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Countries around the world introduced strict restrictions on movement and activities known as 'lockdowns' to restrict the spread of the novel coronavirus disease (COVID-19) from the end of 2019. A sudden improvement in air quality was observed globally as a result of these lockdowns. To provide insight into the changes in air pollution levels in response to the COVID-19 restrictions we have compared surface air quality data in Delhi during four phases of lockdown and the first phase of the restriction easing period (25 March to 30 June 2020) with data from a baseline period (2018–2019). Simultaneously, short-term exposure of PM2.5 and O3 attributed premature mortality were calculated to understand the health benefit of the change in air quality. Ground–level observations in Delhi showed that concentrations of PM10, PM2.5 and NO2 dropped substantially in 2020 during the overall study period compared with the same period in previous years, with average reductions of ~49%, ~39%, and ~39%, respectively. An overall lower reduction in O3 of ~19% was observed for Delhi. A slight increase in O3 was found in Delhi's industrial and traffic regions. The highest peak of the diurnal variation decreased substantially for all the pollutants at every phase. The decrease in PM2.5 and O3 concentrations in 2020, prevented 904 total premature deaths, a 60% improvement when compared to the figures for 2018–2019. The restrictions on human activities during the lockdown have reduced anthropogenic emissions and subsequently improved air quality and human health in one of the most polluted cities in the world. Implications: I am submitting herewith the manuscript entitled "Unprecedented Reduction in Air Pollution and Corresponding Short-term Premature Mortality Associated with COVID-19 Forced Confinement in Delhi, India" for potential publishing in your journal. The novelty of this research lies in: (1) we utilized ground-level air quality data in Delhi during four phases of lockdown and the first phase of unlocking period (25th March to 30th June) for 2020 as well as data from the baseline period (2018–2019) to provide an early insight into the changes in air pollution levels in response to the COVID-19 pandemic, (2) Chatarize the change of diurnal variation of the pollutants and (3) we assess the health risk due to PM2.5 and O3. Results from ground-level observations in Delhi showed that concentrations of PM10, PM2.5 and NO2 substantially dropped in 2020 during the overall study period compared to the similar period in previous years, with an average reduction of ~49%, ~39%, and ~39%, respectively. In the case of O3, the overall reduction was observed as ~19% in Delhi, while a slight increase was found in industrial and traffic regions. And consequently, the highest peak of the diurnal variation decreased substantially for all the pollutants. The health impact assessment of the changes in air quality indicated that 904 short-term premature deaths (~60%) were prevented due to the decline in PM2.5 and O3 concentrations in the study period. The restrictions on human activities during the lockdown have reduced the anthropogenic emissions and subsequently improved air quality and human health in one of the most polluted cities in the world. [ABSTRACT FROM AUTHOR]

Abstract The aim of this study was to provide a simple, cost-effective, risk-based map of terrestrial areas in Ireland where environmental quality may be at risk from atmospheric ammonia. This risk-based approach identifies Natura 2000 sites in Ireland at risk from agricultural atmospheric ammonia, collating best available data using Geographical Information Systems (GIS). In mapping ammonia risk on sensitive habitats (MARSH), the method identifies sources of ammonia, classifying them on a scale of risk from 0 to 5. These sources are subsequently summed based on a weighting determined by their contribution to national emissions divided by their potentially impacted area. A Pearson's correlation coefficient of 0.72 allows for concentrations from United Kingdom's FRAME modelling to be applied to the MARSH model, which are corrected based on recent monitoring. Applying Designation Weighted Indicators (DWI), the MARSH model predicts that 80.7, 34.3 and 5.9% of Natura 2000 sites in Ireland may exceed ambient concentrations of 1, 2, and 3 μg/m3, respectively. A Nitroindex map of Ireland based on available lichen records was also developed and is presented as part of this study. This Nitroindex was used to identify areas where impacts have already been recorded, thus informing the classification of sites "at-risk". The combination of both the MARSH and Nitroindex models ascertains which Natura 2000 sites are most at risk, thereby providing valuable data to relevant authorities. The MARSH model acts as a first step towards screening and assessing Natura 2000 sites most at risk from atmospheric ammonia, providing a tool to demonstrate compliance with the National Emissions Ceilings Directive. Graphical abstract Unlabelled Image Highlights • A GIS risk-based approach gauges atmospheric NH 3 impacts in Ireland • Integrates best available agricultural data to identify "at-risk" areas in Ireland • Provides stakeholders with an atmospheric ammonia risk map for Ireland • 80.7% of Natura 2000 sites likely to exceed critical level of 1 μg/m3 • 5.9% of Natura 2000 sites likely to exceed critical level of 3 μg/m3 [ABSTRACT FROM AUTHOR]

