Health impacts of wind turbines

This report presents the results of a rapid, desk based analysis of peer reviewed UK and international literature from the last four years on the effects of wind turbines on human health. The review covers literature specified by the Scottish government, peer-reviewed original studies and recent peer-reviewed literature reviews. Recent original studies consist mostly of cross-sectional studies and case studies on the effects of wind turbines on local residents. All studies present evidence for annoyance due to wind turbine noise and most concur that there is evidence for sleep disturbance in the presence of wind farms but not necessarily from noise. Both results are in agreement with the effects of noise from other environmental sources. Other health effects are increasingly reported in the presence of wind turbines but the reviewed literature does not provide firm scientific evidence of a causal relationship with wind turbines or even more specifically wind turbine noise. The most widely quoted cross-sectional studies show correlations between annoyance and visual impact, economic benefit and attitude related to wind turbines. Wind turbine sound is reported to be comparatively weakly related to annoyance and inseparable from the other contributing factors. Literature on low frequency noise and infrasound (LFIS) can be categorised as reviews, sound level measurements around windfarms and discussion of mechanisms of perception and response. A Swedish review finds no evidence to support ‘wind turbine syndrome’ while another concludes that further research is required. Regarding noise measurements, there are concerns that a new generation of wind turbines will produce a sound with a spectrum shifted down in frequency. However, a study in Australia concluded that infrasound levels near windfarms were no higher than elsewhere and that higher levels in urban areas were probably due to traffic and other human activity rather than wind turbines. Some other studies found measured sound levels near wind farms to conform with a range of criteria for LFIS. Papers by Salt et al. propose that LFIS may differentially stimulate structures in the human inner ear, and may instigate health effects even when inaudible. The authors seek to build a speculative case utilising experimental data gleaned from guinea pigs and some observations on human experiences with specific pathological conditions. Based upon the documents submitted, the proposal is unproven, and would need clear data from hypothesis driven independent research in humans in order to be credible. A proposal by US consultants that motion sickness-like symptoms reported at one wind farm might be caused by acoustic excitation of the balance organs is not new and has previously been discounted as an explanation for similar reported effects not involving wind turbines. Other evidence on acoustic stimulation of the balance organs has been noted but not reviewed. Health effects from other wind turbine related sources such as shadow flicker have been reported in several studies and guidelines to be less of a problem. Careful wind farm design and operational restrictions are suggested to be sufficient to minimise the impact. The mitigation strategies have been found to vary widely internationally with some countries and federal states using fixed noise limits, others using noise limits relative to existing background levels and many like the UK using a combination of both. Set-back distances are also used internationally but have a number of disadvantages. The relevant UK guideline document ETSU-R-97 aims to provide a reasonable degree of protection to noise sensitive listeners; without unduly restricting the development of wind turbine renewable energy resources. In the international comparison the ETSU-R-97 guidelines tends to result in comparatively low noise limits although direct comparisons between fixed and relative noise limits are difficult. ETSU-R-97 has been criticised for its inconsistent implementation and relative complexity. Good practice guidelines by the Institute of Acoustics which aim to address the implementation issues are due to be published in May

UK-wide support infrastructure for low frequency noise sufferers ('LFN Network')

