A prospective cohort study of adolescents' memory performance and individual brain dose of microwave radiation from wireless communication

BACKGROUND: The potential impact of microwave radiofrequency electromagnetic fields (RF-EMF) emitted by wireless communication devices on neurocognitive functions of adolescents is controversial. In a previous analysis, we found changes in figural memory scores associated with a higher cumulative RF-EMF brain dose in adolescents. OBJECTIVE: We aimed to follow-up our previous results using a new study population, dose estimation, and approach to controlling for confounding from media usage itself. METHODS: RF-EMF brain dose for each participant was modeled. Multivariable linear regression models were fitted on verbal and figural memory score changes over 1 y and on estimated cumulative brain dose and RF-EMF related and unrelated media usage (n = 669-676). Because of the hemispheric lateralization of memory, we conducted a laterality analysis for phone call car preference. To control for the confounding of media use behaviors, a stratified analysis for different media usage groups was also conducted. RESULTS: We found decreased figural memory scores in association with an interquartile range (IQR) increase in estimated cumulative RF-EMF brain dose scores: 0.22 (95% CI: 0.47, 0.03; IQR: 953 mJ/kg per day) in the whole sample, 0.39 (95% CI: 0.67, 0.10; IQR: 953 mJ/kg per day) in right-side users (n = 532), and 0.26 (95% CI: 0.42, 0.10; IQR: 341 mJ/kg per day) when recorded network operator data were used for RF-EMF dose estimation = 274). Media usage unrelated to RF-EMF did not show significant associations or consistent patterns, with the exception of consistent (nonsignificant) positive associations between data traffic duration and verbal memory. CONCLUSIONS: Our findings for a cohort of Swiss adolescents require confirmation in other populations but suggest a potential adverse effect of RF-EMF brain close on cognitive functions that involve brain regions mostly exposed during mobile phone use

Current use pesticides in soil and air from two agricultural sites in South Africa: Implications for environmental fate and human exposure

Concerns about the possible negative impacts of current use pesticides (CUPs) for both the environment and human health have increased worldwide. However, the knowledge on the occurrence of CUPs in soil and air and the related human exposure in Africa is limited. This study investigated the presence of 30 CUPs in soil and air at two distinct agricultural sites in South Africa and estimated the human exposure and related risks to rural residents via soil ingestion and inhalation (using hazard quotients, hazard index and relative potency factors). We collected 12 soil and 14 air samples over seven days during the main pesticide application season in 2018. All samples were extracted, purified and analyzed by high-performance liquid chromatography coupled with tandem mass spectrometry. In soils, nine CUPs were found, with chlorpyrifos, carbaryl and tebuconazole having the highest concentrations (up to 63.6, 1.10 and 0.212 ng g-1, respectively). In air, 16 CUPs were found, with carbaryl, tebuconazole and terbuthylazine having the highest levels (up to 25.0, 22.2 and 1.94 pg m-3, respectively). Spatial differences were observed between the two sites for seven CUPs in air and two in soils. A large dominance towards the particulate phase was found for almost all CUPs, which could be related to mass transport kinetics limitations (non-equilibrium) following pesticide application. The estimated daily intake via soil ingestion and inhalation of individual pesticides ranged from 0.126 fg kg-1 day-1 (isoproturon) to 14.7 ng kg-1 day-1 (chlorpyrifos). Except for chlorpyrifos, soil ingestion generally represented a minor exposure pathway compared to inhalation (i.e. <5%). The pesticide environmental exposure largely differed between the residents of the two distinct agricultural sites in terms of levels and composition. The estimated human health risks due to soil inges-tion and inhalation of pesticides were negligible although future studies should explore other relevant pathways

Quantitative assessment of multiple pesticides in silicone wristbands of children/guardian pairs living in agricultural areas in South Africa

Little is known about personal and time-integrated exposure to past and current used pesticides in agricultural areas and within-family exposure similarities. We aimed to assess exposure to pesticides using silicone wristbands in child/guardian pairs living on farms and in villages within two agricultural areas in South Africa. Using silicone wristbands, we quantified 21 pesticides in child/guardian pairs in 38 households over six days in 2018. Levels (in ng/g wristband) of pesticides and their transformation products (12 current-use pesticides and nine organochlorine pesticides) were measured using GC-MS/MS. We assessed the correlation between pesticide levels and between household members using Spearman correlation coefficients (r(s)). Multivariable generalized least squares (GLS) models, using household id as intercept, were used to determine level of agreement between household members, exposure differences between children and guardians and exposure predictors (study area, household location [farm vs. village] and household pesticide use). We detected 16 pesticides with highest detection frequencies for deltamethrin (89%), chlorpyrifos (78%), boscalid (56%), cypermethrin (55%), and p,p'-DDT (48%). Most wristbands (92%) contained two or more pesticides (median seven (range one to 12)). Children had higher concentrations than guardians for four pesticides. Correlation between the pesticide levels were in most cases moderate (rs 0.30-0.68) and stronger in children than in guardians. Five pesticides showed moderate to strong correlation between household members, with the strongest correlation for boscalid (r(s) 0.84). Exposure differences between the two agricultural areas were observed for chlorpyri fas, diazinon, pmthiofos, cypermethrin, boscalid, p,p'-DDT and p,p'-DDE and within areas for cypermethrin. We showed that for several pesticides children had higher exposure levels than guardians. The positive correlations observed for child/guardian pairs living in the same household suggest non-occupational shared exposure pathways in these communities

Exposure to electric and magnetic fields at intermediate frequencies of household appliances

