Air pollution, deprivation and health: understanding relationships to add value to local air quality management policy and practice in Wales, UK.

Background: Air pollution exposure reduces life expectancy. Air pollution, deprivation and poor-health status combinations can create increased and disproportionate disease burdens. Problems and solutions are rarely considered in a broad public health context, but doing so can add value to air quality management efforts by reducing air pollution risks, impacts and inequalities. Methods: An ecological study assessed small-area associations between air pollution (nitrogen dioxide and particulate matter), deprivation status and health outcomes in Wales, UK. Results: Air pollution concentrations were highest in 'most' deprived areas. When considered separately, deprivation-health associations were stronger than air pollution-health associations. Considered simultaneously, air pollution added to deprivation-health associations; interactions between air pollution and deprivation modified and strengthened associations with all-cause and respiratory disease mortality, especially in 'most' deprived areas where most-vulnerable people lived and where health needs were greatest. Conclusion: There is a need to reduce air pollution-related risks for all. However, it is also the case that greater health gains can result from considering local air pollution problems and solutions in the context of wider health-determinants and acting on a better understanding of relationships. Informed and co-ordinated air pollution mitigation and public health action in high deprivation and pollution areas can reduce risks and inequalities. To achieve this, greater public health integration and collaboration in local air quality management policy and practice is needed.

Spatial variations in airborne microorganism and endotoxin concentrations at green waste composting facilities.

The emission and dispersal of bioaerosols from open-air commercial composting facilities continues to be contentious. A meta-dataset enumerating cultivable microorganism emission and downwind concentrations is not yet available. A dataset derived from repeated and replicated field studies over a period of two years at two commercial composting facilities is presented. The data characterises patterns in Aspergillus fumigatus, actinomycetes, Gram-negative bacteria and endotoxin emission and downwind concentrations. For all bioaerosols, compost agitation activities had a significant impact on concentrations; levels were variable up to 600 m downwind from site. Bioaerosols declined rapidly from source and exhibited a secondary peak 100-150 m from site boundary. All bioaerosols were found downwind from site in elevated concentrations. Compared to those found 100 m upwind, levels were significantly higher at 180 m downwind for A. fumigatus; at 300-400 m for actinomycetes and Gram negative bacteria, and at 100 m for endotoxins. Periodically, elevated concentrations could be found for all bioaerosols at distances further downwind. The evidence provided by this data set provides operators and regulators of facilities with reliable data to inform the location, risk assessment and bioaerosol sampling strategies of commercial composting facilities.

Local air quality management as a risk management process: assessing, managing and remediating the risk of exceeding an air quality objective in Great Britain.

Air quality is managed in Great Britain via an effects-based, risk management process designed to provide a dynamic solution to public health issues associated with elevated concentrations of seven specified air pollutants. This paper is concerned with an examination and evaluation of the process of Local Air Quality Management (LAQM) in Great Britain from the late 1980s to date as a risk management process. The statutory basis of LAQM process is provided by the Environment Act 1995. The Act provides a framework in which national and local actions are required to identify and remediate areas of poor air quality. Within this framework, the implementation of the process at national and local levels is considered, leading to an identification and assessment of risks in the formulation and implementation of air quality management policy and practice. Local Authorities began the process of Review and Assessment in 1999 and the first round of the process concluded in 2001. Following this, some 129 Local Authorities declared one or more Air Quality Management Areas (AQMAs). The Review and Assessment elements of the framework were subjected to an evaluation in 2001 and the essential elements of it were confirmed as fit for purpose. The evaluation led to a confirmation of the process of LAQM but also a simplification based on the experience of Round 1. Now, a two step process is required comprising of an Updating and Screening Assessment and, where a risk of exceeding an Air Quality Objective (AQO) is identified, a Detailed Assessment follows. The Government has identified a time scale for Review and Assessment through to 2010 and also introduced the requirement of a regular Progress Report in order that a Local Authority is able to address routine matters of air quality management. The risks inherent in epidemiological or scientific uncertainty are factored into the LAQM process at an early stage of the process and, by identifying the risks and subjecting them to regular review, the process provides a 'level playing field' across spatial and temporal scales. Whilst the process of LAQM described in this paper has been developed for Great Britain, the generic elements of the process are applicable to other countries challenged by air pollution problems which require both national and local action to resolve them.

