In-vitro cell exposure studies for the assessment of nanoparticle toxicity in the lung: a dialog between aerosol science and biology

The introduction of engineered nanostructured materials into a rapidly increasing number of industrial and consumer products will result in enhanced exposure to engineered nanoparticles. Workplace exposure has been identified as the most likely source of uncontrolled inhalation of engineered aerosolized nanoparticles, but release of engineered nanoparticles may occur at any stage of the lifecycle of (consumer) products. The dynamic development of nanomaterials with possibly unknown toxicological effects poses a challenge for the assessment of nanoparticle induced toxicity and safety.In this consensus document from a workshop on in-vitro cell systems for nanoparticle toxicity testing11Workshop on 'In-Vitro Exposure Studies for Toxicity Testing of Engineered Nanoparticles' sponsored by the Association for Aerosol Research (GAeF), 5-6 September 2009, Karlsruhe, Germany. an overview is given of the main issues concerning exposure to airborne nanoparticles, lung physiology, biological mechanisms of (adverse) action, in-vitro cell exposure systems, realistic tissue doses, risk assessment and social aspects of nanotechnology. The workshop participants recognized the large potential of in-vitro cell exposure systems for reliable, high-throughput screening of nanoparticle toxicity. For the investigation of lung toxicity, a strong preference was expressed for air-liquid interface (ALI) cell exposure systems (rather than submerged cell exposure systems) as they more closely resemble in-vivo conditions in the lungs and they allow for unaltered and dosimetrically accurate delivery of aerosolized nanoparticles to the cells. An important aspect, which is frequently overlooked, is the comparison of typically used in-vitro dose levels with realistic in-vivo nanoparticle doses in the lung. If we consider average ambient urban exposure and occupational exposure at 5mg/m3 (maximum level allowed by Occupational Safety and Health Administration (OSHA)) as the boundaries of human exposure, the corresponding upper-limit range of nanoparticle flux delivered to the lung tissue is 3×10-5-5×10-3μg/h/cm2 of lung tissue and 2-300particles/h/(epithelial) cell. This range can be easily matched and even exceeded by almost all currently available cell exposure systems.The consensus statement includes a set of recommendations for conducting in-vitro cell exposure studies with pulmonary cell systems and identifies urgent needs for future development. As these issues are crucial for the introduction of safe nanomaterials into the marketplace and the living environment, they deserve more attention and more interaction between biologists and aerosol scientists. The members of the workshop believe that further advances in in-vitro cell exposure studies would be greatly facilitated by a more active role of the aerosol scientists. The technical know-how for developing and running ALI in-vitro exposure systems is available in the aerosol community and at the same time biologists/toxicologists are required for proper assessment of the biological impact of nanoparticles.

Municipal distribution of bladder cancer mortality in Spain: Possible role of mining and industry

BACKGROUND Spain shows the highest bladder cancer incidence rates in men among European countries. The most important risk factors are tobacco smoking and occupational exposure to a range of different chemical substances, such as aromatic amines. METHODS This paper describes the municipal distribution of bladder cancer mortality and attempts to "adjust" this spatial pattern for the prevalence of smokers, using the autoregressive spatial model proposed by Besag, York and Molliè, with relative risk of lung cancer mortality as a surrogate. RESULTS It has been possible to compile and ascertain the posterior distribution of relative risk for bladder cancer adjusted for lung cancer mortality, on the basis of a single Bayesian spatial model covering all of Spain's 8077 towns. Maps were plotted depicting smoothed relative risk (RR) estimates, and the distribution of the posterior probability of RR>1 by sex. Towns that registered the highest relative risks for both sexes were mostly located in the Provinces of Cadiz, Seville, Huelva, Barcelona and Almería. The highest-risk area in Barcelona Province corresponded to very specific municipal areas in the Bages district, e.g., Suría, Sallent, Balsareny, Manresa and Cardona. CONCLUSION Mining/industrial pollution and the risk entailed in certain occupational exposures could in part be dictating the pattern of municipal bladder cancer mortality in Spain. Population exposure to arsenic is a matter that calls for attention. It would be of great interest if the relationship between the chemical quality of drinking water and the frequency of bladder cancer could be studied.

Report of Recommendations to Iowa State University of Science and Technology, June 30, 2003

State University Audit Report

Report of Recommendations to Iowa State University of Science and Technology on the Review of Selected General and Application Controls over the University's Accounts Receivable System, April 6th - May 14th 2004

State University Audit Report

Iowa State Center Business Office, Iowa State University of Science and Technology, Independent Auditor's Reports Financial Statements, June 30, 2003 & 2004

State University Audit Report

Report of Recommendations to Iowa State University of Science and Technology on the Review of Selected General and Application Controls over the Tuition System, April 23 to May 23, 2003

State University Audit Report

Ice Arena Facility Revenue Note Funds, Iowa State University of Science and Technology, Independent Auditor's Report, Financial Statements and Supplemental Information, June 30, 2004

State University Audit Report

Dormitory and Dining Services Revenue Bond Funds, Iowa State University of Science and Technology, Independent Auditor's Report Financial Statements and Supplemental Information, June 30, 2004

State University Audit Report

Academic Building Revenue Bond Funds, Iowa State University of Science and Technology, Independent Auditor's Report Financial Statements and Supplemental Information, June 30, 2004

State University Audit Report

Parking System Revenue Bond Funds, Iowa State University of Science and Technology, Independent Auditor's Reports Financial Statements and Supplemental Information, June 30, 2004

State University Audit Report

Indoor Multipurpose Use and Training Facility Revenue Bond Funds, Iowa State University of Science and Technology, Independent Auditor's Report Financial Statements and Supplemental Information, June 30, 2004

State University Audit Report

Hilton Coliseum Revenue Bond Funds, Iowa State University of Science and Technology, Independent Auditor's Report Financial Statements and Supplemental Information, June 30, 2004

State University Audit Report