Editorial

The 7th International Symposium on Modern Principles of Air Monitoring and Biomonitoring (AIRMON 2011) held in Loen, Norway on June 19–23, 2011 was organized by the National Institute of Occupational Health, Norway, the University of Umeå, Sweden, the Institute for Occupational Safety and Health of the German Social Accident Insurance (IFA), Germany, the Institute de Recherche et de Sécurité (INRS), the Finnish Institute of Occupational Health, Finland, the Health & Safety Laboratory (HSL), UK, the National Institute of Safety and Health (NIOSH), USA and the Nordic Institute for Advanced Training in Occupational Health (NIVA).

Six previous AIRMON meetings have been held: at Geilo, Norway in 1993, 1999 and 2008; at Sälen, Sweden in 1996; at Hafjell-Lillehammer, Norway 2002 and at Loen, Norway 2005.

There is a long established requirement of air monitoring within the preventive framework of identifying and controlling health hazards at the work place and in the environment. For the characterisation of exposure to chemical and biological agents, sensitive, selective and user-friendly methods and relevant sampling strategies are needed. In recent years there have been a variety of new developments and it is essential to promote the knowledge of these newly developed methods and strategies for workplace, indoor and ambient air monitoring. The programme for AIRMON 2011 aimed to provide a comprehensive overview of the latest developments in this important field. Therefore some of the world's leading authorities in relevant fields were present, allowing the symposium to be an excellent forum for the exchange of ideas as well as an opportunity for private informal discussions, for all those who are involved in method development, air sampling, exposure assessment, regulatory issues or other areas related to air monitoring and biological monitoring.

The plenary programme of AIRMON 2011 was especially designed to discuss the health risk associated with exposure to fine particles and one day of the conference was organised in collaboration with Nordic Institute for Advanced Training in Occupational Health (NIVA) with focus on the emerging issue of understanding potential health effect differences between engineered and incidentally formed nanoparticles. During the past several years the significance of engineered nano-materials and nano-technologies has grown rapidly. Even though very little is known of the possible occupational and environmental health risk of exposure to engineered nano-particles (ENP), humans have been exposed for centuries to nano- or ultrafine particles (UFP) as incidental products derived from combustion motors, fossil fuel burning or formed in thermal industrial processes. Occupational exposures to such particles frequently occurs at high air concentrations during e.g. production of metals and alloys, welding, metal spraying and production of carbon black. However, the health risks to workers from exposure to ENPs remain largely undocumented. Some UFPs, whether combustion derived or not, are suggested to be of importance for risk assessment of ENPs. Although UFP and ENPs share the nano scale size, and both tend to agglomerate, obvious differences exist. UFPs are more heterogenic, being polydispersed and chemically complex in composition, solubility, volatility, and compounds attached to their surfaces. On the other hand, ENPs, often generated in gas or a liquid phase, are more often solid and monodisperse with a more definite chemical composition. During a full day of the conference a number of internally prominent speakers discussed the importance of similarities and dissimilarities of UFPs and ENPs, for a better understanding of the possibility to use toxicological and human health data obtained from exposure to incidentally formed nano-particles for risk assessment of exposure to ENP.

Although exposure to aerosols has long been known to be associated with a range of health effects, the recent rapid growing interest in addressing the matter of e.g. nano-aerosols is a driving force for improvement of air monitoring equipment and strategies. These important emerging scientific issues were also thoroughly discussed during 8 plenary sessions; I. Environmental and Occupation Exposure Assessment-Strategies and Methodologies; II. Exposure to Incidentally Formed and Engineered Nano-particles: Is There Any Difference in Health Effetcs?; III. Progress in Biomonitoring and Characterisation of Exposure; IV. Bioaerosols-Sampling and Characterisation; V. Quality Assurance of Measurements of Exposure; VII. Measurement and Characterisation of Indoor and Ambient Air Contaminants and VIII. Progress in Sampling and Measurement of Occupational Exposure

In total 44 oral presentation and 7 short courses in addition to 17 posters were part of the scientific programme.

ENPs with their unique beneficial properties also cause safety concerns as their possible impact on human health is not known. A better understanding of how properties of NPs define their interactions with cells in exposed humans is a considerable scientific challenge. This is under focus in the paper by Magdolenova et al. (DOI: 10.1039/C2EM10746E) where the impact of agglomeration and different dispersions of titanium dioxide nanoparticles on the human related in vitro cytotoxicity and genotoxicity is investigated.

Occupational exposure to beryllium (Be) may cause injury to lung and skin through both direct chemical toxic effects and to induce Be antigen-specific sensitisation and granulomatous lung disease. New epidemiological and toxicological data have raised considerable concern that the current occupational exposure limits (OELs) provide insufficient protection for Be exposed workers. In an exposure assessment study among aluminium smelter pot room workers (Skaugset et al. (DOI: 10.1039/C1EM10539F) it is shown that Be is likely to be present as traces in the airborne particulate matter by replacing Al atoms in the condensed fluorides and/or as a major element in a nano particle sized fluoride. The major amount of Be present in the work room atmosphere of Al smelter pot rooms to which workers are exposed, will however always be present in combination with substantial amounts of water soluble Al, F⁻ and Na. This could explain the reduced rate of Be sensitization among pot room workers compared with other Be exposed populations.

