Inhaled Particles X: 2325 September 2008, Sheffield UKKenny, Lee; Hurley, Fintan
doi: 10.1088/1742-6596/151/1/011001pmid: N/A
Multi-disciplinary research is vital to the science of particle-mediated lung disease and a distinctive feature of the Inhaled Particles Conference series. Continuing this tradition, Inhaled Particles X brought together world-renowned and up-and-coming researchers from a wide range of specialist disciplines, but with a common interest and purpose: to understand better the nature of inhalable particles and their effects once inhaled, for the protection of workers' and public health. IPX was an integrative Conference, in three ways. First, as usual with Inhaled Particles, IPX welcomed the full range of disciplines and scientists concerned with protection of health from inhaled particles. This included engineers concerned with dust control; scientists characterising and modelling emissions; exposure measurement, in the field and in the laboratory; experts in particle deposition and clearance; toxicologists discovering mechanisms of damage; epidemiologists developing and applying methods to link exposure with risk; and those concerned with policy with setting standards, with protection of individuals. Secondly, IPX was concerned with particles in the workplace, in outdoor air, and in the general indoor environment; and tried to find common threads and encourage cross-over of ideas between these three broad fields. And thirdly, IPX integrated experience and perspectives internationally, including issues such as silicosis and pneumoconiosis that are now unfashionable as research topics in the developed Western economies but still constitute a major public health risk internationally. Contributors to IPX were invited to submit extended abstracts for publication in these Proceedings; in addition, all authors were asked to prepare a short abstract. These short abstracts (including those attached to extended abstracts and papers) are collected and published together in this Conference Overview, to maintain the integrity of the Proceedings as a record of the Conference as a whole.
Application of a dynamic population-based model for evaluation of exposure reduction strategies in the baking industryMeijster, Tim; Warren, Nick; Heederik, Dick; Tielemans, Erik
doi: 10.1088/1742-6596/151/1/012001pmid: N/A
Recently a dynamic population model was developed that simulates a population of bakery workers longitudinally through time and tracks the development of work-related sensitisation and respiratory symptoms in each worker. Input for this model comes from cross-sectional and longitudinal epidemiological studies which allowed estimation of exposure response relationships and disease transition probabilities This model allows us to study the development of diseases and transitions between disease states over time in relation to determinants of disease including flour dust and/or allergen exposure. Furthermore it enables more realistic modelling of the health impact of different intervention strategies at the workplace (e.g. changes in exposure may take several years to impact on ill-health and often occur as a gradual trend). A large dataset of individual full-shift exposure measurements and real-time exposure measurements were used to obtain detailed insight into the effectiveness of control measures and other determinants of exposure. Given this information a population wide reduction of the median exposure with 50% was evaluated in this paper.
GIS-based models for ambient PM exposure and health impact assessment for the UKStedman, John R; Grice, Susannah; Kent, Andrew; Cooke, Sally
doi: 10.1088/1742-6596/151/1/012002pmid: N/A
GIS-based models have been developed to map ambient PM10 and PM25 mass concentrations across the UK. The resulting maps are used for the assessments of air quality required by the EU ambient air quality directives, health impact assessment and the development of UK air quality policy. Maps are presented for 2006 along with projections to 2020. The largest single contribution to the UK population-weighted mean annual mean background concentrations of PM10 in 2006 is estimated to be from secondary PM (43%), followed by the contribution from primary PM (24%). Concentrations are predicted to decline by 15% for PM10 and 13% for PM25 over the period from 2006 to 2020. The extent of exceedence of the 24-hour limit value is predicted to decline from 1.9% to 0.1% of urban major roads over the same period. The potential health benefits of reductions in ambient PM are large. A reduction in concentration of 0.93 g m-3 as a result of a possible package of measures has been estimated within the UK Air Quality Strategy to result in a reduction in life years lost of approximately 2 - 4 million over a period of 100 years.
