ATMOSPHERIC POLLUTION 
Uncoordinated work on a smaller scale has gone on 
for a number of years in the United States, but with a 
great increase in interest and activity during the past 
five years. Increased industrialization and, in particular, 
the problems of disposing of wastes from atomic energy 
installations have led to fresh attacks on atmospheric 
pollution. The former has produced such acute condi- 
tions in the Los Angeles area that a major investigation 
of all phases of the problem is now in progress. The 
latter have led to valuable studies of the behavior of 
effluents from experimental stacks. 
Having considered the present position, 1 may be 
worth while to devote a little attention to some of the 
problems which may have to be faced in the future. In 
particular, general methods of procedure are worth 
discussing. For present purposes, possible future in- 
vestigations may be classed either as extensive or i1n- 
tensive. 
An extensive program of investigations is defined 
here as one in which a variety of problems are studied 
by a number of small and independent groups, co- 
ordination of effort among the different groups being 
limited to that achieved as a result of voluntary mutual 
consultation and discussion. The writer believes that 
such a program, because it provides the widest scope 
for individual initiative and inspiration, is in most 
cases the more desirable. Studies which have been made 
of pollution from single sources may be thought of as 
comprising an extensive program. The nature of the 
single-source problem is such that substantial progress 
may be made by such groups: the problems chosen for 
study may be delimited without sacrificing the essential 
usefulness of the results; relatively small groups of 
research personnel are sufficient, a few specialists in 
several fields at most being needed; instrumental re- 
quirements for gaining limited objectives are not exces- 
sive; and support and sponsorship by several interested 
organizations will be adequate. Furthermore, for these 
reasons the necessary financial support is not too great 
and can be obtained without undue difficulty. 
However, there are other phases of the atmospheric 
pollution problem the successful solution of which re- 
quires resources and facilities of a higher order of 
magnitude. The outstanding example is that presented 
by multiple sources, as represented by an industrial 
city. Here the problem is one of great complexity and it 
should be studied simultaneously from a number of 
points of view if results of value are to be achieved. 
Such an investigation requires the services of groups of 
specialists and technicians equipped with facilities for 
measuring a variety of variables and for analyzing the 
observations in detail. In addition to substantial finan- 
cial backing, the successful prosecution of such an 
intensive investigation of pollution in an industrial city 
requires the wholehearted cooperation of a number of 
organizations, such as municipal and county authorities, 
federal agencies, research institutions, and various in- 
dustries whose plant operations contribute to the general 
city pollution. To give a specific example, the coopera- 
tion of radio stations in allowing meteorological instru- 
ments to be installed on their transmitting towers would 
1153 
be most helpful. Such an intensive program requires a 
higher degree of coordination and integration of effort 
than do the extensive studies with limited objectives 
referred to above. 
The writer believes that both extensive and intensive 
programs of research will in the future make their 
contribution. The need for more coordination of effort 
in certain areas was clearly recognized at the U. S. 
Technical Conference on Air Pollution, held in Wash- 
ington, D. C., on May 3-5, 1950. A Steering Committee 
was set up by the Conference to explore ways and 
means of extending the areas of cooperation; the mete- 
orological representative on this Committee is Dr. H. 
E. Landsberg. During the meetings of the Meteorology 
Panel of the Conference the need for more research of 
both the extensive and intensive types was expressed. 
A report of the discussions of the Meteorology Panel 
was prepared by a group consisting of Dr. H. E. Lands- 
berg and Dr. H. Wexler, the panel co-chairmen, Dr. 
EK. W. Hewson, the panel chairman, and, by invitation, 
Dr. O. G. Sutton, chairman of the British government’s 
Atmospheric Pollution Research Committee. This re- 
port was presented to the plenary session of the Con- 
ference [93]. Because of the fundamental nature of the 
problems considered, the report is reproduced in full 
below. 
The panel meetings have revealed how extensive and how 
varied is the attack on the meteorological phases of the prob- 
lem of air pollution. We are encouraged by the evidence of 
ereat activity and effort. 
The present position may be summarized as follows. The 
distribution of pollution from a single source, either ele- 
vated or at the ground, has been studied both theoretically 
and experimentally for various meteorological conditions. 
Valuable information has been gained concerning the influence 
of special factors such as the following: diurnal variations of 
atmospheric diffusion; frontal surfaces and subsidence in- 
versions aloft; deposition and coagulation of particulate mat- 
ter in the atmosphere; and topography. Progress has been 
made in the study of pollution from multiple sources, such 
as represented by a city. The average distribution of con- 
taminants in a city is governed by wind, rain, atmospheric 
stability, and topographic features. The contaminants in their 
turn influence rainfall and fog occurrence and persistence. 
However, our knowledge of city pollution and its dependence 
on weather conditions is less complete and detailed than that 
of pollution from a single stack. 
Meteorological studies will aid in programs for minimizing 
pollution. The effects of increasing stack heights and tem- 
peratures have been determined. Rates of emission may, in 
cases where plant operations permit, be varied in accordance 
with clearly defined and precisely stated meteorological 
criteria. Methods of using climatological data to aid in de- 
termining the optimum location of a new industrial plant are 
available. 
In short, there is a substantial fund of meteorological 
knowledge available for use in meeting present problems. 
However, we find we are hampered in several ways. Our 
efforts are not as fruitful as they should be because of: a lack 
of coordination of effort; a lack of a basic theoretical doctrine 
by which to orient our efforts; and a lack of standardization 
of instruments and terminology. Our review of the present 
position has revealed a number of weak spots which require 