Abstract A novel dual excitation wavelength based bioaerosol sensor with multiple fluorescence bands called Spectral Intensity Bioaerosol Sensor (SIBS) has been assessed across five contrasting outdoor environments. The mean concentrations of total and fluorescent particles across the sites were highly variable being the highest at the agricultural farm (2.6 cm−3 and 0.48 cm−3, respectively) and the composting site (2.32 cm−3 and 0.46 cm−3, respectively) and the lowest at the dairy farm (1.03 cm−3 and 0.24 cm−3, respectively) and the sewage treatment works (1.03 cm−3 and 0.25 cm−3, respectively). In contrast, the number-weighted fluorescent fraction was lowest at the agricultural site (0.18) in comparison to the other sites indicating high variability in nature and magnitude of emissions from environmental sources. The fluorescence emissions data demonstrated that the spectra at different sites were multimodal with intensity differences largely at wavelengths located in secondary emission peaks for λex 280 and λex 370. This finding suggests differences in the molecular composition of emissions at these sites which can help to identify distinct fluorescence signature of different environmental sources. Overall this study demonstrated that SIBS provides additional spectral information compared to existing instruments and capability to resolve spectrally integrated signals from relevant biological fluorophores could improve selectivity and thus enhance discrimination and classification strategies for real-time characterisation of bioaerosols from environmental sources. However, detailed lab-based measurements in conjunction with real-world studies and improved numerical methods are required to optimise and validate these highly resolved spectral signatures with respect to the diverse atmospherically relevant biological fluorophores. Graphical abstract Unlabelled Image Highlights • First real world evaluation of a novel dual wavelength excitation multiple fluorescence band bioaerosol sensor • High variability in nature and magnitude of emissions at contrasting sites • Highly resolved emission intensity measurements provide additional spectral information in comparison to existing devices. • Differences in emission spectra from different sites at smaller and lager wavelengths than maxima [ABSTRACT FROM AUTHOR]

UK local air quality action planning has failed to remediate exceedances of air quality targets, particularly for nitrogen dioxide, which are widespread and persistent a decade after the first local action plans were drafted. This paper is relevant to a range of administrations charged with managing air quality. Using a literature review and local authority survey, it explores barriers to improving air quality, i.e. resource limitations, absence of local authority powers, and a lack of intra-governmental co-operation and inter-governmental co-ordination. It concludes that the causes of these inefficiencies are flawed subsidiarity and devolved responsibility decoupled from the powers necessary to implement required actions. Challenging opportunities to reconceptualise air quality action planning to protect public health are suggested. [ABSTRACT FROM AUTHOR]

In this paper the necessity for effective joint working arrangements between Environmental Health Officers and Transport Planners is demonstrated as a fundamental prerequisite for successful management of traffic-related air quality in English local government areas. Current approach to joint working and collaboration between the officers was examined based on the evidence from a three-year study which involved questionnaire surveys and case study interviews. The findings show that despite good administrative devolution and policy integration, the chance of improving specific local air quality situations through the Local Transport Planning process is dependent on other overriding factors which influence the capabilities of the authorities to integrate policies across departments and tiers of governments. Implicit in these findings is the need for a shared paradigm of continuous engagement by all the policy actors and stakeholders if proper integration and the possibility of tangible results in future policy development are to be achieved. The paper proposes a new framework through which such collaborations can be developed and within which solutions to the issues identified can be evaluated. [ABSTRACT FROM AUTHOR]

Approximately half the world's population now lives in urban areas, and about 70% will be city dwellers by 2050. The IEA's World Energy Outlook 2008 estimates the global energy and energy related carbon dioxide (CO2) emission contributions of cities are 67% and 71% respectively. They therefore represent a concentration of carbon dioxide-emitting activities, but equally provide substantial opportunities for effective mitigation. Although international action on climate change is essential, local mitigation will deliver many of the carbon savings, and consequently, cities will play an important role. However, closing the gap between 'where we are now' and 'where we need to be' can be problematic, given the all-encompassing nature of the problem and its cause, and the long timescales involved. Using the example of Bristol in south west England, this paper presents a methodology to overcome such a problem. By engaging local stakeholders through an innovative Delphi-like process, a number of low-carbon scenarios for the future city-region can be imagined. By subsequently using backcasting techniques, together with conventional forecasting, a robust pathway from the present to a future desirable low-emission city can be described. This will bring benefits to planning and policy making, by providing a low emission-pathway beyond the short term, and creates buy-in from key stakeholders through the Delphi-process, who have helped to define the city's future [ABSTRACT FROM AUTHOR]

