Climate change effects on human health: projections of temperature-related mortality for the UK during the 2020s, 2050s and 2080s

Background The most direct way in which climate change is expected to affect public health relates to changes in mortality rates associated with exposure to ambient temperature. Many countries worldwide experience annual heat-related and cold-related deaths associated with current weather patterns. Future changes in climate may alter such risks. Estimates of the likely future health impacts of such changes are needed to inform public health policy on climate change in the UK and elsewhere. Methods Time-series regression analysis was used to characterise current temperature-mortality relationships by region and age group. These were then applied to the local climate and population projections to estimate temperature-related deaths for the UK by the 2020s, 2050s and 2080s. Greater variability in future temperatures as well as changes in mean levels was modelled. Results A significantly raised risk of heat-related and cold-related mortality was observed in all regions. The elderly were most at risk. In the absence of any adaptation of the population, heat-related deaths would be expected to rise by around 257% by the 2050s from a current annual baseline of around 2000 deaths, and cold-related mortality would decline by 2% from a baseline of around 41 000 deaths. The cold burden remained higher than the heat burden in all periods. The increased number of future temperature-related deaths was partly driven by projected population growth and ageing. Conclusions Health protection from hot weather will become increasingly necessary, and measures to reduce cold impacts will also remain important in the UK. The demographic changes expected this century mean that the health protection of the elderly will be vital

Potential health impacts from sulphur dioxide and sulphate exposure in the UK resulting from an Icelandic effusive volcanic eruption

Ash, gases and particles emitted from volcanic eruptions cause disruption to air transport, but also have negative impacts on respiratory and cardiovascular health. Exposure to sulphur dioxide (SO2) and sulphate (SO4) aerosols increases the risk of mortality, and respiratory and cardiovascular hospital admissions. Ash and gases can be transported over large distances and are a potential public health risk. In 2014–15, the Bárðarbunga fissure eruption at Holuhraun, Iceland was associated with high emissions of SO2 and SO4, detected at UK monitoring stations. We estimated the potential impacts on the UK population from SO2 and SO4 associated with a hypothetical large fissure eruption in Iceland for mortality and emergency hospital admissions. To simulate the effects of different weather conditions, we used an ensemble of 80 runs from an atmospheric dispersion model to simulate SO2 and SO4 concentrations on a background of varying meteorology. We weighted the simulated exposure data by population, and quantified the potential health impacts that may result in the UK over a 6-week period following the start of an eruption. We found in the majority of cases, the expected number of deaths resulting from SO2 over a 6-week period total fewer than ~100 for each model run, and for SO4, in the majority of cases, the number totals fewer than ~200. However, the 6-week simulated period with the highest SO2 was associated with 313 deaths, and the period with the highest SO4 was associated with 826 deaths. The single 6-week period relating to the highest combined SO2 and SO4 was associated with 925 deaths. Over a 5-month extended exposure period, upper estimates are for 3350 deaths, 4030 emergency cardiovascular and 6493 emergency respiratory hospitalizations. These figures represent a worst-case scenario and can inform health protection planning for effusive volcanic eruptions which may affect the UK in the future

Forces between electric charges in motion: Rutherford scattering, circular Keplerian orbits, action-at-a-distance and Newton's third law in relativistic classical electrodynamics

Standard formulae of classical electromagnetism for the forces between electric charges in motion derived from retarded potentials are compared with those obtained from a recently developed relativistic classical electrodynamic theory with an instantaneous inter-charge force. Problems discussed include small angle Rutherford scattering, Jackson's recent `torque paradox' and circular Keplerian orbits. Results consistent with special relativity are obtained only with an instantaneous interaction. The impossiblity of stable circular motion with retarded fields in either classical electromagnetism or Newtonian gravitation is demonstrated.Comment: 26 pages, 5 figures. QED and special relativity forbid retarded electromagnetic forces. See also physics/0501130. V2 has typos corrected, minor text modifications and updated references. V3 has further typos removed and added text and reference

Vacuum Cherenkov radiation

Within the classical Maxwell-Chern-Simons limit of the Standard-Model Extension (SME), the emission of light by uniformly moving charges is studied confirming the possibility of a Cherenkov-type effect. In this context, the exact radiation rate for charged magnetic point dipoles is determined and found in agreement with a phase-space estimate under certain assumptions.Comment: 4 pages, REVTeX

Multiple air pollutants and their health impacts for both present-day and future scenarios

