Focus

What's Your IAQ?

Nowhere is the importance of Indoor Air Quality (IAQ) as critical as in hospitals. Today, Indian hospitals are waking up to the need for good IAQ, discovers Sonal Shukla

There are times when a doctor advises a sick patient to go to a hill station for some 'fresh air.' While subconsciously we may be all aware of the significance of fresh air, we have never really pondered upon the 'quality' of air that we breathe. While we can afford to not spend too much time thinking about the concept, the hospital indeed cannot afford to underestimate the value of Indoor Air Quality (IAQ).

The outbreak of infectious diseases such as Severe Acute Respiratory Syndrome (SARS) and the increase in chronic respiratory diseases such as asthma the world over has created a renewed interest and attention to IAQ. Hospitals are always at risk of infection by patients, infection to patients and to staff involved in patient care. A wide variety of surgeries conducted in a hospital on a day-to-day basis wherein human body parts are opened, exposed for the purpose and closed after procedure themselves pose a great risk of airborne infection. These factors necessitate proper IAQ routine infection monitoring programmes in hospitals today.

It is said that compared to the worldwide scenario, the problems of IAQ in India are severe because of population, poor education, standards of living and fast moving lifestyle. In a hospital, not only can the IAQ act as a source of chemical and microbiological contaminants but also a pathway for such contaminants. The US Environmental Protection Agency (EPA) recently called IAQ one of the most important environmental health problems of the 1990s.

According to experts, the significance of IAQ in a hospital is phenomenal and deceptively far reaching for the physical as well as mental health of patients and healthcare workers. Poor IAQ affects everything within the building. Concurs Tejinder Singh, Chief Engineer, Fortis Hospital, Mohali, "It leads to staff discomfort which in turn leads to staff dissatisfaction and staff inefficiencies. It can lead to contagions being transferred from one patient to another. It does, in effect, keep patients in their beds longer than is necessary and can also lead to higher levels of bacterial growth."

IA Q for Healthy Hospitals

"The roof of each bed area will have dedicated AHU outlet creating a near independent air-corridor for each patient" - Dr Biswarup Pal Medical Director Global Hospitals Chennai

Continual advances in medicine and technology necessitate the support of properly designed air-conditioning of hospitals and medical facilities for desired outcomes. It is said that five per cent of all patients who go to hospitals for treatment will develop an infection while they are there. "The complex hospital environment requires special attention to ensure healthy IAQ to protect patients and healthcare workers against nosocomial infections and occupational diseases," says Dr Biswarup Pal, Medical Director and Head of the Department of Anaesthesia and Intensive Care, Global Hospitals, Chennai.

The impact of unfavourable IAQ on healthcare workers is well described in a syndrome called Sick Building Syndrome (SBS), which comprises various non specific symptoms like fatigue, heavyheadedness, headache, difficulty in concentration, itching, burning eyes, nausea and dizziness and difficulty in concentration. The usual reasons that contribute to this condition are bad ventilation system, humidity, static electricity, volatile organic compounds and various odours. SBS in hospital may happen due to a variety of causes like inadequate maintenance of the Heating Ventilation and Air Conditioning (HVAC) system, which becomes a source of contamination, increased load (occupancy and activities) and inadequate fresh air/ ventilation. "In many cases, proper air-conditioning is a factor in patient therapy and in some instances, it is the major requirement. However, the relatively high cost of air conditioning has led to inadequate and improperly designed systems," states Jagdeep Singh, Global Business Head, Desiccant Rotors International (DRI).

Designing Systems

Air quality can be improved in hospitals by designing systems that provide air virtually free of dust, dirt, odours, chemical and radioactive pollutants, bacteria, virus and humidity build-up. According to experts, designers while planning air-conditioning systems need to keep a few design criteria in mind. This includes the need to restrict air movement in and between the various departments, specific requirements for ventilation and filtration to dilute and remove contamination in the form of odour, airborne micro-organisms, viruses, hazardous chemicals and radioactive substances, the different temperature and humidity requirements for various areas and design sophistication needed to permit accurate control of environmental conditions.

