BIOlogical air pollution MOdelling and associations with Lung Disease (BIOMOLD)

Keywords:
Bioaerosol, Compost, Respiratory health, Hospitalisation, Asthma, Chronic Obstructive pulmonary Disease (COPD)

The air we breathe contains a mixture of naturally occurring biological particles, including bacteria, fungi and pollen. These are collectively called bioaerosols. As bioaerosols are very small in size, they can potentially travel deep into the lungs and trigger problems such as asthma and respiratory infections. Composting is an increasingly popular way to manage biodegradable waste on an industrial scale. There are currently around 270 large scale composting sites with outdoor processing of waste in England and this number is increasing. The composting process uses fungi and bacteria to breakdown food and garden waste and results in production of compost that can be used in agriculture. However, the process can results in high levels of emissions of bioaerosols including fungal spores into the atmosphere. While sites are closely regulated and managed to minimise exposure to bioaerosols to neighbouring communities, there are few scientific studies available on health risks from such sites.

In this study, we will predict daily bioaerosol emissions from all composting sites in England from 2005 to 2014 using specialised air pollution modelling software and information from detailed measurements around selected sites. The output of the model will be used to predict ambient concentrations of bioaerosols at a postcode level.

Previous studies of workers at composting sites have suggested potential health impacts on lung health, including asthma. A small number of health studies have been conducted near composting sites and these have found higher rates of reported respiratory symptoms. This study will look at associations between ambient bioaerosol concentrations and respiratory hospital admissions including asthma, to examine potential for serious impacts on lung health. Analyses will also examine whether there are seasonal effects as bioaerosol emissions are higher and their composition may vary at different times of the year.

The proposed study involves researchers specialising in environmental health studies from a national Centre for Environment and Health funded by the Medical Research Council (MRC) and by Public Health England (PHE) and with expertise in exposure assessment from the University of the West of England, Bristol, working on a NERC-funded project called "Detection and characterisation of inflammatory agents associated with bioaerosol emitted from biowaste and intensive agriculture (EndotoxII (NE/M011658/1))". All researchers are at the forefront of research into bioaerosols from composting in the UK.

An important part of this study will be a close collaboration between health and the environmental researchers, and, through EndotoxII, establishing links with another NERC project "RApid Monitoring of Bioaerosols in urban, agricultural and Industrial Environments (RAMBIE)" projects. Both NERC projects are due to be completed in 2018. This will help in development of further health studies into bioerosols research, both from composting and from other activities such as intensive agricultural facilities.

The results of this study may impact how regulatory bodies monitor composting facilities and the measures put in place to protect public health. At present the Environment Agency have put in place precautionary measures, such that bioaerosols must be below pre-defined low levels by 250m downwind of the composting facility, or by the nearest house, school or office (if closer than 250m). The results of this study will explore the suitability of this approach and may provide recommendations for future regulatory policy.

This project will provide a comprehensive assessment of exposure to bioaerosols from composting and will improve the evidence base of potential important health impacts of large-scale composting (respiratory hospital admissions). Benefits and outcomes for each stakeholder group are outlined below.

(i) The funders (NERC).
This project will enhance outputs from the existing NERC-funded project EndotoxII, and help form collaborations with health researchers to facilitate the use of environmental data from EndotoxII in future health studies. Follow-on work may include more detailed exposure assessments (using monitored data and more detailed dispersion modelling), a more detailed health analysis (including collection of biological data) and investigation into other major sources of bioaerosols including emissions from intensive farming and other biowaste facilities. Outputs from the proposed project will be disseminated into the EndotoxII and RAMBIE Programme Integration Group (PIG) (Milestone 3).

(ii) Regulatory bodies (including the Environment Agency (EA) and Public Health England (PHE)) and local authorities
The current EA stance requires selected bioaerosol components to be back to pre-defined concentrations above background at 250m or at the nearest dwelling or place of work. Results would provide the regulators with more scientific evidence, and would be able to help confirm or refute the scientific validity of the EAs current stance. PHE responds to consultations on environmental permit applications made to the EA and the results will help inform PHE guidance. To help disseminate results amongst the regulatory bodies, we plan to hold a meeting with regulatory bodies at the end of the project (Milestone 4).

(iii) People working in the waste composting industry (including site managers)
If the results of this study result in changes to regulatory stances and policy, this may have an impact on the waste permitting process, which would in turn impact upon site managers in the waste industry and local authorities, as well as improve public health.

(iv) The public (particularly those living in close proximity to composting facilities)
This study will provide evidence on public health risks, which will be relevant to people living near existing or proposed composting sites. Some sites give rise to complaints about odours and these have been accompanied by concerns about impacts on health, which are difficult to address given the current limited evidence available.

(v) Other academics
Results from this study will impact on current national and international research in this field, with an expected two peer-reviewed journal publications. This project will help to establish strong links with researchers in existing NERC consortia to further integrate environmental and health research. It will inform future research integrating more detailed analyses and investigating wider sources of bioaerosols, and encourage international collaboration with other groups working in bioaerosols exposure and/or health (for example Inge Wouters (Utrecht University, the Netherlands) Caroline Herr (Giessen University, Germany) Olivier Schlosser (Suez Environment, France), Miguel Sánchez-Monedero (Centre for Soil Science and Applied Biology, Spain) etc.)

To further disseminate project outcomes and expand the project impacts, results will be presented at conferences and meetings. There will also be an element of public engagement, summarising lay results within public health trade magazines and presenting results within community groups (for example the MRC-PHE Centre for Environment and Health Community Advisory Board and the IAQM Dispersion Modelling Users Group ).