Wireless phone use in childhood and adolescence and neuroepithelial brain tumours: Results from the international MOBI-Kids study

In recent decades, the possibility that use of mobile communicating devices, particularly wireless (mobile and cordless) phones, may increase brain tumour risk, has been a concern, particularly given the considerable increase in their use by young people. MOBI-Kids, a 14-country (Australia, Austria, Canada, France, Germany, Greece, India, Israel, Italy, Japan, Korea, the Netherlands, New Zealand, Spain) case-control study, was conducted to evaluate whether wireless phone use (and particularly resulting exposure to radiofrequency (RF) and extremely low frequency (ELF) electromagnetic fields (EMF)) increases risk of brain tumours in young people. Between 2010 and 2015, the study recruited 899 people with brain tumours aged 10 to 24 years old and 1,910 controls (operated for appendicitis) matched to the cases on date of diagnosis, study region and age. Participation rates were 72% for cases and 54% for controls. The mean ages of cases and controls were 16.5 and 16.6 years, respectively; 57% were males. The vast majority of study participants were wireless phones users, even in the youngest age group, and the study included substantial numbers of long-term (over 10 years) users: 22% overall, 51% in the 20-24-year-olds. Most tumours were of the neuroepithelial type (NBT; n = 671), mainly glioma. The odds ratios (OR) of NBT appeared to decrease with increasing time since start of use of wireless phones, cumulative number of calls and cumulative call time, particularly in the 15-19 years old age group. A decreasing trend in ORs was also observed with increasing estimated cumulative RF specific energy and ELF induced current density at the location of the tumour. Further analyses suggest that the large number of ORs below 1 in this study is unlikely to represent an unknown causal preventive effect of mobile phone exposure: they can be at least partially explained by differential recall by proxies and prodromal symptoms affecting phone use before diagnosis of the cases. We cannot rule out, however, residual confounding from sources we did not measure. Overall, our study provides no evidence of a causal association between wireless phone use and brain tumours in young people. However, the sources of bias summarised above prevent us from ruling out a small increased risk.

Mental health and COVID-19 in a general population cohort in Spain (COVICAT study)

PURPOSE

Mental health conditions may affect outcome of COVID-19 disease, while exposure to stressors during the pandemic may impact mental health. The purpose of this study was to examine these factors in relation to ocurrence of depression and anxiety after the first outbreak in Spain.

METHODS

We contacted 9515 participants from a population-based cohort study in Catalonia between May and October 2020. We drew blood samples to establish infection to the virus. Pre-pandemic mental health conditions were confirmed through Electronic Health Registries. We used the Hospital Anxiety and Depression Scale to assess severe depression and anxiety post-pandemic. Exposure to proximal, financial and wider environment stressors during the lockdown were collected. We calculated Relative Risks (RR), adjusting for individual- and contextual covariates.

RESULTS

Pre-pandemic mental health disorders were not associated with SARS-CoV-2 infection , but were associated with severity of COVID-19 disease. People with pre-existing mental health disorders showed higher prevalence of severe depression (25.4%) and anxiety (37.8%) than those without prior mental disorders (4.9% and 10.1%). Living alone was a strong predictor of severe depression among mental health patients (RR = 1.6, 95% CI 1.2-2.2). Among those without prior mental health disorders, post-lockdown depression and anxiety were associated with household interpersonal conflicts (RR = 2.6, 95% CI 2.1-3.1; RR = 2.1, 95% CI 1.9-2.4) and financial instability (RR = 2.2, 95% CI 1.8-2.9; 1.9, 95% CI 1.6-2.2).

CONCLUSIONS

The COVID-19 pandemic and the lockdown were associated with increased post-lockdown depression and anxiety. Patients with pre-existing mental health conditions are a vulnerable group for severe COVID-19 disease.

Social mobility and healthy behaviours from a gender perspective in the Spanish multicase-control study (MCC-Spain)

There is evidence for the influence of socioeconomic status (SES) on healthy behaviours but the effect of social mobility (SM) is not yet well known. This study aims to analyse the influence of origin and destination SES (O-SES and D-SES) and SM on healthy behaviours and co-occurrence, from an integrated gender and age perspective. Data were obtained from the controls of MCC-Spain between 2008-2013 (3,606 participants). Healthy behaviours considered: healthy diet, moderate alcohol consumption, non-smoking and physical activity. SM was categorized as stable high, upward, stable medium, downward or stable low. Binary and multinomial logistic regression models were adjusted. Those aged <65, with a low O-SES, D-SES and stable low SM are less likely to have healthy behaviours in the case of both women (physically active: OR = 0.65 CI = 0.45-0.94, OR = 0.71 CI = 0.52-0.98, OR = 0.61 CI = 0.41-0.91) and men (non-smokers: OR = 0.44 CI = 0.26-0.76, OR = 0.54 CI = 0.35-0.83, OR = 0.41 CI 0.24-0.72; physically active: OR = 0.57 CI = 0.35-0.92, OR = 0.64 CI = 0.44-0.95, OR = 0.53 CI = 0.23-0.87). However, for those aged ≥65, this probability is higher in women with a low O-SES and D-SES (non-smoker: OR = 8.09 CI = 4.18-15.67, OR = 4.14 CI = 2.28-7.52; moderate alcohol consumption: OR = 3.00 CI = 1.45-6.24, OR = 2.83 CI = 1.49-5.37) and in men with a stable low SM (physically active: OR = 1.52 CI = 1.02-1.26). In the case of men, the same behaviour pattern is observed in those with a low O-SES as those with upward mobility, with a higher probability of co-occurring behaviours (three-to-four behaviours: OR = 2.00 CI = 1.22-3.29; OR = 3.13 CI = 1.31-7.48). The relationship of O-SES, D-SES and SM with healthy behaviours is complex and differs according to age and gender.

