Building design and infrastructure can be key to curbing the spread of infectious diseases. Dr Ka man Lai, director of the Healthy Infrastructure Research Centre (HIRC), at University College London, describes a new initiative to take cleanroom concepts into the wider environment to combat diseases.
In the wake of various new and emerging diseases in the 21st century, such as avian flu (H5N1), SARS (Severe Acute Respiratory Syndrome), MRSA (Methicillin-resistant Staphylococcus aureus) and the recent swine flu (H1N1) outbreak, can buildings and infrastructure be improved to protect us from exposure to deadly diseases?
The controlled environment of a cleanroom is designed to eliminate contamination through the installation of appropriate filters, designed airflow patterns and controlled ventilation rates. To meet industrial standards, cleanrooms are classified by the cleanliness of the air, which is measured by airborne particle counts of specific particle size ranges. In sectors such as pharmaceutical manufacturing, for example, microbiological levels in the air and surfaces are monitored at different stages of the operation.
A cleanroom is not necessarily a sterile room and contamination is not only from biological sources, but to be classified as “clean”, it needs to fulfill a specified set of requirements for its particular function. Can the same idea and modified standards be applied to create a “Living Cleanroom” – a disease-resistant environment where people can live, work or recuperate?
At HIRC, we believe it is not a dream to make a “Living Cleanroom”. We can transform and design infrastructure to make people healthy. Taking the 2003 SARS outbreak in Hong Kong as an example, disused water traps were found to have provided a means for the spread of pathogens from one flat to others, and more than 300 people were infected within a few weeks of transmission. This housing estate in Hong Kong is less than 30 years old.
With the UK’s legacy of aged infrastructure, this project is particularly important. The London Underground and Bazalgette’s sewerage system are more than 100 years old. What is the role of this aged infrastructure in disease transmission in the 21st century? What are we breathing in every day? What is living around us?
On the other hand, the UK is leading the world in building sustainable, low/no carbon and eco-friendly buildings and communities. How can building companies make our future infrastructure even better and more functional than merely environmentally friendly?
Sick Building Syndrome (SBS) has been linked by some to the energy crisis and the tight building movement of the 1970s. According to the Health and Safety Executive (HSE): “SBS is an imprecise term used to describe those buildings in which there is a prevalence of a range of symptoms causing discomfort and a sense of being unwell rather than a distinct illness.” Researchers and other related professionals are key to ensuring that the green and sustainable drive of the 21st century will not create another syndrome in the future.
Our vision is to revolutionise infrastructure design, construction and function to help fight the spread of infectious diseases in our diverse environment. Our aim is not to produce a germ- or particle-free environment but to understand and find a balance between complex people and lifestyles, infrastructure and pathogen systems, so that we are not making an easy pathway for the germs to propagate and travel around.
Infrastructure may not stop disease transmission (unless it is the source of pathogens) but infrastructure can reduce the risk and extent of the pathogens reaching and infecting people. Infrastructure and infectious diseases can be broadly linked in four different ways:
• The infrastructure that directly kills or removes pathogens – what infrastructure should be put in place to treat 21st century pathogens? • The infrastructure that unintentionally becomes a source or harbour of pathogens – how do ageing, misuse and failure of these existing infrastructures cause problems and how do we identify and transform them? • The infrastructure that creates an environment that facilitates disease transmission – where are these environments? • The infrastructure that can facilitate other non-engineering control measures during a disease outbreak – how do we prepare for a pandemic?
Can we apply current and future cleanroom technology to solve some of the problems?
HIRC is not a research project. It is a vibrant and exciting place for all people interested in knowledge, research and education about the ways in which infrastructure can be designed and operated to minimise infection to work together.
To support this idea and assist a wider research and industrial community, HIRC has built a climate-controlled chamber for bioaerosol and other infrastructure and disease transmission research. It has equipped a brand new laboratory with both engineering and microbiology research facilities to build a bridge between two normally separated disciplines. We are developing a team with knowledge and skills in four areas:
1. Architecture and building environments 2. Environmental microbiology 3. Innovation and technology 4. People and environment
In this complex changing world, HIRC believes that this multidisciplinary and systems engineering approach is essential to solve current and future health challenges. Since the initiative started in April 2009, HIRC has linked and worked in partnership with the local Heath Protection Agency, schools and hospitals on various projects and case studies. In the cleanroom context, HIRC has carried out environmental monitoring, such as particle counts, temperature, relative humidity, carbon dioxide levels and air pressure in these places, as well as observation studies on how people interact with the environment.
The results from the work on “Airborne transmission of diseases – outside the research of air flow?” was presented at a one-day meeting on airborne spread of disease in the hospital environment at UCL in June 2009. In this presentation, HIRC proposed the idea of monitoring the transient particle profile as a new way to analyse the environment in relation to the risk of airborne disease transmission in hospitals, and how these data can benefit the current infection control practice.
Similar to the cleanroom technology standards, we measured particle counts at different sizes and during the rest and operation period in an office and a hospital intensive care unit (see Figures 1, 2 & 3). Different patterns of the particle profile were recorded in these places, which provide an insight further to develop this concept into a diagnostic and assessment tool.
In conclusion, the world is experiencing unprecedented rates of new and emerging diseases and we need to prepare for living with both climate and environmental change. All these challenges require us to think outside the box so that new solutions can lead us to a better world.
UCL’s historic legacy in environmental health engineering
More than 100 years ago, people thought about how to build a water supply that would reduce water-borne diseases, such as cholera. UCL took a leading role in research and education in water and wastewater engineering and improved the public health dramatically.
Well-designed infrastructure can help to prevent and control transmission of infectious diseases. Poor sanitation in British cities was also the source of disease during the 18th and 19th centuries. As a result of better infrastructure, people in the UK no longer need to worry about water cleanliness and whether cholera is in the water.
Today, HIRC dreams about how to fix the air and our living environment. It is fitting, therefore, that the HIRC is housed in the Chadwick Building, named after the 19th century sanitary reformer, Sir Edwin Chadwick.
The HIRC’s new laboratory is in the exact location where a previous generation of water researchers invented new technology to transform our world. Perhaps airborne diseases, and others that take advantage of our infrastructure for transmission, will one day become history.
Engineering out the pathways for infectious diseases
As well as investigating how new infrastructure can restrict disease transmission, HIRC will investigate ways of making old infrastructure healthier. It will also evaluate the precise impact that simple steps, such as improving ventilation (e.g. by opening more windows) and understanding the influence hand-washing facilities could have in stopping the spread of pathogens.
HIRC has already started an initiative with the North East & North Central London Health Protection Unit to investigate the relationship between physical environment and tuberculosis transmission in an office. HIRC is also working with Great Ormond Street Hospital to improve some infection control practices.
HIRC is part funded by the UK’s Engineering and Physical Sciences Research Council (EPSRC). A five-year project ‘Infrastructure and 21st century infectious diseases’ began in April 2009 and will receive EPSRC funding of just over £1m.
Since the project started, a new office and a new laboratory have been built for HIRC. The laboratory is equipped with an environmental chamber, which will be fitted with different sets of aerosolisation instruments and aerosol samplers. Areas are also designated for molecular microbiology and environmental health engineering research.
The aim of combining these facilities is better to understand the evolution and ecology of micro-organisms in physical environments and thus the implications of infrastructure for infection transmission in urban environments.
Contact Dr Ka man Lai Department of Civil, Environmental and Geomatic Engineering University College London London, UK T +44 20 7679 1368 .(JavaScript must be enabled to view this email address)