Pooled analysis of recent studies of magnetic fields and childhood leukemia.

BACKGROUND: Over forty epidemiologic studies have addressed an association between measured or calculated extremely-low-frequency magnetic fields (MF) and childhood leukemia. These studies have been aggregated in a series of pooled analyses, but it has been 10 years since the last such. METHODS: We present a pooled analysis combining individual-level data (24,994 cases, 30,769 controls) from four recent studies on MF and childhood leukemia. RESULTS: Unlike previous pooled analyses, we found no increased risk of leukemia among children exposed to greater MF: odds ratio (OR) = 1.01, for exposure ≥0.4 µT (µT) compared with exposures <0.1 µT. Similarly, no association was observed in the subset of acute lymphoblastic leukemia, birth homes, studies using calculated fields, or when geocoding accuracy was ignored. In these studies, there is a decline in risk over time, also evident when we compare three pooled analyses. A meta-analysis of the three pooled analyses overall presents an OR of 1.45 (95% CI: 0.95-2.20) for exposures ≥0.4 µT. CONCLUSIONS: Our results are not in line with previous pooled analysis and show a decrease in effect to no association between MF and childhood leukemia. This could be due to methodological issues, random chance, or a true finding of disappearing effect.

Health Literacy, Knowledge, and Risk Factors for Fatty Liver Disease among Asian American and Pacific Islanders and Latinos in Los Angeles.

BACKGROUND: Fatty liver disease (FLD) is associated with increased risk for hepatocellular carcinoma (HCC) and is associated with rising rates of diabetes and obesity. The prevalence of FLD is rising among Asian American and Pacific Islanders (AAPIs) and Latinos. This study examined health literacy, knowledge, and risk factors for FLD among AAPIs and Latinos in Los Angeles. METHODS: Data from in-person interviews and clinical measures (body mass index (BMI), body fat percentage, and blood pressure) were obtained from adults aged 18-82 years at four health fairs from November 2018 to March 2019. Interviews assessed knowledge about FLD, access to health resources, and satisfaction with current physician. Correct responses to knowledge questions were summed to generate a FLD knowledge score. Linear regression models were used to examine the association between knowledge score and age, sex, and race/ethnicity. RESULTS: A total of 102 subjects were AAPI and 33 were Latino. Over 65% of participants had heard of FLD but demonstrated limited knowledge about FLD. Only 24% of subjects reported receiving FLD resources in their preferred language. Most subjects failed to identify several risk factors and key symptoms of FLD. Mean knowledge score for subjects who had heard of FLD was 7.58 (95% CI 7.15-8.01) out of a possible 16 points, and for those who had not who had not heard of FLD it was 5.71 (5.00-6.42) (p <0.0001). CONCLUSIONS: A lack of culturally competent resources and effective communication strategies between physicians and patients regarding FLD contributes to a lower awareness about the increased risk of FLD among AAPIs and Latinos. Future studies should investigate optimal methods to educate these communities about FLD and its associations with HCC.

The sensitivity of reported effects of EMF on childhood leukemia to uncontrolled confounding by residential mobility: a hybrid simulation study and an empirical analysis using CAPS data.

PURPOSE: Residential mobility is considered as a potential source of confounding in studies assessing environmental exposures, including in studies of electromagnetic field (EMF) exposures and childhood leukemia. METHODS: We present a hybrid simulation study where we simulate a synthetic dataset based on an existing study and use it to assess the sensitivity of EMF-leukemia associations to different scenarios of uncontrolled confounding by mobility under two major hypotheses of the infectious etiology of childhood leukemia. We then used the findings to conduct sensitivity analysis and empirically offset the potential bias due to unmeasured mobility in the California Power Line Study dataset. RESULTS: As expected, the stronger the assumed relationship between mobility and exposure and outcome, the greater the potential bias. However, no scenario created a bias strong enough to completely explain away previously observed associations. CONCLUSIONS: We conclude that uncontrolled confounding by residential mobility had some impact on the estimated effect of EMF exposures on childhood leukemia, but that it was unlikely to be the primary explanation behind previously observed largely consistent, but unexplained associations.

Proximity to overhead power lines and childhood leukaemia: an international pooled analysis.

BACKGROUND: Although studies have consistently found an association between childhood leukaemia risk and magnetic fields, the associations between childhood leukaemia and distance to overhead power lines have been inconsistent. We pooled data from multiple studies to assess the association with distance and evaluate whether it is due to magnetic fields or other factors associated with distance from lines. METHODS: We present a pooled analysis combining individual-level data (29,049 cases and 68,231 controls) from 11 record-based studies. RESULTS: There was no material association between childhood leukaemia and distance to nearest overhead power line of any voltage. Among children living < 50 m from 200 + kV power lines, the adjusted odds ratio for childhood leukaemia was 1.33 (95% CI: 0.92-1.93). The odds ratio was higher among children diagnosed before age 5 years. There was no association with calculated magnetic fields. Odds ratios remained unchanged with adjustment for potential confounders. CONCLUSIONS: In this first comprehensive pooled analysis of childhood leukaemia and distance to power lines, we found a small and imprecise risk for residences < 50 m of 200 + kV lines that was not explained by high magnetic fields. Reasons for the increased risk, found in this and many other studies, remains to be elucidated.

Residential magnetic fields exposure and childhood leukemia: a population-based case-control study in California.

PURPOSE: Studies have reported an increased risk of childhood leukemia associated with exposure to magnetic fields. We conducted a large records-based case-control study of childhood leukemia risk and exposure to magnetic fields from power lines in California. METHODS: The study included 5,788 childhood leukemia cases (born in and diagnosed in California 1986-2008) matched to population-based controls on age and sex. We calculated magnetic fields at birth addresses using geographic information systems, aerial imagery, historical information on load and phasing, and site visits. RESULTS: Based on unconditional logistic regression controlling for age, sex, race/ethnicity, and socioeconomic status using subjects geocoded to a basic standard of accuracy, we report a slight risk deficit in two intermediate exposure groups and a small excess risk in the highest exposure group (odds ratio of 1.50 (95% confidence interval [0.70, 3.23])). Subgroup and sensitivity analyses as well as matched analyses gave similar results. All estimates had wide confidence intervals. CONCLUSION: Our large, statewide, record-based case-control study of childhood leukemia in California does not in itself provide clear evidence of risk associated with greater exposure to magnetic fields from power lines, but could be viewed as consistent with previous findings of increased risk.