Compositional analysis of dietary patterns

Instead of looking at individual nutrients or foods, dietary pattern analysis has emerged as a promising approach to examine the relationship between diet and health outcomes. Despite dietary patterns being compositional (i.e. usually a higher intake of some foods implies that less of other foods are being consumed), compositional data analysis has not yet been applied in this setting. We describe three compositional data analysis approaches (compositional principal component analysis, balances and principal balances) that enable the extraction of dietary patterns by using control subjects from the Spanish multicase-control (MCC-Spain) study. In particular, principal balances overcome the limitations of purely data-driven or investigator-driven methods and present dietary patterns as trade-offs between eating more of some foods and less of others.

Abstract P3-09-01: Withdrawn

This abstract was withdrawn by the authors.

Recurrent urinary tract infection and risk of bladder cancer in the Nijmegen bladder cancer study

BACKGROUND

Controversy exists on whether urinary tract infection (UTI) is a risk factor for urinary bladder cancer (UBC). Here, the association is investigated using data from one of the largest bladder cancer case-control studies worldwide.

METHODS

Information on (i) history and age at onset of regular cystitis ('regular low-UTI') and (ii) number and age at onset of UTI treated with antibiotics ('UTI-ab') from 1809 UBC patients and 4370 controls was analysed. Odds ratios (ORs) and 95% confidence intervals (CI) adjusted for age, education, smoking, and use of aspirin/ibuprofen were generated, for men and women separately.

RESULTS

Regular low-UTI was associated with an increased UBC risk (men: OR (95% CI) 6.6 (4.2-11); women: 2.7 (2.0-3.5)), with stronger effects in muscle-invasive UBC. Statistically significant decreased risks (ORs ∼0.65) were observed for up to five UTI-ab, specifically in those who (had) smoked and experienced UTI-ab at a younger age. In women, UTI experienced after menopause was associated with a higher UBC risk, irrespective of the number of episodes.

CONCLUSIONS

Regular cystitis is positively associated with UBC risk. In contrast, a limited number of episodes of UTI treated with antibiotics is associated with decreased UBC risk, but not in never-smokers and postmenopausal women.

Work in the textile industry in Spain and bladder cancer

BACKGROUND/OBJECTIVE

Textile manufacturing is a complex industry that has frequently been associated with bladder cancer. However, results have not been consistent. This study investigated the risk of bladder cancer in Spanish textile workers.

METHODS

We analysed data from a multicentre hospital-based case-control study carried out in Spain (1998-2001) including 1219 cases of bladder cancer and 1271 controls. Of those, 126 cases and 122 controls reported a history of employment in the textile industry. Lifetime occupational history was obtained using a computer-assisted personal interview. Occupations, locations and materials used in the textile industry were assessed using a detailed questionnaire and expert assessment.

RESULTS

Overall, no increased risk of bladder cancer was found for textile workers, including duration of employment analysis. Increased risks were observed for weavers (OR = 1.82, 95% CI 0.95 to 3.47), for workers in winding/warping/sizing (OR 4.11, 95% CI 1.58 to 10.71) and for those exposed to synthetic materials (OR 1.89, 95% CI 1.00 to 3.56). Working for more than 10 years appeared to be associated with an increased risk for weavers (OR 2.27, 95% CI 0.97 to 5.34), for those who had ever worked in winding/warping/sizing (OR 11.03, 95% CI 1.37, 88.89), for workers in the weaving room (OR 2.94, 95% CI 1.24 to 7.01) and for those exposed to synthetic (OR 2.62, 95% CI 1.14 to 6.01) or cotton (OR 2.00, 95% CI 1.04 to 3.87) materials. Statistically significant higher risks were also found for specific combinations of occupations or locations with exposure to synthetics and cotton.

CONCLUSIONS

There was no overall increased risk for textile workers, but increased risks were found for specific groups of workers. Our findings indicate that observed risks in previous studies may be better evaluated by analysis of materials used or section worked within the industry and occupation.

