M. Pinkham, M.D< Time for A Change > . 11-17-2016 > > > Since
lead was taken out of gasoline in 1980, the public has been told that lead is
the most serious toxic agent. Flint Michigan parents were told that their children
were being permanently damaged by exposure to lead in water. The public
has been old that removing lead from gasoline which lowered blood lead levels
dramatically has made the air cleaner. What is wrong with this message? > In the last 30 years I have made an
extensive search of the world literature on lead and cadmium and
other toxic substances known to have an adverse effect on health. This was
triggered by a finding in a hair analysis study that I did on children in 1986.
The children in my study with the highest levels of lead and cadmium in their
hair had the lowest scores on achievement. This was statistically significant
for lead but not cadmium. All the children were exposed to cadmium from a
large waste incineration plant in operation for 2 years, a very significant
source of cadmium pollution and other chemicals that act in synergy with
cadmium. Only 2 of the 60 were exposed to passive smoke, another very
significant source of cadmium air pollution exposure in humans. The
children with the higher levels of lead and cadmium were experiencing stress
from having learning problems. The hair lead levels were associated with very
low levels of blood lead. The children had minimal exposure to lead.
Although the cadmium levels were elevated in the children with learning
problems, the high variability in hair cadmium compared to hair lead resulted
in an insignificant statistical correlation. > > From my literature search, I discovered that it
is the statistical correlation of small
elevations of blood leads at any level along the line from a blood lead of 20
ug/dL to zero that is the main proof that lead is so toxic. In studies where
lead is given for long periods of time to show adverse effects in experimental animals,
there was no attempt to see what happens to other metals, especially cadmium in
most studies. In the few where that was studied researchers showed that ingestion
of lead in water increased cadmium uptake into the brain. Just the fact that when blood lead levels
averaged 15 the toxic children had blood lead levels of 20 and when the average
was 5 the toxic children had 10 and now when the average blood lead level is
less than one a blood lead level of 5 is considered toxic should make one
suspicious that lead exposure may not be the cause of the linear correlation. .
Clearly all the children in the 1960’s
and 70s were not being poisoned by lead.
An alternate explanation which makes more
sense is that blood lead is not just an indicator of exposure. Small increases
over a background level is actually an indicator of a toxic effect that is
increasing the presence of lead ions in blood. My next blog will explain the
biochemical basis for this effect.