Re: lead in soil
- David Stephensen wrote:
>There is some good data on this site that you found. As you said it
> >Hi Mike
> My researches have located a good fact sheet on lead in soil, explaining how to avoid problems with it. It includes lists of vegetables with lead uptake risks. The main problem seems to be contaminated soil sticking to the vegetable rather than lead absorption.
> You may wish to publish it on TT
lists which vegetables take in the most and least lead.
Research indicates that some leafy vegetables and herbs collect
from the air as well as the soil more readily than other
remember to thoroughly wash all fruit and vegetables prior to
eating. Peel root vegetables.
HIGH uptake of lead Lettuce, Spinach, Carrot,
MODERATE uptake Onion, Mustard, Potato,
LOW uptake Corn, Cauliflower, Asparagus,
VERY LOW uptake of lead Beans, Peas, Melon, Tomatoes,
If your soil is high in organic matter and at an approximately
level (i.e. a pH of about 6.5 to 7), most of the lead that is
present in the soil will
become bound to soil particles in a way that prevents it from
incorporated into growing crops. You can adjust your pH level if
it is too
acidic (under 6.5) by adding wood ashes (but NOT ashes from
which may have contained lead) or an appropriate commercial
Organic matter can be added by using kitchen scraps that have
How are we affected by lead?
You or your children could have elevated blood lead levels and not
know it because even though serious, long term damage is occurring,
patients usually do not show symptoms until levels are very high. Low
levels of lead can cause brain damage, learning difficulties,
behavioural problems, kidney damage, hearing impairment, growth
retardation and many other affects, but these are often difficult to
recognize until the damage is done. High levels of lead can cause
miscarriage, birth defects, coma and death.
Symptoms, when they do occur are often subtle and are attributed to
other causes. In children these can be irritability, tiredness or
decreased play activity, loss of appetite, abdominal pain, muscle aches,
vomiting, diarrhoea, constipation and headaches. Adults can also suffer
loss of libido, infertility and elevated blood pressure.
Women of child bearing age : The human body mistakes lead for calcium
and stores lead in our bones.
During pregnancy a womans hormones may mobilise calcium for the
growth of the baby and also mobilise any lead that she has laid down on
her bones anytime throughout her life. Lead has a half life in the bone
for almost 30 years.
Men : Very small amounts of lead can affect libido, fertility and blood
pressure. This hypertension (high blood pressure) increases the risk of
heart attack and stroke.
Health Impacts of Lead Poisoning can be found in detail at
Identification and Management of Lead Affected People at:
Blood lead level
Symptoms / Indicators
(10 25 µg/dL)
Symptoms will not be
present at these levels,
but can show up later as
reduced IQ, learning
difficulties, delays in
(25 45 µg/dL)
2.17 2.66 µmol/L
(45 55 µg/dL)
>2.66 µmol/L( >55 µg/dL)
Severe lead poisoning
severe head ache
>3.38 µmol/L( >70 µg/dL)
gingival lead line
Note: I cut an pasted into this e-mail some of the more important things
we need to have as a reference.