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Nazelle A.D.,University of North Carolina at Chapel Hill | Nazelle A.D.,Center for Research in Environmental Epidemiology | Nazelle A.D.,Municipal Institute of Medical Research IMIM Hospital Del Mar | Nazelle A.D.,CIBER ISCIII | And 2 more authors.
Environmental Science and Technology | Year: 2010

States in the USA are required to demonstrate future compliance of criteria air pollutant standards by using both air quality monitors and model outputs. In the case of ozone, the demonstration tests aim at relying heavily on measured values, due to their perceived objectivity and enforceable quality. Weight given to numerical models is diminished by integrating them in the calculations only in a relative sense. For unmonitored locations, the EPA has suggested the use of a spatial interpolation technique to assign current values. We demonstrate that this approach may lead to erroneous assignments of nonattainment and may make it difficult for States to establish future compliance. We propose a method that combines different sources of information to map air pollution, using the Bayesian Maximum Entropy (BME) Framework. The approach gives precedence to measured values and integrates modeled data as a function of model performance. We demonstrate this approach in North Carolina, using the States ozone monitoring network in combination with outputs from the Multiscale Air Quality Simulation Platform (MAQSIP) modeling system. We show that the BME data integration approach, compared to a spatial interpolation of measured data, improves the accuracy and the precision of ozone estimations across the State. © 2010 American Chemical Society.


Basagana X.,Center for Research in Environmental Epidemiology | Basagana X.,Municipal Institute of Medical Research IMIM Hospital del Mar | Basagana X.,CIBER ISCIII | Spiegelman D.,Harvard University
Statistics in Medicine | Year: 2010

Existing study design formulas for longitudinal studies have assumed that the exposure is time-invariant. We derived sample size formulas for studies comparing rates of change by exposure when the exposure varies with time within a subject, focusing on observational studies where this variation is not controlled by the investigator. Two scenarios are considered, one assuming that the effect of exposure on the response is acute and the other assuming that it is cumulative. We show that accurate calculations can often be obtained by providing the intraclass correlation of exposure and the exposure prevalence at each time point. When comparing rates of change, studies with a time-varying exposure are, in general, less efficient than studies with a time-invariant one. We provide a public access program to perform the calculations described in the paper (http://www.hsph.harvard.edu/faculty/spiegelman/optitxs.html). Copyright © 2009 John Wiley & Sons, Ltd.


Zock J.-P.,Center for Research in Environmental Epidemiology | Zock J.-P.,Municipal Institute of Medical Research IMIM Hospital del Mar | Zock J.-P.,CIBER ISCIII | Vizcaya D.,Center for Research in Environmental Epidemiology | And 4 more authors.
Current Opinion in Allergy and Clinical Immunology | Year: 2010

PURPOSE OF REVIEW: The present study summarizes the recent literature on the relation between cleaning exposures and respiratory health, in particular asthma, including reviews, epidemiological surveys, surveillance programmes and exposure studies. The authors also aimed to identify gaps in the current knowledge and to recommend future research on the topic. RECENT FINDINGS: A large international general population study showed an increased risk of new-onset asthma associated with cleaning work, with professional use of cleaning products and with domestic use of cleaning sprays. Three surveillance studies confirm the recognition of occupational asthma cases among cleaners and among others who use cleaning products at work. Six workforce-based studies show that respiratory symptoms are partly work-related, and are associated with certain specific exposures including sprays, chlorine bleach and other disinfectants. SUMMARY: Recent studies have strengthened the evidence of asthma and other adverse respiratory effects in cleaning workers. Similar effects are seen in other settings in which cleaning products are used such as healthcare professionals and homemakers. Both new-onset asthma and work-exacerbated asthma due to cleaning exposures may play a role. Exposure to cleaning sprays, chlorine bleach and other disinfectants may be particularly relevant. The predominant effect mechanisms remain largely unclear and may include both specific sensitization and irritant-related features. © 2010 Wolters Kluwer Health | Lippincott Williams & Wilki.