Aerosol exposure: Concepts, criteria, standards and applicationsVincent, James H
doi: 10.1088/1742-6596/151/1/012003pmid: N/A
This paper places Inhaled Particles X in the context of the whole sequence of such symposia, going back to the first one in 1961. It draws together some of the essential principles that have been learned since that earlier meeting about the nature of exposure and exposure assessment and thus provides a framework by which to integrate the new knowledge presented at this latest one. In the process, the importance of understanding the formal definition of aerosol exposure is stressed, including the distinction between exposure intensity and exposure history, and how that relates to some measure of cumulative dose which, in turn, may be linked with knowledge about intrinsic toxicity, etc. This then leads to a definition of exposure standards, and the important ingredients of criteria, sampling and limit values. A summary is provided of the current set of particle size-selective criteria that have been widely agreed in the international occupational and environmental health community. Some ideas are presented about how this set might be expanded for certain applications, the important case of ultrafine aerosols being one of them.
Occupational exposure to Polycyclic Aromatic Hydrocarbons in wood dustHuynh, C K; Schüpfer, P; Boiteux, P
doi: 10.1088/1742-6596/151/1/012004pmid: N/A
Sino-nasal cancer (SNC) represents approximately 3% of Oto-Rhino-Laryngology (ORL) cancers. Adenocarcinoma SNC is an acknowledged occupational disease affecting certain specialized workers such as joiners and cabinetmakers. The high proportion of woodworkers contracting a SNC, subjected to an estimated risk 50 to 100 times higher than that affecting the general population, has suggested various study paths to possible causes such as tannin in hardwood, formaldehyde in plywood and benzo(a)pyrene produced by wood when overheated by cutting tools. It is acknowledged that tannin does not cause cancer to workers exposed to tea dust. Apart from being an irritant, formaldehyde is also classified as carcinogenic. The path involving carcinogenic Polycyclic Aromatic Hydrocarbons (PAHs) emitted by overheated wood is attractive. In this study, we measured the particle size and PAHs content in dust emitted by the processing of wood in an experimental chamber, and in field situation. Quantification of 16 PAHs is carried out by capillary GC-ion trap Mass Spectrometric analysis (GC-MS). The materials tested are rough fir tree, oak, impregnated polyurethane (PU) oak. The wood dust contains carcinogenic PAHs at the level of g.g-1 or ppm. During sanding operations, the PU varnish-impregnated wood produces 100 times more PAHs in dust than the unfinished wood.
Exposure to respirable crystalline silica in South African farm workersSwanepoel, Andrew; Rees, David; Renton, Kevin; Kromhout, Hans
doi: 10.1088/1742-6596/151/1/012005pmid: N/A
Although listed in some publications as an activity associated with silica (quartz) exposure, agriculture is not widely recognized as an industry with a potential for silica associated diseases. Because so many people work in agriculture; and because silica exposure and silicosis are associated with serious diseases such as tuberculosis (TB), particular in those immunological compromised by the Human immunodeficiency virus (HIV), silica exposure in agriculture is potentially very important. But in South Africa (SA) very little is known about silica exposure in this industry. The objectives of this project are: (a) to measure inhalable and respirable dust and its quartz content on two typical sandy soil farms in the Free State province of SA for all major tasks done on the farms; and (b) to characterise the mineralogy soil type of these farms. Two typical farms in the sandy soil region of the Free State province were studied. The potential health effects faced by these farm workers from exposure to respirable crystalline silica are discussed.
Indoor concentrations of fine particles and particle-bound PAHs in Gothenburg, SwedenJohannesson, S; Bergemalm-Rynell, K; Strandberg, B; Sällsten, G
doi: 10.1088/1742-6596/151/1/012006pmid: N/A
Fine particles are formed in a variety of processes, both natural and anthropogenic. Epidemiological studies have shown an association between exposure to particulate matter and adverse health effects. Airborne particles contain a variety of compounds, including polycyclic aromatic hydrocarbons (PAHs), and several of the PAHs are known or suspected carcinogens. In this study, stationary measurements of PM2.5 were performed in the residences of 20 study participants along with simultaneous monitoring at an urban background site. The collected particle mass was then analyzed for its content of some particle-bound PAHs using GC-MS. The median level of PM2.5 indoors was 7.3 g/m3 and in urban background 5.3 g/m3. For benzo(a)pyrene (B(a)P) the corresponding results were 10 pg/m3 and 35 pg/m3, respectively. There were significant correlations between indoor and ambient levels for both PM2.5 (rs=0.58, p=0.02) and B(a)P (rs=0.67, p=0.007). No significant correlation was, however, found between the concentration of PM2.5 and the associated levels of the investigated PAH compounds. This finding implies that exposure to B(a)P or other particle-bound PAH components needs to be separately assessed.
