Review
A systematic review of the public health risks of bioaerosols from intensive farming

https://doi.org/10.1016/j.ijheh.2017.10.019Get rights and content
open access

Abstract

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.

Abbreviations

AFO
Animal feeding operation
AHR
Airway hyper-responsiveness
ATS
American thoracic society
BAL
Bronchoalveolar lavage
BAT
Best available technique
BPI
Bactericidal permeability-increasing
BREF
Reference document
CAFOs
Concentrated animal feeding operations
CAP
Community-acquired pneumonia
CI
Confidence interval
COPD
Chronic obstructive pulmonary disease
CRP
C-reactive protein
ECP
Eosinophilic cationic protein
EMR
Electronic medical records
ERS
European respiratory society
EU
Endotoxin units
FEF25-75
Forced expiratory flow between 25 and 75%
FEV1
Forced expiratory volume in the first second
FVC
Forced vital capacity
GI
Gastrointestinal
GP
General practitioner
GRADE
Grads of recommendations, assessment, development and evaluation
ICS
Inhaled corticosteroid
IED
Industrial emissions directive
IL
Interleukin
ISAAC
International study of asthma and allergies in childhood
LPS
Lipopolysaccharides
MBL
Mannose-binding lectin
MRC
Medical research council
MOOSE
Meta-analyses and systematic reviews of observational studies
NIHR HPRU
National institute for health research health protection research unit
OR
Odds ratio
PEF
Peak expiratory flow
PHE
Public health England
PM10
Particles with aerodynamic diameter 10 μm or less
PR
Prevalence ratios
RR
Relative risk
RV
Residual volume
SD
Standard deviation
SSLW
Steady state live weight
TLC
Total lung capacity
TLR
Toll-like receptor
TNF
Tumour necrosis factor
VC
Vital capacity
WBC
White blood count
WIBS
Wideband integrated bioaerosol sensor

Keywords

Bioaerosols
Farming
Intensive
Health
Exposure
Intensive
Review

Cited by (0)

1

Joint first authors.