The Health Protection Agency (the Agency) supports Primary Care Trusts (PCTs) and Local Health Boards (LHBs) in their role as 'Statutory Consultees' for the Pollution Prevention Control (PPC) regime. Statutory Consultees are considered to have special knowledge or expertise. Guidance on PPC is available from the Integrated Pollution Prevention Control pages.
Intensive Farming is subject to regulation under PPC Sector 6.02. These installations are likely to be of a low public health impact. While a large number of applications (over 1000) are expected, the information on which to base a health response will be extremely limited as this sector does not have a history of similar environmental regulation. Furthermore, the Regulator will be adopting a streamlined approach with this sector and will not be requiring an extensive amount of information pre-permit issue. Moreover, if monitoring and detailed risk assessment is necessary this is likely to be undertaken after the statutory health response is required.
Consequently, the Agency's Chemicals Hazards and Poisons Division have produced this position statement on the public health consequences of these processes in order to help inform the debate. It is also worth acknowledging that most applications will relate to existing installations.
About the Sector
PPC applies to larger pig and poultry farms with capacity for more than:
Pigs reared outdoors are excluded from PPC, but free-range poultry (egg-laying and chickens reared for meat) are included. A permit to operate will cover all aspects of farm management, from feed delivery to manure management. Animal welfare is not covered by PPC.
Pig and poultry installations may affect the environment through a number of ways including fugitive emissions to air, discharges to water, manure management and nuisance issues.
Fugitive Emissions to Air
Pig and poultry farms have the potential to release a number of pollutants to air but the Agency would expect operational and permit conditions to minimise fugitive emissions to air from the installation.
Ammonia may be emitted from livestock and from manure, litter and slurry and may potentially impact on local people or vegetation (permits may be refused if critical loads to the environment are exceeded). The health effects of exposure to ammonia at low levels include cough, phlegm, headaches, nausea, wheezing, breathing difficulties and asthma.
However, it is unlikely that ammonia emissions from a well run and regulated farm will be sufficient to cause ill health. Levels of ammonia will decrease rapidly once diluted in ambient air and operational requirements should ensure that emissions are kept as low as is reasonably possible. Proper construction and operation of farm buildings, appropriate management of manure and slurry, and management of protein levels in feed/feeding cycles will all serve to minimise ammonia emissions. Furthermore, in exceptional circumstances ammonia scrubbers may be installed to reduce ammonia emission by dissolving the gas in water. All these measures will also reduce odour emissions from the unit.
The need for monitoring of ammonia will be decided by the Regulator depending on the distance to sensitive receptors, complaint history and level of emissions. This will be decided on a case-by-case basis and any existing monitoring data should be included in the application.
Bioaerosols are airborne particles that contain living organisms, fragments, toxins, and waste products. Possible health effects include exposure to infectious diseases, allergic reactions, respiratory symptoms and lung function impairment .
Clearly, intensive farming has the potential to generate bioaerosols. Recent research in the United States found that those living up to 150 metres downwind of an intensive swine farming installation could be exposed to multi-drug resistant organisms . However, current information is limited and the potential public health issues arising from bioaerosols from intensive farming need further evaluation. Such information is necessary when the Regulator has to make decisions such as the proximity of sensitive receptors to sites. It is likely that the dispersion of bioaerosols from intensive farming sites will be dependant on environmental circumstances such as local topography and prevailing weather conditions. Mitigation measures addressing occupational health of workers will also contribute to the protection of local communities.
Given the very limited direct evidence of bioaerosol emissions from intensive farming we have considered information on bioaerosol generation from large scale composting facilities. Composting sites are known to produce considerable quantities of bioaerosols and when permitting these industries the Regulator has prescribed a minimum distance of 250 metres from local communities . Exceptions to this 'limit' are allowed if effective mitigation techniques are employed. This limit is based on published studies which indicate that bioaerosols are generally reduced to background levels within 250 metres of the facility, although it is accepted that under certain circumstances, such as stable atmospheric conditions, bioaerosol concentrations may occasionally not be reduced to background levels within 250 metres. We anticipate that further information on the potential of intensive farming industries to generate bioaerosols will become available over the next few years and we would expect this information to be incorporated into future reviews of PPC permits.
