Center for Research in Environmental Epidemiology
Center for Research in Environmental Epidemiology
Cardis E.,Center for Research in Environmental Epidemiology |
Schuz J.,International Agency for Research on Cancer IARC
Cancer Epidemiology | Year: 2011
Background: The rapid increase in mobile telephone use has generated concern about possible health risks of radiofrequency electromagnetic fields from these devices. Methods: A case-control study of 1105 patients with newly diagnosed acoustic neuroma (vestibular schwannoma) and 2145 controls was conducted in 13 countries using a common protocol. Past mobile phone use was assessed by personal interview. In the primary analysis, exposure time was censored at one year before the reference date (date of diagnosis for cases and date of diagnosis of the matched case for controls); analyses censoring exposure at five years before the reference date were also done to allow for a possible longer latent period. Results: The odds ratio (OR) of acoustic neuroma with ever having been a regular mobile phone user was 0.85 (95% confidence interval 0.69-1.04). The OR for ≥10 years after first regular mobile phone use was 0.76 (0.52-1.11). There was no trend of increasing ORs with increasing cumulative call time or cumulative number of calls, with the lowest OR (0.48 (0.30-0.78)) observed in the 9th decile of cumulative call time. In the 10th decile (≥1640. h) of cumulative call time, the OR was 1.32 (0.88-1.97); there were, however, implausible values of reported use in those with ≥1640. h of accumulated mobile phone use. With censoring at 5 years before the reference date the OR for ≥10 years after first regular mobile phone use was 0.83 (0.58-1.19) and for ≥1640. h of cumulative call time it was 2.79 (1.51-5.16), but again with no trend in the lower nine deciles and with the lowest OR in the 9th decile. In general, ORs were not greater in subjects who reported usual phone use on the same side of the head as their tumour than in those who reported it on the opposite side, but it was greater in those in the 10th decile of cumulative hours of use. Conclusions: There was no increase in risk of acoustic neuroma with ever regular use of a mobile phone or for users who began regular use 10 years or more before the reference date. Elevated odds ratios observed at the highest level of cumulative call time could be due to chance, reporting bias or a causal effect. As acoustic neuroma is usually a slowly growing tumour, the interval between introduction of mobile phones and occurrence of the tumour might have been too short to observe an effect, if there is one. © 2011 Elsevier Ltd.
Garcia-Aymerich J.,Center for Research in Environmental Epidemiology |
Pitta F.,Laboratory of Research in Respiratory Physiotherapy LFIP
Clinics in Chest Medicine | Year: 2014
Patients with chronic respiratory diseases are usually physically inactive, which is an important negative prognostic factor. Therefore, promoting regular physical activity is of key importance in reducing morbidity and mortality and improving the quality of life in this population. A current challenge to pulmonary rehabilitation is the need to develop strategies that induce or facilitate the enhancement of daily levels of physical activity. Because exercise training alone, despite improving exercise capacity, does not consistently generate similar improvements in physical activity in daily life, there is also a need to develop behavioral interventions that help to promote activity. © 2014 Elsevier Inc.
Anto J.M.,Center for Research in Environmental Epidemiology
Current Allergy and Asthma Reports | Year: 2012
The present review aims to identify and summarize epidemiologic investigations published during 2011 on the environmental risk factors for asthma. Potentially eligible papers were identified by a MEDLINE search. In total, 1,130 items were retrieved. Based on a broad definition of environment, the following topics were included: obesity, diet, vitamin D, air pollution, farming environment, and social factors. Some of the more relevant contributions included evidence that 1) obesity precedes asthma, 2) fruit consumption is longitudinally associated with a lower risk of asthma and atopy, 3) a comprehensive statewide smoking ban was followed by a reduction in hospital admissions for asthma, 4) asthma is one of the diseases showing the largest burdens due to environmental tobacco smoke, 5) trafficrelated urban air pollution is associated with bronchial inflammation as measured by fractional exhaled nitric oxide and uncontrolled asthma, 6) aeroallergens and desert dust may contribute to the short-term effects of air pollution and asthma, and 7) maternal exposure to air pollution before and during pregnancy may alter the immune competence in offspring. © Springer Science+Business Media, LLC 2012.
Basagana X.,Center for Research in Environmental Epidemiology
American Journal of Epidemiology | Year: 2013
Multiple imputation is a common technique for dealing with missing values and is mostly applied in regression settings. Its application in cluster analysis problems, where the main objective is to classify individuals into homogenous groups, involves several difficulties which are not well characterized in the current literature. In this paper, we propose a framework for applying multiple imputation to cluster analysis when the original data contain missing values. The proposed framework incorporates the selection of the final number of clusters and a variable reduction procedure, which may be needed in data sets where the ratio of the number of persons to the number of variables is small. We suggest some ways to report how the uncertainty due to multiple imputation of missing data affects the cluster analysis outcomes - namely the final number of clusters, the results of a variable selection procedure (if applied), and the assignment of individuals to clusters. The proposed framework is illustrated with data from the Phenotype and Course of Chronic Obstructive Pulmonary Disease (PAC-COPD) Study (Spain, 2004-2008), which aimed to classify patients with chronic obstructive pulmonary disease into different disease subtypes. © 2013 The Author.
