Untersuchungen zur nasalen Depositionse ffi zienz f ü r Weizenmehl-und Maisst ä rke-Staub Investigations of Nasal Deposition E ffi ciency of Wheaten Flour and Corn

Investigations of Nasal Deposition Effi ciency of Wheaten Flour and Corn Starch ▼ Background: In-vivo-evaluation of the nasal deposition effi ciency is problematic, because a postnasal measurement of the dust particle concentration is diffi cult. A new method is represented, which measures in front of the nose the dust loading after orthoand retronasal passage relative easily. Methods: 36 healthy subjects were nasally dust-exposed sitting in an exposure chamber. With the help of dust sampling system (Respicon TM ) the particle size-referred dust loading before and after the nasal airfl ow passage was gravimetrically determined. The constant fl ow rate was 3.11 l per minute. A contamination with breathing air was excluded by an active velopharyngeal closure. The subjects breathed orally over a breathing tube clean air. They were in each case 15 min exposed to the constant pre-nasal wheaten fl our or corn starch dust produced over a brush disperser (Palas, RBG 1000 TM ). The time interval between both exposures was seven days excluding cross over eff ects. Results: The deposition effi ciency of both types of food powder was particle size dependent. Highest it was -as expectedwith the particle sizes between 5 – 100 μ m. Here it lay between 92 % and 99 % . The small particles of wheaten fl our respective corn starch with an aerodynamic diameter between 1 – 4 μ m deposited nasally 31 % respectively 74 % . Conclusions: The new relatively simple method of measurement of nasal deposition effi ciency does not load the deeper respiratory tract. The results confi rm the good fi ltering capability of the healthy nose for large dust particles. The nasal deposition of particles smaller than 5 μ m is reduced but not absent. The small dust particles of wheaten fl our and corn starch are very diff erent nasally deposited. The diff erent electrostatic charges of the two food powders may explain these diff erences. Literatur 1 Keck T , Leiacker R , Klotz M et al . Detection of particles within the nasal airways during respiration . Eur Arch Otorhinolaryngol 2000 ; 257 : 493 – 497 2 Hounam RF , Black A , Walsh M . Deposition of aerosol particles in the nasopharyngeal region of the human respiratory tract . Nature 1969 ; 221 : 1254 – 1255 3 Fry FA , Black A . Regional deposition and clearance of particles in the human nose . Aerosol Science 1973 ; 4 : 113 – 124 4 Lippmann M , Albert RE . The eff ect of particle size on the regional deposition of inhaled aerosols in the human respiratory tract . American Industrial Hygiene Association Journal 1969 ; 30 : 257 – 275 5 Recommendation from the scientifi c committee on occupational exposure limits for fl our dust . In: Europ ä ische Kommission, Besch ä ftigung und Soziales, Gesundheitsschutz und Sicherheit am Arbeitsplatz, SCOEL, SUM/123, M ä rz 2007, after consultation 6 Kobal G , Plattig KH . Objective olfactometry: methodological annotations for recording olfactory EEG-responses from the awake human . EEG EMG Z Elektroenzephalogr Elektromyogr Verwandte Geb 1978 ; 9 : 135 – 145 7 Martonen TB , Zhang Z . Comments on recent data for particle deposition in human nasal passages . J Aerosol Sci 1992 ; 23 : 667 – 674 8 Itoh H , Smaldone GC , Swift DL , Wagner HN . Mechanisms of aerosol deposition in a nasal model . J Aerosol Sci 1985 ; 16 : 529 – 534 9 Scott WR , Taulbee DB , Yu CP . Theoretical study of nasal deposition . Bulletin of Mathematical Biology 1978 ; 40 : 581 – 603 10 Nieuwenhuijsen MJ , Sandiford CP , Lowson D et al . Peak exposure concentrations of dust and fl our aeroallergen in fl our mills and bakeries . Ann Occup Hyg 1995 ; 39 : 193 – 201 11 Landillon V , Cassan D , Morel MH , Cuq B . Agglomeration and rheological properties of diff erent wheat millings . In, Fifth World Congress on Particle Technology Orlando, Florida ; 2006 ; 262e 12 Park SS , Wexler AS . Size-dependent deposition of particles in the human lung at steady-state breathing . J Aerosol Sci 2008 ; 39 : 266 – 276 13 Heyder J , Gebhart J , Rudolf G , Schiller CF , Stahlhofen W . Deposition of particles in the human respiratory tract in the size range 0.005 – 15 μ m . J Aerosol Sci 1986 ; 17 : 811 – 825 14 Cheng YS . Aerosol deposition in the extrathoracic region . Aerosol Science and Technology 2003 ; 37 : 659 – 671 15 Bennett WD , Zeman KL , Jarabek AM . Nasal contribution to breathing and fi ne particle deposition in children versus adults . J Toxicol Environ Health A 2008 ; 71 : 227 – 237 16 Martonen TB , Bell KA , Phalen RF , Wilson AF , Ho A . Growth rate measurements and deposition modelling of hygroscopic aerosols in human tracheobronchial models . Ann Occup Hyg 1982 ; 26 : 93 – 108 1 Die Studie wurde durch die Berufsgenossenschaft Nahrungsmittel und Gastst ä tten (BGN), Mannheim, unterst ü tzt. H er un te rg el ad en v on : U ni ve rs ity o f B rit is h C ol um bi a. U rh eb er re ch tli ch g es ch üt zt .