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Q:
I'm worried about a specific drinking water contaminant
(lead, nitrate, radon, Cryptosporidium, etc). What should
I know?
A: Drinking water, including bottled water, may reasonably
be expected to contain at least small amounts of some
contaminants. As long as they occur below EPA's standards,
they don't pose a significant threat to health, although
people with severely compromised immune systems and
children may have special needs. For more information
about a specific contaminant, see EPA's fact
sheets on drinking water contaminants, which have
more detailed information on every contaminant EPA currently
sets standards for and those EPA is considering setting
standards for.
Q:
Does a point-of-use filter removes the natural, healthy
trace minerals such as calcium, magnesium, and potassium?
A: No a good drinking water system retains healthy,
naturally occurring minerals in water.
Q:
How can filters takes out contaminants like VOC's but
not the natural minerals?
A: Minerals are totally dissolved in solution and do
not have an actual physical size; thus, the minerals
pass through the filter unchanged. The materials used
in a good drinking water are specially selected for
their ability to react with the chemicals in the water
but not with natural minerals. The ability to leave
the natural, healthy minerals in while reducing harmful
contaminants was a vital factor in the development of
solid carbon block filters available in the market.
The medical community has always maintained that certain
minerals were essential for a healthy body, and a recent
study in the Journal of the American Dietetic Association
found that drinking water with high levels of beneficial,
healthful minerals may reduce the risk of heart disease.
Q:
If the unit does not remove minerals, how does it take
out lead?
A: Solid carbon block filters are specially devised
in such a way whereby certain dissolved impurities,
such as lead and chemicals, are adsorbed to the carbon
surface by chemical reaction and adsorption. Adsorption
(as opposed to adsorption) is defined as "the adhesion
in a thin layer of molecules to the surface of solid
bodies with which they are in contact" (Webster's
Collegiate Dictionary). Thus the solid carbon block
can be analogized to a magnet that metal shavings (Lead,
in the analogy) adhere to.
Q:
If a filter can take out Chlorine, can it also take
out Trihalomethanes (disinfection by-products)?
A: Usually drinking water systems have been tested and
certified to reduce Chlorine and Trihalomethanes. However,
not all filters certified to reduce Chlorine can reduce
Trihalomethanes (although some disreputable companies
would have you believe so!). Chlorine is a substance
that is relatively easy to remove. But, chlorine that
has interacted with organic material to form Trihalomethanes
(thus having a completely different molecular structure)
is extremely difficult to remove.
Q:
How much Fluoride is in the water and do we add any?
A: Fluoride is not added to most water sources because
it occurs naturally at levels less than 0.05 mg/L. Contact
your dentist if you are interested in fluoride drops.
Q:
What is lead?
A: Lead is a naturally occurring bluish-gray metal found
in small amounts in the earth's crust. It has no characteristic
taste or smell. Metallic lead does not dissolve in water
and does not burn. It can combine with other chemicals
to form lead compounds or lead salts. Some lead salts
can dissolve in water. It is known to be harmful to
humans if inhaled or ingested. Because of the use of
lead in manmade products, including past use as a gasoline
additive, it has become widespread in the environment.
Lead can be found in the air, in the water, and on land.
Q:
What are the uses of lead?
A: Lead has many uses. Lead is found in some types of
batteries and is used in the production of ammunition,
sheet lead, solder, some brass and bronze products,
pipes, paints, medical equipment, and some ceramic glazes.
Lead was also found in the chemicals added to gasoline
to increase octane ratings, but its use was banned in
1996.
Q:
What happens to lead when it enters the environment?
A: When released to land, lead binds with the soils
and does not migrate to ground water. In surface waters
it binds to sediments. It does not accumulate in fish,
but does accumulate in some shellfish, such as mussels.
Q:
What are the primary sources of lead exposure in humans?
A: Nationally, the primary source of lead exposure is
lead paint. The two primary lead exposure routes for
humans are inhalation and ingestion. Lead from airborne
sources has been reduced since the phase out and elimination
of lead additives in gasoline. Lead is also found in
urban areas with older homes containing leaded paint
which is also a source of soil contamination. Once lead
enters the soil it adheres to the soil particles. Soil
containing lead may also be blown by the wind, exposing
people to lead containing dust. Movement of lead into
groundwater is unlikely unless the water is acidic;
a common situation in acid mine drainage areas. Sources
of lead in surface water or sediment include deposits
of lead-containing dust from the atmosphere, waste water
from industries that handle lead (iron and steel and
lead producers), urban runoff, and mining piles. Foods
such as fruits, vegetables, meats, grains, seafood,
soft drinks, and wine may contain lead. Cigarette smoke
also contains small amounts of lead. Lead gets into
food from water during cooking and into foods and beverages
from dust that contains lead falling onto food during
processing. The amount of lead found in canned food
(lead solder joints) decreased 87% between 1980-88.
