Table Of ContentAMERICAN INDUSTRIAL HYGIENE ASSOCIATION
and
U. S. ATOMIC ENERGY COMMISSION
(Division of Technical Information)
MONOGRAPH SERIES ON
INDUSTRIAL HYGIENE
GEORGE D. CLAYTON, Managing Editor
AMERICAN INDUSTRIAL HYGIENE ASSOCIATION
ADVISORY COMMITTEE
EDGAR C. BARNES, Westinghouse Electric Corporation
HAROLD C. HODGE, University of Rochester
JACK C. RADCLIFFE, Ford Motor Company
HARRY F. SCHULTE, LOS Alamos Scientific Laboratory
JAMES H. STERNER, Eastman Kodak Company
CHARLES R. WILLIAMS, Liberty Mutual Insurance Company
REVIEWERS OF THIS MONOGRAPH
PAUL E. MORROW, University of Rochester
HERBERT E. STOKINGER, U.S. Public Health Service, Division of Occupational Health
ARTHUR J. VORWALD, Wayne State University
MONOGRAPH TITLES
Pulmonary Deposition and Retention of Inhaled Aerosols
(IN PREPARATION)
Beryllium—Its Industrial Hygiene Aspects
Technique of Particle Size Analysis
PULMONARY DEPOSITION
AND RETENTION
OF INHALED AEROSOLS
by
THEODORE F. HATCH
Department of Occupational Health
Graduate School of Public Health
University of Pittsburgh
Pittsburgh, Pennsylvania
and
PAUL GROSS
Graduate School of Public Health
Mellon Institute
Industrial Hygiene Foundation
University of Pittsburgh
Pittsburgh, Pennsylvania
Prepared under the direction of the American Industrial
Hygiene Association for the Division of Technical
Information, United States Atomic Energy Commission
1964
($
ACADEMIC PRESS • New York • London
COPYRIGHT ASSIGNED TO THE GENERAL MANAGER OF THE UNITED STATES
ATOMIC ENERGY COMMISSION. ALL ROYALTIES FROM THE SALE OF THIS BOOK
ACCRUE TO THE UNITED STATES GOVERNMENT. NO REPRODUCTION IN ANY FORM
(PHOTOSTAT, MICROFILM, OR ANY OTHER MEANS) OF THIS BOOK IN WHOLE OR
IN PART (EXCEPT FOR BRIEF QUOTATION IN CRITICAL ARTICLES OR REVIEWS)
MAY BE MADE WITHOUT WRITTEN AUTHORIZATION FROM THE PUBLISHERS.
COPYRIGHT © 1964 BY ACADEMIC PRESS INC.
ALL RIGHTS RESERVED.
NO PART OF THIS BOOK MAY BE REPRODUCED IN ANY FORM,
BY PHOTOSTAT, MICROFILM, OR ANY OTHER MEANS, WITHOUT
WRITTEN PERMISSION FROM THE PUBLISHERS.
ACADEMIC PRESS INC.
Ill Fifth Avenue, New York, New York 10003
United Kingdom Edition published by
ACADEMIC PRESS INC. (LONDON) LTD.
Berkeley Square House, London W.l
LIBRARY OF CONGRESS CATALOG CARD NUMBER: 63-23200
PRINTED IN THE UNITED STATES OF AMERICA
FOREWORD
This treatise inaugurates a new program for the American Industrial
Hygiene Association. This is the first completed volume of a monograph
series now being written under auspices of the United States Atomic Energy
Commission's Division of Technical Information on titles pertaining to
selected industrial hygiene aspects of the United States atomic energy
programs.
Industrial hygiene is devoted to recognizing, evaluating, and controlling
those physical factors of the workplace environment that may cause sickness,
impaired health or well-being, resulting in significant discomfort or in-
efficiency among people working there. Therefore, industrial hygiene encom-
passes the dual aspect of evaluating both the workplace environment and
this environment's biological effect. The workplace environment is primarily
the concern of technical people with backgrounds in physics, chemistry,
engineering, biology, and other such scientific disciplines. The effects of the
environment, on the other hand, are studied by toxicologists, physiologists,
physicians, and other medical scientists. There is, however, an overlapping
area of concern.
The physical scientist or engineer responsible for measuring and control-
ling the environment cannot properly do his work without a knowledge of
the effects on man of toxic materials and conditions. Similarly, the medical
scientist and physician cannot deal adequately with these effects of the work
environment without being familiar with the environment itself. Industrial
hygiene is the beneficial melding of these broad scientific disciplines.
The American Industrial Hygiene Association, founded in 1939, is the pro-
fessional society that bonds together these scientists of diverse backgrounds.