The project was set up to meet a need for improved treatment of Low Frequency Noise (LFN) complaints in cases where no noise source could be found. Such cases can be highly distressing for the complainant and difficult to handle by the Environmental Health Officers (EHOs) concerned and so tend to result in disproportionate use of resources. The hypothesis is that, irrespective of the (unknown) cause of the LFN perception, the perception may be lessened through application of techniques specifically adapted from the field of tinnitus and hyperacusis therapy. The aim of the project was therefore to establish, on a trial basis, a national network of treatment centres for sufferers of LFN located within the existing network of tinnitus clinics in the UK. A network of nine audiology centres was established, including eight with a good geographical spread in England and one in Scotland. A treatment protocol, specific to LFN cases, was then developed through discussions with the centres and a referral pathway was also established. Each centre made contact initially with EHOs in one or two local authorities in their vicinity to offer the service which was widened to a larger catchment area if sufficient referrals were not forthcoming. Fourteen subjects took part, eleven of which were referred from EHOs, the remaining three being self-referred. Outcome measures were based on a combination of validated questionnaires for general health, anxiety, depression, tinnitus handicap (with LFN substituted for tinnitus) and hyperacusis, combined with visual-analogue scales specifically developed for LFN to measure the pitch and loudness of the perceived LFN and the associated distress. Qualitative and open questions were also used. Potential benefits to EHOs of being able to make referrals were evaluated by semi-structured telephone interviews in which five EHOs participated. Generally, EHOs were very positive about the service and wanted it to continue. It was clear that LFN cases require significant resources which can be reduced if the referral service is available. Audiologists’ experience was evaluated in a similar way: they were generally willing to take part in the scheme and wanted it to continue and there was a feeling that they would have liked more referrals to get more experience in the use of the protocol. The results showed a mixed picture with some clients, three in particular, showing improved scores across a range of measures with little or no benefit for others and a worsening for one case. The improvement of some clients is positive given the lack of options available for this client group, however, the success of the approach can be considered partial at best. The questionnaire scores indicated that individuals taking part were significantly agitated, stressed and distressed. Those individuals with LFN complaint have a significant clinical need although in the main they were not clinically anxious or depressed. The model proposed of stress and increased auditory gain is a plausible explanation for the symptoms noted in LFN cases. In particular, the involvement of the sympathetic autonomic nervous system, and of the emotional brain, is likely to be a faithful representation of the clinical situation. A number of useful signposts for future development were derived. First, EHOs as well as audiologists should ideally receive training in best practice to help them to handle the particular sensitivities of LFN cases. More awareness and information for GPs is also recommended. A simplification of the referral route, potentially going direct to the audiologist rather than via the GP would also be beneficial. A strong argument for the continuation of the service is that some EHOs are now taking the initiative in contacting audiologists independently to refer LFN complainants in ‘No Noise Found’ cases. Without adequate training things could be made worse but access to a specific LFN protocol and associated training is likely to increase the chances of success significantly. It is recommended that existing guidance for EHOs be extended to include details of audiology services, guidelines for EHOs in making referrals and reference to the LFN treatment protocol. Using data from the study two independent estimates of the incidence rates of LFN cases can be derived. It is estimated that there are up to 160 complainants per year in the NHS corresponding to 0.32 cases per 100 thousand per year. The incidence rate based on referrals made by EHOs is 1.01 per 100 thousand per year within local authorities. It is not known to what extent, if any, these populations overlap

An Exact Calculation of the Energy Density of Cosmological Gravitational Waves

In this paper we calculate the Bogoliubov coefficients and the energy density of the stochastic gravitational wave background for a universe that undergoes inflation followed by radiation domination and matter domination, using a formalism that gives the Bogoliubov coefficients as continous functions of time. By making a reasonable assumption for the equation of state during reheating, we obtain in a natural way the expected high frequency cutoff in the spectral energy density.Comment: 12 pages+5 figures, uuencoded file,DF/IST-2.9

Excitation and Disruption of a Giant Molecular Cloud by the Supernova Remnant 3C391

