Learning from Katrina: environmental health observations from the SWCPHP response team in Houston.

Hurricane Katrina provided an opportunity to observe the public health and medical care response system in practice and provided vital lessons about identifying and learning critical response measures as well as about ineffective investments of time and effort. The Southwest Center for Public Health Preparedness (SWCPHP) response team, while working among evacuees housed at Reliant Park in Houston, Texas, made a number of observations related to environmental public health. This summary reports firsthand observations which are, to a great extent, supported by the Federal Response to Hurricane Katrina: Lessons Learned report, and it provides a contextual backdrop for improvement in the areas of volunteer and citizen preparedness training and education. Katrina provided an opportunity to see public health in a highly stressed practice setting and to identify and reinforce the fundamental tenets of public health with which all individuals responding to an event should be familiar. Knowledge gained from Katrina should be integrated into future efforts related to disaster response planning; specifically, it is imperative that volunteers receive standardized training in the areas of incident command systems (ICS), basic hygiene, transmission of disease, and food and water safety principles.

Experimental and numerical smoke carcinogen deposition in a multi-generation human replica tracheobronchial model.

A better understanding of submicron particle deposition in the respiratory tract is needed to study the health effects caused by carcinogenic particles. Recent studies indicate that random diffusion is not sufficient to describe the motion of these particles in complex geometries, rendering conventional models inaccurate. A solid replica of excised human lung segments was used to create digital and hollow models of the tracheobronchial region to investigate deposition of mainstream (MS) and sidestream (SS) cigarette smoke particles. Particle sizes for the carcinogen Benzo(a)pyrene (BaP) in SS smoke, and total particulate matter (UVPM) in SS and MS smoke were measured and used to compare the simulation to experimental data. Excellent agreement was found between predicted and measured results. Random diffusion was not found to be significant for submicron particles indicating that particles were instead transported to the airway wall by convective diffusion. BaP in SS smoke was an average 0.3 mum compared to 0.36 mum for UVPM in SS smoke. The trends in both experimental and numerical results indicated that the BaP in SS smoke deposits at a slightly higher efficiency than the UVPM, indicating that carcinogen-specific deposition, rather than total particulate matter should be considered when investigating health effects.

Replication of human tracheobronchial hollow airway models using a selective laser sintering rapid prototyping technique.

Exposures to toxic or pathogenic aerosols are known to produce adverse health effects. The nature and severity of these effects often are governed in large part by the location and amount of aerosol deposition within the respiratory tract. Morphologically detailed replica hollow lung airway casts are widely used in aerosol deposition research; however, techniques are not currently available that allow replicate deposition studies in identical morphologically detailed casts produced from a common reference anatomy. This project developed a technique for the precision manufacture of morphologically detailed human tracheobronchial airway models based on high-resolution anatomical imaging data. Detailed physical models were produced using the selective laser sintering (SLS) rapid prototyping process. Input to the SLS process was a three-dimensional computer model developed by boundary-based two-dimension to three-dimension conversion of anatomical images from the original National Institutes of Health/National Library of Medicine Visible Human male data set. The SLS process produced identical replicate models that corresponded exactly to the anatomical section images, within the limits of the measurement. At least five airway generations were achievable, corresponding to airways less than 2 mm in diameter. It is anticipated that rapid prototyping manufacture of respiratory tract structures based on reference anatomies such as the Visible Male and Visible Female may provide "gold standard" models for inhaled aerosol deposition studies. Adaptations of the models to represent various disease states may be readily achieved, thereby promoting exploration of pharmaceutical research on targeted drug delivery via inhaled aerosols.