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

© 2018, Cancer Research UK. 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

Methodologic Issues in the Studies of Childhood Leukemia and Overhead Power Lines

Aims: While studies have consistently found an association between childhood leukemia risk and magnetic fields, similar associations between childhood leukemia and distance to overhead power lines suggest that other factors associated with magnetic fields and proximity to overhead power lines may be responsible for observed associations including bias, confounding, or other methodologic challenges, particularly when it comes to residential mobility and dwelling type. Methods: First, 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. We then analyzed a single study from California to assess predictors of residential mobility between birth and diagnosis, and account for potential confounding due to residential mobility. Next, we simulated a synthetic dataset based on that study and used it to assess the sensitivity of electromagnetic field (EMF)-leukemia associations to different scenarios of uncontrolled confounding by mobility under two major hypotheses of the infectious etiology of childhood leukemia; then used the findings to conduct sensitivity analysis and empirically offset the potential bias due to unmeasured mobility in the actual California study. Finally, we assessed whether dwelling type is a risk factor for childhood leukemia, what covariates are related to dwelling type, whether dwelling type behaves as a confounder or as a potential effect measure modifier in the EMF-leukemia relationship.Results: Although we found no material association between childhood leukemia and distance to nearest overhead power line of any voltage, there was a slight increase in risk of leukemia among children living &lt;50 m from 200+ kilovolt power lines, consistent with some previous findings. There was no association found with calculated magnetic fields in this set of studies, however, and odds ratios (ORs) remained unchanged with adjustment for potential confounders in the pooled analysis.In the California study, we found that mobility was strongly associated with age, dwelling type, and SES. Both EMF-leukemia associations were stronger in the stratum of non-movers, too, but adjustment for proxy variables had no effect. In the hybrid-simulation study, 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. In all mobility analyses, only dwelling type seemed to affect the relationship based on a small subset of subjects, However, when expanded to a larger subset, dwelling type was neither associated with childhood leukemia risk, nor functioned as a confounder. Stratification revealed potential effect measure modification by dwelling type only.Conclusion: Although uncontrolled confounding by residential mobility had some impact on the estimated effect of EMF exposures on childhood leukemia, it is unlikely to be the primary explanation for the associations observed between power lines exposure and childhood leukemia. Similarly, dwelling type does not appear to play a significant role as either a risk factor or confounder. Future research should explore the role of dwelling and mobility as an effect measure modifier and potential interaction effects

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.

PurposeResidential 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.MethodsWe 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&nbsp;Line Study dataset.ResultsAs 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.ConclusionsWe 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

Residential mobility and childhood leukemia.

AIMS: Studies of environmental exposures and childhood leukemia studies do not usually account for residential mobility. Yet, in addition to being a potential risk factor, mobility can induce selection bias, confounding, or measurement error in such studies. Using data collected for California Powerline Study (CAPS), we attempt to disentangle the effect of mobility. METHODS: We analyzed data from a population-based case-control study of childhood leukemia using cases who were born in California and diagnosed between 1988 and 2008 and birth certificate controls. We used stratified logistic regression, case-only analysis, and propensity-score adjustments to assess predictors of residential mobility between birth and diagnosis, and account for potential confounding due to residential mobility. RESULTS: Children who moved tended to be older, lived in housing other than single-family homes, had younger mothers and fewer siblings, and were of lower socioeconomic status. Odds ratios for leukemia among non-movers living &lt;50 meters (m) from a 200+ kilovolt line (OR: 1.62; 95% CI: 0.72-3.65) and for calculated fields ≥ 0.4 microTesla (OR: 1.71; 95% CI: 0.65-4.52) were slightly higher than previously reported overall results. Adjustments for propensity scores based on all variables predictive of mobility, including dwelling type, increased odds ratios for leukemia to 2.61 (95% CI: 1.76-3.86) for living &lt; 50 m from a 200 + kilovolt line and to 1.98 (1.11-3.52) for calculated fields. Individual or propensity-score adjustments for all variables, except dwelling type, did not materially change the estimates of power line exposures on childhood leukemia. CONCLUSION: The residential mobility of childhood leukemia cases varied by several sociodemographic characteristics, but not by the distance to the nearest power line or calculated magnetic fields. Mobility appears to be an unlikely explanation for the associations observed between power lines exposure and childhood leukemia

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

PurposeStudies 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.MethodsThe 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.ResultsBased 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.ConclusionOur 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

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

BackgroundFatty 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.MethodsData 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.ResultsA 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 &lt;0.0001).ConclusionsA 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

Serum lipids are associated with nonalcoholic fatty liver disease: a pilot case-control study in Mexico.