Levels
of lead may build up in plants and animals in areas
where air, water, or soil are contaminated. If animals
eat contaminated plants or animals, most of the lead
they eat will pass through their bodies. In general,
very little lead is found in the groundwater or surface
waters sources of drinking water (lakes, rivers, streams).
Groundwater that is acidic may cause lead found in pipes,
leaded solder, and brass faucets to enter water. Public
water systems are required to treat water to make it
less corrosive; this may include decreasing the acidity
of the water.
Q:
What are the health impacts from lead?
A: Lead can cause a variety of adverse health effects
when people are exposed to it at levels above the U.S.
EPA drinking water Action Level of 15 parts per billion
for relatively short periods of time. Short term health
effects may include interference with red blood cell
chemistry, delays in normal physical and mental development
in babies and young children, slight deficits in attention
span, hearing, and learning abilities of children. Long-term
exposure to lead levels above the U.S. EPA drinking
water Action Level may cause stroke, kidney failure,
and cancer. See questions C3 and C5 for additional information.
Q:
What is the relationship between the EPA Action Level
for water and lead levels in blood?
A: This is not easily answered and not fully understood.
First of all, the EPA Action Level for lead of 15 parts
per billion (ppb) in water was established based on
reasonable risk assessments. It is the level that, when
reached, EPA requires additional corrective and educational
actions. It does not necessarily directly correlate
to blood lead levels, because lead levels in water may
be only one of a number of contributors to lead to humans.
As for blood lead levels, they are reflective of a variety
of factors, i.e., age, pregnancy, nursing, diet, other
lead exposure (dusts, paint chips, soil), and the amount
of water consumed daily. In addition, there are health
studies that demonstrate that various health effects
may be correlated to blood lead levels.
Q:
How much lead is harmful?
A: Blood lead levels of 10 micrograms of lead per deciliter
of blood (mcg/dL) or greater are considered harmful.
This level has been associated with decreased intelligence,
behavior problems, reduced physical stature and growth,
and impaired hearing. A child is estimated to lose 2
IQ points for each 10-mcg/dL increase lead in blood
lead concentrations. A variety of intervention actions
are taken at various thresholds above 10 mcg/dL. Pregnant
women and women who are nursing are also at risk from
lead exposure. Fetuses have been shown to receive lead
from their mothers and nursing mothers can pass lead
through their breast milk. In both cases, the unborn
and young children are taking in levels of lead that
have more of an impact due to their smaller size. It
should be noted that local and state health departments
recommend that children be routinely screened for lead
at 9 months and again at 24 months.
Q:
Does a high level of lead in tap water cause health
effects?
A: High levels of lead in tap water can cause adverse
health effects because the lead may enter the bloodstream
and cause an elevated blood lead level. Most studies
show that exposure to lead-contaminated water alone
would not be likely to elevate blood lead levels in
most adults, even with exposure to water with lead content
close to the EPA "Action Level" of 15 ppb.
Risk will vary depending upon the individual, the circumstances,
and the amount of water consumed. For example, infants
who drink formula prepared with lead contaminated water
are considered to be at higher risk because of the large
volume of water they consume relative to their body
size.
Q:
Are some people more at risk than others from lead in
drinking water?
A: Yes. Children under the age of 6, pregnant women,
and nursing mothers are considered to be most at risk.
Children because of their smaller body size and pregnant
and breast feeding mothers because of leads ability
to pass through the placenta and through breast milk
to the child. If you fall into one of these categories
and are concerned, contact your local health department
or physician.
Q:
What can I do to minimize my exposure to lead contaminated
water?
A: If you have lead service lines, then;
r The best option is to
work with your water supplier, and/or licensed plumber
to replace any service lines and plumbing containing
lead.
r Run your cold water
flushing the system for 10 minutes (see also Section
E: Water Conservation). After flushing for ten minutes,
flush the kitchen tap for 60 seconds before using the
water for drinking or cooking. (boiling water will not
remove lead)
r As part of recommended
pipe flushing and to minimize wasted water bathe, use
the bathroom, run your dishwasher or washing machine.
r Use only cold water
or bottled water for cooking and drinking. Heated water
tends to concentrate more lead.
r Once your lines are
flushed, fill some clean containers with water and refrigerate
for drinking water later on.
r Periodically, remove
and clean the strainer/aerator device on your faucet
to remove debris.
r Install and use NSF
certified water filters.
General
guidance for minimizing exposure to lead:
r Avoid paints and pigments
used in make-up, or hair coloring that contains lead.
r Wash children's hands
and faces often to remove potential lead dusts and soil,
and regularly clean the house of dust and tracked-in
soil.
r Avoid exposure to sources
of lead.
r Do not allow children
to chew or mouth painted surfaces that may have been
painted with lead-based paint (homes built before 1978).
r For specific guidance
related to drinking water, contact your water utility.
Q:
Do lead water filters work to remove lead, and where
can I get one?
