United States
Environmental Protection
Agency
Office of Water
4601
EPA 811-F-9 5-003 e-C
October 1995
&EPA
National Primary Drinking
Water Regulations
Benzo(a)pyrene
This is a factsheet about a chemical that may be found in some public
or private drinking water supplies. It may cause health problems if
found in amounts greater than the health standard set by the United
States Environmental Protection Agency (EPA).
WHAT is
BENZO(A)PYRENE
AND HOW IS IT USED?
DRINKING WATER
STANDARDS:
MCLG:
MCL:
ZERO
0.2 PPB
Benzo(a)pyrene, or BaP, is one of a group of compounds called polycyclic
aromatic hydrocarbons (PAHs). They are not produced or used commercially but
are very commonly found since they are formed as a result of incomplete
combustion of organic materials.
WHY is
BENZO(A)PYRENE
BEING REGULATED?
WHAT ARE THE
HEALTH EFFECTS?
In 1974, Congress passed the Safe Drinking Water Act. This law requires EPA
to determine safe levels of chemicals in drinking water which do or may cause
health problems: These non-enforceable levels, based solely on possible health
risks and exposure, are called Maximum Contaminant Level Goals.
The MCLG for benzo(a)pyrene has been set at zero because EPA believes this
level of protection would not cause any of the potential health problems described
below.
Based on this MCLG, EPA has set an enforceable standard called a Maximum
Contaminant Level (MCL). MCLs are set as close to the MCLGs as possible,
considering the ability of public water systems to detect and remove contaminants
using suitable treatment technologies.
The MCL has been set at 0.2 ppb because EPA believes, given present
technology and resources, this is the lowest level to which water systems can
reasonably be required to remove this contaminant should it occur in drinking
water.
These drinking water standards and the regulations for ensuring these stan-
dards are met, are called National Primary Drinking Water Regulations. All public
water supplies must abide by these regulations.
Short-term: EPA has found benzo(a)pyrene to potentially cause the following
health effects when people are exposed to it at levels above the MCL for relatively
short periods of time: red blood cell damage, leading to anemia;
suppressed immune system.
Long-term: Benzo(a)pyrene has the potential to cause the TRADE NAMES AND
following effects from a lifetime exposure at levels above the SYNONYMS:
MCL: developmental and reproductive effects; cancer. BAP
3,4-BENZ(A)PYRENE
October1995
Consumer Version
Printed on Recycled Paper
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PAHs are found in exhaust from motor vehicles and other gasoline and diesel
engines, emission from coal-, oil-, and wood-burning stoves and furnaces,
cigarette smoke; general soot and smoke of industrial, municipal, and domestic
origin, and cooked foods, especially charcoal-broiled; in incinerators, coke ovens,
and, asphalt processing and use.
There are two major sources of PAH:. Ii drinking water: 1) contamination of raw
water supplies from natural and man-made sources, and 2) leachate from coal
tar and asphalt linings in water storage tanks and distribution lines. PAHs in raw
water will tend to adsorb to any particulate matter and be removed by filtration
before reaching the tap.
PAHs in ‘tap ‘water will mainly be due to the presence of PAH-containing
materials in water storage and distribution systems. Though few data are’
available for estimating the potential for PAH release to water. from these
materials, there are reports that levels can reach 0.01 mg/L with optimum leaching
conditions.
Released benzo(a)pyrerie is moderately persistent in the environment. It
readily binds to soils and should not leach to ground water,, though it has been
detected in some ground water. If released to water, it will adsorb very strongly
to sediments and particulate matter. In most waters and in sediments it will resist’.
breakdown by microbes or reactive chemicals, but it may evaporate or be
degraded by sunlight Benzo(a)pyrene is expected to bioqoncentrate in aquatic
organisms that can not metabolize it, including plankton, oysters and some fish.
The regulation for BaP became effective in 1994. Between 1993 and 1995, EPA
required your water supplier to collect water samples every 3 months for one year
and analyze them to find out if BaP is present above 0.02 ppb. If it is present above
this level, the system must ôontinue to monitor this contaminant. -
If contaminant levels are found to be, consistently above the MCL, your water
supplier must’take steps to reduce the amount of BaP so that it is consistently
below that level. The following treatment methods have been approved by EPA
for removing BaP: Granular activated charcoal.
If the levels of BaP exceed the MCL, 0.2 ppb, the system must notify the public
via newspapers, radio, TV and other means. Additional actions, such as providing
alternative drinking water supplies, may be required to prevent serious risks to
public health. ‘
How MUCH
BENZO(A)PYRENE
IS PRODUCED AND’
RELEASED TO THE.
ENViRONMENT?
WHATHAPPENS To
BENZO(A)PYRENE
WHEN IT IS RELEASED TO
THE ENVIRONMENT?
How 1LL
BENZO(A)PYRENE
BE DETECTED IN AND
REMOVED FROM
MY DRINKING WATER?
H0W W1LLIKN OWIF
BENZO(A)PYRENE IS IN MY
DRINKING WATER?
Learn more about your drinking water!
EPA strongly encourages people to learn more
about their drinking water, and to support local efforts
to protect and upgrade’the supply of safe drinking
water. Your Water bill .or telephone book’s govern-,
ment listings are a good starting point.
Your local water supplier can give you a list of the
chemicals’they test for in your water, as well as how
your water is treated. .
Your state Department of Health/Environment is also a
valuable source of information.
For help in locating these agencies or for information on
drinking water in general, call:
EPA’s Safe Drinking Water Hotline: (800) 426-4791.
For additional information on ‘the uses and releases of
chemicals in your state, contact the:
Community Right-to-Know Hotline: (800) 535-0202.
1995
Consumer Version
Paqe 2
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