Blood lead
testing: who to test, when, and how to respond to the result
By Elizabeth
O’Brien, Global Lead Advice and Support Service (GLASS),
August 2009
Who should have a blood lead
test and when?
All children under the age of
6 years should have a blood lead test at least annually,
starting from the age of crawling, and more frequently if the
blood lead level exceeds 2 micrograms per decilitre (µg/dL), if
they live in a house built before 1997 or if they suffer from
pica (eating non-food items) or iron deficiency anaemia.
All children with learning
difficulties, autism, ADD, ADHD or aggressive behaviour should
be blood lead tested.
For everyone born before
leaded petrol was banned in Australia in 2002, after the age of
6, a blood lead test should be done every 5 years throughout
life, or more frequently if the blood lead level exceeds 2 µg/dL.
Anyone planning to move into
and especially if you’re planning to renovate a pre-1997
building in Australia should have a blood lead test prior to
beginning the work and again within a couple of weeks of
starting the work (especially preparation of paint for
repainting or any demolition) to determine that their renovation
methods are indeed lead-safe. If the family must remain in a
home during renovation, all family members should be tested.
If your neighbour or your
landlord starts demolishing or drysanding or waterblasting paint
off their old building or your’s, take everyone to the doctor
for a blood lead test – get a copy of the results in case it
ends up in a tribunal hearing.
People who work with lead or
are involved in hobbies (leadlighting, ceramics,
jewellery-making, fishing-sinker or diving weight or
bullet-making, artist’s painting, etc) which use lead, should
have blood lead testing, prior to beginning the work or hobby,
then a couple of weeks into it, and as often as dictated by the
result and changes made to work-practices to reduce the blood
lead level, but at least annually to ensure that the blood lead
level never goes above 2 µg/dL. If it does, consider switching
to other non-lead work or hobbies.
Shooters should particularly
be required to have blood lead tests before they ever take up a
gun (or apply for a licence) and shortly after beginning their
training, especially if they practice at an indoor firing range.
Regular blood lead monitoring will let your doctor know whether
you have the genotype or shooting frequency that dictate that
you really are not safe to use a gun.
Anyone who has a lodged lead
shot or bullet in them should have a blood lead test every 6
months or more frequently if the blood lead level rises above 2
µg/dL. This can occur especially if the lodged lead object or
fragment moves into the synovial fluid of a joint. Your doctors
should be made aware that you have been shot and have retained
the leaded ammunition, so that they can better monitor not only
your blood lead level but also your nutritional status and
regularly weigh the risks of surgical removal of the lead
pellets against the risks of lead poisoning.
Couples planning to conceive
should aim to have a blood lead level as low as possible but
certainly below 5 µg/dL and for the father, this level should
be achieved before the sperm are manufactured (ie at least three
months before conception).
People who are about to move
to a known high-lead-risk area such as the communities
surrounding lead mining, smelting, manufacturing or recycling
facilities, should test everyone in their family, and themselves
especially if they are about to start work at the lead facility.
Due to the synergistic
effects of lead and mercury, anyone in the above categories who
also has mercury amalgam fillings should have a blood lead test
every couple of years throughout life and consider having their
mercury amalgam fillings replaced if their blood lead level is
above 2 µg/dL.
Because blood lead levels
above 2 µg/dL have been found to have adverse effects on the
developing brain in the foetus and in early childhood, we
recommend that women in early pregnancy and again at the birth
have a blood lead test. Pregnancies will generally raise the
blood lead level (some pregnancies more than others). The early
blood lead level and final umbilical cord blood lead level are
good baseline levels to know for the baby. (Organise in advance
for the test to be carried out at the birth.) The placenta does
not filter lead out so these results can be considered to be the
baby's first blood lead tests. The peak blood lead level for a
pregnancy (typically reached at the birth) will depend on a
woman’s lifetime exposure to lead so is a very important
figure to obtain.
Anyone who has a high hair
lead test result should have a blood lead test to determine if
there is a problem and to have a result (the blood lead result)
which will be followed up by the health department.
A blood lead test result can
demonstrate that despite no obvious sources or pathways of
current lead poisoning, lead is indeed currently being taken up.
Additionally, a blood lead test can demonstrate that stored lead
is moving from the bones back into the bloodstream. The movement
of lead out of the bone stores and back into the bloodstream is
a complex business and not all the provocations for that
movement are fully understood.
Seventy-five percent of a
child’s body burden of lead and 95% of an adult’s body
burden of lead is stored in the bones. For this reason, in the
absence of historical blood lead results, the best way to assess
long-ago lead poisoning is with a bone XRF machine.
Unfortunately no bone XRF machine is currently operational in
Australia.
Testing for lead in the blood
answers the critical question: is lead moving out of the bones
or coming in from the environment, and being circulated to all
organs and tissues, via the blood? The type of change that can
move lead out of bone storage, includes, but may not be limited
to: treatments for lead poisoning (eg saunas, chelation therapy
etc including mega doses of Vitamin C, which is known as
"the natural chelator"), some drug treatments for
other conditions (eg cortisone), bone breaks, drastic changes in
exercise level (eg suddenly training for a marathon without
previous running experience, or suddenly being immobilised in
hospital for a period), the bone demineralisation associated
with pregnancy, lactation, menopause and ageing, and possibly
excess sun exposure.
