Ben Williams

A review of evidence on the cost-effectiveness of local authority activities to reduce exposure to air pollution from road traffic

© 2017 WIT Press. This paper presents a systematic review of evidence of the cost-effectiveness of local authority activities to reduce exposure to air pollution from road traffic. The work was undertaken as part of an evidence review for the National Institute for Health and Care Excellence (NICE) and contributes to the economic model produced by Eunomia, which underpins draft guidance for local government published by the Public Health and Social Care Centre (PHSCC) within NICE. The draft guidance was released for consultation in December 2016 and the final publication is expected in July 2017. The review addresses the scope outlined by the PHSCC and was undertaken following NICE search protocols with PHSCC approval. The scope covers interventions that could be delivered by local authorities to reduce road-traffic-related emissions by: reducing overall mileage; altering the type of fuel used or driving style; aiding dispersion or deposition of pollutants; and altering personal behaviour to reduce exposure to pollutants. This paper concludes that there is a lack of available published evidence on the cost-effectiveness of such measures and makes recommendations for further research to address this evidence gap.

Scoping studies to establish the capability and utility of a real-time bioaerosol sensor to characterise emissions from environmental sources

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.

The relationship between buildings and health: a systematic review

Abstract Background The built environment exerts one of the strongest directly measurable effects on physical and mental health, yet the evidence base underpinning the design of healthy urban planning is not fully developed. Method This study provides a systematic review of quantitative studies assessing the impact of buildings on health. In total, 7127 studies were identified from a structured search of eight databases combined with manual searching for grey literature. Only quantitative studies conducted between January 2000 and November 2016 were eligible for inclusion. Studies were assessed using the quality assessment tool for quantitative studies. Results In total, 39 studies were included in this review. Findings showed consistently that housing refurbishment and modifications, provision of adequate heating, improvements to ventilation and water supply were associated with improved respiratory outcomes, quality of life and mental health. Prioritization of housing for vulnerable groups led to improved wellbeing. However, the quality of the underpinning evidence and lack of methodological rigour in most of the studies makes it difficult to draw causal links. Conclusion This review identified evidence to demonstrate the strong association between certain features of housing and wellbeing such as adequate heating and ventilation. Our findings highlight the need for strengthening of the evidence base in order for meaningful conclusions to be drawn.

The challenges, uncertainties and opportunities of bioaerosol dispersion modelling from open composting facilities

Bioaerosols are ubiquitous organic particles that comprise viruses, bacteria and coarser fractions of organic matter. Known to adversely affect human health, the impact of bioaerosols on a population often manifests as outbreaks of illnesses such as Legionnaires Disease and Q fever, although the concentrations and environmental conditions in which these impacts occur are not well understood. Bioaerosol concentrations vary from source to source, but specific human activities such as water treatment, intensive agriculture and composting facilitate the generation of bioaerosol concentrations many times higher than natural background levels. Bioaerosols are not considered ‘traditional’ pollutants in the same way as PM10, PM2.5, and gases such as NO2, and consequently dispersion models do not include a bespoke method for their assessment. As identified in previous studies, priority areas for improving the robustness of these dispersion models include: 1) the development of bespoke monitoring studies designed to generate accurate modelling input data; 2) the publication of a robust emissions inventory; 3) a code of practice to provide guidelines for consistent bioaerosol modelling practices; and 4) a greater understanding of background bioaerosol emissions. The aim of this research project, funded by the Natural Environmental Research Council (NERC), is to address these key areas through a better understanding of the generation, concentration and potential dispersion of bioaerosols from intensive agricultural and biowaste facilities, using case studies developed at specific locations within the UK. The objective is to further refine existing bioaerosol monitoring and modelling guidelines to provide a more robust framework for regulating authorities and site operators. This contribution outlines the gaps that hinder robust dispersion modelling, and describes the on-site bioaerosol data collection methods used in the study, explaining how they might be used to close these gaps. Examples of bioaerosol dispersion modelled using ADMS 5 are presented and discussed.

A critical review of the robustness of the UK government's Air Quality Plan and expected compliance dates

Globally, poor air quality is the most significant environmental health concern. Across Europe, 400,000 deaths were attributed to air pollution in 2012, whilst in the UK over 50,000 deaths per year are due to a combination of gaseous and particulate matter air pollution. The deadline for achieving the EU limit value for NO2 was the 1st of January 2010, yet the UK remains non-compliant in 38 of 43 zones and agglomerations. As a consequence, in April 2015, the government was ordered by the UK Supreme Court to draw up new air quality plans to achieve the EU limit values in the shortest time possible. In response the UK government consulted on a draft national air quality plan, which estimated compliance with the EU Air Quality Directive by 2020 in all zones and agglomerations except London (compliance by 2025). The plan introduces the concept of a Clean Air Zone (CAZ) to address the non-compliant zones but overall has significant weaknesses in many zones and agglomerations and compliance by 2020 (and 2025 in London) is considered to be overly optimistic. The plan’s predictive models use vehicle emission factors that are not considered representative of actual driving conditions, and transparency in the data underlying vehicle fleet turnover calculations is lacking. The suitability of CAZ as a cornerstone of the plan is of particular concern. This contribution examines new evidence that challenges the robustness of the UK government’s air quality plan. If air quality within the UK is to improve within the shortest time possible, significant improvements in the analysis and proposed solutions will be required.