Krista Yorita Christensen

The Risk of Lung Cancer Related to Dietary Intake of Flavonoids

It has been hypothesized that flavonoids in foods and beverages may reduce cancer risk through antioxidation, inhibition of inflammation, and other antimutagenic and antiproliferative properties. We examined associations between intake of 5 flavonoid subclasses (anthocyanidins, flavan-3-ols, flavones, flavonols, and flavanones) and lung cancer risk in a population-based case-control study in Montreal, Canada (1061 cases and 1425 controls). Flavonoid intake was estimated from a food frequency questionnaire that assessed diet 2 yr prior to diagnosis (cases) or interview (controls). Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using unconditional logistic regression. Overall, total flavonoid intake was not associated with lung cancer risk, the effect being similar regardless of sex and smoking level. However, low flavonoid intake from food, but not from beverages, was associated with an increased risk. The adjusted ORs (95% CIs) comparing the highest vs. the lowest quartiles of intake were 0.63 (0.47–0.85) for total flavonoids, 0.82 (0.61–1.11) for anthocyanidins, 0.67 (0.50–0.90) for flavan-3-ols, 0.68 (0.50–0.93) for flavones, 0.62 (0.45–0.84) for flavonols, and 0.70 (0.53–0.94) for flavanones. An inverse association with total flavone and flavanone intake was observed for squamous cell carcinoma but not adenocarcinoma. In conclusion, low flavonoid intake from food may increase lung cancer risk.

Risk of selected cancers due to occupational exposure to chlorinated solvents in a case-control study in Montreal.

Objective: To evaluate the association between exposure to chlorinated solvents and cancer. Methods: We conducted a case–control study of occupational exposures and cancer in Montreal, Quebec, Canada, including 3730 cancer cases and 533 population controls. Occupational exposures were derived using a combination of subject-reported job history and expert assessment. We examined the associations between two chemical families and six chlorinated solvents with 11 sites of cancer. Results: The majority of the associations examined were null, although many were based on small numbers. We found two significantly elevated odds ratios (ORs), one between perchloroethylene and prostate cancer (OR = 4.3; 95% CI: 1.4 to 13) and another between trichloroethylene and melanoma (OR = 3.2; 95% CI: 1.0 to 9.9). Conclusions: There was little evidence of associations between chlorinated solvents and cancer. Limited power precludes strong inferences about absence of risk. We raise hypotheses about two possible associations: perchloroethylene with prostate cancer and trichloroethylene with melanoma.

Risk of lung cancer associated with six types of chlorinated solvents: results from two case–control studies in Montreal, Canada

Objectives To determine whether exposure to various chlorinated solvents is associated with lung cancer. Methods Two case–control studies of occupation and lung cancer were conducted in Montreal, and included 2016 cases and 2001 population controls. Occupational exposure to a large number of agents was evaluated using a combination of subject-reported job history and expert assessment. We examined associations between lung cancer among men and six specific chlorinated solvents and two chemical families (chlorinated alkanes and alkenes). ORs were calculated using unconditional multivariate logistic regression. Results When the two studies were pooled, there were indications of an increased risk of lung cancer associated with occupational exposure to perchloroethylene (ORany exposure 2.5, 95% CI 1.2 to 5.6; ORsubstantial exposure 2.4, 95% CI 0.8 to 7.7) and to carbon tetrachloride (ORany exposure 1.2, 95% CI 0.8 to 2.1; ORsubstantial exposure 2.5, 95% CI 1.1 to 5.7). No other chlorinated solvents showed both statistically significant associations and dose–response relationships. ORs appeared to be higher among non-smokers. When the lung cancer cases were separated by histological type, there was a suggestion of differential effects by tumour type, but statistical imprecision and multiple testing preclude strong inferences in this regard. Conclusions There were suggestive, albeit inconsistent, indications that exposure to perchloroethylene and carbon tetrachloride may increase the risk of lung cancer. Results for other solvents were compatible with absence of risk.

