Page 131 - Fundamentals of Air Pollution

II. Total Body Burden 101

The atmospheric movement of pollutants from sources to receptors is
only one form of translocation. A second one involves our attempt to control
air pollutants at the source. The control of particulate matter by wet or
dry scrubbing techniques yields large quantities of waste materials—often
toxic—which are subsequently taken to landfills. If these wastes are not
properly stored, they can be released to soil or water systems. The prime
examples involve the disposal of toxic materials in dump sites or landfills.
The Resource Conservation and Recovery Act of 1976 and subsequent
revisions are examples of legislation to ensure proper management of solid
waste disposal and to minimize damage to areas near landfills (4).

II. TOTAL BODY BURDEN

The presence of air pollutants in the surrounding ambient air is only
one aspect of determining the impact on human beings. An air pollution
instrument can measure the ambient concentration of a pollutant gas, which
may or may not be related to its interaction with individuals. More detailed
information about where and for how long we are breathing an air pollutant
provides additional information about our actual exposure. Finally, how
an air pollutant interacts with the human body provides the most useful
information about the dose to a target organ or bodily system.
The human body and other biological systems have a tremendous capac-
ity to take in all types of chemicals and either utilize them to support some
bodily function or eliminate them. As analytical capabilities have improved,
lower and lower concentrations of chemicals have been observed in various
parts of the body. Some of these chemicals enter the body by inhalation.
The concept of total body burden refers to the way a trace material accumu-
lates in the human system. The components of the body that can store
these materials are the blood, urine, soft tissue, hair, teeth, and bone. The
blood and urine allow more rapid removal of trace materials than the soft
tissue, hair, and bone (5). Accumulation results when trace materials are
stored more rapidly than they can be eliminated. It can be reversed when
the source of the material is reduced. The body may eliminate the trace
material over a period of a few hours to days, or may take much longer—
often years.
The effect of accumulation in various systems depends greatly on the
quantity of pollutants involved. Many pollutants can be detected at concen-
trations lower than those necessary to affect human health. For pollutants
which are eliminated slowly, individuals can be monitored over long peri-
ods of time to detect trends in body burden; the results of these analyses
can then be related to total pollutant exposure. Following are two examples
of air pollutants that contribute to the total body burden for lead and carbon
monoxide.