James C. Matthews

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

Abstract:  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.

Modulation of urban atmospheric electric field measurements with the wind direction in Lisbon (Portugal)

Atmospheric electric field measurements (potential gradient, PG) were retrieved in the urban environment of the city of Lisbon (Portugal). The measurements were performed with a Benndorf electrograph at the Portela Meteorological station in the suburbs of the city (NE from the centre). The period of 1980 to 1990 is considered here. According to wind direction, different content and types of ions and aerosols arrive at the measurement site causing significant variations to the PG. To the south there are significant pollution sources while to the north such sources are scarcer. The Iberian Peninsula is found east of the station and the Atlantic Ocean covers the western sector, Wind directions are divided in four sectors: i) NW: 270° ≤ θ ≤ 360°; ii) NE: 0 ≤ θ ≤ 90°; iii) SE: 90 ≤ θ ≤ 180°; iv) SW: 180° ≤ θ ≤ 270°. Analysis of weekly cycle, caused by anthropogenic pollution related with urban activity, was undertaken for each wind sector. NW sector has been shown to be less affected by this cycle, which is attributed to the effect of marine air. The daily variation of NE sector for weekends reveals a similar behaviour to the Carnegie curve, which corresponds to a clean air daily variation of PG, following universal time, independent of measurement site.

Fixed site monitoring of potential gradient fluctuations near to AC high voltage power lines

A fixed site monitoring station recorded the potential gradient disturbances near to two high voltage power lines during 2008. The full years results show that the electrical environment downwind of power lines is modified compared to that upwind. Potential gradient disturbance was greater on days when there was rainfall. Humidity was inversely correlated with mean potential gradient when the station was both downwind and upwind of both power lines. Wind speed is weakly correlated with the standard deviation of a 10 minute sample of potential gradient downwind of both power lines, but not upwind. The distributions of mean and standard deviation of potential gradient in 10 minute samples showed that the field was more negative overnight and on days where there was rain, but less variable at night and on dry days. Upwind of the power lines, the average 24 hour trace exhibits the natural background Carnegie curve, with peaks corresponding to increased global thunderstorm activity, while local effects mask this trace when the FSMS is downwind of the power lines. The results show that corona ions can cause potential gradient disturbances downwind of high voltage power lines, most particularly during rain and high humidity, and overnight.

Urban pollutant transport and infiltration into buildings using perfluorocarbon tracers

People spend the majority of their time indoors and therefore the quality of indoor air is worthy of investigation; indoor air quality is affected by indoor sources of pollutants and from pollutants entering buildings from outdoors. In this study, unique perfluorocarbon tracers were released in five experiments at a 100 m and ~2 km distance from a large university building in Manchester, UK and tracer was also released inside the building to measure the amount of outdoor material penetrating into buildings and the flow of material within the building itself. Air samples of the tracer were taken in several rooms within the building, and a CO2 tracer was used within the building to estimate air-exchange rates. Air-exchange rates were found to vary between 0.57 and 10.90 per hour. Indoor perfluorocarbon tracer concentrations were paired to outdoor tracer concentrations, and in-out ratios were found to vary between 0.01 and 3.6. The largest room with the lowest air-exchange rate exhibited elevated tracer concentrations for over 60 min after the release had finished, but generally had the lowest concentrations, the room with the highest ventilation rates had the highest concentration over 30 min, but the peak decayed more rapidly. Tracer concentrations indoors compared to outdoors imply that pollutants remain within buildings after they have cleared outside, which must be considered when evaluating human exposure to outdoor pollutants.

Spectral response of atmospheric electric field measurements near AC high voltage power lines

To understand the influence of corona ion emission on the atmospheric electrical field, measurements were made near to two AC high voltage power lines. A JCI 131 field-mill recorded the atmospheric electric field over one year. Meteorological measurements were also taken. The data series is divided in four zones (dependent on wind direction): whole zones, Z0; zone 1, Z1; zone 2, Z2; zone 3, Z3. Z3 is the least affected by corona ion emission and for that reason it is used as a reference against Z1 and Z2, which are strongly influenced by this phenomena. Analysis was undertaken for all weather days and dry days only. The Lomb-Scargle strategy developed for unevenly spaced time-series is used to calculate the spectral response of the aforementioned zones. Only frequencies above 1 minute are considered.

Re-creation of aerosol charge state found near HV power lines using a high voltage corona charger

Corona ionisation from AC HV power lines (HVPL) can release ions into the environment, which have the potential to electrically charge pollutant aerosol in the atmosphere. It has been hypothesised that these charged particles have an enhanced probability of being deposited in human airways upon inhalation due to electrostatic attraction by image charge within the lung, with implications for human health. Carbonaceous aerosol particles from a Technegas generator were artificially charge-enhanced using a corona charger. Once generated, particles were passed through the charger, which was either on or off, and stored in a 15 litre conducting bag for ~20 minutes to observe size and charge distribution changes over time. Charge states were estimated using two Sequential Mobility Particle Sizers measuring the size and mobility distributions. Charge-neutral particles were measured 7 times and positive particles 9 times, the average charge-neutral value of x was 1.00 (sd = 0.06) while the average positive value was 4.60 (0.72). The system will be used to generate positive or charge neutral particles for delivery to human volunteers in an inhalation study to assess the impact of charge on ultrafine (size < 100 nm) particle deposition.

Aerosol charge state characterisation using an ELPI

A new technique has been developed to measure the size distribution and charge state of highly charged aerosols using an Electrical Low Pressure Impactor (ELPI). The internal charger was switched alternately on and off and the time between stable charge states found to be ~ 10 s. The size distribution of aerosols was found when the charger was on, from which the charge distribution can be estimated when the charger is off using the current at each impactor stage. This method was tested in background conditions, when a candle was burning and when a negative air ioniser was used. The ELPI electrometers were not sensitive enough to accurately measure the charge state on background and candle air, but gave a value for air charged by an ioniser. Comparing results from the ELPI with other techniques showed inaccuracies in this method that need to be addressed before further use of this technique.