Low levels of exposure to libby amphibole asbestos and localized pleural thickening.

Objective: To explore the relationship between low levels of exposure to Libby amphibole asbestos (LAA) and pleural abnormalities, specifically localized pleural thickening (LPT). Methods: Three studies presenting the risks associated with quantitative LAA exposure estimates were reviewed, paying particular attention to lower exposure ranges. Results: Studies reviewed were conducted among workers exposed to LAA at mining and milling operations in Libby, Montana, at a vermiculite processing facility in Marysville, Ohio, and community residents exposed to LAA from a vermiculite processing facility in Minneapolis, Minnesota. Pleural abnormalities were evaluated using radiographs. Despite differences in study populations and design, each study found that cumulative inhalation LAA exposure was associated with increased risk of LPT even at low levels of exposure. Conclusions: Inhalation exposure to LAA is associated with increased risk of LPT even at the lowest levels of exposure in each study.

Lack of a protective effect of cotton dust on risk of lung cancer: evidence from two population-based case-control studies

BackgroundLung cancer is the leading cause of cancer death in North America. Exposure to cotton dust has previously been reported to decrease the risk of lung cancer.MethodsWe used data from two large case-control studies conducted in Montreal from 1979-1986 (Study 1) and 1996-2002 (Study 2) respectively, to examine the association between occupational exposure to cotton dust and risk of lung cancer. Cases were diagnosed with incident histologically-confirmed lung cancer (857 in Study 1, 1203 in Study 2). Population controls were randomly selected from electoral lists and frequency-matched to cases by age and sex (533 in Study 1, 1513 in Study 2). Interviews for the two studies used a virtually identical questionnaire to obtain lifetime occupational and smoking history, and several lifestyle covariates. Each participant’s lifetime occupational history was reviewed by experts to assess exposure to a number of occupational agents, including cotton dust. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by unconditional logistic regression, adjusting for potential confounders.ResultsThe lifetime prevalence of exposure to cotton dust was approximately 10%-15% in both studies combined, with some variation by study and by sex. Overall there was no decreased risk of lung cancer among subjects exposed to cotton dust. Rather, among all subjects there was a suggestion of slightly increased risk associated with any lifetime exposure to cotton dust (OR = 1.2, 95% CI: 1.0-1.5). This risk appeared to be concentrated among cases of adenocarcinoma (OR = 1.6, 95% CI: 1.2-2.2), and among moderate and heavy smokers (OR = 1.3, 95% CI: 1.0-1.7). There was no association when restricting to cases of either squamous cell or small cell cancer, or among never smokers and light smokers. An analogous examination of subjects exposed to wool dust revealed neither increased nor decreased risks of lung cancer.ConclusionsThere was no evidence that cotton dust exposure decreased risks of lung cancer.

Fish Consumption, Levels of Nutrients and Contaminants, and Endocrine-Related Health Outcomes Among Older Male Anglers in Wisconsin.

Objective: The aim of this study was to examine associations between endocrine disorders, fish consumption habits, and biomarkers of contaminants and nutrients Methods: Male anglers aged at least 50 years living in Wisconsin (n = 154) completed a questionnaire and provided biological samples. Adjusted logistic regression models were used to evaluate risk factors for endocrine outcomes. Results: Nineteen percent of anglers reported either pre-diabetes or diabetes, while 4.6% reported thyroid disease. There were few associations between endocrine disease and fish consumption, fish meal source, or species, aside from a notable increase in diabetes risk with lake trout consumption. Docosahexaenoic acid, certain polychlorinated biphenyls (PCBs), and perfluorinated compounds were associated with an increased risk of diabetes or pre-diabetes. PCBs were associated with a decreased risk of thyroid disease. Conclusion: Fish consumption patterns may affect risk for endocrine outcomes, but direction and magnitude of association may depend on the balance of the contaminants and nutrients in the individual diet.