Grazuleviciene R.,Vytautas Magnus University | Kapustinskiene V.,Vytautas Magnus University | Kapustinskiene V.,Lithuanian University of Health Sciences | Vencloviene J.,Vytautas Magnus University | And 4 more authors.
Occupational and Environmental Medicine | Year: 2013

Objectives Congenital anomalies have been inconsistently associated with maternal crude estimated exposure to drinking water trihalomethane (THM). We investigated the relationship between individual THM uptake during the first trimester of pregnancy and congenital anomalies. Methods We estimated maternal THM uptake for 3074 live births using residential tap water concentrations, drinking water ingestion, showering and bathing, and uptake factors of THM in the blood. Multiple logistic regression was used to investigate the association of THM exposure with congenital anomalies. Results We observed no statistically significant relationships between congenital anomalies and the total THM internal dose. We found little indication of a doseresponse relationship for brominated THM and congenital heart anomalies. The relationship was statistically significant for bromodichloromethane (BDCM) (OR=2.16, 95% CI 1.05 to 4.46, highest vs lowest tertile) during the first month of pregnancy. During the first trimester of pregnancy, the probability of developing heart anomalies increased for every 0.1 μg/d increase in the BDCM and for every 0.01 μg/d increase in the internal dibromochloromethane (DBCM) dose (OR 1.70, 95% CI 1.09 to 2.66, and OR 1.25, 95% CI 1.01 to 1.54, respectively). A dose-response relationship was evident for musculoskeletal anomalies and DBCM exposure during the first and second months of pregnancy, while BDCM exposure tended to increase the risk of urogenital anomalies. Conclusions This study shows some evidence for an association between the internal dose of THM and the risk of congenital anomalies. In particular, increased prenatal exposure to brominated THM might increase the risk of congenital heart and musculoskeletal anomalies.


Suarez D.,Autonomous University of Barcelona | Borras R.,Autonomous University of Barcelona | Basagana X.,Center for Research in Environmental Epidemiology | Basagana X.,Municipal Institute of Medical Research IMIM Hospital Del Mar | Basagana X.,CIBER ISCIII
Epidemiology | Year: 2011

Background: Marginal structural models were developed to address time-varying confounding in nonrandomized exposure effect studies. It is unclear how estimates from marginal structural models and conventional models might differ in real settings. Methods: We systematically reviewed the literature on marginal structural models since 2000. Results: Data to compare marginal structural models and conventional models were obtained from 65 papers reporting 164 exposureoutcome associations. In 58 (40%), estimates differed by at least 20%, and in 18 (11%), the 2 techniques resulted in estimates with opposite interpretations. In 88 papers, marginal structural models were used to analyze real data; only 53 (60%) papers reported the use of stabilized inverse-probability weights and only 28 (32%) reported that they verified that the mean of the stabilized inverseprobability weights was close to 1.0. Conclusions: We found important differences in results from marginal structural models and from conventional models in real studies. Furthermore, reporting of marginal structural models can be improved. © 2011 by Lippincott Williams & Wilkins.


Rojas-Rueda D.,Center for Research in Environmental Epidemiology | Rojas-Rueda D.,Municipal Institute of Medical Research IMIM Hospital del Mar | Rojas-Rueda D.,University Pompeu Fabra | Rojas-Rueda D.,CIBER ISCIII | And 6 more authors.
Preventive Medicine | Year: 2013

