United States
Environmental Protection
Agency
Office of
Public Awareness (A-107)
Washington DC 20460
OPA-104/8
&EPA
Environmental
Information
Standard Set
for Airborne
Lead
Health Effects
of Lead Pollution
Children Found
Most Sensitive
A new national ambient air quality standard to
protect the public health from exposure to lead
became effective October 5, 1978. The standard
for this pollutant which at low levels may harm
human nervous and blood-forming systems was set
at 1.5 micrograms per meter of air based on a
three-month average.
This is the first national ambient air standard
EPA has issued since 1971.
It is well known that at certain levels, lead is
highly toxic, but increasingly there is evidence
that even at low levels lead may have more harmful
effects than was previously believed.
Lead enters the human body principally through
ingestion and inhalation with subsequent absorption
into the blood stream and distribution to all body
tissues. Exposure to airborne lead can occur directly
by breathing or indirectly by eating lead-contaminated
food, water, or non-food materials including dust
and soil. Lead accumulates in the human body
throughout life, to a large extent immobilized in
bone. A significant amount of body lead is in the
blood and soft tissues.
Lead has its most pronounced effects on the blood
forming, nervous, and kidney systems, but may also
harm the reproductive, endocrine, hepatic (liver)
cardiovascular, immunologic and gastrointestinal
systems. Exposure to high lead levels may have
severe and sometimes fatal consequences such as
brain disease, colic, palsy and anemia.
In establishing the new standard, EPA determined
that young children, ages 1 to 5, are the most
sensitive to lead exposure. In 1970 there were
20 million children in the United States^under five
years old. Of these 12 million lived in urban areas
and 5 million lived in center cities where lead
exposure is the highest.
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Where Does
Airborne Lead
Come From?
Lead in the
Workplace
Other Sources
of Lead
Exposure
The new standard is based on preventing children
from experiencing exposure where their blood level
would exceed 30 micrograms of lead per deciliter
of blood. Blood lead levels above 30 micrograms
are associated with an impairment in cell function
which EPA regards as adverse to the health of
chronically exposed children. There are a number
of other adverse health effects associated with
higher blood lead levels in children, including
the possibility of nervous system damage even
without overt symptoms of lead poisoning.
The greatest source of airborne lead is automobiles
using leaded gasoline. Of the more than 160,000
metric tons of lead emitted into the Nation's air
annually, about 90 percent comes from automobile
exhaust. This is an especially acute problem in
urban areas and EPA's phasedown of lead in gasoline
(to be completed by October 1979) is helping to
reduce lead levels in urban children.
The second principal source of airborne lead is
from industrial plants such as non-ferrous smelters.
Currently in the United States there are six primary
lead smelters, 16 primary copper smelters and over
50 secondary lead smelters. Most primary smelters
are located in sparsely populated areas. But even
these smelters can pose a definite health hazard to
those people living near them.
Reducing lead emissions from smelters will be diffi-
cult. EPA plans to work closely with the States and
the affected industry firms to develop plant-by-plant
analysis of how serious the problems are and what a
reasonable compliance program is for each smelter.
EPA's goal is to formulate control strategy which
will avoid significant disruption in the non-ferrous
smelting industry, without compromising protection
of human health.
The Occupational Safety and Health Administration
(OSHA) has set a standard to protect workers from
lead exposure. EPA coordinated with OSHA in develop-
ing standards and compliance strategies.
In addition to air pollution there are other sources
of lead exposure. Lead is found in paint, inks,
water supply and distribution systems, pesticides
and fresh and processed food.
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In other actions to control lead in the environment,
EPA, in 1975, set national drinking water standards
for lead, and by 1979 will develop industrial water
pollution rules for this pollutant. Regulations have
also been issued to control lead arsenate pesticides
and to require safe disposal procedures for all lead-
containing pesticides. Under the Resource Conservation
and Recovery Act of 1976, EPA is authorized to regulate
the recycling and disposal of used crankcase oil, lead
acid batteries and other wastes containing lead.
Other Federal Other Federal agencies which have or will take
Agency Actions actions concerning lead are the Department of
Housing and Urban Development, the Consumer Product
Safety Commission, the Food and Drug Administration,
and the Center for Disease Control.
February 1979
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