The adverse health impacts of air pollution, both short-term and long-term, have been widely studied in recent years; however there are a number of uncertainties to consider when carrying out health impact assessments. Health effects attributable to exposure to air pollutants are typically estimated using measured or modelled pollutant concentrations which vary both temporally and spatially. The goal of this thesis is to perform health impact assessments using modelled pollutant concentrations for present-day and future. The specific aims are: (i) to study the influence of model horizontal resolution on simulated concentrations of ozone (O3) and particulate matter less than 2.5 μm in diameter (PM2.5) for Europe and the implications for health impact assessments associated with long-term exposure (ii) to model air pollutant concentrations during two air pollution episodes in July 2006 together with the corresponding short-term health impact in the UK (iii) to estimate potential future health burdens associated with long-term pollutant exposure under future UK emission changes for 2050 in the UK. First, the impact of model horizontal resolution on simulated concentrations of O3 and PM2.5, and on the associated long-term health impacts over Europe is examined, using the HadGEM3–UKCA (UK Chemistry and Aerosol) chemistry– climate model to simulate pollutant concentrations at a coarse (~140 km) and a finer (~50 km) horizontal resolution. The attributable fraction (AF) of total mortality due to long-term exposure to warm season daily maximum 8-hr running mean (MDA8) O3 and annual-mean PM2.5 concentrations is then estimated for each European country using pollutant concentrations simulated at each resolution. Results highlight seasonal variations in simulated O3 and PM2.5 differences between the two model resolutions in Europe. Simulated O3 concentrations averaged for Europe at the coarse resolution are higher in winter and spring (~10 and ~6 %, respectively) but lower in summer and autumn (~-1 and ~-4 %, respectively) compared to the finer resolution results. These differences may be partly explained by differences in nitrogen dioxide (NO2) concentrations simulated at the two resolutions. Compared to O3, the opposite seasonality in simulated PM2.5 differences between the two resolutions is found. In winter and spring, simulated PM2.5 concentrations are lower at the coarse compared to the finer resolution (~-8 and ~-6 % averaged for Europe, respectively) but higher in summer and autumn (~29 and ~8 %, respectively). Differences in simulated PM2.5 levels are largely related to differences in convective rainfall and boundary layer height between the two resolutions for all seasons. These differences between the two resolutions exhibit clear spatial patterns for both pollutants that vary by season, and exert a strong influence on country to country variations in the estimated AF of mortality for the two resolutions. Results demonstrate that health impact assessments calculated using modelled pollutant concentrations, are sensitive to a change in model resolution with differences in AF of mortality between the countries ranging between ~-5% and ~+3%. Under climate change, the risk of extreme weather events, such as heatwaves, is likely to increase. Thus the UK health burden associated with short-term exposure to MDA8 O3 and daily mean PM2.5 is examined during two five-day air pollution episodes during a well-known heatwave period in July 2006 (1st - 5th July and 18th – 22nd July) using the UK Met Office air quality model (AQUM) at 12 km horizontal resolution. Both episodes are found to be driven by anticyclonic conditions (mean sea-level pressures ~1020hPa over the UK) with light easterly and south easterly winds and high temperatures that aided pollution build up in the UK. The estimated total mortality burden associated with short-term exposure to O3 is similar during the each episode with about 70 daily deaths brought forward summed across the UK. The estimated health burden associated with short-term exposure to daily mean PM2.5 concentrations differs between the first and second episode resulting in about 43 and 36 daily deaths brought forward, respectively. The attributable fraction of all-cause (excluding external) mortality for both pollutants differs between UK regions and ranges between 1.6% to 5.2% depending on the pollution levels in each episode; the overall total estimated health burdens are highest in regions with higher population totals. Results show that during these episodes, short-term exposure to MDA8 O3 and daily mean PM2.5 is between 36- 38% and 39-56% higher, respectively, than if the pollution levels represented typical seasonal-mean concentrations. Finally, emission scenarios for the UK following three Intergovernmental Panel on Climate Change (IPCC) Representative Concentration Pathways (RCPs); RCP2.6, RCP6.0 and RCP8.5 are used to simulate future concentrations of O3, NO2 and PM2.5 for 2050 relative to 2000 using the AQUM air quality model at 12km resolution. The present-day and future AF of mortality associated with long-term exposure to annual mean MDA8 O3, NO2 and PM2.5 and the corresponding mortality burdens are estimated for each region in the UK. For all three RCPs, simulated annual mean MDA8 O3 concentrations in 2050 are estimated to increase compared to 2000, due to decreases in nitrogen oxides (NOx) emissions reducing titration of O3 by NO, and to increases in methane (CH4) levels across all of the UK. In contrast, annual mean NO2 concentrations decrease everywhere. This highlights that the whole of the UK is simulated to be in a NOx-saturated chemical environment. PM2.5 concentrations decrease under all RCPs for the 2050s mostly driven by decreases in NOx and sulphur dioxide (SO2) emissions affecting secondary inorganic aerosols concentrations. For all pollutants the largest changes are estimated under RCP8.5 while the smallest changes are estimated for RCP6.0 in 2050 as compared to present-day. Consequently, these two RCPs represent the high and low end of the AF and mortality burden difference range relative to present-day for all three pollutants. For all UK regions and all three RCPs, the AF of mortality associated with long-term exposure to O3 is estimated to increase in 2050 while the AF associated with long-term exposure to NO2 and PM2.5 is estimated to decrease as a result of higher and lower projected pollutant concentrations, respectively. Differences in the UK-wide mortality burden attributable to long-term exposure to annual mean MDA8 O3 across the RCPs range from +2,529 to +5,396 additional attributable deaths in 2050 compared to 2000. Long-term exposure to annual mean NO2 and PM2.5 differences in health burdens are between - 9,418 and -15,782 and from - 4,524 to -9,481 avoided attributable deaths in 2050 relative to present-day, respectively. These mortality burdens are also sensitive to future population projections. These results demonstrate that long-term health impact assessments estimated using modelled pollutant concentrations, are sensitive to a change in model resolution across Europe, especially in southern and eastern Europe. In addition, air pollution episodes are shown to have the potential to cause substantial short-term impacts on public health in the UK. Finally the sensitivity of future MDA8 O3-, NO2- and PM2.5-attributable health burdens in the UK to future emission scenarios as well as population projections is highlighted with implications for informing future emissions control strategies for the UK