The emphasis should be on monitoring of energy consumption and efficiency, selection of energy efficient equipment for cost effectiveness in terms of life cycle cost, bio guard paints scheme to interiors, Ultraviolet light C Energy (UV-C) for Air Handling Units (AHU) to limit infection due to accumulation of stagnant water, routine pest control programmes, hospital owned in-house infection monitoring team, acoustic lined air supply ducts, electronic filters, high heat resistant value insulation material, environment friendly systems and activated carbon air filtering arrangement. Inadequate controls of IAQ may lead to increased infections, cost implications and less productivity.

At Apollo Hospitals, Chennai the internal controls have prevented the spread. "Our Hospital has controlled IAQ through fume hoods, biological safety cabinets, laminar flow, and additional exhaust ventilation, dilution, and decontamination and fumigation methodologies," reveals George Eapen, CEO, Apollo Hospitals, Chennai. In addition to this, employees are trained in hand hygiene practices and wearing of appropriate personal protective equipment.

Apollo Hospitals, Chennai (Case Study)

The multispeciality tertiary care hospital uses many hazardous chemicals namely Formaldehyde, Xylene, Ethylene trioxide etc which are harmful and carcinogenic in nature. However, at the point of use, in respective laboratories safety systems are built like class I / class II / biological safety cabinets and laminar hoods. "The effectiveness of these hoods is periodically certified by competent engineers. In addition to this, provisions have been made for emergency eye wash /face protection for employees. The chemical hazards are rated and communicated to all concerned," states George Eapen, CEO, Apollo Hospitals, Chennai. Environmental safety programmes in the Hospital provide good information to access the efficiency of the HVAC systems and provide a suitable guide for the maintenance engineers and environmental engineers. Relative humidity affects human comforts, directly and indirectly. Some examples are thermal sensation, skin moisture, discomfort and tactile sensation of fabrics, health and perception of air quality. "We follow Occupational Safety & Health Administration (OSHA) and ASHRAE standards and maintain a thermal humidity between 35-50 percent. We don't have Indian standards on IAQ," says Eapen. The new innovative strategies being followed include the purchase and use of environment-friendly chemicals, installation of dust tight barriers, negative pressures in the patient rooms for effective air control, installation of branded and approved air purifier, and implementation of air purifying technology. In addition to this, other measures like limitation and minimisation of use of mercury, recycling of fluorescent bulbs, changing latex gloves to nitrile gloves are initiated for ensuring IAQ as well as environment safety. "The IAQ problem in our hospital has never caused any serious losses so far, except fungal growth, which has been immediately attended. Areas which are prone to fungal growth have been painted with anti-fungal paint and the causes for the moisture are traced and attended," states Eapen.

In 'Focus'

The very crucial areas for maintaining good IAQ in a hospital are said to be operating theatres, CCU, ICU and laboratories, and particularly the microbiology lab. The primary task of the ventilation system in an Operating Room (OR) is to provide an acceptable indoor climate for personnel and patients, to remove odour and released anaesthetic gases and to reduce the risk of infection in the operating area.

According to experts, the greatest amount of bacteria found in OR comes from the surgical team and is a result of their activity during surgery. "The airborne contamination in an OR is mainly derived from the personnel in the OR. The other factors are the number of individuals present, ventilation and airflow directions. These are the most important means of controlling air-borne infections in ORs and ICUs. The average temperature should be maintained around 21-22 Celsius," states Dr Pal. According to him, to maintain oxygenation for 10 people in an OR, a volume of 350 cubic metres of fresh air will be required per hour. "Fresh /outside air is required to remove contamination from the Inside Air of the hospital and the requirement is measured as number of fresh air changes per hour (ACH). Studies show that while one ACH of fresh air takes eight hours to remove contaminating particles, eight fresh ACH take only one hour. However, since fresh air requires more energy to cool, optimisation is necessary. However, the minimum number of fresh ACH are best governed by ASHRAE standards," states Tejinder Singh.