Objective: Quantify the health impacts on morbidity of reduced car trips and increased public transport and cycling trips. Methods: A health impact assessment study of morbidity outcomes related to replacing car trips in Barcelona metropolitan (3,231,458 inhabitants). Through 8 different transport scenarios, the number of cases of disease or injuries related to physical activity, particulate matter air pollution <2.5μm (PM2.5) and traffic incidents in travelers was estimated. We also estimate PM2.5 exposure and cases of disease in the general population. Results: A 40% reduction in long-duration car trips substituted by public transport and cycling trips resulted in annual reductions of 127 cases of diabetes, 44 of cardiovascular diseases, 30 of dementia, 16 minor injuries, 0.14 major injuries, 11 of breast cancer and 3 of colon-cancer, amounting to a total reduction of 302 Disability Adjusted Life Years per year in travelers. The reduction in PM2.5 exposure in the general population resulted in annual reductions of 7 cases of low birth weight, 6 of preterm birth, 1 of cardiovascular disease and 1 of lower respiratory tract infection. Conclusions: Transport policies to reduce car trips could produce important health benefits in terms of reduced morbidity, particularly for those who take up active transportation. © 2013 Elsevier Inc.


Garcia-Aymerich J.,Center for Research in Environmental Epidemiology | Garcia-Aymerich J.,Municipal Institute of Medical Research IMIM Hospital del Mar | Garcia-Aymerich J.,CIBER ISCIII | Garcia-Aymerich J.,University Pompeu Fabra | And 6 more authors.
Thorax | Year: 2011

Background: Hospitalisations and their sequelae comprise key morbidities in the natural history of chronic obstructive pulmonary disease (COPD). A study was undertaken to examine the associations between lung function impairment and COPD hospitalisation, and COPD hospitalisation and mortality. Methods: The analysis included a population-based sample of 20 571 participants with complete demographic, lung function, smoking, hospitalisation and mortality data, with 10-year median follow-up. Participants were classified by prebronchodilator lung function according to the modified Global Initiative on Obstructive Lung Disease (GOLD) criteria. Hospitalisations were defined by the presence of a COPD discharge diagnosis (ICD-9 codes 490-496). Incidence rate ratios (IRR) of COPD admissions and hazard ratios (HR) of mortality with respective 95% CI were calculated, adjusted for potential confounders. Results: The prevalence of modified GOLD categories was normal (36%), restricted (15%), GOLD stage 0 (22%), GOLD stage 1 (13%), GOLD stage 2 (11%) and GOLD stages 3 or 4 (3%). Adjusted IRRs (and 95% CI) indicated an increased risk of COPD hospitalisation associated with each COPD stage relative to normal lung function: 4.7 (3.7 to 6.1), 2.1 (1.6 to 2.6), 3.2 (2.6 to 4.0), 8.0 (6.4 to 10.0) and 25.5 (19.5 to 33.4) for the restricted, GOLD stage 0, GOLD stage 1, GOLD stage 2 and GOLD stages 3 or 4, respectively. Hospitalisation for COPD increased the risk of subsequent mortality (HR 2.7, 95% CI 2.5 to 3.0), controlling for severity, number of prior hospitalisations and other potential confounders. The increase in mortality associated with admission was very similar across the modified GOLD stages. Conclusions: COPD severity was associated with a higher rate of severe exacerbations requiring hospitalisation, although severe exacerbations at any stage were associated with a higher risk of short-term and long-term all-cause mortality.


Viel J.-F.,French National Center for Scientific Research | Tiv M.,French National Center for Scientific Research | Moissonnier M.,International Agency for Research on Cancer | Cardis E.,Municipal Institute of Medical Research IMIM Hospital del Mar | Hours M.,INRETS
Environmental Research | Year: 2011

Although measurement of the radiofrequency (RF) exposure can today be performed with personal exposure meters, this approach would be very expensive and time-consuming for large studies, and long term measurements would require considerable commitment of the study participants. Thus, there is a need for validated exposure assessment methods that do not require individual measurements for each study participant. Among the potential predictors, one of the most amenable to being recorded adequately is the day of the week. Drawing upon an existing population-based study, our goal was therefore to assess variability of individual RF exposure across days of the week. The random sample consisted of 34 people who were supplied with a personal exposure meter for seven consecutive days, and kept a time-location-activity diary. A total of 225,414 electric field strength measurements were recorded in 12 different RF bands. Summary statistics were calculated with the robust regression on order statistics method. We found evidence for statistically significant variability of individual RF exposure across days of the week, though the relative magnitude of the differences observed was small. Larger studies are needed to validate these results and determine whether day of the week is an important determinant for inclusion in individual RF exposure prediction models that remain urgently needed to conduct epidemiological studies on potential health effects. © 2011 Elsevier Inc.


