Impact of local and national policies to reduce agriculture-related air pollution through improving diet and farm management: the AMPHoRA mixed methods study.

内容摘要

This study employed an interdisciplinary approach to assess the impact of agricultural production modifications and dietary changes on ammonia emissions, health outcomes and health inequalities. Statistical and econometric methods were applied to analyse agricultural emission trends and dietary patterns. Spatial data analysis and numerical modelling techniques were used to simulate the dispersion and transformation of atmospheric pollutants. Health impact modelling estimated mortality and morbidity outcomes under various policy scenarios, while cost-effectiveness and cost-benefit analyses supported decision-making. A participatory approach involving multistakeholder engagement was utilised to enhance policy relevance and implementation feasibility. A systematic scoping review of academic studies on agricultural-derived air pollution and clinically coded outcomes revealed very limited research on this topic, which presents an inconsistent picture as to whether agricultural-derived particulate matter affects health. Key findings indicate that dietary modifications have greater potential health benefits than direct reductions in particulate matter exposure from ammonia emissions. Small reductions in meat and dairy consumption, supported by taxation and subsidies, could help achieve environmental and health targets. A 20% meat and dairy tax, coupled with a 20% subsidy on fruits and vegetables, could reduce meat consumption by 21.5% and increase fruit and vegetable intake by up to 13.5%. These dietary shifts also significantly lower greenhouse gas emissions and water use. While ammonia's environmental effects are well documented, its direct health impacts remain uncertain. Epidemiological studies suggest a possible association between ammonium-derived particulate matter and increased mortality and cardiorespiratory diseases, though findings are inconsistent. Toxicological assessments indicate limited intrinsic toxicity of ammonium nitrate and sulfate. A 'high-ambition mitigation' scenario integrating ammonia reduction measures with dietary shifts could prevent 67,000 premature deaths and 270,000 cases of respiratory diseases over 30 years. Notably, older adults and lower-income populations would experience the greatest health benefits. Most farm-based ammonia reduction strategies demonstrated net economic benefits, with only a few measures having limited abatement potential. Additionally, reduced greenhouse gas emissions further amplified the benefits of each scenario. Despite robust modelling techniques and multistakeholder engagement, several limitations exist. The direct health effects of ammonia-derived particulate matter remain an area of uncertainty, necessitating further epidemiological research. Additionally, while economic and environmental benefits were quantified, behavioural responses to policy interventions - such as consumer acceptance of dietary changes - require further exploration. The study primarily focused on UK-specific data, limiting generalisability to other regions with different agricultural practices and policy landscapes. Finally, unintended consequences of dietary shifts on food security and cultural preferences were not fully explored, indicating the need for future research to refine policy recommendations. The Assessing Mitigation Pathways to Realise Public Health Benefits of Air Pollutant Emission Reductions from Agriculture project provides a comprehensive, interdisciplinary framework for evaluating integrated policy measures. It underscores the importance of sustainable agricultural and dietary transitions in achieving cobenefits for public health and environmental sustainability, while emphasising the need for continued research to address remaining uncertainties. More detailed spatial and temporal analyses are required to fully understand the potential importance of significant local sources on human health in specific areas/times of year. There is a need to better align evidence of studies, such as Assessing Mitigation Pathways to Realise Public Health Benefits of Air Pollutant Emission Reductions from Agriculture, with toxicological studies which suggest that (pure) ammonium nitrate and sulfate have only very modest toxicity. This study is registered as PROSPERO CRD42020172116. This award was funded by the National Institute for Health and Care Research (NIHR) Public Health Research programme (NIHR award ref: NIHR129440) and is published in full in Public Health Research; Vol. 14, No. 3. See the NIHR Funding and Awards website for further award information. Agriculture is a main driver of air pollution in the United Kingdom and other countries. This is because it is responsible for emissions of ammonia and other nitrogen compounds into the atmosphere from livestock farming, fertiliser use and other activities. These chemicals contribute to air pollution and are harmful to health, leading to heart and lung disease, stroke, cancer, type 2 diabetes and early death. Solutions to reduce agricultural emissions and improve air quality and health can also support people’s efforts to eat healthier diets and reduce greenhouse gas emissions from food production. Such solutions were the focus of the Assessing Mitigation Pathways to Realise Public Health Benefits of Air Pollutant Emission Reductions from Agriculture project. Assessing Mitigation Pathways to Realise Public Health Benefits of Air Pollutant Emission Reductions from Agriculture evaluated the impact on health of past and future policy options. This was in order to see how policies could work together to: reduce agriculture-related air pollution to support healthy eating and act on climate change. It took account of the interconnections between how people eat, farming and agricultural production, and the social and economic consequences of policies. The project developed a list of existing and future policy actions and looked at different ways of improving agricultural technology, land-use management and other factors. It studied their impact on air pollution, United Kingdom diets and nutrition, and greenhouse gas emissions. Computer models calculated impacts on health arising from the effects of lower air pollution and better diets. Lastly, it compared the costs of policy interventions to the benefits they create. From the start, Assessing Mitigation Pathways to Realise Public Health Benefits of Air Pollutant Emission Reductions from Agriculture involved the public and other key stakeholders to give guidance to the project. We involved policy-makers, regulators, farmers, food producers, retailers, health professionals and food/environment advocates to help Assessing Mitigation Pathways to Realise Public Health Benefits of Air Pollutant Emission Reductions from Agriculture draw on many perspectives. We used this to craft research questions, analyse data and share results. The project found that agricultural technologies and changing land-use practices could reduce air pollution and improve health in the United Kingdom. However, combining these actions with policies that encourage people to eat healthier diets with less meat and more fruits and vegetables could result in much larger benefits for health. The evidence gathered by Assessing Mitigation Pathways to Realise Public Health Benefits of Air Pollutant Emission Reductions from Agriculture aims to shape policy. It will provide critical evidence for how efforts to reduce outdoor air pollution can play a lead role and support a holistic approach to human health.