Association between rice consumption and risk of cancer incidence in the California Teachers Study

Long-Term Exposure to Arsenic in Community Water Supplies and Risk of Cardiovascular Disease among Women in the California Teachers Study

BACKGROUND

Inorganic arsenic in drinking water (wAs) is linked to atherosclerosis and cardiovascular disease. However, risk is uncertain at lower levels present in US community water supplies (CWS), currently regulated at the federal maximum contaminant level of 10 μ g / L .

OBJECTIVES

We evaluated the relationship between long-term wAs exposure from CWS and cardiovascular disease in the California Teachers Study cohort.

METHODS

Using statewide health care administrative records from enrollment through follow-up (1995-2018), we identified fatal and nonfatal cases of ischemic heart disease (IHD) and cardiovascular disease (CVD). Participants' residential addresses were linked to a network of CWS boundaries and annual wAs concentrations (1990-2020). Most participants resided in areas served by a CWS (92%). Exposure was calculated as a time-varying, 10-year moving average up to a participant's event, death, or end of follow-up. Using Cox models, we estimated hazard ratios (HRs) and 95% confidence intervals (95% CIs) for the risk of IHD or CVD. We evaluated wAs exposure categorized by concentration thresholds relevant to regulation standards (< 1.00 , 1.00-2.99, 3.00-4.99, 5.00-9.99, ≥ 10 μ g / L ) and continuously using a log2-transformation (i.e., per doubling). Models were adjusted for baseline age, neighborhood socioeconomic status, race/ethnicity, body mass index (BMI), and smoking status. We also stratified analyses by age, BMI, and smoking status.

RESULTS

Our analysis included 98,250 participants, 6,119 IHD cases, and 9,936 CVD cases. The HRs for IHD at concentration thresholds (reference, < 1 μ g / L ) were 1.06 (95% CI: 1.00, 1.12), 1.05 (95% CI: 0.94, 1.17), 1.20 (95% CI: 1.02, 1.41), and 1.42 (95% CI: 1.10, 1.84) for 1.00 - 2.99 μ g / L , 3.00 - 4.99 μ g / L , 5.00 - 9.99 μ g / L , and ≥ 10 μ g / L , respectively. HRs for every doubling of wAs exposure were 1.04 (95% CI: 1.02, 1.06) for IHD and 1.02 (95% CI: 1.01, 1.04) for CVD. We observed statistically stronger risk among those ≤ 55 vs. > 55 years of age at enrollment (p interaction = 0.006 and 0.012 for IHD and CVD, respectively).

DISCUSSION

Long-term wAs exposure from CWS, at and below the regulatory limit, may increase cardiovascular disease risk, particularly IHD. https://doi.org/10.1289/EHP14410.

Dietary Manganese Intake and Risk of Liver Cancer in Japanese Men and Women: The JACC Study

We explored the association between dietary manganese intake and the risk of liver cancer in 14,517 men and 21,583 women who participated in the Japan Collaborative Cohort Study for Cancer Risk Assessment. We assessed dietary manganese intake using a food frequency questionnaire and incident liver cancer by reviewing cancer registries. According to manganese intake, we estimated the liver cancer risk by Cox regression analyses. During the 513,657 person-year follow-ups within a median of 17.9 years of 36,100 participants, there were 239 incident cases of liver cancer. The multivariable hazard ratio (HR) (95% confidence interval [CI]; P-trend) for liver cancer risk in the highest vs. the lowest quintiles of dietary manganese intake was 0.56 (0.32-0.99; 0.04) in men and 1.16 (0.56-2.40; 0.79) in women; P-interaction = 0.06. The history of liver disease modified the observed association in men (P-interaction = 0.02), in which the multivariable HR (95%CI) of liver cancer risk comparing the highest vs. lowest quintiles of dietary manganese intake was 0.32 (0.14-0.74) in Japanese men without a history of liver disease, while it was 1.54 (0.62-3.79) in men with a history of liver disease. In conclusion, a higher dietary manganese intake was associated with a lower risk of liver cancer in men without a history of liver disease.