odds ratios (OR) and 95% confidence intervals (95% CI) were calculated from conditional logistic regression models. Results Overall, night work was not associated with a risk of hematological cancers. We observed a small but non-significantly increased risk for leukemia (OR 1.07, 95% CI 0.99–1.16), especially for acute myeloid leukemia (OR 1.15, 95% CI 0.97–1.36) among workers exposed to a high level of cumulative night work exposure. Night work exposure was not associated with lymphatic cancers and multiple myeloma. Conclusion This study did not support associations between night-shift work and hematological cancers