Characterisation and quantification of the sources of PM10 during air pollution episodes in the UK.

Data for concentrations of PM(10) and gaseous pollutants from sites in the UK Automatic Urban and Rural Network have been examined during periods of elevated concentrations of PM(10). The ratios of concentrations of PM(10) to those of the other pollutants were used to determine the most probable source of the additional particles. The hypothesis is that because the concentrations of PM(10) were divided by those of the other pollutants, the ratio should decrease when PM(10) and the other pollutants have a common source. Conversely, the ratio should increase when the sources are different. During episodes where road traffic was the most probable source of the additional particles, the ratios of concentrations of PM(10) to carbon monoxide and oxides of nitrogen did decrease, but the comparable ratios for sulphur dioxide and ozone increased. In contrast, during episodes known to have been caused by construction activity, all these ratios increased. This is taken to show that the basic hypothesis is valid. For prolonged episodes, it was possible to use data averaged over the total duration of the episode for the purposes of source identification. For sporadic construction, or other short-duration episodes, it was necessary to use time series data. The data have also been used to calculate the differences between hourly average concentrations of pollutants measured during episodes and long-term hourly average concentrations. These have been used to model the additional PM(10) during air pollution episodes associated with construction activities and road traffic emissions. This confirms the lack of relationship between PM(10) and other pollutants during construction works. During episodes arising from road traffic emissions, there was good agreement between measured and modelled additional concentrations of PM(10) when an appropriate factor, F, related to the contribution of road traffic emissions to PM(10) at different site types was applied. The values used were 0.2 (Suburban), 0.3 (Urban Background/Urban Centre), and 0.5 (Roadside), representing 20%, 30%, and 50% contributions from road traffic, respectively.

Outcomes of the first round of local authority air quality Review and Assessments under the UK's air quality strategy.

In 1997, the UK government instigated the practice of Local Air Quality Management (LAQM) in the UK. This process is based on local authorities undertaking Review and Assessments of air quality within their areas. The first round of Review and Assessments have now been completed and represents the most extensive and coordinated analysis of air pollution ever undertaken in the UK, and probably in Europe. This paper takes a broad look at the outcomes of this process so far and identifies some of the key areas where lessons have/can be learnt both about patterns of air pollution in the UK and about the framework for investigating these that has been implemented under the LAQM regime. The process has led to a much higher number of local authorities finding problems with air pollution than initially expected. It has also challenged many assumptions about the significance of various pollutants and their sources.

Critical evaluation of the role of scientific analysis in UK local authority AQMA decision-making: method development and preliminary results.

Over the past 4 years, local government in the UK has undertaken a process of scientific review and assessment of air quality, which has culminated in a suite of designated air quality management areas (AQMAs) in over 120 of the 403 local authorities in England (including London), Scotland and Wales. Methods to identify specific pollution hot-spots have involved the use of advanced and complex air-quality dispersion modelling and monitoring techniques, and the UK government has provided guidance on both the general and technical methods for undertaking local air quality review and assessments. Approaches to implementing UK air quality policy, through the local air quality management (LAQM) process (Air Quality Strategy 2000) has not been uniform across the UK, as an inevitable consequence of non-prescriptive guidelines. This has led to a variety of outcomes with respect to how different tools and techniques have been applied, the interpretation of scientific uncertainty and the application of caution. A technique to appraise the scientific approaches undertaken by local government and to survey local government officers involved in the LAQM process have been devised, and a conceptual model proposed to identify the main influences in the process of determining AQMAs. Modelling tools used and the consideration of modelling uncertainty, error and model inputs have played a significant role in AQMA decision-making in the majority of local authorities declaring AQMAs in the UK.