Women being treated with
Hormone Replacement Therapy (HRT) and anyone on cortisone should
have a blood lead test every 6 months to determine whether the
treatment or the medical problem is associated with a rise in
the blood lead level.
Anyone suffering any of the
health effects or behaviour problems mentioned in "Dangers
of a blood lead level above 2 µg/dL and below 10 µg/dL to both
adults and children" and in “Lead,
Ageing and Death” should also ask their GP or
specialist for a blood lead test.
Various
individual and government responses to blood lead levels
For the individual who knows
the dangers of a blood lead level above 2 µg/dL, the critical
steps in responding to a blood lead level above 2 µg/dL are to
identify the sources of lead and remove them (or remove the
person from the lead), as well as to implement nutritional
intervention. A well-informed doctor can assist greatly in these
two vital responses.
Government health agencies
should be able to help in the lead source identification process
(home lead assessment etc), but, should it be necessary, you can
find details of The LEAD Group's excellent DIY-sampling
for lab lead testing (in Australia) kits
“Acceptable” blood
lead levels
The National Health and
Medical Research Council has issued a statement on 6th August
2009 that the goal is that all Australians should have a blood
lead level below 10 micrograms per 100 millilitres of blood (10
µg/dL). This is the level recommended by the US Centers for
Disease Control and Prevention in 1991 and the World Health
Organisation in 1992. It is also the level which the NHMRC
itself recommended in 1993.
The LEAD Group believes that
the “acceptable” blood lead level should be two micrograms
per decilitre (100 millilitres), based on research referred to
below. By “acceptable” we mean a level below which the
harmful effects of lead are acceptable considering what a huge
boost to the Australian economy lead mining, smelting and export
affords us. As a “goal”, that is, a level which all
Australians should be below, we propose 5 micrograms per 100
millilitres of blood (5 µg/dL). As a marker on the way to
achieving this, we proposed below 10 µg/dL as a “target”
level for all Australians – to be reached by 2012. We do not
find it acceptable that the current occupational level for
moving a worker from a lead task is 50 µg/dL. Workers are
people too and a little bit of extra pay doesn’t make up for
early death, especially if you are not advised that that is the
risk you are taking.
“Notifiable” blood
lead levels
In NSW, Queensland or
Tasmania, if a non-occupationally exposed person’s blood lead
level is found by a pathology laboratory to be 15 micrograms per
decilitre (15 µg/dL) or over, the lab must notify the state
department of health. A home lead assessment would normally then
be carried out by the local Public Health Unit.
In other states and
territories there is no requirement in public health regulations
to notify the health department if your blood lead level is
above 15 µg/dL. We therefore advise you or your GP or
obstetrician to request the relevant state department to do a
home lead assessment. This is done by phoning:
-
Environmental Health
Unit, Department of Human Services, Victoria on 1300761874;
-
Department of Health,
South Australia on 0882266000;
-
Health Department,
Western Australia on 0893884999;
-
ACT (Australian Capital
Territory) Health Protection Service on 0262051700;
-
Northern Territory
Environmental Health Department, Territory Health Services
on 0889227152.
Actions recommended by
government departments at blood lead levels less than 15 µg/dL
The Western Australian Health
Department is now following up blood lead levels above 5
micrograms per decilitre in Esperance, Western Australia and the
Queensland Health Department is following up blood lead levels
above 10 micrograms per decilitre in Mount Isa lead mining &
smelter town.
If anyone in your family has
a blood lead level below 15 micrograms per decilitre but above 2
micrograms per decilitre, then you would be wise to do some
testing in your home or otherwise think about any potential lead
exposure in work or hobbies, in order to identify and then
eliminate any lead sources. You could also try phoning your
state health department to ask them to carry out a home lead
assessment in view of policies elsewhere.
See above list and
additionally:
-
Department of Health, New
South Wales on 0293919000;
-
Queensland Health on
0732340111;
-
Department of Health and
Human Services (DHHS) Tasmania on 1300135513.
In the United Kingdom,
doctors are advised to carry out blood lead testing on children
diagnosed with learning difficulties and autism.
All state and local health
departments in the United States were, on 7th August 2009,
recommended to increase the rate of blood lead screening of
at-risk children under 6 years of age, in just one of many
strategies to achieve the US national Healthy People target, set
in 2000, that no child between the ages of 1 to 6 years in the
US should have a blood lead level higher than 10 µg/dL by 2010.
In some government agencies
in the United States, the follow-up (search for sources) blood
lead level has been set at 5 µg/dL. For instance
"Understanding Your Child’s Lead Test" by the Oregon
Department of Human Services (DHS), states: “parents should
take steps to identify possible sources of lead in their
child’s environment in order to prevent any further
exposure” [if the blood lead level is 5 µg/dL or higher].
The Forsyth County (North
Carolina - Winston-Salem area) Board of Health approved, in
November 2008, regulations requiring environmental
investigations for children with a blood lead level of 8 µg/dL
or higher and allows parents with children with a level of 5 µg/dL
or higher to request inspections.
* DISCLAIMER:
The views expressed herein are not necessarily the views of the
Australian Government, and the Australian Government does not
accept responsibility for any information or advice contained
herein.
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