"The more we learn about lead, the more we find adverse effects at lower and lower levels,"
says Joel Schwartz, senior scientist at the EPA. "Drinking water is now a major source of
lead for a sizeable portion of the population. It's a matter of considerable concern."
The age of
your home can be an important indicator of whether lead might be a
contaminant in your
drinking water.
This information comes mostly from the EPA and
the Institute of Agriculture and Natural
Resources. Most well or city water does not naturally
contain lead. Water usually picks up lead inside your
home from household
plumbing that is made with lead containing materials.
Boiling the
water will not reduce the amount of lead. Boiling so
that significant amounts of water
evaporate will actually concentrate any lead
and other non-volatile contaminants in the water.
Lead-contaminated
drinking water is most often a problem in houses that are either very old or
very new. Up through the early 1900's, it was common practice, in some areas
of the country, to use
lead pipes for interior plumbing. Also, lead piping was
often used for the service connections that join
residences to public water
supplies. (This practice ended only recently in some localities.)
Plumbing
installed before 1930 is most likely to contain lead. Copper pipes have
replaced lead
pipes in most residential plumbing. However, the use of lead
solder with copper pipes is widespread.
Lead solder was banned in the US in
1987, but the ban has not been universally adhered to. Experts
regard
this lead solder as the major cause of lead contamination of household water in
U.S. homes
today.
New brass faucets and fittings can also leach lead,
even though they are labeled "lead-free".
Scientific data indicates that
the newer the home, the greater the risk of lead contamination. Lead levels
decrease as a building ages. This is because, as time passes, mineral deposits
form a
coating on the inside of the pipes (if the water is not corrosive). This
coating insulates the water from the
solder. But, during the first five years
(before the coating forms) water is in direct contact with the lead. More
likely than not, water in buildings less than five years old has high levels of
lead contamination (EPA). The article, Drinking
Water: Lead, contains more important information about this topic.
The
information above pertains specifically to US homes, not necessarily to homes in other
countries,
but it would be wise to check out plumbing codes and practices in your area.
Indicators for high lead content in your drinking
water
Lead levels in your drinking
water are likely to be highest if: your home has faucets or fittings of brass which
contains some lead, or your home or water system has lead pipes, or your home has copper pipes with lead solder, and the
house is less than five years old, or you
have naturally soft water, or your water is acidic,
(pH below 7), or water
often sits in the pipes for several hours, or you
use hot water from the tap to make formula or drinks you
regularly notice blue/green stains on sinks, tubs, and fixtures (this
is probably copper, but
it is an indication of corrosive water which will
also dissolve lead).
Check for lead water pipes
Inside your home - Locate
the pipe leading to the kitchen tap, and follow it
as far as possible until it
exits your home.
Unpainted lead pipes are dull
gray
and
soft.
If you scrape the surface gently with a knife, you will see
the shiny, silver-colored
metal beneath.
If possible, the supply line
from the water main to your home - Try to find
a place where the supply
line is accessible (water meter for example) and
check for indications of
lead pipe. Other types of pipe in use Copper - bright copper-brown
color may have silver colored metal around
the
soldered joints - the solder may contain lead.
Iron/Steel - black, may be
rusty, and is quite hard. The
pipe may have a
shinny
galvanized coating. Plastic - may be white, blue,
gray, black, etc. Lead compounds may
also be
present in some plastic plumbing components. Lead may be
used in
the manufacture of the plastic plumbing products as a
plasticizer. Plastic plumbing components that are certified by the NSF
International do not contain lead. Plastic materials certified by NSF are
recommended for potable water plumbing applications. Plumbing
components made of bronze and brass contain 3% to 8% lead. Ace
Hardware Guide to Water Pipes
Within one week's time I got these
two questions concerning
lead contamination.
Even though I run this site and should know
better, I am sometimes lulled into a false sense of
security that
everything's OK "out there" - that people know about the dangers of
lead, and
everyone has taken precautions to minimize exposure - both in their homes and
in their drinking
water. These questions, however, prompted me to
place even more emphasis on lead education
for those at risk.
Lead is a serious threat to human health and
can adversely affect almost every
organ in the human body. The most
sensitive is the central nervous system, but
immune system, red blood cell, and
kidney damage are also common effects. Lead
exposure during pregnancy can lead
to spontaneous fetal abortion, decreased infant size
and irreversible brain
damage.
