In today’s world, most children are exposed to various manmade electromagnetic fields (EMFs). EMFs are electromagnetic waves less than 300 GHz. A developing child’s brain is vulnerable to electromagnetic radiation; thus, their caregivers’ concerns about the health effects of EMFs are increasing. EMF exposure is divided into 2 categories: extremely low frequencies (ELFs; 3–3,000 Hz), involving high-voltage transmission lines and in-house wiring; and radiofrequencies (RFs; 30 kHz to 300 GHz), involving mobile phones, smart devices, base stations, WiFi, and 5G technologies. The biological effects of EMFs on humans include stimulation, thermal, and nonthermal, the latter of which is the least known. Among the various health issues related to EMFs, the most important issue is human carcinogenicity. According to the International Agency for Research on Cancer’s (IARC’s) evaluation of carcinogenic risks to humans, ELFs and RFs were evaluated as possible human carcinogens (Group 2B). However, the World Health Organization’s (WHO’s) view of EMFs remains undetermined. This article reviews the current knowledge of EMF exposure on humans, specifically children. EMF exposure sources, biological effects, current WHO and IARC opinions on carcinogenicity, and effects of EMF exposures on children will be discussed. As well-controlled EMF experiments in children are nearly impossible, scientific knowledge should be interpreted objectively. Precautionary approaches are recommended for children until the potential health effects of EMF are confirmed.
Objectives: We aimed to investigate the association between smartphone use and adverse behavioral health outcomes using nationwide Korea Youth Risk Behavior Web-based Survey data for 2017 and 2020. Methods: The 2020 data (N = 54,809) were used to analyze the relationships between daily smartphone usage time (non-user, 0–2 h [hour], 2–4 h, 4–6 h, 6–8 h, and > 8 h), and adverse health outcomes (stress, sleep, depression, suicide, substance use, and smartphone overdependence). A 1:1 propensity score matching (PSM) was used to control for confounding variables. Results: A total of 40,998 adolescents with < 4 h/day and > 4 h/day of usage were included. Adolescents’ mean smartphone usage time in 2020 increased compared to that in 2017 (weighted % of > 2 h/day; 64.3% vs. 85.7%). The curvilinear relationships between smartphone usage time and adverse health outcomes were prominent after > 4 h/day. Adolescents using smartphones 2–4 h/day showed no increased adverse health outcomes compared to non-users, except for smartphone overdependence. Using a smartphone > 4 h/day was significantly associated with stress perception (1.16; 1.11–1.22), suicidal ideation (1.22; 1.13–1.31), and substance use (alcohol, 1.66; 1.57–1.75) after PSM. Conclusions: Our study demonstrated the curvilinear relationship between smartphone usage time and adverse health outcomes in adolescents. Our findings can help establish smartphone usage guidelines for adolescents.
Respiratory syncytial virus (RSV) infection can cause various neurological complications. This study aimed to investigate the RSV-associated neurologic manifestations that present with seizures. We retrospectively reviewed the medical records of patients aged less than 15 years with laboratory-confirmed RSV infections and seizures between January 2011 and December 2016 in a regional hospital in South Korea. During this period, 1,193 patients with laboratory-confirmed RSV infection were identified. Of these, 35 (35 of 1,193, 2.93%; boys, 19; girls, 16; mean age: 20.8±16.6 months) presented with seizures. Febrile seizure was the most common diagnosis (27 of 35, 77.1%); simple febrile seizure in 13 patients (13 of 27, 48.1%) and complex febrile seizure in 14 (14 of 27, 51.9%). Afebrile seizures without meningitis or encephalopathy were observed in 5 patients (5 of 35, 14.3%), seizures with meningitis in 2 (2 of 35, 5.7%), and seizure with encephalopathy in 1 (1 of 35, 2.9%) patient. Lower respiratory symptoms were not observed in 8 patients. In a patient with encephalopathy, brain diffusion-weighted magnetic resonance imaging revealed transient changes in white matter, suggesting cytotoxic edema as the mechanism underlying encephalopathy. Most patients recovered with general management, and progression to epilepsy was noted in only 1 patient. Although febrile seizure is the most common type of seizure associated with RSV infection, the proportion of patients with complex febrile seizure was higher than that of general febrile seizure. Transient cytotoxic edema may be a pathogenic mechanism in RSV-related encephalopathy with seizures.