Skip directly to search Skip directly to A to Z list Skip directly to page options Skip directly to site content

NIOSHTIC-2 Publications Search

Search Results

Aerosol generation by modern flush toilets.

Authors
Johnson-D; Lynch-R; Marshall-C; Mead-K; Hirst-D
Source
Aerosol Sci Tech 2013 Sep; 47(9):1047-1057
NIOSHTIC No.
20043244
Abstract
A microbe-contaminated toilet will produce bioaerosols when flushed. We assessed toilet plume aerosol from high efficiency (HET), pressure-assisted high efficiency (PAT), and flushometer (FOM) toilets with similar bowl water and flush volumes. Total and droplet nuclei "bioaerosols" were assessed. Monodisperse 0.25-1.9-um fluorescent microspheres served as microbe surrogates in separate trials in a mockup 5 m3 water closet (WC). Bowl water seeding was approximately 1012 particles/mL. Droplet nuclei were sampled onto 0.2-umpore sizemixed cellulose ester filters beginning 15 min after the flush using open-face cassettesmounted on the WC walls. Pre- and postflush bowl water concentrations were measured. Filter particle counts were analyzed via fluorescent microscopy. Bowl headspace droplet count size distributions were bimodal and similar for all toilet types and flush conditions, with 95% of droplets<2 um diameter and>99%<5 um. Up to 145,000 droplets were produced per flush, with the high-energy flushometer producing over three times as many as the lower energy PAT and over 12 times as many as the lowest energy HET despite similar flush volumes. The mean numbers of fluorescent droplet nuclei particles aerosolized and remaining airborne also increased with flush energy. Fluorescent droplet nuclei per flush decreased with increasing particle size. These findings suggest two concurrent aerosolization mechanisms-splashing for large droplets and bubble bursting for the fine droplets that form droplet nuclei.
Keywords
Microorganisms; Aerosol-particles; Aerosols; Biological-agents; Exposure-levels; Risk-factors; Particulates; Air-sampling; Airborne-particles; Air-contamination
Contact
David Johnson, Department of Occupational and Environmental Health, University of Oklahoma Health Science Center, P.O. Box 26901, CHB Room 139E, Oklahoma City, OK 73126-0907
CODEN
ASTYDQ
Publication Date
20130901
Document Type
Journal Article
Email Address
david-johnson@ouhsc.edu
Funding Type
Grant
Fiscal Year
2013
NTIS Accession No.
NTIS Price
Identifying No.
Grant-Number-T01-OH-008614; M102013
Issue of Publication
9
ISSN
0278-6826
NIOSH Division
DART
Source Name
Aerosol Science and Technology
State
OK; OH
Performing Organization
University of Oklahoma Health Sciences Center - Oklahoma City
TOP