Recently published studies focused on potential sources of indoor UFPs, e.g. from combustion processes, have demonstrated that laser printers and photocopiers release, during the heating in printing processes, substances that represent a human health hazard. Generally, the evaluation of occupational exposure to NPs in the workplace needs dimensional and chemical characterization. However, the main problem is linked to the choice of the appropriate sampling and dimensional separation techniques. A convenient multiparametric approach for the study of laser printers emissions to improve the knowledge on NPs is described in the contribution by Castellano et al. (DOI: 10.1039/C2EM10696E).

The exposure assessment of bioaerosol exposed populations is still in a developmental stage. Microorganisms represent a highly diverse group with many different species, and only exposure criteria for endotoxins and fungal spores have been proposed. The complex composition of bioaerosols represent a major challenge for future risk assessments. However, this scientific field is rapidly progressing. This is discussed and under focus by Eduard et al. (DOI: 10.1039/C2EM10717A). For further exposure assessment measurements, concentrations of airborne cultivable microorganisms and endotoxins were investigated in 10 indoor composting facilities in France differing by the organic matters being processed (household wastes, industrial and sewage sludges and residential organic wastes, green waste), the process used (aeration, type of mechanical) and the level of confinement (Duquenne et al. (DOI: 10.1039/C2EM10714G).

Amines can be found in various environments from synthetic raw building products, indoor equipment, industrial or livestock areas to wastes. Because of their fishy-like odor activity, there is an interest to determine low concentration levels of amines looking for the air quality improvement. A major indoor source of amines is the polyurethane foam, because of the application of amines as foaming catalysts. An ion chromatography–tandem mass spectrometry method has been developed by Verriele et al. (DOI: 10.1039/C2EM10636A) for the determination of a large variety of amines in air samples in the presence of ammonia.

One of the new European Community occupational limit values concerns the most important industrially used acid, sulphuric acid. Particularly striking at first sight is the low numeric value of 0.05 mg m⁻³. What is new, however, is that the thoracic particle fraction is now identified as the relevant particle fraction for sulphuric acid. Although the thoracic particle fraction was for a long time known and defined in the field of occupational safety & health, no limit values have so far been established for this particle fraction in Europe. For the sampling of thoracic sulphuric acid particulates suitable sampling systems are therefore rare and experience with them is limited. However, Breuer et al. (DOI: 10.1039/C2EM10659K) have successfully developed a sulphuric acid resistant steel cyclone for collection of sulphuric acid aerosols.

Inductively coupled plasma–mass spectrometry (ICP-MS) is also becoming more widely used for trace element analysis in the occupational hygiene field, and consequently new ICP-MS international standard procedures have been promulgated by ASTM International and ISO. However, there is a dearth of interlaboratory performance data for this analytical methodology. In an effort to fill this data void, an interlaboratory evaluation of ICP-MS for determining trace elements in workplace air samples was conducted, towards the fulfillment of method validation requirements for international voluntary consensus standard test methods. (Oatts et al., DOI: 10.1039/C1EM10688K). For work room air filter measurement of Be, samples have been prepared with high-fired beryllium oxide and certified based on results from an interlaboratory study (Ashley et al., DOI: 10.1039/C1EM10695C).

Exposure assessment of individuals can be performed with either environmental monitoring (EM) and biological monitoring (BM) or both. The setting of acceptable exposure limits is based on the assumption that there is no appreciable risk at levels below these limits for all or almost all the persons exposed. Although the recommended admissible concentration in work room air have been commonly used and accepted, it has become clear that various factors can affect exposure. These include additional absorption through the skin, differences in individual behavior in the general environment and poor working practice, different uptake at the same air concentration, and the use and effectiveness of personal protection devices. In view of the possible influence of these individual factors, the concept of BM making possible evaluation of uptake of chemicals was developed. BM was for a long time considered as a method complementary to EM. At present this attitude is changing and in certain areas BM is applied as the method of choice for exposure assessment. This is put into perspective by Jakubowski DOI: 10.1039/C1EM10706B).

These are just some of the papers included, please take at look at the rest of the issue for more high quality research on air and biomonitoring.

Loen in Stryn Community in Inner Nordfjord offers some of the most magnificent landscapes in Europe with beautiful fjords, glittering turquoise lakes, cascading waterfalls, wild glaciers and steep mountains. The conference venue, Hotel Alexandra, is located in the midst of all this. During an outdoor get-together in the Alexandra Spa, a half-day conference excursion through the Geiranger Fjord and a outdoor farewell party at the Briksdalen Glacier, the one hundred participants representing 19 countries and a variety of scientific disciplines and a mixture of working backgrounds, once again demonstrated the true interdisciplinary nature of modern science.

On behalf of the Organising Committee,

Yngvar Thomassen

National Institute of Occupational Health

Oslo, Norway

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