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from the electoral list for Montreal, and frequency-matched to cases using 5-year age groups. We elicited information on occupational history and potential risk factors. An occupational hygienist coded all jobs to the International Standard Classification of Occupations 1988 (ISCO88); these occupation codes were linked to an ELF-MF job exposure matrix (JEM) to obtain mean workday-average ELF-MF exposure. Logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) for incident breast cancer and past ELF-MF cumulative exposure (CE) and average exposure (AE), adjusting for individual-level and ecological covariates. Separate analyses were conducted restricting exposure before the first full-term pregnancy or age 35 for women who were never pregnant and for hormonal receptor phenotypes.Results We recruited 592 controls and 663 cases. The fully adjusted ORs per increase in the interquartile range (IQR=2.12 mT-years) of CE was 0.99 (95% CI: 0.94-1.06) and for AE (IQR=1.54 mT) was 0.96 (95% CI: 0.90-1.02). The associations between breast cancer and ELF-MF CE and AE were consistent with linearity. Adjustments for various combinations of potential confounders did not change these patterns. We found no evidence of associations for different breast cancer subtypes or exposure before the first full-term pregnancy or the age of 35. Conclusions Our findings suggest that occupational exposure to ELF-MF, assigned here using a JEM, may not be associated with the risk of incident postmenopausal breast cancer.

Background: Lyme disease is the most common vector-borne illness in the United States. Incidence is related to specific environmental conditions such as temperature, metrics of land cover, and species diversity. Objective: To determine whether greenness, as measured by the Normalized Difference Vegetation Index (NDVI), and other selected indices of land cover were associated with the incidence of Lyme disease in the northeastern USA, 2000-2018. Materials and Methods: We conducted an ecological analysis of incidence rates in counties of 15 high incidence states and the District of Columbia for 2000-2018. Annual counts of Lyme disease by county were obtained from the US Centers for Disease Control and values of NDVI were acquired from the Moderate Resolution Imaging Spectroradiometer instrument aboard Terra and Aqua Satellites. County-specific values of population density, area of land and water were obtained from the US Census. Using quasi-Poisson regression, multivariable associations were estimated between the incidence of Lyme disease NDVI, land cover variables, human population density, and calendar year. Results: We found that incidence increased by 7.1% per year (95% confidence interval: 6.8-8.2%). Land cover variables showed complex non-linear associations with incidence: average county-specific NDVI showed a u-shaped association, the standard deviation of NDVI showed a monotonic upward relationship, population density showed a decreasing trend, areas of land and water showed n-shaped relationships. We found an interaction between average and standard deviation of NDVI, with the highest average NDVI category, increased standard deviation of NDVI showed the greatest increase in rates. Discussion: These associations cannot be interpreted as causal but indicate that certain patterns of land cover may have the potential to increase exposure to infected ticks and thereby may contribute indirectly to increased rates. Public health interventions could make use of these results in informing people where risks may be high.

BackgroundBreast cancer is the most diagnosed cancer among women and recognized risk factors explain 25%–47% of cases. Organic solvents are used widely in the workplace and exposure may increase the risk of developing breast cancer, yet there are insufficient data to confirm this hypothesis. We sought to determine whether past occupational exposures to selected organic solvents were associated with the incidence of invasive breast cancer in postmenopausal women in Montréal, Canada.MethodsFrom a population‐based case–control study (2008–2011), using in‐depth interviews we elicited information on risk factors and lifetime occupational histories. Industrial hygienists and chemists translated job descriptions into specific chemical and physical exposures. We assessed 11 individual solvents and four solvent groups. Unconditional logistic regression was used to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for metrics of past exposures to selected solvents. Exposure metrics included any previous exposure, average frequency in hours per week, duration in years, and average cumulative concentration weighted by hours per workweek exposed.ResultsWe enrolled 695 cases and 608 controls. We found increased ORs for average cumulative concentration of exposure to mononuclear aromatic hydrocarbons (OR: 1.52, 95% CI: 1.04, 2.28), chlorinated alkanes (OR: 2.42, 95% CI: 1.23, 5.68), toluene (OR: 1.59, 95% CI: 1.02, 2.59), and a group of organic solvents with reactive metabolites (OR: 1.53, 95% CI: 1.08, 2.24). Positive associations were found across all exposure metrics and were higher among women with estrogen‐positive/progesterone‐negative tumors.ConclusionOur findings suggest occupational exposure to certain organic solvents may increase the risk of incident postmenopausal breast cancer.