Chaotic and pseudochaotic attractors of perturbed fractional oscillator

We consider a nonlinear oscillator with fractional derivative of the order alpha. Perturbed by a periodic force, the system exhibits chaotic motion called fractional chaotic attractor (FCA). The FCA is compared to the ``regular'' chaotic attractor. The properties of the FCA are discussed and the ``pseudochaotic'' case is demonstrated.Comment: 20 pages, 7 figure

Gravitoelectromagnetism in a complex Clifford algebra

A linear vector model of gravitation is introduced in the context of quantum physics as a generalization of electromagnetism. The gravitoelectromagnetic gauge symmetry corresponds to a hyperbolic unitary extension of the usual complex phase symmetry of electromagnetism. The reversed sign for the gravitational coupling is obtained by means of the pseudoscalar of the underlying complex Clifford algebra.Comment: 10 pages Latex2

Covid-19 mobility restrictions: impacts on urban air quality and health

In 2020, Covid-19-related mobility restrictions resulted in the most extensive human-made air-quality changes ever recorded. The changes in mobility are quantified in terms of outdoor air pollution (concentrations of PM2.5 and NO2) and the associated health impacts in four UK cities (Greater London, Cardiff, Edinburgh and Belfast). After applying a weather-corrected machine learning (ML) technique, all four cities show NO2 and PM2.5 concentration anomalies in 2020 when compared with the ML-predicted values for that year. The NO2 anomalies are –21% for Greater London, –19% for Cardiff, –27% for Belfast and –41% for Edinburgh. The PM2.5 anomalies are 7% for Greater London, –1% for Cardiff, –15% for Edinburgh, –14% for Belfast. All the negative anomalies, which indicate air pollution at a lower level than expected from the weather conditions, are attributable to the mobility restrictions imposed by the Covid-19 lockdowns. Spearman rank-order correlations show a significant correlation between the lowering of NO2 levels and reduction in public transport (p < 0.05) and driving (p < 0.05), which is associated with a decline in NO2-attributable mortality. These positive effects of the mobility restrictions on public health can be used to evaluate policies for improved outdoor air quality

Future air pollution related health burdens associated with RCP emission changes in the UK

Intergovernmental Panel on Climate Change (IPCC) Representative Concentration Pathways (RCPs) are used to simulate future ozone (O3), nitrogen dioxide (NO2), and fine particulate matter (PM2.5) in the United Kingdom (UK) for the 2050s relative to the 2000s with an air quality model (AQUM) at a 12 km horizontal resolution. The present-day and future attributable fractions (AF) of mortality associated with long-term exposure to annual mean O3, NO2 and PM2.5 have accordingly been estimated for the first time for regions across England, Scotland and Wales. Across the three RCPs (RCP2.6, RCP6.0 and RCP8.5), simulated annual mean of the daily maximum 8-hr mean (MDA8) O3 concentrations increase compared to present-day, likely due to decreases in NOx (nitrogen oxides) emissions, leading to less titration of O3 by NO. Annual mean NO2 and PM2.5 concentrations decrease under all RCPs for the 2050s, mostly driven by decreases in NOx and sulphur dioxide (SO2) emissions, respectively. The AF of mortality associated with long-term exposure to annual mean MDA8 O3 is estimated to increase in the future across all the regions and for all RCPs. Reductions in NO2 and PM2.5 concentrations lead to reductions in the AF estimated for future periods under all RCPs, for both pollutants. Total mortality burdens are also highly sensitive to future population projections. Accounting for population projections exacerbates differences in total UK-wide MDA8 O3-health burdens between present-day and future by up to a factor of ~3 but diminishes differences in NO2-health burdens. For PM2.5, accounting for future population projections results in additional UK-wide deaths brought forward compared to present-day under RCP2.6 and RCP6.0, even though the simulated PM2.5 concentrations for the 2050s are estimated to decrease. Thus, these results highlight the sensitivity of future health burdens in the UK to future trends in atmospheric emissions over the UK as well as future population projections