Ecological momentary assessment study of exposure to radiofrequency electromagnetic fields and non-specific physical symptoms with self-declared electrosensitives.

The main objective of the study is to determine if non-specific physical symptoms (NSPS) in people with self-declared sensitivity to radiofrequency electromagnetic fields (RF EMF) can be explained (across subjects) by exposure to RF EMF. Furthermore, we pioneered whether analysis at the individual level or at the group level may lead to different conclusions. By our knowledge, this is the first longitudinal study exploring the data at the individual level. A group of 57 participants was equipped with a measurement set for five consecutive days. The measurement set consisted of a body worn exposimeter measuring the radiofrequency electromagnetic field in twelve frequency bands used for communication, a GPS logger, and an electronic diary giving cues at random intervals within a two to three hour interval. At every cue, a questionnaire on the most important health complaint and nine NSPS had to be filled out. We analysed the (time-lagged) associations between RF-EMF exposure in the included frequency bands and the total number of NSPS and self-rated severity of the most important health complaint. The manifestation of NSPS was studied during two different time lags - 0-1 h, and 1-4 h - after exposure and for different exposure metrics of RF EMF. The exposure was characterised by exposure metrics describing the central tendency and the intermittency of the signal, i.e. the time-weighted average exposure, the time above an exposure level or the rate of change metric. At group level, there was no statistically significant and relevant (fixed effect) association between the measured personal exposure to RF EMF and NSPS. At individual level, after correction for multiple testing and confounding, we found significant within-person associations between WiFi (the self-declared most important source) exposure metrics and the total NSPS score and severity of the most important complaint in one participant. However, it cannot be ruled out that this association is explained by residual confounding due to imperfect control for location or activities. Therefore, the outcomes have to be regarded very prudently. The significant associations were found for the short and the long time lag, but not always concurrently, so both provide complementary information. We also conclude that analyses at the individual level can lead to different findings when compared to an analysis at group level

Long-term estimates of adult survival rates of urban Herring Gulls Larus argentatus

Urban gull populations have increased dramatically in the last 40 years, leading to widespread concerns about potential nuisance to humans, but little accompanying research into their ecology. This study aimed to provide the first long-term estimates of apparent adult survival rates for urban Herring Gulls Larus argentatus and Lesser Black-backed Gulls L. fuscus, based on colour ringing in Bristol, southwest England. Resightings of adult birds covering 18 years (1990–2007) were analysed using capture–mark–recapture methods, with candidate models testing for differences in survival and/or resighting rate through time and between the sexes. Both species showed high apparent annual survival rates (>0.90) in the early 1990s that declined to <0.70 by 2007. Male survival rates were higher than female rates in Lesser Black-backed Gulls, and male resighting rates were higher in both species. In the early 1990s, Bristol's urban gulls displayed similar adult survival rates to published estimates for rural colonies. Both species showed evidence of long-term declines in apparent survival, which may either reflect actual reductions in survival or increased permanent emigration from the Bristol colony. Anecdotal evidence supports the latter, linking emigration to urban redevelopment or human intervention