According to OR experts, separate Air Handling Units (AHU) are required for each OR. Also, across the hospital a gradient of pressure should be maintained for different areas to avoid cross-contamination i.e., a positive pressure should be maintained in the ORs, rooms for immunocompromised patients and sterile storing areas to avoid any contamination from lesser critical areas. And in the isolation room where the infectious patients are admitted, dirty utility areas and dirty linen areas, a negative pressure should be maintained so that the contaminated air inside will not mix with the air circulating in the remaining areas. The ORs need to maintain the positive pressure with a minimum of 20 air changes per hour (ASHRAE). The air entering the OR should be through a High Efficiency Particulate Air (HEPA) filter. If the Hospital is having a central sterile supply unit, a gradient of positive pressures need to be maintained from sterile areas to unclean areas. "All these require separate ducting systems, which need to be planned and implemented during the project stage itself. Once the hospital is built and functional, modifying the air circulation system to get the required results is a difficult task," feels Dr Ravindra Karanjekar, Associate VP, Wockhardt Hospitals Group, Mumbai.

In Wockhardt Hospital, Mumbai, all the ORs and critical areas get the air circulated through separate AHUs, which avoids the possibility of the cross contamination of the air. "We have our ORs equipped with the laminar airflow mechanism and HEPA filters. In addition, HEPA filters are also installed in critical areas like the transplant ICU. The laminar flow mechanism finds its application in the microbiology lab and the chemotherapy drug preparation area also. In these areas, the laminar flow mechanism protects the user/ operator from the harmful micro-organisms and the fumes of the cytotoxic drugs," states Karanjekar.

Global Hospitals, Chennai, is creating AHU outlets for each bed in its transplant ICUs. "The roof of each bed area will have an dedicated AHU outlet. This will create a near independent air-corridor for each patient. This initiative will definitely mitigate the risk of infections," says Dr Pal. In Ruby Hall Clinic, Pune, the ICUs have cubicles with partitions made of ionised materials and are right up to the ceiling. This prevents cross infection amongst the patients in the ICUs. Mumbai-based Hinduja Hospital has thermostatic control walls, which depending upon the temperature in the area, control the chilled water flow in AHUs.

Air Cleaning Options

"Areas which are prone to fungal growth have been painted with anti-fungal paint" - George Eapen CEO, Apollo Hospitals Chennai

"High cost of air conditioning has led to inadequate & improperly designed systems" - Jagdeep Singh Global Business Head Desiccant Rotors International

There are basically two ways in which air quality can be improved in a hospital i.e., filtration and ventilation. A variety of filters and air cleaning equipment are today available in the market. Ionisers and ozone generators, mechanical filter air cleaners, electronic air cleaners (e.g electrostatic precipitators) and hybrid air cleaners are a few examples.

Specialists believe that even though air cleaners are not an appropriate 'single solution' to IAQ problems, they can be useful as an adjunct to effective source control and adequate fresh air ventilation. However, air cleaning alone cannot adequately remove all pollutants typically found in indoor air, and the solution to pollution is dilution, believes Jagdeep Singh. "Increased fresh air ventilation is the answer. The only solution to mitigate the unacceptable levels of air-borne pollutants in the hospital are addressing the source of pollution and addressing the level of contaminants in the air. These may be referred to as 'source control' and 'removal' respectively. The right solution is the use of energy recovery devices of which the energy/ heat wheel is the most appropriate," he adds. According to Jagdeep Singh, the technology of energy wheel could be an answer.

The Energy Wheel

The energy wheel pre-conditions fresh outside air before it is introduced to a building. "The system can easily be tapped in to an existing ventilation system. A portion of the air that would normally be re-circulated through the system is exhausted through the wheel and fresh air is introduced into the building in its place. Operating in virtually any climate zone, a single desiccant wheel operated with just a small motor to rotate the wheel can deliver fresh air on a year round basis that is generally within 3-7 degrees and 10 per cent RH of inside conditions, regardless of what outside conditions are (without any type of mechanical cooling or heating)," explains Jagdeep Singh. The cost to provide high levels of fresh air ventilation becomes minimal compared to the normal heating cooling requirements of the building.