Associations Between Fish Consumption and Contaminant Biomarkers With Cardiovascular Conditions Among Older Male Anglers in Wisconsin.

Objective: The aim of this study was to determine fish consumption habits and contaminant exposures associated with adverse cardiovascular outcomes among older male anglers. Methods: One hundred fifty-four men aged 50 years and older living and fishing in Wisconsin completed a detailed survey and provided hair and blood samples. Associations between fish consumption and body burdens of several contaminants, with self-reported cardiovascular outcomes, were evaluated. Results: Consuming fish species with higher methyl mercury content was positively associated with odds of angina, coronary heart disease (CHD), or heart attack, while consuming fattier species was negatively associated with high blood pressure or high cholesterol. Total mercury in blood was associated with 27% higher odds of heart attack, and certain classes of polychlorinated biphenyls were positively associated with CHD. Conclusion: Total mercury exposures may affect cardiovascular outcomes. Educational interventions promoting consumption of fish low in methyl mercury among older male anglers are needed.

Notes from the Field: Occupational Lead Exposures at a Shipyard — Douglas County, Wisconsin, 2016

On March 28, 2016, the Minnesota Poison Control System was consulted by an emergency department provider regarding clinical management of a shipyard worker with a blood lead level (BLL) >60 μg/dL; the National Institute for Occupational Safety and Health defines elevated BLLs as ≥5 μg/dL (1). The Minnesota Poison Control System notified the Minnesota Department of Health (MDH). Concurrently, the Wisconsin Department of Health Services (WDHS) received laboratory reports concerning two workers from the same shipyard with BLLs >40 μg/dL. These three workers had been retrofitting the engine room of a 690-foot vessel since January 4, 2016. Work was suspended during March 29–April 4 in the vessel’s engine room, the presumptive primary source of lead exposure. On March 29, the shipyard partnered with a local occupational health clinic to provide testing for workers. Employees and their household members were also tested by general practitioners and local laboratories. The shipyard hired sanitation crews for lead clean-up and abatement and provided personal protective equipment for its employees. On April 1, WDHS and MDH issued advisories to alert regional health care organizations, local public health agencies, and tribal health departments to the situation and launched a joint investigation on April 4. Subsequently, WDHS activated its Incident Command System and worked with MDH to compile a list of potentially exposed workers. By August 31, a total of 357 workers who might have been employed at the shipyard during December 2015–March 2016 had been identified. During April–July 2016, WDHS and MDH attempted telephone interviews with workers. The goal of the interviews was to gather information regarding employment history, work tasks, personal exposure prevention, symptoms commonly associated with lead exposures, and take-home contamination prevention and household composition and to convey health messages. As of August 31, a total of 233 (65.3%) of 357 workers received at least one BLL test and 185 (51.8%) completed interviews. Among 233 tested workers (median = 16.0 μg/dL; interquartile range = 4.4–30.6 μg/dL), 171 (73.4%) had BLLs ≥5 μg/ dL, 151 (64.8%) had BLLs ≥10 μg/dL, 33 (14.2%) had BLLs≥40 μg/dL, and two (0.9%) had BLLs ≥60 μg/dL. Among 341 household members identified through worker interviews, 46 (13.5%) received a BLL test; none had an elevated BLL. Not all exposed workers and household members were tested for lead, and not every BLL test result might have been reported to WDHS or MDH. At this time, WDHS and MDH have concluded their joint investigation of the shipyard. The Occupational Safety and Health Administration enforcement investigation began on February 10, 2016 because of lead exposure hazards and revealed that shipyard workers were exposed to lead at ≥20 times the reduced permissible exposure limit of 40 μg/m3 (2,3). This investigation highlights timely laboratory-based BLL reporting and efficient interstate collaboration. Moreover, it emphasizes the importance of implementing proper engineering controls and periodic BLL monitoring of employees exposed to lead (4) and providing correct personal protective equipment for workers in the shipbuilding industry (3).