Title: AIM-HEALTH: Effectiveness of agricultural interventions to minimise the health impacts of air pollution
Funder: Chief Scientist Office, Scotland

Abstract: Air pollution damages health by worsening lung and heart diseases. This can contribute to premature death and hospital admissions which puts pressure on the NHS and social care system. The health effects from air pollution are associated with exposure to very small particles in the air that are released from many sources or formed in the atmosphere through chemical reactions. Exposure to gases and particles in the air, including very small particles that contain microorganisms, can have negative impacts on lung health. Agriculture and farming are responsible for the release of a large proportion of ammonia gas in the air that can result in the formation of these particles. Farms also release airborne particles containing microorganisms which can affect people living nearby. These risks to health are likely to increase in the future as larger farming sites are developed. _x000D_ The aim of this study is to see how effective improved cattle housing and manure storage and application are at reducing the amount of gases and particles released. Previous research projects have identified that some improvements in farming could reduce levels of UK ammonia gas and particles released. However, it is unknown how effective these are in relation to the health of people and the environment. Their impact on the gases released and the health of communities and susceptible groups living near farms have also not been assessed. This study will fulfil this important research gap by considering the results of previous studies, measuring pollution in the air (ammonia gas, very small particles, microorganisms) close to six selected farms and using a computer model to estimate exposure to the gases at different locations near the six farms. In addition, the study will also estimate the health impacts (deaths and hospital admissions prevented) of different types of improvements at the farms. We will also look at the positives and negatives of introducing the improvements in relation to the environment, society and NHS savings. The benefits to health and additional consequences for local communities will also be analysed. _x000D_ This project builds on a series of Department for Environment, Food and Rural Affairs (DEFRA) workshops with farmers and others, and builds on a Public Health England project which assessed previous research in this topic. As part of this project, we will work with farmers, DEFRA and other Government Agencies, Directors of Public Health, local rural communities and patient organisations. We will discuss with them how changes in cattle housing and manure storage and application are introduced, reasons why they are not introduced, and what helps to introduce them. We will communicate the project findings to farmers, public health practitioners, decision-makers, researchers, and the public by writing electronic bulletins, factsheets, policy briefs, social media posts, scientific journal papers and presenting at conferences and workshops. The aim is for the results to inform and increase the implementation and the number of farmers improving cattle housing and manure storage and application. The project will also inform the development of additional farming improvements as well as health advice for those affected by air pollution from farming.

Lay abstract: Research question: Are interventions included in the National Clean Air Strategy effective and cost-effective in minimising the adverse health impacts and inequalities of outdoor air pollution from agricultural sources? _x000D_ Background: UK air pollution (AP) emissions from agriculture are not declining, and are attracting public health attention. Recent evidence assessment of agricultural interventions to improve air quality (AQ) did not find sufficient evidence for effectiveness of interventions on public health, and little evidence on cost-effectiveness and distributional effects. New research is urgently needed to fill this knowledge gap._x000D_ Aims and objectives: AIM: to assess the effectiveness and cost-effectiveness of two related interventions: improved housing facilities for farmed animals; and improved manure application to soils to reduce ammonia and microbial aerosol emissions. OBJECTIVES: assess health impact of AP from intensive agriculture, for different levels of intervention adoption; evaluate effectiveness and cost-effectiveness of interventions at local, regional and national level; evaluate potential for further uptake of proposed interventions; assess impact on health equity, for populations living near intensive farming; assess environmental co-benefits and trade-offs. _x000D_ Methods: (i) identify mitigation efficiency values from published studies for relevant interventions, engaging residents in rural areas via focus groups and survey (WP1); (ii) carry out national survey of farmers to establish current adoption levels and barriers/enablers for intervention implementation (WP2); (iii) measure emissions around selected farms with good and less-good practices reflecting relevant interventions (WP3); (iv) AQ modelling, with farm AQ measurements, to calculate emissions, generate emissions scenarios for alternative levels of intervention implementation, use chemical transport and dispersion modelling to estimate population exposure to AP (WP4) at local, regional and national level; (v) use Health Impact Assessment (HIA) to estimate the potential health benefits and distributional effects associated with the interventions (WP5); (vi) apply economic evaluation methods, including damage costs and impact pathways, to estimate cost-effectiveness of the interventions and associated trade-offs (WP6). _x000D_ Timelines for delivery: This is a 3-year study, extended by a further 18 months following COVID-related delays. Phase 1 comprises literature review, surveys/ focus groups with local residents and farmers; selection of farms; emission and health data gathering; start of AQ monitoring/modelling. Phase 2 comprises monitoring/modelling of emissions/AQ, and HIA/ economic analyses. Phase 3 comprises dissemination and knowledge transfer activities._x000D_ Anticipated impact and dissemination: Dissemination methods will include email bulletins, social media posts and knowledge exchange workshops; providing the farming and local communities and policy makers with better information on impacts of agricultural air pollution and intervention effects. Impacts include increased adoption of interventions, increased awareness of health impacts of agricultural emissions and cost-effectiveness of proposed interventions, and reduced population exposure to ammonia, secondary nitrate aerosols, ozone, and bioaerosols. The interventions will also benefit the environment, particularly via reduction of nitrogen deposition to sensitive habitats such as grassland, heath, dunes and bogs.

Research activity codes: 3.2 INTERVENTIONS TO ALTER PHYSICAL AND BIOLOGICAL ENVIRONMENTAL RISKS
Health categories: RESPIRATORY;GENERIC HEALTH RELEVANCE