Nieuwenhuijsen M.J.,Center for Research in Environmental Epidemiology
Environmental health : a global access science source | Year: 2013
Various epidemiological studies have suggested associations between environmental exposures and pregnancy outcomes. Some studies have tempted to combine information from various epidemiological studies using meta-analysis. We aimed to describe the methodologies used in these recent meta-analyses of environmental exposures and pregnancy outcomes. Furthermore, we aimed to report their main findings. We conducted a bibliographic search with relevant search terms. We obtained and evaluated 16 recent meta-analyses. The number of studies included in each reported meta-analysis varied greatly, with the largest number of studies available for environmental tobacco smoke. Only a small number of the studies reported having followed meta-analysis guidelines or having used a quality rating system. Generally they tested for heterogeneity and publication bias. Publication bias did not occur frequently.The meta-analyses found statistically significant negative associations between environmental tobacco smoke and stillbirth, birth weight and any congenital anomalies; PM2.5 and preterm birth; outdoor air pollution and some congenital anomalies; indoor air pollution from solid fuel use and stillbirth and birth weight; polychlorinated biphenyls (PCB) exposure and birth weight; disinfection by-products in water and stillbirth, small for gestational age and some congenital anomalies; occupational exposure to pesticides and solvents and some congenital anomalies; and agent orange and some congenital anomalies. The number of meta-analyses of environmental exposures and pregnancy outcomes is small and they vary in methodology. They reported statistically significant associations between environmental exposures such as environmental tobacco smoke, air pollution and chemicals and pregnancy outcomes.
Rondeau V.,French Institute of Health and Medical Research |
Mazroui Y.,French Institute of Health and Medical Research |
Gonzalez J.R.,Center for Research in Environmental Epidemiology
Journal of Statistical Software | Year: 2012
Frailty models are very useful for analysing correlated survival data, when observations are clustered into groups or for recurrent events. The aim of this article is to present the new version of an R package called frailtypack. This package allows to fit Cox models and four types of frailty models (shared, nested, joint, additive) that could be useful for several issues within biomedical research. It is well adapted to the analysis of recurrent events such as cancer relapses and/or terminal events (death or lost to follow-up). The approach uses maximum penalized likelihood estimation. Right-censored or left-truncated data are considered. It also allows stratification and time-dependent covariates during analysis.
Carrasco-Turigas G.,Center for Research in Environmental Epidemiology
Journal of environmental and public health | Year: 2013
Disinfection by-products (DBPs) are ubiquitous contaminants in tap drinking water with the potential to produce adverse health effects. Filtering and boiling tap water can lead to changes in the DBP concentrations and modify the exposure through ingestion. Changes in the concentration of 4 individual trihalomethanes (THM4) (chloroform (TCM), bromodichloromethane (BDCM), dibromochloromethane (DBCM), and bromoform (TBM)), MX, and bromate were tested when boiling and filtering high bromine-containing tap water from Barcelona. For filtering, we used a pitcher-type filter and a household reverse osmosis filter; for boiling, an electric kettle, a saucepan, and a microwave were used. Samples were taken before and after each treatment to determine the change in the DBP concentration. pH, conductivity, and free/total chlorine were also measured. A large decrease of THM4 (from 48% to 97%) and MX concentrations was observed for all experiments. Bromine-containing trihalomethanes were mostly eliminated when filtering while chloroform when boiling. There was a large decrease in the concentration of bromate with reverse osmosis, but there was a little effect in the other experiments. These findings suggest that the exposure to THM4 and MX through ingestion is reduced when using these household appliances, while the decrease of bromate is device dependent. This needs to be considered in the exposure assessment of the epidemiological studies.