Modern Techniques

Heating, Ventilation and Air Conditioning (HVAC): This is a rather complexly integrated but well-established and well recognised engineering technology. HVAC has all components functioning together to introduce, distribute and condition air in a building for human comfort.

Hospitals should have a HVAC system design based on the guidelines of ASHRAE. Three stage and two stage air filtration systems comprise pre-filter (filtration level 20 microns) 20-40 per cent efficiency, microvee filter (filtration level 5 microns) efficiency 90 per cent and HEPA filter (filtration level 0.3 micron) efficiency 99.97 per cent based on clean, sterile, semi sterile area and process requirement of hospitals. According to Reference CDC. "Addition of fresh air is done to dilute the contaminations concentration in conditioned spaces; this helps to improve the IAQ. IAQ recommends 20 cfm outside air per person. We have laminar flow units for diagnostic process requirements like pathology lab, blood bank, IVF and air sterilisers for IVF, ICCU and ICU departments," says Anil Dhamdhere, Senior Engineer, Dr LH Hiranandani Hospital, Mumbai. It helps in providing improved particulate control, air disinfection system, moisture control, temperature control and pressurisation strategies. It achieves its goal by combining the components of ventilation, filtration, air-balance and pressurisation, temperature control and humidification/ dehumidification.

"Good IAQ in hospitals is maintained through properly designed HVAC systems. A failure or malfunction of any component of the HVAC system may subject patients and staff to discomfort and exposure to airborne contaminants. There can be infectious disease outbreaks and adverse outcomes among high-risk patients when HVAC systems are poorly maintained," believes Tejinder Singh.

American Institute of Architects (AIA) guidelines prohibit US hospitals and surgical centres from shutting down their HVAC systems for purposes other than required maintenance, filter changes, and construction. Airflow can be reduced; however, sufficient supply, return, and exhaust must be provided to maintain required pressure relationships when the space is not occupied.

When the HVAC systems are not properly maintained, it may lead to hospital acquired infections in high-risk patients leading to prolonged stays and thus increase healthcare costs. This also leads to lesser productivity due to longer occupancy and lesser availability of beds.

High Efficiency Particulate Air (HEPA) filter: "The reason for poor IAQ is invariably poorly-designed ventilation and air-conditioning systems. Another crucial factor is the lack of a proper maintenance schedule of ventilation systems," feels Dr J Damodharan, Medical Director, Sri Ramachandra Medical Center (SRMC), Chennai. And hospitals have unique ventilation requirements. The purpose of ventilation is to assist in providing a safe, comfortable and healthy environment for the patients and staff in a healthcare facility.

According to experts, HEPA filters and ultraviolet germicidal irradiation lights may be used to decontaminate air since there are often large open wounds that remain exposed for long periods in a hospital. "The injection of fresh air into the system to maintain adequate gas exchange must involve appropriate filtration both at the inlet and at the outlet in the user area. Special areas like operation theatres must have extremely efficient filtration systems. The currently available and commonly used ones are HEPA filter and Ultra-Low Penetration Air (ULPA) filter," says Dr Pal.

HEPA filters can remove at least 99.97 per cent of airborne particles of at least 0.3 microns in diameter. This size particles are most difficult to filter and thus considered 'Most Penetrating Particle Size' ( MPSS). HEPA filters are a mat of randomly arranged fibres. They trap particles by interception, impaction and diffusion. Today, HEPA filter is a mandatory component for any good quality operation theatre along with laminar flow. Ruby Hall Clinic has installed HEPA filters in all its ICUs as well as OTs. "Besides incorporating HEPA filters, it is very crucial to maintain and clean them on regular basis or otherwise they can be a potent source of fungus," cautions Dr Sujata Malik, Medical Superintendent, Ruby Hall Clinic.