Human exposure to electric and magnetic fields has been amply investigated in the extremely-low frequency (ELF) and radiofrequency (RF) ranges. However, research on typical emissions in the intermediate-frequency (IF) range remains limited. In this study, an extensive measurement survey was performed on the levels of electric and magnetic fields at intermediate frequencies typically emitted by a wide range of household appliances. The emissions contained either harmonic signals, with fundamental frequencies between 6 kHz and 100 kHz, or much more capricious spectra, dominated by 50 Hz harmonics emanating far in the IF domain. Use of appliances at close distance (20 cm) of certain appliances may result in a relatively high exposure, but no appliance's IF emissions exceeded the ICNIRP2010 exposure summation rule (maximum electric-and magnetic-field exposure quotients were respectively 1.00, for a compact fluorescent lamp, and 0.13, for an induction cooker)

Seasonal variations in air concentrations of 27 organochlorine pesticides (OCPs) and 25 current-use pesticides (CUPs) across three agricultural areas of South Africa

For decades pesticides have been used in agriculture, however, the occurrence of legacy organochlorine pesticides (OCPs) and current-use pesticides (CUPs) is poorly understood in Africa. This study investigates air concentrations of OCPs and CUPs in three South African agricultural areas, their spatial/seasonal variations and mixture profiles. Between 2017 and 2018, 54 polyurethane foam-disks passive air-samplers (PUF-PAS) were positioned in three agricultural areas of the Western Cape, producing mainly apples, table grapes and wheat. Within areas, 25 CUPs were measured at two sites (farm and village), and 27 OCPs at one site (farm). Kruskal-Wallis tests investigated area differences in OCPs concentrations, and linear mixed-effect models studied differences in CUPs concentrations between areas, sites and sampling rounds

Clinical features of headache associated with mobile phone use: a cross-sectional study in university students

<p>Abstract</p> <p>Background</p> <p>Headache has been reported to be associated with mobile phone (MP) use in some individuals. The causal relationship between headache associated with MP use (HAMP) and MP use is currently undetermined. Identifying the clinical features of HAMP may help in clarifying the pathophysiology of HAMP and in managing symptoms of individuals with HAMP. The aim of the present study is to describe the clinical features of HAMP.</p> <p>Methods</p> <p>A 14-item questionnaire investigating MP use and headache was administered to 247 medical students at Hallym University, Korea. Individual telephone interviews were subsequently conducted with those participants who reported HAMP more than 10 times during the last 1 year on the clinical features of HAMP. We defined HAMP as a headache attack during MP use or within 1 hour after MP use.</p> <p>Results</p> <p>In total, 214 (86.6%) students completed and returned the questionnaire. Forty (18.9%) students experienced HAMP more than 10 times during the last 1 year in the questionnaire survey. In subsequent telephone interviews, 37 (97.4%) interviewed participants reported that HAMP was triggered by prolonged MP use. HAMP was usually dull or pressing in quality (30 of 38, 79.0%), localised ipsilateral to the side of MP use (32 of 38, 84.2%), and associated with a burning sensation (24 of 38, 63.2%).</p> <p>Conclusion</p> <p>We found that HAMP usually showed stereotyped clinical features including mild intensity, a dull or pressing quality, localisation ipsilateral to the side of MP use, provocation by prolonged MP use and often accompanied by a burning sensation.</p

Exposure to Moderate Air Pollution during Late Pregnancy and Cord Blood Cytokine Secretion in Healthy Neonates

Ambient air pollution can alter cytokine concentrations as shown in vitro and following short-term exposure to high air pollution levels in vivo. Exposure to pollution during late pregnancy has been shown to affect fetal lymphocytic immunophenotypes. However, effects of prenatal exposure to moderate levels of air pollutants on cytokine regulation in cord blood of healthy infants are unknown. In a birth cohort of 265 healthy term-born neonates, we assessed maternal exposure to particles with an aerodynamic diameter of 10 µm or less (PM₁₀), as well as to indoor air pollution during the last trimester, specifically the last 21, 14, 7, 3 and 1 days of pregnancy. As a proxy for traffic-related air pollution, we determined the distance of mothers' homes to major roads. We measured cytokine and chemokine levels (MCP-1, IL-6, IL-10, IL-1ß, TNF-α and GM-CSF) in cord blood serum using LUMINEX technology. Their association with pollution levels was assessed using regression analysis, adjusted for possible confounders. Mean (95%-CI) PM₁₀ exposure for the last 7 days of pregnancy was 18.3 (10.3-38.4 µg/m³). PM₁₀ exposure during the last 3 days of pregnancy was significantly associated with reduced IL-10 and during the last 3 months of pregnancy with increased IL-1ß levels in cord blood after adjustment for relevant confounders. Maternal smoking was associated with reduced IL-6 levels. For the other cytokines no association was found. Our results suggest that even naturally occurring prenatal exposure to moderate amounts of indoor and outdoor air pollution may lead to changes in cord blood cytokine levels in a population based cohort

Ionizing radiation and radiofrequency electromagnetic fields : Further clarification of particular risks

International audience•Epidemiological studies involving people exposed to low levels of ionizing radiation from the environment (natural and artificial sources), occupations or medical diagnostic procedures demonstrate that the risk of leukaemia and other cancers increases with radiation dose. •The latency between exposure to ionizing radiation and occurrence of an excess risk of cancer varies from several years to several decades. In addition, host factors such as age at exposure, attained age and sex modify the dose-risk relationship. •Most of the epidemiological research does not support an association between mobile phone use and tumours occurring in the head, the body part with the highest exposure to radiofrequency electromagnetic fields. Sporadic reports of associations are most likely false positive findings and the consequences of bias such as recall bias in retrospective exposure assessment