Background: Population growth, increasing food demands, and economic efficiency have been major driving forces behind farming intensification over recent decades. However, biological emissions (bioaerosols) from intensified livestock farming may have the potential to impact human health. Bioaerosols from intensive livestock farming have been reported to cause symptoms and/or illnesses in occupational-settings and there is concern about the potential health effects on people who live near the intensive farms. As well as adverse health effects, some potential beneficial effects have been attributed to farm exposures in early life. The aim of the study was to undertake a systematic review to evaluate potential for adverse health outcomes in populations living near intensive livestock farms. Material and methods: Two electronic databases (PubMed and Scopus) and bibliographies were searched for studies reporting associations between health outcomes and bioaerosol emissions related to intensive farming published between January 1960 and April 2017, including both occupational and community studies. Two authors independently assessed studies for inclusion and extracted data. Risk of bias was assessed using a customized score. Results: 38 health studies met the inclusion criteria (21 occupational and 1 community study measured bioaerosol concentrations, 16 community studies using a proxy measure for exposure). The majority of occupational studies found a negative impact on respiratory health outcomes and increases in inflammatory biomarkers among farm workers exposed to bioaerosols. Studies investigating the health of communities living near intensive farms had mixed findings. All four studies of asthma in children found increased reported asthma prevalence among children living or attending schools near an intensive farm. Papers principally investigated respiratory and immune system outcomes. Conclusions: The review indicated a potential impact of intensive farming on childhood respiratory health, based on a small number of studies using self-reported outcomes, but supported by findings from occupational studies. Further research is needed to measure and monitor exposure in community settings and relate this to objectively measured health outcomes.
|Number of pages||40|
|Journal||International Journal of Hygiene and Environmental Health|
|Publication status||Published - Mar 2018|
Bibliographical noteFunding Information:
The work of the UK Small Area Health Statistics Unit is funded by Public Health England (PHE) as part of the MRC-PHE Centre for Environment and Health, funded also by the UK Medical Research Council (MRC). This research also received funding from the National Institute for Health Research Health Protection Research Unit (NIHR HPRU) in Health Impact of Environmental Hazards at King’s College London in partnership with PHE. We thank PHE library services for their assistance with the literature search, Joanna Wilding (formally PHE, now RSK consultants) for her assistance screening articles by title and abstract and Ceri Riley (PHE) for her help with the bias assessment. Thanks also to colleagues on our Steering Group and to Professor Debbie Jarvis (Imperial College London), Dr Elizabeth Johnson (PHE) and Clare Pearson (Formally Imperial College London, now Cancer Research UK and PHE (NCRAS) partnership) for reviewing the search strings. The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR, the MRC, the Department of Health or PHE.