Berkowska M.A.,Erasmus Medical Center | Driessen G.J.A.,Erasmus Medical Center | Driessen G.J.A.,Erasmus University Rotterdam | Bikos V.,G Papanicolaou Hospital | And 11 more authors.
Blood | Year: 2011

Multiple distinct memory B-cell subsets have been identified in humans, but it remains unclear how their phenotypic diversity corresponds to the type of responses from which they originate. Especially, the contribution of germinal center-independent responses in humans remains controversial. We defined 6 memory B-cell subsets based on their antigen-experienced phenotype and differential expression of CD27 and IgH isotypes. Molecular characterization of their replication history, Ig somatic hypermutation, and class-switch profiles demonstrated their origin from 3 different pathways. CD27-IgG + and CD27+IgM+ B cells are derived from primary germinal center reactions, and CD27+IgA+ and CD27+IgG+ B cells are from consecutive germinal center responses (pathway 1). In contrast, natural effector and CD27 -IgA+ memory B cells have limited proliferation and are also present in CD40L-deficient patients, reflecting a germinal center-independent origin. Natural effector cells at least in part originate from systemic responses in the splenic marginal zone (pathway 2). CD27 -IgA+ cells share low replication history and dominant Igλ and IgA2 use with gut lamina propria IgA+ B cells, suggesting their common origin from local germinal center-independent responses (pathway 3). Our findings shed light on human germinal center-dependent and -independent B-cell memory formation and provide new opportunities to study these processes in immunologic diseases. © 2011 by The American Society of Hematology.


Carsin A.-E.,National Cancer Registry Ireland | Carsin A.-E.,Center for Research in Environmental Epidemiology | Carsin A.-E.,Municipal Institute of Medical Research IMIM Hospital del Mar | Sharp L.,National Cancer Registry Ireland | Comber H.,National Cancer Registry Ireland
British Journal of Dermatology | Year: 2011

Background: Nonmelanoma skin cancer (NMSC) is the most common cancer in white populations worldwide. International comparisons in incidence are limited because few registries collect comprehensive population-based data. Objectives: We describe spatial, urban/rural and socioeconomic variations in NMSC incidence in Ireland, overall and for basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) separately. Methods: NMSC cases (n = 47 347) diagnosed during 1994-2003 were extracted from the National Cancer Registry. Each case was allocated to a small area (electoral district, ED) based on address at diagnosis. Standardized incidence ratios (SIRs) were calculated and smoothed using a Bayesian conditional autoregressive model. Associations between disease and census-derived area-based socioeconomic factors (unemployment, employment type, early school leavers, deprivation category, population density) were investigated using negative binomial regression. Results: The spatial and socioeconomic distributions differed by subtype, suggesting aetiological differences. For BCC, areas of higher risk were concentrated around the main cities, with small patches on the south and west coast. Higher risks for SCC were seen in the north-east, on the south, mid and north-west coast. BCC risk in males and females, and SCC in males, was significantly higher in those living in the least deprived areas. Risk of BCC and SCC in females was higher in the most densely populated areas. Conclusions: We observed striking geographical variation in NMSC incidence, which cannot be satisfactorily explained on the basis of known risk factors. Differences by deprivation category and population density may reflect better access to cancer surveillance or care, as well as differences in risk factor exposure. ©The Authors BJD ©British Association of Dermatologists 2011.

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