Vafeiadi M.,Center for Research in Environmental Epidemiology
Environmental health perspectives | Year: 2013
Anogenital distance in animals is used as a measure of fetal androgen action. Prenatal exposure to dioxins and dioxin-like compounds in rodents causes reproductive changes in male offspring and decreases anogenital distance. We assessed whether in utero exposure to dioxins and dioxin-like compounds adversely influences anogenital distance in newborns and young children (median age, 16 months; range, 1-31 months). We measured anogenital distance among participants of the "Rhea" mother-child cohort study in Crete and the Hospital del Mar (HMAR) cohort in Barcelona. Anogenital distance (AGD; anus to upper penis), anoscrotal distance (ASD; anus to scrotum), and penis width (PW) were measured in 119 newborn and 239 young boys; anoclitoral (ACD; anus to clitoris) and anofourchetal distance (AFD; anus to fourchette) were measured in 118 newborn and 223 young girls. We estimated plasma dioxin-like activity in maternal blood samples collected at delivery with the Dioxin-Responsive Chemically Activated LUciferase eXpression (DR CALUX®) bioassay. Anogenital distances were sexually dimorphic, being longer in males than females. Plasma dioxin-like activity was negatively associated with AGD in male newborns. The estimated change in AGD per 10 pg CALUX®-toxic equivalent/g lipid increase was -0.44 mm (95% CI: -0.80, -0.08) after adjusting for confounders. Negative but smaller and nonsignificant associations were observed for AGD in young boys. No associations were found in girls. Male infants may be susceptible to endocrine-disrupting effects of dioxins. Our findings are consistent with the experimental animal evidence used by the Food and Agriculture Organization/World Health Organization to set recommendations for human dioxin intake.
Robinson O.,Center for Research in Environmental Epidemiology |
Vrijheid M.,Center for Research in Environmental Epidemiology
Current environmental health reports | Year: 2015
The exposome concept takes a holistic approach facilitated by new and emerging technologies to describe 'the totality of human environmental (i.e. non-genetic) exposures from conception onwards, complementing the genome'. It provides a framework to advance the environmental epidemiology field that has until now focused almost exclusively on single-exposure health effects. The exposome includes an external domain, measured by methods including geo-spatial modelling, questionnaire and biomonitoring of external exposures while the internal domain is commonly assessed through molecular omics platforms. The internal domain, in part, reflects the biological response to the external domain. New statistical frameworks are required to integrate and assess exposome-health effects. The pregnancy period is a key starting point to describe the dynamic exposome, due to its heightened sensitivity and potential lifetime impact. A handful of studies have started to move towards an exposome approach in assessing the effects of the multiple exposures during pregnancy on child development. New research projects are underway to test the exposome approach on a large scale.
News Article | September 26, 2016
Many of today’s solutions to prevent or treat diseases are often patient-centered. We look at lifestyle changes like exercise or healthy eating. We consider innovative medicines or surgical procedures. But a new trend in addressing global health focuses on the cities in which we live. Are the cities themselves leading us to poorer health? And if so, can a change in city planning improve our health outcomes? According to the United Nations, more than half the world’s population, 54 percent, lives in cities. That number is projected to climb to 66 percent by the year 2050, with much of that growth taking place in Asia and Africa. Many large cities already struggle with infrastructure challenges that can impact health. Cities in developing countries often deal with pollution, inconsistent power and water supply, and sanitation issues. A closer look into just one of these issues, pollution, reveals some alarming statistics. The nonprofit Global Citizen reports that just under half of the 4.4 million children in Delhi, India, live with irreversible lung damage caused by air pollution. Meanwhile, Time magazine reports air pollution leads to 3 million premature deaths each year, with more than two-thirds of those taking place in India and China. These two countries claim four of the top 10 most populous cities in the world, so the impact of air pollution is no surprise. Emissions from millions of vehicles on overcrowded roads and residential heating and cooking create an unhealthy amount of smoke that drives air pollution. Green urban planning, and aggressive policy, may help. Starting in 2016, New Delhi implemented a plan restricting drivers on city roads every other day based on their license plate number to help reduce traffic emissions. The plan, commonly called “road space rationing,” is modeled after a similar plan in Beijing. China has also completed its first real world road test of its Transit Elevated Bus concept. The innovative design encourages public transportation using a bus that straddles the highway, so existing traffic can pass below — and it’s powered by electricity. Developed nations face some different challenges. Physical inactivity, especially among children, is a significant health concern that could lead to chronic illnesses like heart disease, stroke and diabetes. Here in the United States, many children in urban areas lack access to parks, or the parks may not be well-maintained. Simply incorporating accessible, well-maintained, green space in these urban areas could have a long-term impact on the health of the children who live there. According to the Center for Research in Environmental Epidemiology, people who live near green space have longer life expectancy and lower risk of heart disease, obesity, mental health issues, and complications during pregnancy like lower birth weight. Community gardens have also taken root as another planning strategy to impact public health. A study of health impacts of community gardening examined urban agriculture in Toronto, Canada. The authors reported community gardening improves physical activity, improved access to food, and improved nutrition — all of which can boost a community’s health. The authors point to the results as a need for local city planners to continue supporting community gardens. The question remains: Can city planners, in both developed and underdeveloped nations, stay ahead of the impacts of the rising population through innovative green solutions? Global health is at stake, of both our planet and its people.