Cancer epidemiology: study designs and data analysis

Among the scientific interests of cancer epidemiology is the identification of both environmental and genetic factors associated with cancer development. Observational designs requiring sophisticated methodology are applied to control for potential confounding factors. The enormous biotechnological potential developed in the last two decades has allowed the integration of a plethora of new biomarkers in epidemiological studies to better define the exposure and "neoclassic" outcomes, as well as incorporating genetic susceptibility factors in both classical and new epidemiological designs. The integration of scopes, objectives, data and tools coming from different disciplines also benefits epidemiology, thus evolving into "systems epidemiology". In this manuscript, we review the basic concepts of study designs and data analysis and introduce readers to the more innovative aspects that are now being applied in epidemiological studies.

Performance of a high-volume cascade impactor in six European urban environments: mass measurement and chemical characterization of size-segregated particulate samples

The performance of a modified Harvard high-volume cascade impactor (HVCI) was evaluated in six field campaigns with size-segregated particulate samplings for chemical and toxicological characterization. The 7-week sampling campaigns in 2002-2003 in Duisburg (autumn), Prague (winter), Amsterdam (winter), Helsinki (spring), Barcelona (spring), and Athens (summer) were selected to represent contrasting urban environments and seasons of public health interest due to high particulate concentrations or previous findings in epidemiological studies. Particulate samples were collected in parallel with the HVCI (PM(10-2.5), PM(2.5-1), PM(1-0.2), PM(0.2)), a virtual impactor (VI; PM(10-2.5), PM(2.5)), and a Berner low-pressure impactor (BLPI; 10 stages between 0.035 and 10 mum in particle diameter) using a 3- or 4-day sampling duration. The campaigns exhibited different profiles with regard to particulate mass concentration, size distribution, chemical composition and meteorological conditions, thus providing a demanding setup for an overall field comparison of the HVCI with the VI and BLPI reference samplers. Size-segregated particulate mass concentration could be reasonably well measured with the present HVCI configuration. The coarse (PM(10-2.5)) and fine (PM(2.5)) particulate mass agreed within 10% with the low-volume reference samplers, and the four-stage size distribution of the HVCI followed the modal pattern of urban aerosol. The concentrations of chemical constituents measured and integrated especially for the HVCI-PM(2.5) differed to some extent from those measured from the corresponding VI-PM(2.5) samples. This implies that when investigating the association of toxicological responses with the chemical constituents of particulate matter, it is necessary to use the chemical composition data of the same samples as used in toxicological experiments.

Assessment of lifetime exposure to trihalomethanes through different routes

OBJECTIVES

To evaluate lifetime exposure to trihalomethanes (THM) through ingestion, inhalation, and dermal absorption in a hospital based case-control study of bladder cancer conducted between 1998 and 2001 in five areas of Spain. The study base was comprised of subjects living in the catchment areas of the participating hospitals.

METHODS

Individual information on water related habits was obtained from personal interviews of 1219 cases and 1271 controls: residential and occupational history, drinking water source at each residence and job, amount of water consumption, frequency and duration of showering, bathing, and swimming pool attendance. THM levels, water source history, and year when chlorination started in study areas were ascertained through measurements in drinking water samples and questionnaires to water companies and local authorities. Estimates of THM levels covered 79% of the subjects' person-years of exposure.

RESULTS

Current and historical average THM levels in water were correlated. Control subjects reported that drinking water source in the last residence was municipal for 63%, bottled for 22%, private well for 2%, and other sources for 13%. For the time window between age 15 and the time of interview, average residential THM level was 32.2 mug/l. THM exposure through ingestion was 23.7 mug/day on average, and was correlated with the ingestion THM level in the workplace. Overall, 79% usually took showers, 16% usually took baths, and 13% had ever attended a swimming pool. Between 21% and 45% of controls unexposed to THM through ingestion were evaluated as moderately or highly exposed through showering or bathing, and 5-10% were exposed through swimming in pools.

CONCLUSION

The importance of evaluating different routes is underscored by findings from experimental studies showing substantial differences in THM uptake and internal distribution by route.

Biomarkers of exposure to polycyclic aromatic hydrocarbons from environmental air pollution

Metabolites of pyrene and DNA adducts have been used as biomarkers of high level exposure to polycyclic aromatic hydrocarbons (PAHs). A systematic review was performed to evaluate whether these biomarkers are also valid markers of low level environmental exposure to PAHs. Thirty five studies were identified with more than 10 subjects that evaluated environmental air pollution to PAHs in relation to metabolites of PAHs, mainly hydroxypyrene (1-OHP), PAH-DNA adducts, or protein adducts. PAH metabolites and, to a less extent, PAH-DNA adducts correlated well at the group level with exposure to B(a)P even at low levels of air pollution. The use of these biomarkers should be more widely implemented in combination with more traditional techniques for the assessment of general population exposure to PAHs from ambient air pollution.