The unique contribution of AIHA has been this melding together of physical
and medical scientists. From the outset no man has been more articulate in
pointing out the urgency of AIHA's embracing physical and medical
scientists alike than the senior author of this monograph. In co-authoring
this monograph the authors, one an engineer and the other a physician,
exhibit a perfect example of this teamplay between the physical and medical
professions that is the essence of industrial hygiene.
This thesis of cooperation between the physical and the medical scientist
is the essence of the monograph itself. Toxic substances in the atmosphere in
increasing number and variety threaten man's health. The physical scientist
and engineer can, and must, control these contaminants. The medical
scientist and physician can, and must, deal with the pathological consequence
of these on the body. But there is an important overlapping zone of concern
v
VI FOREWORD
that is not in the specific domain of either the environmental or the medical
scientist; indeed, it is the equal concern of both.
The American Industrial Hygiene Association, in order to implement the
monograph program, appointed a Series Editor and established a Monograph
Committee consisting of some of its outstanding members. This Committee,
with the Series Editor as its coordinator, guides the monograph program.
Monograph subjects are selected. Arrangements are completed to secure
outstanding investigators as authors, and each monograph is carried through
to the stage of final draft manuscript completion.
One member of the Committee is assigned a specific monograph and
acts in liaison capacity between the author, the Series Editor, and the
Committee. His responsibility is to assist the authors in the mechanics of
manuscript preparation. Each monograph is finally reviewed by three quali-
fied reviewers. In the final rewriting their pertinent criticisms and sugges-
tions are incorporated into the final draft manuscript.
The preparation of technical data in book or data-sheet form for the
dissemination of knowledge is not a new program in our Association. The
American Industrial Hygiene Association for many years has had some ten
technical committees writing on various facets of industrial hygiene. Examples
are the AIHA Noise Manual, AI H A Air Pollution Manual, and Hygienic
Guides, the latter appearing sporadically in the AIHA Journal, These well-
received technical publications are each prepared by sizable committees of
experts who gave many hours to this writing and editing. The AIHA-AEC
monograph program now complements AIHA's notable and lively interests
in the field of technical committee publications.
The AIHA-AEC monograph program differs mainly from the AIHA's
other technical writing interests in that these monographs delve into more
specific topics. Monographs are usually authored by one or, in this case, two
individuals who have devoted years to personal investigation, gaining new
knowledge in these areas far beyond the ken of other industrial hygienists.
AIHA manuals, on the other hand, are more comprehensive, attacking many
or all aspects of a broad topic with the skill and knowledge of many authors,
each handling a small portion of the writing. The function of this AIHA
monograph series and the method of preparing them are different from the
AIHA technical manuals. One complements the other.
Material in these monographs would never be written were it not for the
impetus of the AIHA-AEC Monograph Program. The emolument, the specter
of the contractual completion date, and gentle prodding by the Series Editor
or an AIHA monograph committeeman contrive to give birth to a document
that the author otherwise "would like to write up—but probably won't tackle
for another couple of years."
FOREWORD vii
The authors of this treatise explore at length the intermediate factors that
operate between the contaminated atmosphere and the internal tissue damage
or disease caused by the gas or dust.
These important but neglected factors include site of deposition of a dust
or absorption of a gas, plus particle size, shape, density, and air-flow pattern ;
the all-important clearance mechanisms, knowledge of which is limited as
compared with our understanding of initial deposition; and knowledge of
where in the body the aerosol will produce its harm, for this site of injury
is seldom at the very point where the contaminant first makes contact with
the body.
With skill and thoroughness the authors have drawn up this first of the
AIHA monograph series. In the words of Bacon, "Some books are to be
tasted, others to be swallowed, and some few to be chewed and digested." In
this monograph is much meat to be chewed and digested—and enjoyed.
W. G. HAZARD, President
May, 1963 American Industrial Hygiene Association
PREFACE
An ever-increasing number and variety of toxic substances in the atmos-
pheric environment threaten man's health. To bring these under control
requires a refined knowledge of the man-environment relationships which
determine, in each case, the nature and magnitude of the health hazard. It
is not enough for the physical scientist and engineer, who are responsible
for correction of the environment, simply to know that a particular causative
agent is involved and to deal with it solely as a physical phenomenon in the
external environment. Nor can the medical scientist and physician deal
adequately with the internal problem if their understanding starts with the
basic mechanism of biochemical or physiological disturbance at the final
critical site within the body and they focus their interest only on the pathologi-
cal consequence of such disturbance.