On average, it is
estimated that lead in drinking water contributes between 10 and 20
percent of total lead exposure in young children... Young
children, infants and fetuses
appear to be particularly vulnerable to lead poisoning. A
dose of lead that would
have little effect on an adult can have a big effect on a
small body. Also, growing children
will more rapidly adsorb any lead they consume. A child's
mental and physical
development can be irreversibly stunted by over-exposure to
lead. In infants, whose diet
consists of liquids made with water - such as baby formula -
lead in drinking water makes
up an even greater proportion of total lead exposure (40 to
60 percent). (EPA)
Since lead may enter your
drinking water from the pipes in your home or apartment
building, the only way to know if there is lead in your drinking water
is to have it tested
at your tap (see below).
The EPA’s regulation for lead in drinking water allows up to
15 parts per
billion of lead in up to 10 percent of all houses that water providers sample.
If test results show
more than 15 ppb of lead in over 10 percent of samples, then water
providers must develop a plan for
reducing lead levels.
However unless your home is
included in that sample, the fact that the water
utility complies with the lead regulation
does not give an individual family
assurance that their tap water is safe. Read full report.
You
have the greatest health risk from lead exposure, even with short term exposure, if: you are a young child - check
out (Protect
Your Children From Lead
Poisoning), or
you
are pregnant - During pregnancy, hormone
changes can cause lead stored for years in a woman's
bones to be released
into the blood. This lead probably won't affect the mother, but could pose
risks for
an unborn baby - Understanding
lead poisoning.
If your drinking water has
not been tested for lead (particularly if you notice
blue/green
staining), or if it does contain lead, seriously consider taking
the following
precautions.
Install one of the several treatment methods that are effective at
removing lead: activated carbon filtration, ion exchange resins, reverse osmosis, or
distillation (make certain filters are NSF certified to remove
lead).
If you remove the lead from your
drinking water, you do not have to worry about the other precautions
below. There are water treatments that remove only lead, however.
if you make the decision to remove lead you might want to
look at a more comprehensive treatment solution that would protect
against a wider range of contaminants as well as lead.
If
the water has not been used in a particular faucet for six hours or longer, run
the cold
water tap until the water is noticeably colder, about a
minute, to "flush" the pipes. The
longer water has been sitting in your home's pipes, the more
lead and other dissolved
metals the water may contain. Buildings built prior to
about 1930 may have service
connectors made of lead. Letting the water run for an extra
15 seconds after it cools
should also flush this service connector. You may wish
to fill water bottles and store them
in the refrigerator for later use after flushing the water
lines. Flushing may not be
effective in a high-rise building.
Use only cold water for
drinking, cooking, and especially
making
baby formula. Hot
water dissolves materials better than cold water
and thus may contain higher levels of
lead.
Frequently clean the screens and aerators in faucets to remove
captured lead particles. If building or remodeling, only use "lead free" piping
and materials for plumbing. Still, as
noted above, even "lead free"
brass fixtures probably have traces of lead in them.
If you are served by a public water system contact your supplier
and ask whether or not
the supply system contains lead piping, and
whether your water is corrosive. If either
answer is yes, ask what
steps the supplier is taking to deal with the problem of lead
contamination.
An adequate calcium intake can help protect against
lead poisoning. It has been observed in
animals and humans that both the
absorption and retention of lead decreases as calcium
intake increases. Many
children at risk for exposure to excess lead are also those who live at
the
poverty level, and may consume a diet with insufficient calcium. Therefore,
increasing
consumption of low-cost, calcium rich foods can reduce the severity
of the effects of lead
exposure. The RDA for calcium for children ages 1
to 10 is 800 mg per day. Nutrition
and Childhood Lead Poisoning. From another
source, dietary calcium may also help
prevent the transfer of lead from a
pregnant women to her developing fetus.
*
Please be
advised that the information on this page and on this site is for
general educational information only and is NOT
intended to make any
specific health claims or recommend any specific treatment method or
preventative advice for any
health issue or problem. Consult
your physician or a health specialist for specific steps to take for
your specific health or
nutrition requirements!