A: Yes. There are a variety of water filters on the
market certified to remove lead. They come in a variety
of shapes, sizes, and technologies. They range from
units that filter all the water entering the house to
units that attach to the faucet, to units that water
drips through into a pitcher. These filters in general
remove about 98% of the lead. When purchasing a filter,
look for filters certified to remove lead by the National
Sanitation Federation International. Finally, be sure
to maintain the filter as instructed by the manufacturer.
You might also check with your water provider to find
out if they have a list of recommended brands. EPA Region
III has recently suggested that residents, who have
been advised to filter water, filter water after the
appropriate flushing procedures have been performed.
Flushing is to ensure that lead levels entering the
filtration devices are within the range that can be
removed by most commercially-available filters.
Q:
Can I bathe, wash clothes, or wash dishes with water
that has lead?
A: Yes. Bathing and showering, and washing dishes or
clothes should be safe for you and your children, even
if the water contains lead over the EPA Action Level.
Human skin DOES NOT absorb lead from the water. The
primary route of lead exposure is through ingestion.
Q:
Is lead contaminated water safe for my pet?
A: Changes in pet behavior as a result of drinking lead
contaminated water are not likely be noticeable. In
general, pets are more likely to obtain lead as a result
of eating an object containing much higher lead levels
(lead paint chips). To be safe check with your veterinarian
and/or give your pet filtered or bottled water if elevated
levels of lead are found in your drinking water.
Q:
How does lead get into my drinking water?
A: Although sometimes found in natural deposits near
drinking water sources, lead contamination generally
occurs from the corrosion of lead pipes either between
the water main and a customer's home (lead service lines)
or in a home or building's plumbing system. Even in
homes not served by a lead service line, corrosive water
may cause lead to leach from lead pipes, lead solder,
and brass fixtures.
Q:
What is my water provider doing to reduce the likelihood
of lead in my drinking water?
A: All water utilities are regulated under U.S. EPA
drinking water regulations, including requirements that
help limit lead in drinking water. Actions taken by
utilities to reduce lead exposure may include replacement
of lead water service lines, water treatment to control
corrosion, as well as regular testing and monitoring
to ensure compliance with EPA drinking water regulations.
Q:
If I have a groundwater well for drinking water, do
I have to worry about lead contamination?
A: Drinking water from wells using submersible pumps
made of brass or copper may contain lead at levels that
could pose risks to human health. If the submersible
pump is made of plastic or stainless steel components,
lead from the pump should not be a concern. If you have
an individual household well, you will need to test
the water yourself; if you are concerned see question
D8 for information on water testing labs.
Q:
How can I tell if there are lead pipes, lead solder,
or other lead components in my household plumbing?
A: The existence of lead service lines is often difficult
to determine unless the lines are dug up and examined
or unless there are records available. The first thing
to do is to check with your water provider. They should
be able to tell you if you have lead service lines to
your house. Homes that are more likely to have lead
lines are generally those built either in the early
1900's, during the 1930's, or during World War II when
there was a copper shortage, and lead service lines
were used. Inside the home, the use of lead service
lines and lead solder is not generally known by the
water provider and would be up to the homeowner to investigate.
Brass fixtures, fittings and valves can contain up to
8% lead. Even new brass fittings can leach a considerable
amount of lead in contact with corrosive water. The
use of lead solder for plumbing was banned in 1985.
Q:
What does the EPA Action Level for lead in drinking
water mean?
A: EPA has established an Action Level for lead in drinking
water of 15 ppb. The Action Level was not designed to
measure health risks from water represented by individual
samples. Rather, it is a statistical trigger value that
if exceeded, may require additional types of treatment,
public education, and possibly lead service line replacement.
Q:
How do I know if I should be concerned about lead in
my drinking water?
A: The only way to know whether your tap water contains
lead is to have it tested. Lead can normally not be
seen, tasted, or smelled in drinking water. First, check
with your water provider to find out what testing has
been done in your areA: For homes served by public water
systems, information on lead in tap water may be available
on the internet from your local water provider. If not
call your water provider to find out. For more information
on how to test your water system see question D8.
Q:
How can I get my water tested for presence of lead?
A: If you are concerned about the possibility of lead
in your drinking water, first contact your water provider.
Unless there is a recognized lead problem, most water
providers will not offer testing for individual homes
or businesses. Nevertheless, they may be able to provide
you with a contact list of private laboratories certified
to perform a lead water test.
Q:
Are there limits on how much lead can be in drinking
water?
A: Yes. The US EPA has set an Action Level for lead
at 15 ppb. Given present technology and resources, this
is the level to which water systems can reasonably be
required to control this contaminant should it occur
in drinking water in homes. Fewer than 1 in 10 homes
sampled are allowed to exceed this Action Level. If
the Action Level is exceeded in 10 % or more of the
homes tested, then additional corrective actions are
required under federal regulation.
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