Because of the lack of effective methodology, the biological effects of environmental endotoxin have not been assessed. Here we have collected and measured airborne endotoxin at different locations around composting sites. Increased endotoxin concentrations were observed close to composting activities and also at nearby boundary areas. Analysis of proinflammatory effects of the environmental endotoxin on interleukin (IL)-8 and IL-6 release from human D562 pharyngeal epithelial and MM6 monocytic cell cultures showed an association between endotoxin level and cytokine induction. The cytokine-inducing effect of bioaerosol extracts was inhibited by polymyxin B, indicating that endotoxin was the cause of cytokine responses we found. The environmental endotoxin was also more active for stimulating cytokines in airway epithelial cells than commercially purified Escherichia coli endotoxin. Our results suggest that these in vitro inflammatory cell models may contribute to the assessment of health impacts of environmental endotoxin. Environ. Toxicol. Chem. 2011; 30:602-606. © 2011 SETAC [ABSTRACT FROM AUTHOR]

This paper describes an exploratory study of endotoxin emissions and dispersal from a commercial composting facility. Replicated samples of air were taken by filtration at different locations around the facility on 10 occasions. Measurements were made of endotoxin and associated culturable microorganisms. The inflammatory response of cell cultures exposed to extracts from the filters was measured. Endotoxin was detected in elevated concentrations close to composting activities. A secondary peak, of lesser magnitude than the peak at source was detected at 100-150 m downwind of the site boundary. Unexpectedly high concentrations of endotoxin were measured at the most distant downwind sampling point. Extracted endotoxin was found to stimulate human monocytes and a human lung epithelial cell line to produce significant amounts of pro-inflammatory cytokines. On a weight basis, endotoxin extracted from the composting source has a greater inflammatory cytokine inducing effect than commercial E. coli endotoxin. [ABSTRACT FROM AUTHOR]

Abstract: An investigation was conducted into the influence of manure composition on the odour emission rate (OER) and the emission rate of ammonia (NH3), when diets containing 130, 160, 190 and 210gkg−1 crude protein (CP) were fed to finishing pigs. A group of four boars and four gilts, housed in environmentally sealed pens, were assigned to each diet for a 23-day experimental period which was replicated three times (n =3). Ventilation air from each pen was sampled for NH3 and odour, by olfactometry, on four days during the trial period. Simultaneous collections of manure were taken from the surface and base of each pit. The pH and the concentrations of dry matter, total Kjeldahl nitrogen (TKN), total ammoniacal nitrogen (TAN) and volatile fatty acids in the manure were measured. Manure composition differed between samples from the surface and base of the pit (P <0.05). Reducing dietary CP concentration decreased the emission of NH3 (linear, P <0.001). The acetic acid:propionic acid ratio in manure samples was correlated to OER (r =0.79, P <0.001). There was a quadratic relationship between dietary CP concentration and OER (P <0.05). OER decreased between 210gkg−1 and 160gkg−1 CP and increased between 160gkg−1 and 130gkg−1 CP. In conclusion, reducing dietary crude protein levels could be used effectively to reduce ammonia emissions and OER, although no significant advantage was to be gained in OER from reducing crude protein level below 160gkg−1. [Copyright &y& Elsevier]

Technological approaches to carbon emission and air pollution data modelling consider where the issues are located and what is creating emissions. This paper argues that more focus should be paid to people—the drivers of vehicles or households burning fossil fuels ('Who') and the reasons for doing so at those times ('Why'). We applied insights from social psychology (social identity theory and social cognitive theory) to better understand and communicate how people's everyday activities are a cause of climate change and air pollution. A new method for citizen-focused source apportionment modelling and communication was developed in the ClairCity project and applied to travel data from Bristol, U.K. This approach enables understanding of the human dimension of vehicle use to improve policymaking, accounting for demographics (gender or age groups), socio-economic factors (income/car ownership) and motives for specific behaviours (e.g., commuting to work, leisure, shopping, etc.). Tailored communications for segmented in-groups were trialled, aiming to connect with group lived experiences and day-to-day behaviours. This citizen-centred approach aims to make groups more aware that 'people like me' create emissions, and equally, 'people like me' can take action to reduce emissions. [ABSTRACT FROM AUTHOR]