The potential for particles to cause health effects is related to their size. Dust emitted from intensive farming may include fine particles with an aerodynamic diameter of less than or equal to 10 µm (termed PM 10 ). This size fraction of inhaled particles may penetrate the respiratory system beyond the larynx. Agriculture in the UK may be a significant source of PM 10 with an estimated national contribution ranging between five to fifteen percent [ 7, 8, 9], with poultry houses responsible for some five percent of UK emissions. Both long and short-term exposure to ambient levels of particles (including PM 10 ) are associated with respiratory and cardiovascular illness and mortality . People with pre-existing lung and heart disease, the elderly and children are particularly sensitive to particulate air pollution. For the most part, people will not notice any serious or lasting ill health effects from levels of particles commonly experienced in the UK .
Sources of PM 10 within the intensive farming industry may include feed delivery, storage and transport, dusty wastes and vehicle movements. It is possible that large farms may make a substantial contribution to local PM 10 levels but in such circumstances we would expect Local Authorities to consider farms within their local air quality review and assessment.
The Agency would expect that the use of Best Available Techniques (BAT) will minimise the amount of dust released. On-site m itigation measures addressing occupational health of workers will also reduce off site emissions. It is recommended that the Regulator act on any dust complaints and, if necessary, seek advice on the risk to health from the local PCT.
We would expect further data on the impact of intensive farming industries on local air quality to become available over the next few years, particularly once these processes become regulated under PPC. Consequently we recommend that the Regulator will consider any new data in future reviews of PPC permits.
Emissions to Water
The potential impact to water should be low since emissions to ground or surface water should fully comply with the regulations and limits set out in Groundwater Regulations 1998 and the European Groundwater Directive (80/68/EEC). In addition to compliance with domestic regulations for surface and groundwater, the Regulator must ensure that any emissions to sewer from the installation are within consent limits.
Correct storage of liquid feeds, fuel oil, pesticides and veterinary medicines in secured and bunded areas will further reduce the potential for spillages and pollution of water courses. The Operator should also maintain records of any chemicals used. This should apply to the annual quantities used and the quantities stored at any given point in time.
We would expect that the design, construction and management of manure and slurry storage will prevent or minimise emissions and that this will be controlled through standard permit conditions. As part of the permit, we understand that the applicant will be required to draw, maintain and review a manure management plan detailing what and where substances will be applied to land. Manure can contain a range of zoonotic pathogens and incorrect storage can encourage the development of large fly populations that can have nuisance or disease transmission potential.
Intensive farming sites may occasionally present nuisance issues, such as odour, noise, vermin and insect infestation. The Regulator should ensure there is "no reasonable cause for annoyance" beyond the boundary of the site. Any substantiated complaints should be properly investigated and, if necessary, changes in operations may be required as part of a site's improvement plan.
The applicant may need to produce an odour management plan if there are local communities within 400 metres of the site boundary and/or if the installation has a history of substantiated odour-related complaints. This plan should be completed before permit issue and should detail the odour problems of the installation, the actions to be taken to resolve these issues and a suitable timescale for implementation. Furthermore, an odour impact assessment will be carried out if an impact assessment is required under planning or if the applicant has failed to control odour emissions and abatement is required.
Where necessary the applicant should produce a management plan for verifying and responding to complaints about odour and noise. Noise should be appropriately assessed by the Regulator and local authority, who are also statutory consultees to this application.
Intensive farms may cause pollution but provided they comply with modern regulatory requirements any pollutants to air, water and land are unlikely to cause serious or lasting ill health in local communities. The Agency, not least through its role in advising PCTs and LHBs, will continue to work with Regulators to ensure that this sector does not contribute significantly to ill-health.
3. Noise Management at Intensive Livestock Installations. Available at: http://www.npa-uk.net/ds_portal/library/IPPC%20Noise%20Guidance.pdf#search
5. Gibbs S. G et a l (2006) Isolation of Antibiotic-Resistant Bacteria from the Air Plume Downwind of a Swine Confined or Concentrated Feeding Operation. Environmental Health Perspectives; 14(7), 1032-7.
6. The Composting Association and Health and Safety Laboratory (2003) Research Report 130 - Occupational and environmental exposure to bioaerosols from composts and potential health effects - A critical review of published data. Report produced for the Health and Safety Executive.
10 COMEAP (1998). Quantification of the Effects of Air pollution on Health in the United Kingdom . Department of Health Committee on the Medical Effects of Air Pollutants. The Stationery Office, London .
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Last reviewed: 15 December 2010