Overhead AC powerlines and rain can alter the electric charge distribution on airborne particles - Implications for aerosol dispersion and lung deposition.

Corona ions from high voltage power lines (HVPL) can increase electrostatic charge on airborne pollutant particulates, possibly increasing received dose upon inhalation. To investigate the potential increased risk of childhood leukemia associated with residence near alternating current (AC) HVPL, we measured the particle charge state and atmospheric electricity parameters upwind, downwind and away from HVPL. Although we observed noticeable charge state alteration from background levels, most HVPL do not significantly increase charge magnitude. Particular HVPL types are shown to have most effect, increasing net charge to 15 times that at background. However, the magnitude of charge alteration during rainfall is comparable with the most extreme HVPL measurement. On current evidence, based on the current adult lung model, we suggest that although charge is sometimes enhanced to levels which may alter atmospheric particle dynamics, increased lung deposition is unlikely.

Can disturbances in the atmospheric electric field created by powerline corona ions disrupt melatonin production in the pineal gland?

Recent epidemiological studies have reported an increased risk of leukemia in adults and children near overhead high voltage powerlines at distances beyond the measured range of the direct electric and magnetic fields. Corona ions are emitted by powerlines, forming a plume that is carried away from the line by the wind. The plume generates highly variable disturbances in the atmospheric electric field of tens to a few hundred V/m on time scales from seconds to minutes. Such disturbances can be seen up to several hundred meters from powerlines. It is hypothesized that these random disturbances result in the disruption of nocturnal melatonin synthesis and related circadian rhythms, in turn leading to increased risk of a number of adverse health effects including leukemia. In support of the hypothesis, it is noted that melatonin is highly protective of oxidative damage to the human hemopoietic system. A review of electric field studies provides evidence that (i) diurnal variation in the natural atmospheric electric field may itself act as a weak Zeitgeber; (ii) melatonin disruption by electric fields occurs in rats; (iii) in humans, disturbances in circadian rhythms have been observed with artificial fields as low at 2.5 V/m. Specific suggestions are made to test the aspects of the hypothesis.

Aggregating disparate epidemiological evidence: comparing two seminal EMF reviews.

Two seminal reviews (IARC, 2002; CDHS, 2002) of possible health effects from power-frequency EMFs reached partly different conclusions from similar epidemiological evidence. These differences have an impact on precautionary policy. We examine the statistical aggregation of results from individual disparate studies. Without consistent exposure metrics, the advantage of meta-analysis to estimate magnitude of effect is lost. However, counting positive and statistically significant results yields important information. This is not a substitute for meta-analysis, but a fall-back when meaningful meta-analysis is not available. Representative results from 33 independent adult leukemia studies tabled by IARC yielded 23.5 positives (p approximately 0.01) and 9 significant-positives (p<10(-7)). From 43 representative results from CDHS, there were 32 positive (p<0.001) and 14 significant-positives (p<10(-12)). There were no significant-negative results in either list. Results for adult brain cancer gave a similar, but less clear, message. Childhood leukemia EMF studies have been sufficiently comparable to allow selective pooled analysis, which was important in classifying carcinogenicity. Aggregating all the studies suggests that results for childhood leukemia are not stronger, numerically, than those for adult leukemia. CDHS did not note the number of significant-positives, but noted the meta-analytic summary and the number of positives, forming a view about the strength of these findings. IARC shows no evidence of considering the aggregation of results other than subjectively. It considered individual studies but this led to a tendency to fragment and dismiss evidence that is intrinsically highly significant. We make recommendations for future reviews.

Brain Tumours: Rise in Glioblastoma Multiforme Incidence in England 1995-2015 Suggests an Adverse Environmental or Lifestyle Factor.

Objective: To investigate detailed trends in malignant brain tumour incidence over a recent time period. Methods: UK Office of National Statistics (ONS) data covering 81,135 ICD10 C71 brain tumours diagnosed in England (1995-2015) were used to calculate incidence rates (ASR) per 100k person-years, age-standardised to the European Standard Population (ESP-2013). Results: We report a sustained and highly statistically significant ASR rise in glioblastoma multiforme (GBM) across all ages. The ASR for GBM more than doubled from 2.4 to 5.0, with annual case numbers rising from 983 to 2531. Overall, this rise is mostly hidden in the overall data by a reduced incidence of lower-grade tumours. Conclusions: The rise is of importance for clinical resources and brain tumour aetiology. The rise cannot be fully accounted for by promotion of lower-grade tumours, random chance or improvement in diagnostic techniques as it affects specific areas of the brain and only one type of brain tumour. Despite the large variation in case numbers by age, the percentage rise is similar across the age groups, which suggests widespread environmental or lifestyle factors may be responsible. This article reports incidence data trends and does not provide additional evidence for the role of any particular risk factor.

Observations on the relationship between magnetic field characteristics and exposure conditions.

The authors have been investigating metrics of extremely low frequency magnetic field exposure under different circumstances. In this paper, we describe the properties of magnetic fields in homes, in the vicinity of powerlines, on trains and from a library security system. We conclude that there are key differences between each of these fields. This suggests that there may be a characterizable pattern for magnetic fields in different situations.

An investigation into the vector ellipticity of extremely low frequency magnetic fields from appliances in UK homes.

Elliptically polarized magnetic fields induce higher currents in the body compared with their plane polarized counterparts. This investigation examines the degree of vector ellipticity of extremely low frequency magnetic fields (ELF-MFs) in the home, with regard to the adverse health effects reportedly associated with ELF-MFs, for instance childhood leukaemia. Tri-axial measurements of the magnitude and phase of the 0-3000 Hz magnetic fields, produced by 226 domestic mains-fed appliances of 32 different types, were carried out in 16 homes in Worcestershire in the summer of 2004. Magnetic field strengths were low, with average (RMS) values of 0.03 +/- 0.02 microT across all residences. In contrast, background field ellipticities were high, on average 47 +/- 11%. Microwave and electric ovens produced the highest ellipticities: mean respective values of 21 +/- 21% and 21 +/- 17% were observed 20 cm away from these appliances. There was a negative correlation between field strength and field polarization, which we attribute to the higher relative field contribution close to each individual (single-phase) appliance. The measurements demonstrate that domestic magnetic fields are extremely complex and cannot simply be characterized by traditional measurements such as time-weighted average or peak exposure levels. We conclude that ellipticity should become a relevant metric for future epidemiological studies of health and ELF-MF exposure.

Do magnetic fields cause increased risk of childhood leukemia via melatonin disruption?

Epidemiological studies have reported associations between exposure to power frequency magnetic fields and increased risk of certain cancer and noncancer illnesses. For childhood leukemia, a doubling of risk has been associated with exposures above 0.3/0.4 microT. Here, we propose that the melatonin hypothesis, in which power frequency magnetic fields suppress the nocturnal production of melatonin in the pineal gland, accounts for the observed increased risk of childhood leukemia. Such melatonin disruption has been shown in animals, especially with exposure to electric and/or rapid on/off magnetic fields. Equivocal evidence has been obtained from controlled laboratory magnetic field exposures of volunteers, although the exposure conditions are generally atypical of neighborhood exposures. In contrast, support for the hypothesis is found in the body of studies showing magnetic field disruption of melatonin in human populations chronically exposed to both electric and magnetic fields associated with electricity distribution. Further support comes from the observation that melatonin is highly protective of oxidative damage to the human haemopoietic system. Aspects of the hypothesis are amenable to further investigation.