Good quality air is fundamental to people’s health and well-being. Indoor air quality (IAQ) is an important issue from social and economic points of view. Various studies have shown that two out of three IAQ problems involve the HVAC system of a hospital. Continual advances in medicine and technology necessitate constant re-evaluation of the air conditioning needs of hospitals and medical facilities. The application of air conditioning to health facilities presents many problems, not encountered in the usual comfort air conditioning design.

Dr M Ramaswamy

Hospital air conditioning assumes a more important role than just the promotion of comfort. IAQ in hospitals is more critical as, the patients have less immunity and hospital buildings involve complex installations. In a typical hospital, the level of airborne infectious contaminant increases proportionately with the increased population density of infected individuals. A few decades ago, Fisk et al. (1997) reported that estimates place the direct health care costs of poor IAQ in the United States at USD 30 billion, with sick leave and productivity losses adding almost USD 100 billion annually. It is reported that five per cent of all patients who go to hospitals for treatment will develop an infection, while they are there (O’Neal, 2000). The levels of some hazardous pollutants in indoor air, at some places, have been found to be up to 70 times greater than in outdoor air. Besides, the complex hospital environment requires special attention to ensure healthful IAQ to protect patients and healthcare workers against nosocomial infections and occupational diseases. According to WHO, bad indoor air quality is a real health hazard and can have significant impact on the shortening of life expectancy. Children and the elderly are especially affected by polluted indoor air.

Various institutions across the world have begun to address IAQ problems through different measures. During the last few years, the IAQ concept in hospitals is emerging as a modern field of specialisation among engineers and healthcare professionals. The importance of containing contaminants during a healthcare-related construction project has recently become better understood by the design and construction industry. Over the past several years, many professional organisations, such as the AIA (American Institute of Architects), CDC (Centers for Disease Control), JCAHO (Joint Commission for Accreditation of Health Care Organisations) and ASHRAE have published guidelines to assist owners, design professionals and contractors in preventing the spread of contaminants during construction-related activities. Air quality at hospitals needs special precautions during the design and maintenance stages to prevent infections from spreading. The basic difference between air conditioning for hospitals and related
health facilities and that for other building types stems from:
• The need to restrict air movement in and between the various departments;
• The specific requirements for ventilation and filtration to dilute and remove contamination in the forms of odour,   air-borne microorganisms and viruses, and hazardous chemical and radioactive substances;
• The different temperature and humidity requirements for various areas;
• The design sophistication needed to permit accurate control of environmental conditions.

The United States Environmental Protection Agency (EPA) publishes data for US cities in terms of the size of particulate matter (PM). The three common levels are PM10 – particles 10 microns or less, PM2.5 – particles 2.5-microns or less, and PM1 – particles 1 micron or less. PM1 is the most common by count of all particles in the air, as that is the range where 99% of all airborne particles reside. Typically, these particles are produced from everyday activity, such as automobiles, factories and even utilities. They are also the most dangerous size particles, as those under 1-micron in size can go deep into the lungs and enter the alveoli, where there can be direct exchange with the blood. A few strategies and tips to improve IAQ in hospitals are mentioned in this article.

Elimination of contaminants at source during the design stage
Many IAQ problems occur because IAQ was not considered at the beginning of the design process. Basic design decisions related to site selection, building orientation, location of outdoor air intakes and how the building will be heated, cooled and ventilated are critical to good IAQ. Always follow guidelines such as ASHRAE/, WHO and NADCA. during the design and maintenance stages. Apply techniques of elimination of contaminants at source itself. This is the most effective and least expensive strategy. During the design stage, use special care for space design for infection control. Segregation of sterile areas, separate paths for movement of dirty materials, provision of staff changing/washing areas and sealed rooms are a few important factors to be considered during the space design, as strategies for infection control.

Effective maintenance of systems
Regularly check and correct ventilation standards to dilute and remove impurities. Consider use of air purifiers or other methods to improve indoor air quality. Do regular inspection and testing for gases, particles and microbiological organisms, and take immediate actions to rectify the problems, if any.
Provide local hooding with exhaust for bathrooms and kitchen. Routine monitoring of various parameters of HVAC systems, proper maintenance of all parts of the system and regular inspection and cleaning of air conditioning ducts are some of the airborne infection control techniques. Examination of floor and wall surfaces for cleanability, regular ‘deep clean’ after infectious patients leave the site, measurement of air quality periodically and regular microbiological testing are some of the routine monitoring strategies for infection control.

Involvement of hospital infection control team
Effective functioning of an infection control committee in a hospital – in which a pathologist, infection control officer, head of nursing affairs, representative from the surgery department and hospital engineer are the members – is very crucial to monitor IAQ in healthcare institutions. The infection control team of the healthcare unit is to be involved at all stages of the hospital’s construction, from pre-design through to opening, and adequate time for commissioning should be built into the schedule, including an allowance of time for microbiological assessments, particularly in hospital operation theatres. Commissioning is a task for both the engineering department and the infection control team, and cooperation and coordination between them is important. The infection control committee has to review the surveillance data routinely in order to identify/detect problems with regard to inherent potentials for unusual epidemics, clusters of infections, infections due to unusual pathogens or any occurrence of
nosocomial infection that exceeds baseline levels, and also to ensure strict compliance by all departments with the hospital’s infection control policies and procedures.

Awareness among healthcare service staff
Create awareness among the staff and public about the importance of IAQ and encourage them to observe the following:
• Do not bring non-sterile objects into the room – particularly in designated clean areas.
• Do not open windows unnecessarily – frequent opening of windows allows external pollutants in.
• Change prescribed clothes before entering into the clean areas and wash hands after touching infectious items.
• Do not allow too many visitors around patients.

A few easy tips to improve IAQ
• Ventilate – airflow is crucial for good indoor air quality. Use proper ventilation requirements, as per the healthcare     standards.
• Keep HVAC system spotless – it is critical to regularly clean filters according to the manufacturer’s instructions.
• Use of activated charcoal – activated charcoal reduces air contaminants. It is present in many HEPA filters used in     HVAC systems.
• Plant houseplants – some houseplants can help to remove toxins from the air, whilst providing additional oxygen.  Identify such plants and keep them at appropriate locations in the hospital.
• Use of eco-friendly cleaning products – encourage the housekeeping and cleaning unit of the hospital to use eco-friendly cleaning products, as industrial cleaners can leave residue that will affect air quality badly.

Conclusion
A healthy solution should be achieved if good standards of design, commissioning, operation and maintenance are followed and proper functioning of the infection control department of a hospital is ensured. A common strategy to maintain a proper IAQ in healthcare units is required. The strategies, once ready, can be enforced through local government regulations. The strategies should include various codes, practices, documents, procedures and
commissioning formats.

REFERENCES
Fisk, W. and Rosenfeld, A., ‘Improved Productivity and Health from Better Indoor Environments’, Center for Building Science Newsletter, Lawrence-Berkeley Labs, Summer, 1997.
O’Neal, C. ‘Infection control: Keeping diseases at bay a full-time effort for healthcare professionals’, The Fort Worth Star Telegram. September 24, 2000.

The writer is a Technical Expert from the Royal Court Affairs, Sultanate of Oman. He can be contacted at mramaswamy@rca.gov.om.