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In CHINA -
Blood lead testing: who to test, when, and how to respond to
the result
By
Elizabeth O’Brien and Emma Tao Xu, Global Lead Advice and
Support Service (GLASS), September 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 and in China in 2001（PCFV,
January 2009）,
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 dry
sanding or water blasting 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 pregnancy 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
of Australia 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 in “Dangers of a blood lead level
above 2 µg/dL [two micrograms per
decilitre] and below 10 µg/dL to both adults and children”
By
“acceptable”, governments mean a level below which the
harmful effects of lead are acceptable considering what a huge boost
to the national economy lead mining, smelting
and export affords the country.
As a
“goal”, that is, a level which all Australians or all
Chinese 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
propose below 10 µg/dL as a
“target” level for all Australians and Chinese – to be
reached by 2012. We do not find it acceptable that the current
occupational action level for moving a worker from a lead task
is 50 µg/dL under the Australian
standard. 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. In China the
occupational action level for moving a worker from a lead task
is 60 µg/dL.( MOH, China, 1st Jun
2002)
“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:
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Environmental
Health Unit, Department of Human Services, Victoria on 1300761874;
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Department
of Health, South Australia on 0882266000;
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Health
Department, Western Australia on 0893884999;
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ACT
(Australian Capital Territory) Health Protection Service on 0262051700;
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Northern
Territory Environmental Health Department, Territory Health
Services on 0889227152.
Action
required in China for children’s elevated blood lead levels
The
following paragraphs are taken from a document published by MOH
China (9th Feb 2006)
1.
Diagnosis and classification
Plumbism
and lead poisoning in children, high lead blood lead levels of
children should be the basis for diagnosis.
-
High
lead plumbism: two consecutive blood lead level of 10 ~ 19.9 µg/dL;
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Plumbism:
two consecutive blood lead levels equal to or greater than 20 µg/dL;
and based on blood lead levels were divided into mild, moderate
and severe lead poisoning.
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Mild
lead poisoning: blood lead level of 20 ~ 24.9 µg/dL;
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Moderate
lead poisoning: blood lead level of 25 ~ 44.9 µg/dL;
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Severe
lead poisoning: blood lead levels equal to or greater than 45 µg/dL;
2. Regulations
for Children Plumbism
Children
with high lead plumbism and should be managed for lead poisoning
at medical and health institutions qualified to conduct such
treatment. Medical personnel should be in the process of
complying with environmental interventions, health education and
treatment of the basic principles of driving lead and help to
identify lead sources of pollution, and inform the children's
guardians as soon as possible sources of pollution from lead; be
suitable for various situations of Health guidance, the views of
nutrition helps; right lead poisoning, children should be
appropriate and timely treatment.
(A)
Sources of pollution from lead
When
the children's blood lead level of 10 µg/dL or more should be
asked in detail about environmental pollution and living
conditions, family members and peers has a long history of lead
exposure and lead poisoning in history. Blood lead level of 10
~ 19.9 µg/dL,
often hard to find a clear lead pollution sources, but should
actively seek, and strive to cut the lead pollution sources and
channels; blood lead level of 20 µg/dL or more, often able to
find more clear-cut sources of lead contamination, should
actively help to find a specific lead sources, and as soon as
possible out of.
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:
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Department
of Health, New South Wales on 0293919000;
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Queensland
Health on 0732340111;
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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.
References
for information about China
PCFV
(Partnership for Cleaner Fuels and Vehicles), United Nations
Environment Program (UNEP), ASIA-PACIFIC LEAD MATRIX - Last
updated Jan 2009 www.unep.org/pcfv/PDF/APLeadMatrix-Jan09.PDF
MOH,
China (Ministry of Health of the People's Republic of China),
Diagnostic Criteria of Occupational Chronic Lead Poisoning. (1st
Jun 2002)
MOH,
China (Ministry of Health of the People's Republic of China),
Lead poisoning in children, high lead acidosis
and the principles of classification and treatment (9th Feb
2006)
*
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.
English
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