BackgroundNonalcoholic fatty liver disease (NAFLD) is a leading cause of chronic liver disease and cirrhosis. NAFLD is mediated by changes in lipid metabolism and known risk factors include obesity, metabolic syndrome, and diabetes. The aim of this study was to better understand differences in the lipid composition of individuals with NAFLD compared to controls, by performing direct infusion lipidomics on serum biospecimens from a cohort study of adults in Mexico.MethodsA nested case-control study was conducted with a sample of 98 NAFLD cases and 100 healthy controls who are participating in an on-going, longitudinal study in Mexico. NAFLD cases were clinically confirmed using elevated liver enzyme tests and liver ultrasound or liver ultrasound elastography, after excluding alcohol abuse, and 100 controls were identified as having at least two consecutive normal alanine aminotransferase (ALT) and aspartate aminotransferase (AST) (&lt; 40 U/L) results in a 6-month period, and a normal liver ultrasound elastography result in January 2018. Samples were analyzed on the Sciex Lipidyzer Platform and quantified with normalization to serum volume. As many as 1100 lipid species can be identified using the Lipidyzer targeted multiple-reaction monitoring list. The association between serum lipids and NAFLD was investigated using analysis of covariance, random forest analysis, and by generating receiver operator characteristic (ROC) curves.ResultsNAFLD cases had differences in total amounts of serum cholesterol esters, lysophosphatidylcholines, sphingomyelins, and triacylglycerols (TAGs), however, other lipid subclasses were similar to controls. Analysis of individual TAG species revealed increased incorporation of saturated fatty acyl tails in serum of NAFLD cases. After adjusting for age, sex, body mass index, and PNPLA3 genotype, a combined panel of ten lipids predicted case or control status better than an area under the ROC curve of 0.83.ConclusionsThese preliminary results indicate that the serum lipidome differs in patients with NAFLD, compared to healthy controls, and suggest that assessing the desaturation state of TAGs or a specific lipid panel may be useful clinical tools for the diagnosis of NAFLD

Intent among Parents to Vaccinate Children before Pediatric COVID-19 Vaccine Recommendations, Minnesota and Los Angeles County, California&mdash;May&ndash;September 2021

Objectives: This study assessed the associations between parent intent to have their child receive the COVID-19 vaccination, and demographic factors and various child activities, including attendance at in-person education or childcare. Methods: Persons undergoing COVID-19 testing residing in Minnesota and Los Angeles County, California with children aged &lt;12 years completed anonymous internet-based surveys between 10 May and 6 September 2021 to assess factors associated with intention to vaccinate their child. Factors influencing the parents&rsquo; decision to have their child attend in-person school or childcare were examined. Estimated adjusted odds rations (AORs, 95% CI) were computed between parents&rsquo; intentions regarding children&rsquo;s COVID-19 vaccination and participation in school and extra-curricular activities using multinomial logistic regression. Results: Compared to parents intending to vaccinate their children (n = 4686 [77.2%]), those undecided (n = 874 [14.4%]) or without intention to vaccinate (n = 508 [8.4%]) tended to be younger, non-White, less educated, and themselves not vaccinated against COVID-19. Their children more commonly participated in sports (aOR:1.51 1.17&ndash;1.95) and in-person faith or community activities (aOR:4.71 3.62&ndash;6.11). A greater proportion of parents without intention to vaccinate (52.5%) indicated that they required no more information to make their decision in comparison to undecided parents (13.2%). They further indicated that additional information regarding vaccine safety and effectiveness would influence their decision. COVID-19 mitigation measures were the most common factors influencing parents&rsquo; decision to have their child attend in-person class or childcare. Conclusions: Several demographic and socioeconomic factors are associated with parents&rsquo; decision whether to vaccinate their &lt;12-year-old children for COVID-19. Child participation in in-person activities was associated with parents&rsquo; intentions not to vaccinate. Tailored communications may be useful to inform parents&rsquo; decisions regarding the safety and effectiveness of vaccination

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 &lt; 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 &lt; 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