Using the IRAM 30-m telescope, we observed the supernova remnant 3C 391 (G31.9+0.0) and its surroundings in the CO(2-1), HCO+(1-0), CS(2-1), CS(3-2), and CS(5-4) lines. The ambient molecular gas at the distance (9 kpc) of the remnant comprises a giant molecular cloud whose edge is closely parallel to a ridge of bright non-thermal radio continuum, which evidently delineates the blast-wave into the cloud. We found that in a small (0.6 pc) portion of the radio shell, the molecular line profiles consist of a narrow (2 km/s) component, plus a very wide (> 20 km/s) component. Both spectral components peak within 20" of a previously-detected OH 1720 MHz maser. We name this source 3C 391:BML (broad molecular line); it provides a new laboratory, similar to IC 443 but on a larger scale, to study shock interactions with dense molecular gas. The wide spectral component is relatively brighter in the higher-excitation lines. We interpret the wide spectral component as post-shock gas, either smoothly accelerated or partially dissociated and reformed behind the shock. The narrow component is either the pre-shock gas or cold gas reformed behind a fully dissociative shock. Using the 3 observed CS lines, we measured the temperature, CS column density, and H2 volume density in a dense clump in the parent molecular cloud as well as the wide-line and narrow-line portions of the shocked clump. The physical conditions of the narrow-line gas are comparable to the highest-density clumps in the giant molecular cloud, while the wide-line gas is both warmer and denser. The mass of compressed gas in 3C 391:BML is high enough that its self-gravity is significant, and eventually it could form one or several stars

Effects of Policies Designed to Keep Firearms from High-Risk Individuals

This article summarizes and critiques available evidence from studies published between 1999 and August 2014 on the effects of policies designed to keep firearms from high-risk individuals in the United States. Some prohibitions for high-risk individuals (e.g., those under domestic violence restraining orders, violent misdemeanants) and procedures for checking for more types of prohibiting conditions are associated with lower rates of violence. Certain laws intended to prevent prohibited persons from accessing firearms -- rigorous permit-to-purchase, comprehensive background checks, strong regulation and oversight of gun dealers, and requiring gun owners to promptly report lost or stolen firearms -- are negatively associated with the diversion of guns to criminals. Future research is needed to examine whether these laws curtail nonlethal gun violence and whether the effects of expanding prohibiting conditions for firearm possession are modified by the presence of policies to prevent diversion

Enzyme-catalyzed resolution of chlorinated esters.

It has been found that lipase from the yeast Candida rugosa (formerly C. cylindracea) will stereoselectively hydrolyze racemic mixtures of the partially water soluble methyl-2- chloropropionate. This will not occur in an aqueous reaction medium, so the substrate was made less water soluble by dissolving it in a water-immiscible organic solvent. The complete reaction mixture was a biphasic system comprising the water immiscible organic solvent plus reactant and an aqueous phase containing the enzyme and buffer component. The hydrolysis products were ideally present in the aqueous phase. The course of the reaction could be followed by the determination of the proportions of D- and L-(a)-chloropropionic acid using a triple-linked enzyme assay. The resolutions of the racemic ester were of a practical or pre-pilot scale. Screening of the 5 soil samples was undertaken in an attempt to isolate some microor ganisms that may possess some unusual or enantiospecific lipase or esterase enzymes. Individual microbes were isolated but not identified, several of which were shown to be secreting an exolipase capable of hydrolysing an olive oil emulsion

Gaussian Sum-Rules and Prediction of Resonance Properties

Techniques for using Gaussian QCD sum-rules to predict hadronic resonance properties are developed for single-resonance and two-resonance phenomenological models, and criteria are developed for determining which of these models is required for analyzing a particular hadronic channel. The vector current sum-rule coupled to the $\rho$ meson is shown to be consistent with a single resonance model, and the Gaussian sum-rule analysis results in an accurate $\rho$ mass prediction which exhibits excellent agreement between the theoretical prediction of the Gaussian sum-rule and the phenomenological model. A two-resonance model is shown to be necessary for the Gaussian sum-rule for the non-strange quark scalar ($\bar n n$) currents. The two-resonance Gaussian sum-rule analysis of the isoscalar and isovector ($I=0,1$) $\bar n n$ scalar mesons exhibits excellent agreement between the theoretical prediction and phenomenological model. The prediction of the resonance properties of the $I=0,1$ $\bar n n$ scalar mesons in this two-resonance model provides valuable information for the interpretation of the scalar mesons, including the X(1775).Comment: latex2e, 29 pages, 10 eps figures embedded in latex2e. Revised version includes additions to reference [28] and correction to equation (56