Bioaerosol emissions arising from biowaste treatment are an issue of public concern. To better characterise the bioaerosols, and to assess a range of measurement methods, we aerosolised green waste compost under controlled conditions. Viable and non-viable Andersen samplers, cyclone samplers and a real time bioaerosol detection system (Spectral Intensity Bioaerosol Sensor (SIBS)) were deployed simultaneously. The number-weighted fraction of fluorescent particles was in the range 22–26% of all particles for low and high emission scenarios. Overall fluorescence spectral profiles seen by the SIBS exhibited several peaks across the 16 wavelength bands from 298 to 735 nm. The size-fractionated endotoxin profile showed most endotoxin resided in the 2.1–9 μm aerodynamic diameter fraction, though up to 27% was found in a finer size fraction. A range of microorganisms were detected through culture, Matrix Assisted Laser Desorption and Ionisation Time of Flight Mass Spectrometry (MALDI-TOF) and quantitative polymerase chain reaction (qPCR), including Legionella pneumophila serogroup 1. These findings contribute to our knowledge of the physico-chemical and biological characteristics of bioaerosols from composting sites, as well as informing future monitoring approaches and data interpretation for bioaerosol measurement. [ABSTRACT FROM AUTHOR]

Bioaerosols have been associated with adverse respiratory-related health effects and are emitted in elevated concentrations from composting facilities. We used modelled Aspergillus fumigatus concentrations, a good indicator for bioaerosol emissions, to assess associations with respiratory-related hospital admissions. Mean daily Aspergillus fumigatus concentrations were estimated for each composting site for first full year of permit issue from 2005 onwards to 2014 for Census Output Areas (COAs) within 4 km of 76 composting facilities in England, as previously described (Williams et al., 2019). We fitted a hierarchical generalized mixed model to examine the risk of hospital admission with a primary diagnosis of (i) any respiratory condition, (ii) respiratory infections, (iii) asthma, (iv) COPD, (v) diseases due to organic dust, and (vi) Cystic Fibrosis, in relation to quartiles of Aspergillus fumigatus concentrations. Models included a random intercept for each COA to account for over-dispersion, nested within composting facility, on which a random intercept was fitted to account for clustering of the data, with adjustments for age, sex, ethnicity, deprivation, tobacco sales (smoking proxy) and traffic load (as a proxy for traffic-related air pollution). We included 249,748 respiratory-related and 3163 Cystic Fibrosis hospital admissions in 9606 COAs with a population-weighted centroid within 4 km of the 76 included composting facilities. After adjustment for confounders, no statistically significant effect was observed for any respiratory-related (Relative Risk (RR) = 0.99; 95% Confidence Interval (CI) 0.96–1.01) or for Cystic Fibrosis (RR = 1.01; 95% CI 0.56–1.83) hospital admissions for COAs in the highest quartile of exposure. Similar results were observed across all respiratory disease sub-groups. This study does not provide evidence for increased risks of respiratory-related hospitalisations for those living near composting facilities. However, given the limitations in the dispersion modelling, risks cannot be completely ruled out. Hospital admissions represent severe respiratory episodes, so further study would be needed to investigate whether bioaerosols emitted from composting facilities have impacts on less severe episodes or respiratory symptoms. • One of the largest studies to date on community health effects of composting. • Used a newly available model of A. fumigatus emissions from composting facilities. • Examined respiratory hospital admissions near 76 facilities (population >17 million). • There was no excess in respiratory admissions in higher exposed areas. • Further study is required to investigate potential impacts on symptoms. [ABSTRACT FROM AUTHOR]

Because of the lack of effective methodology, the biological effects of environmental endotoxin have not been assessed. Here we have collected and measured airborne endotoxin at different locations around composting sites. Increased endotoxin concentrations were observed close to composting activities and also at nearby boundary areas. Analysis of proinflammatory effects of the environmental endotoxin on interleukin (IL)-8 and IL-6 release from human D562 pharyngeal epithelial and MM6 monocytic cell cultures showed an association between endotoxin level and cytokine induction. The cytokine-inducing effect of bioaerosol extracts was inhibited by polymyxin B, indicating that endotoxin was the cause of cytokine responses we found. The environmental endotoxin was also more active for stimulating cytokines in airway epithelial cells than commercially purified Escherichia coli endotoxin. Our results suggest that these in vitro inflammatory cell models may contribute to the assessment of health impacts of environmental endotoxin., (Copyright © 2011 SETAC.)

This paper describes an exploratory study of endotoxin emissions and dispersal from a commercial composting facility. Replicated samples of air were taken by filtration at different locations around the facility on 10 occasions. Measurements were made of endotoxin and associated culturable microorganisms. The inflammatory response of cell cultures exposed to extracts from the filters was measured. Endotoxin was detected in elevated concentrations close to composting activities. A secondary peak, of lesser magnitude than the peak at source was detected at 100-150 m downwind of the site boundary. Unexpectedly high concentrations of endotoxin were measured at the most distant downwind sampling point. Extracted endotoxin was found to stimulate human monocytes and a human lung epithelial cell line to produce significant amounts of pro-inflammatory cytokines. On a weight basis, endotoxin extracted from the composting source has a greater inflammatory cytokine inducing effect than commercial E. coli endotoxin.