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Human EXposure to Aerosol Contaminants in Modern Microenvironments

Final Report Summary - HEXACOMM (Human EXposure to Aerosol Contaminants in Modern Microenvironments)

Project Overview and Research & Training Objectives

The main research goal of HEXACOMM is to apply scientifically-based modelling and experimental methods to relate concentrations of particulate matter in the indoor domestic environment to its sources and human exposure implications. The second research objective is to determine the human exposure arising from such exposure at both individual and collective (population) scales at modern microenvironments. Contributions from outdoor air will be taken into account. The central idea of HEXACOMM is that a combination of tools and methods will enable us to relate indoor air quality to aerosol contaminants in urban homes, offices, vehicles with human exposure in a quantitative manner. To achieve our goal and objectives a carefully designed validation programme at the European scale combining specifically targeted indoor air quality measurements, source apportionment studies, micro-environmental modelling, dosimetry modelling and exposure studies was undertaken. Ultimately, our vision is that such enhanced understanding of the underpinning science will lead to improved indoor air quality in European domestic environments, while facilitating development of strategies to mitigate the impacts of aerosols on human exposure.

HEXACOMM has 3 complementary research objectives (ROs):
RO1: to improve our comprehension of the sources, emission rates, source apportionment methodologies, mechanisms and concentration characteristics of aerosols in the indoor environment including nanoparticles and their chemical composition and bioaerosols (achieved through WP1).

RO2: to develop an understanding of the impact of indoor particulate matter on human exposure. An important component will be the development of methods via which exposure of those sectors of the population considered as most susceptible to the health impacts of air pollution can be monitored. Exposure via inhalation of indoor air will be studied both at the individual and the population level. Different aerosol metric parameters will be employed to determine human exposure (achieved through WP2).

RO3: to advance our knowledge of the indoor aerosol exposure at specific modern microenvironments (a) urban houses (b) modern offices (c) metro stations and (d) industry (Occupational exposure to engineered nanoparticles) (achieved through WP1 and WP2).

HEXACOMM’s research objectives are structured through 2 Work Packages (WPs):
(1) Air Pollution Characterization Indoors
(2) Human Exposure (Sources and Monitoring)

The aim of the Training Programme is to increase the knowledge base and experience of a cohort of trainees (12 ESRs and 2 ERs) in the different research areas (i.e. aerosol measurements, analytical and environmental chemistry, exposure assessment and mathematical modelling) that are relevant to the challenge of achieving adequate indoor air quality in an environmentally sustainable fashion. HEXACOMM aims to maximise the potential of ESRs/ERs by developing their professional skills through a coherent training programme that is closely integrated with their research project. The aim of the project was to match the skills the trainees acquired with those expected by employers in the academic, commercial, regulatory, and public research sectors; thus building capacity for innovation and scientifically rigorous risk assessment within the EU economy.

All of the ESRs and ER completed their work, whereas all ESRs were registered for a PhD and 5 were already completed their PhD. To date the trainees have undergone extensive training in both project-specific and complementary skills, both at their host organisations and at other partners during secondments. Project-specific research skills acquired by trainees included training in operation of aerosol/gaseous sampling and laboratory equipment, such as aerosol samplers, chemical analytical techniques, state-of-the-art nanoparticle instruments, modeling techniques and CFD analysis including aerosol dose and exposure tools. Trainees have gained experience of presenting their research results by active participation in a variety of national and international conferences, workshops, and symposia.

Main Results Achieved are:
The main scientific achievements of the HEXACOMM project can be summarized as:
• Comprehensive understanding of particulate matter characteristics in metros across Europe (Barcelona, Prague, Athens, Oporto)
• Volatility experiments for the fate of particles indoors/outdoors
• Measurements of new particle formation in indoor environment arising from painting materials
• Development of mathematical models aiming to determine the deposition of particles in the human respiratory tract
• Data that enhance our understating of particle emissions under variable activities indoors under different settings and in chamber studies
• Effectiveness of ventilation systems in modern environments for removing particles from outdoor origin
• Data and modeling results on particle resuspension indoors
• Understanding of personal and population exposure in urban settings using dosimetry models combined with GIS system
• Data on PAH of settled indoor dust at a European scale
• Engineering approaches for reduction of human exposure to gaseous and aerosol pollutants in a hospital setting
• Occupational exposure to engineered nanoparticles

HEXACOMM completed five Advanced Training Courses (ATCs) The topics of the courses were
ATC1: Techniques for Monitoring air pollutants including aerosols indoors/outdoors
ATC2: Techniques for Monitoring Exposure to aerosols
ATC3: Techniques for Evaluating Human Exposure at modern microenvironments to aerosols
ATC4: Mathematical Modelling Approaches to Understanding Environmental Fate and Behaviour of aerosols
ATC5: The Role of Science outside Academia: Communication with other Stakeholders

HEXACOMM aims at advancement of the Scientific State-of-the-Art with performing the main research objectives. We anticipate that HEXACOMM will enhance our knowledge of:

1. The emission rates of aerosols indoors, their chemical/size characteristics and impact on human exposure and the influence of outdoor pollution
2. Modelling and measurement platforms to calculate exposure and dose indoors at a population and individual scale
3. Aerosol metrics for studying human exposure and dose and engineered solutions for reduction of such exposures
4. The extent to which particles influence human health in specific microenvironments

Relevant target groups included policy makers in national and local levels, the general public such as metro commuters and office workers. Other groups include workers in the nanotechnology industry and office workers.

Improvement of trainees’ career prospects
HEXACOMM improves the trainee’s prospects through scientific training in the host institutes, secondments, participation in common research activities and participation in the ATCs. Other channels for enhancement of the capacities of the trainees are as follows:

• Research training in different geographical environments in Europe through research collaboration and secondments. This will enhance the building of a personal scientific network and will open new possibilities for their career.

• HEXACOMM trainees participated actively in many international conferences which will advance their communication skills and career profiles and also will enhance their scientific visibility in the international level. During the project the trainees participated at over 50 international conferences/workshops.
• Dissemination of the project results through publication in international journals. These publications will have significant input in future career perspectives. Up to now 38 such publications exist.

In conclusion, we expect that in addition to the delivering a cohort of 14 highly-trained early career scientists, the scientific results of HEXACOMM will advance our understanding of the processes via particles that are emitted and enter the indoor environment in conjunction with human exposure and internal dose.

Further information
More information about the HEXACOMM project may be found at
You may also email the Coordinator Professor Mihalis Lazaridis