Mesothelioma in Qingdao, PRC (2000 2007)Frank, Arthur L; Zengchang, Pang; Huaqiang, Zhang; Yun, Zhang
doi: 10.1088/1742-6596/151/1/012007pmid: N/A
The city of Qingdao, PRC has been the site of two asbestos product facilities that operated for almost fifty years, as well as a shipyard. Because of a new computerized data collection system for death certificates, almost all 48,000 yearly deaths from a population base of 7.5 million are now recorded with cause of death and "usual occupation". All mesothelioma deaths from 2000 through 2007 are reviewed and the unusual finding is that of a predominance of cases in females. The issues of competing causes of death and potential underreporting are discussed.
Heterogeneity of exposure and attribution of mesothelioma: Trends and strategies in two American countiesCase, B W; Abraham, J L
doi: 10.1088/1742-6596/151/1/012008pmid: N/A
As mesothelioma risk has begun to decline in the United States, two trends are gaining relative importance. "Legacy" exposures causing this disease are most important in locales having past asbestos industry, shipyards, and/or local distribution of asbestos amphibole-containing material as a result. "Future" exposures are of particular concern in relation to so-called "naturally occurring asbestos" (NOA) areas which include unequivocally asbestiform amphibole. In this paper, Jefferson Parish, Louisiana is used as an example of the first trend, and El Dorado County, California as an example of the second. Available tumor registry, epidemiology, historical and mineralogical data, and lung-retained fibre content are used as indicators of disease and exposure. Jefferson Parish, LA was chosen as the prototype of "legacy" exposures on the basis of historical evidence of asbestos plants with known mesotheliomas in the workforce, known shipyards in the same area, EPA records of distribution of crocidolite-containing scrap to and remediation of over 1400 properties, NIOSH published data on mesothelioma by county, and exposure data including lung-retained fibre analyses in victims, where available. El Dorado, CA was chosen as the prototype of NOA amphibole exposures on the basis of tumor registry data, activity-based EPA sampling data in one area, and lung-retained fibre analyses in area pets, and future risk assessment based on tremolite-specific modelling in Libby, Montana and elsewhere. As expected, the legacy exposure area was high in mesothelioma incidence and mortality. Lung-retained fibre content confirms crocidolite exposures in exposed plant-workers and those exposed to crocidolite-containing scrap, and amosite in shipyard workers. In contrast, to date, cancer registry data in the NOA-amphibole ("future") county does not show a clear increase in incidence or mortality, but grouped county data from the area show a shift in higher incidence rates to the NOA areas and away from California "legacy" (e.g., shipyard) areas from 1988-2005. EPA active sampling has confirmed excess tremolite/ actinolite fibre(s) in air, although there is debate about its nature and the appropriateness of the area sampled. Lung-retained fibre in local pets shows unequivocally elevated asbestiform tremolite/ actinolite in areas thought to be most affected, but numbers are small. Future risk is expected to rise due to a vastly increased population base coupled with exposures potentially created by related construction activities. Although legacy exposures are producing smaller numbers of cases with time, they continue to occur at high rates, and new sources of legacy exposure are being discovered in highly localized "hotspots". Differential exposure sources remain a problem in attribution, but continued remediation seems the best strategy for prevention. In the "future" risk county and surrounding areas, incidence trends are less clear, but again highly localized exposures as opposed to broad areas seem important. Activity-based air sampling; targeted soil samples, and lung-retained fibre analyses may be useful in defining areas of highest future risk and potential prevention.