Some important events take place in the course of passage of the agent
from the point of initial contact with man until it has reached the site within
the body where the toxic action takes place—events which may have great
influence upon the relationship between the external stress and the internal
response. Thus, there exists an important overlapping zone of concern which
does not fall exclusively within the domain of either the environmental or
medical specialist, but is the equal concern of both. It is a joint area of
biological and physical science.
The assessment of an environmental exposure is not just an exercise in
physics or chemistry but, rather, it makes use of physical measurements in
order to predict a biological event. The basic criteria which determine the
appropriateness of the measurement come from biophysical rather than
physical considerations alone. These same biophysical considerations provide
an essential basis for understanding the causation of disease which cannot
be derived from knowledge of biological factors alone. The medical specialist
must have a quantitative appreciation of the physical side of the man-environ-
ment equation, which modifies his thinking, and the specialist on the physical
side, similarly, must modify his understanding of the physical characteristics
of the environment in recognition of the fact that he is dealing with a bio-
logical problem.
This book deals with such an overlapping zone as it applies to the assess-
ment of health hazards from exposure to air-borne particulate matter. It is
concerned with the respiratory deposition and retention of inhaled aerosols,
starting with initial intake and concluding with events that precede patho-
logical tissue response, drawing equally upon both the physical and biological
ix
X PREFACE
aspects of the subject. It is hoped that the book will help the specialists from
both sides as well as technical and administrative personnel to acquire a
common understanding of the important intermediate factors that operate
between the outside dusty atmosphere and the internal tissue damage and
disease—factors that may operate to make one exposure dangerous to life
and another altogether innocuous.
November, 1963 THEODORE HATCH
Pittsburgh, Pennsylvania PAUL GROSS
GLOSSARY
Aerodynamic size is the diameter of a unit density sphere having the same
settling velocity as the particle in question of whatever shape
and density.
Airways are those portions of the respiratory tract which are not lined
in part or in toto by alveolar epithelium. This excludes the
respiratory bronchiole and all of its connecting peripheral
hollow structures.
Allergen is a substance capable of sensitizing tissue so that the latter
will respond with enhanced reactivity when later challenged
by the specific substance.
Apocrine cell is a gland cell which loses part of its protoplasm while secret-
ing.
Carina is the keel- or ridgelike structure formed by the bifurcation
of the trachea.
Ciliated columnar cells are cylindrical epithelial cells possessing hairlike processes at
their free end. These processes or cilia are capable of a
rhythmic whipping motion.
Cytotoxicity is the quality of a substance to induce degenerative changes
in cells which may lead to cell death. In the case of cytotoxic
dust particles, degeneration and death of cells may occur
following cellular ingestion of the dust.
Goblet cells are cylindrical epithelial cells which are distended with
mucin so as to have a goblet shape. This mucin is capable
of being discharged upon the epithelial surface,
Inert dust is a dust which when inhaled and deposited in the lungs will
not produce significant collagenous fibrosis.
Interstitium is the loose connective tissue which surrounds and accom-
panies vessels and bronchi as they are distributed throughout
the lungs. It also comprises in large part the septa which
divide the lungs incompletely into lobules. This loose connec-
tive tissue, which begins in the hilar region, surrounding the
major vessels and bronchi, has its peripheral terminal connec-
tions with the reticulin and elastic fibers of the alveolar wall.
Mediastinitis is an inflammation of mediastinal connective tissue. The latter
is a loose connective tissue situated between the sternum and
the vertebral column.
Metal fume fever is a fever associated with other systemic signs and symptoms
and is caused by the inhalation of fumes from molten metals.
The most common of these fumes is composed of zinc oxide.
Minute volume is the volume of air respired in 1 minute.
Phagocytosis is the process by which a cell engulfs solid material.
Pulmonary air spaces are those air-containing structures in the lung which are lined
in part or in toto by alveolar epithelium. They include the
respiratory bronchioles and all structures distal to them.
Xlll
xiv GLOSSARY
Reynolds number is a dimensionless parameter of fluid flow, the value of which
indicates whether the flow is laminar (Re < 2000) or turbulent
(Re > 3000).
Squamous epithelial cells are flattened surface-covering cells similar to those found on
the skin and in the mouth.
Tidal volume is the volume of air inhaled and exhaled during an ordinary
respiration.
True lung air is the air which has received the C02 of the alveolar capillary
blood and has given up a portion of its 0 to the latter,
2
Upper respiratory tract is that portion of the respiratory system which extends from
the nares to the terminal bronchioles inclusively.
Vestibular portion of the
pulmonary air spaces is that portion of the pulmonary air spaces exclusive of the
alveoli.