Fortis Hospital, Mohali (Case Study)

The Hospital has been using Building Management System (BMS), which ensures proper schedules, monitoring and recording of the HVAC systems and parameters, thus bringing in efficiency, optimisation and economy in HVAC operations. It also uses heat energy wheels for exchange of energy between supply and exhaust air for effective energy saving and magnets for avoiding scaling in condenser coils. The hospital uses 100 per cent fresh air for the OTs which is supplied through laminar flow system and has regular monitoring systems for isolation rooms, positive pressure areas and choking and replacement of HEPA filters. The Hospital plans to include UVC Emitters for AHUs that shall help to substantially improve IAQ by destroying viruses and bacteria through ultraviolet 'c' energy and keep the AHU coils clean avoiding formation of biofilms on AHU coils and will reduce the power costs by improving heat transfer and also increase net cooling capacity. "Variable Frequency Drives for AHU with HEPA filters will ensure energy management over the life period of a HEPA filter by maintaining constant airflow and BacComber water treatment system, a non chemical solution - not only to decrease scale formation but also to remove existing scale and arrest the multiplication of bacteria by altering their DNA," states Tejinder Singh Chief Engineer, Fortis Hospital, Mohali.

Issues and Challenges

Today, hospitals come across some major challenges while maintaining good IAQ.

According to experts, old facilities are generally very difficult to upgrade for better IAQ. "This would not only involve high costs but also shutdowns and redesigning. Sometimes it may not be possible to provide centralised HVAC systems and controls due to deficient roof heights and service areas," opines Tejinder Singh.

Biological contaminants such as bacteria, mould and viruses can breed in stagnant water that has gradually accumulated in ducts, humidifiers and drain pans of the ventilation system or water that has collected on ceiling tiles, carpeting, or insulation. This is particularly a problem in older hospital buildings that may have broken fans or other maintenance problems. "Such maintenance problems may be common since many healthcare facilities are always looking for ways to save money. All parts of the humidification and dehumidification systems must be kept clean and dry to prevent growth of bacteria and fungi. Otherwise, micro-organisms, such as aspergillus spores, can become airborne and infect patients who have suppressed immune systems," opines Jagdeep Singh.

Moisture in other areas may also contribute to the growth of mould from increased humidity. For example, certain respiratory care equipment produces a lot of mist, which can increase the humidity levels in a room. These rooms need to be cleaned particularly well to prevent the growth of mould. Experts therefore believe that appropriate humidity maintenance in a hospital is absolutely key in preventing discomfort as well as proliferation of microorganisms. "A relative humidity which is less than 45 per cent will be uncomfortable for personnel and also it will cause undue drying of surgically exposed tissues. At the same time, a relative humidity of 75 per cent will cause a two to three times higher colony count of microorganisms in air," states Dr Pal. Experts lay stress on having a full fledged maintenance department to take care of the maintenance of all the requirements.

Other challenges include lack of knowledge on part of design agencies and engineers, absence of regulatory body in India to set up a facility without proper inspection or clearance of HVAC systems and lack of any Indian standards for healthcare environment. Consequently, the hospitals that do follow the international standards like American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) and the American Institute of Architects (AIA) end up with added costs. "Hospitals with IAQ implementation programme are definitely going through the costly affair. It is a heavy cost for best quality and more productivity," Dhamdhere concedes.

Today, hospitals are also facing issues like acute shortage and rising price of electricity. The cost is huge to maintain IAQ, for example, high efficiency particulate air filters, UV emitters, air sterilisers, laminar flow units, validation of equipment and IAQ. "Cost of electricity to maintain HVAC system is high, as more than 60 per cent of entire electricity cost is just for HVAC power consumption," shares Dhamdhere. Nevertheless, when it comes to the 'quality' of air that the hospital inmates breathe, sooner or later, they have and will realise that there can be zero compromise in this arena and the process should start right since inception or the designing stage. As Dr Pal concludes, "The application of these theories involves an extremely intimate and most sincere co-ordination between professionals of at five disciplines (architects, clinicians, structural engineers, contractors and countless grassroots level workers at the time of building and installation of a hospital building.

But, the matter does not end there. There has to be an aware, dedicated team of maintenance staff working in tandem with the facilities managers and clinicians in a painstaking manner to sustain the quality every day for months and years.

People involved in the whole matter must actually themselves believe in its utmost importance, because only then they can convince themselves and others to spend time money and energy on IAQ."

sonal.shukla@expressindia.com