Respiratory Deposition

TF Hatch, P Gross. Physical factors in respiratory deposition of aerosols. In Pulmonary Deposition and Retention of Inhaled Aerosols. New York Academic Press, 1964, pp. 27 43. 

Cohen J. 1987. Respiratory deposition and absorption of lead particles. Memo to Fred Miller and Ted Martonen. Research Triangle Park, NC U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards. October 7, 1987. 

Swift, D.B. and Proctor, D.F. (1982). Human respiratory deposition of particles during oronasal breathing. Atmos. Environ. 16 2279-2282. 

For inhalation exposure, an appropriate default methodology estimates respiratory deposition of particles and gases, and estimates internal doses of gases with different absorption characteristics. 

Cheng YS, Fu CS, Yazzie D, Zhou Y. Respiratory deposition patterns of salbutamol pMDI with CFC and HFA-134a formulations in a human airway replica. J Aerosol Med 2001 14(2)255-266. 

This chapter begins by summarising the recent review articles on this topic. Other topics such as sources and physico-chemical characteristics of ambient and emerging nanoparticles (i.e. ENPs) are then covered briefly for the completeness of the article. This is then followed by the assessment of nanoparticles in numerous European cities, estimation of respiratory deposition doses and a brief discussion on current and future prospects of their regulatory control. In what follows, the terms airborne nanoparticle and ENP refer to total particles, currently mainly produced by vehicles, and nanomaterials-derived products, respectively. 

Inhalation dosimetry plays a vital role in determining the links between exposure and human health effects. In the following paragraph, preliminary estimates of respiratory deposition doses are made for indicating exposure-response-doses at various European locations. These estimates are made based on the observed... 

Fig. 5 Typical respiratory deposition doses in different European cities. Standard deviation values are derived used the average PNCs plotted in Fig. 3 and the standard deviation values of deposition fraction (i.e. 0.03)...

A number of models have been developed to attempt to predict respiratory deposition, especially in the lower airways—the alveolar region. Experimental studies have tended to confirm the validity of the models, recognizing that there is much individual variation and thus a great spread in the results. The results have been clear enough, however, to indicate that till else being equal, deposition of particles in the lungs is greatly influenced by particle size and particle density. 

Roy, C.J., Hale, M., Hartings, J.M., Pitt, L., Duniho, S. (2003). Impact of inhalation exposure modality and particle size on the respiratory deposition of ricin in BALB/c mice. Inhal. Toxicol. 5 619-38. 

Inhalation and ingestion (of water, food, paint, soil and/or dust) are the primary routes of human exposure to lead (OECD, 1993). Percutaneous absorption is minimal in humans. The absorption of lead from air to blood involves two processes the deposition of airborne particles in the respiratory tract and the absorption and clearance from the respiratory tract into the circulation. The respiratory deposition of airborne lead is in the range of 30-50% and varies with particle size, chemical speciation, solubility in body fluids and ventilation rate. Higher deposition rates may occur with larger particles, but this deposition takes place in the upper respiratory tract. The smaller particles of inhaled lead (generated by automobile exhaust) are almost (>90%) completely absorbed after deposition in the lower respiratory tract (WHO, 1995). 

Holleman D, Martz D, Schiager K. 1969. Total respiratory deposition of radon daughters from inhalation of uranium mine atmospheres. Health Phys 17 187-192. 

Hinds, W. C. 1999. Aerosol Technology Properties, Behavior, and Measurement of Airborne Particles, 2nd ed. New York John Wiley Sons. An upper-division/graduate-level text covering, for example, bioaerosols. Brownian motion and diffusion, respiratory deposition models, measurement, and sampling. 

Canhoto, O., Phnzari, F., FaneUi, C., Magan, N., 1996. Effect of relative humidity on the aerodynamic diameter and respiratory deposition of fungal spores. Atmos. Environ. 30 (23), 3967-3974. 

Chapters are arranged in the order in which they are covered in class, starting with simple mechanics and progressing to more complicated subjects. Particle statistics is delayed until the student has a preliminary understanding of aerosol properties and can appreciate the need for the involved statistical characterization. Applications are discussed in each chapter after the principles have been presented. The more complicated applications, such as filtration and respiratory deposition, are... 

---