Lecture 2 Flashcards
Why was lead used in the metal age and why would we want to use it to make things?
-abundant in earths crust (naturally occurring), easy to obtain, low melting point, readily to
make tools and weapons, ability to form
alloys, stands up to weather condition,
highly corrosion resistant, holds pigments
well, and inexpensive
When was lead toxicity recognized?
As early as 2000 BC
Lead poisoning in the Roman Empire:
-Lead poisoning was a disease of
the wealthy: leaden cooking
utensils, pots, wine (naturally sweet in taste) containers,
plumbing and piping (Latin
“plumbum” means “lead”)
- Historians believe that Lead Poisoning contributes to the decline of the Roman Empire
Uses of lead in everyday life:
-naturally occurring element
-Found in air, soil, water, in our homes
-Gasoline, paint, plumbing pipes,
ceramics, solders, batteries, and
even cosmetics.
Metal Fume Fever
Symptoms similar to influenza
* Fever, chills, nausea, headache, fatigue, muscle ache
* Generally, lasts 1 – 2 days
* Acute response to metal oxides
* Zinc, cadmium, manganese, chromium, copper, lead
* Tolerance builds up during the week
* “Monday morning fever”
* Often occurs among welders working with galvanized steel
(contains zinc or other metals).
* Severe condition leads to serious illness or even death
What are the health effects of lead for children?
-Lead can affect almost every organ and system in your body. Children six years old and younger are most
susceptible to the effects of lead.
-Even low levels of lead in the blood of
children can result in:
*Behavior and learning problems
*Lower IQ and Hyperactivity
*Slowed growth
*Hearing Problems
*Anemia
In rare cases, ingestion of lead can cause
seizures, coma and even death
What are the health effects of lead for pregnant women?
Lead can accumulate in our bodies over time, where it
is stored in bones along with calcium.
* During pregnancy, lead is released from the mother’s
bones along with calcium and can pass from the
mother exposing the fetus or the breastfeeding infant to
lead.
* This can result in serious effects to the developing fetus
and infant, including:
*Cause the baby to be born too early or too small;
*Hurt the baby’s brain, kidney’s, and nervous system;
*Increase the likelihood of learning or behavioral
problems; and
*Put the mother at risk for miscarriage.
What are the health effects of Lead on adults?
Adults exposed to lead can suffer from:
* Cardiovascular effects, increased blood
pressure and incidence of hypertension;
* Decreased kidney function; and
* Reproductive problems (in both men and
women).
Blood Lead Levels and Clinical states:
NO SAFE BLL but, BLLs greater than 5 ug/dL are considered elevated
- At 5 ug/dL, there is possibility of Developmental Toxicity (placental transfer, decreased IQ, decreased hearing and growth)
-At 20 ug/dL, there are Minor clinical signs (increased risk of HTN…)
-At 50 ug/dL, there are Evident Clinical signs (Colic, anemia, nephropathy…)
-At 100 ug/dL, death can occur
Blood lead levels in Kentucky workers
-Elevated blood lead levels
-Average rates are 40% higher than the estimated national prevalence rate.
Lead replaces what in the body?
-Lead replaces calcium in the body, interfering with many
physiological processes.
- Target organs include blood, brain, gastrointestinal, kidneys,
reproductive system. - Lead is stored in bones for 20- 30 years.
What is the impact that increased BLL has on the bran?
-Reduces hippocampal volume (impacts memory and increases the risk of Alzheimer disease which is the leading cause of demensia)
-Pb-exposed workers
-amyloid-B plaques build up inside cells causing neuronal loss
A brain with Alzheimer disease has:
1) Shrinkage of cerebral cortex
2) Enlarged ventricles
3) Shrinkage of hippocampus
Risk factors for Alzheimer disease:
-Older ages are more at risk
-Head injuries can cause accumulation of plaques
-sedentary lifestyle
-Environmental factors
-others
Treatment of B-Amyloid plaques and AD:
-Aducanumab
-Lecanemab
-antibodies that bond and remove AB plaques in the brain for treatment of AD
-both have shown clinical benefits to dissolve amyloid plaques and slow down cognitive decline
Approaches for age-related accumulation of Amyloid Plaques in Human Brains:
-Scanning brain ahead of time (can have amyloid plaque buildup years before having any symptoms)
-Preventative treatment
Blood Brain Barrier and Pb poisoning
-Pb causes damage to the Blood-brain barrier
-Since damaged, they are more susceptible to infections and toxins passing to the brain
Lead in drinking water
-Lead can enter drinking water from
plumbing materials that contain lead, such
as pipes, faucets, and solder.
-Lead can leach into water when these materials
corrode, especially in water that is acidic
or low in minerals
Lead pipe replacement
-In 2023, EPA launched Lead Service
Line Replacement Accelerators
(LSLR) initiative
- Removal of lead service lines in
contact with drinking water provides
an opportunity to significantly reduce
the risk of exposure to lead in drinking
water
Acute vs chronic lead exposures:
Acute:
-Occupational: mining, smelting, welding
-Manufacturing: shipyard, construction, battery,
weapons
Chronic:
-House: Homes built before 1950, Home remodeling activities
-Personal: past living conditions, hobbies…
-Others: use of glazed ceramics, drinking water source and pipes
Main sources of everyday Cadmium (Cd) exposure
-Air
-Food (meat, fish, crops)
-Cigarette
-Occupational: Batteries, metal coating, metal alloys, smelting
-stored in our liver and in bone
Target organs of cadmium:
-Kidney (primary)
-skeletal system
-Lungs
-Testis
Itai-Itai Disease
Happened in Japan (Industrialization pollution and cadmium 1950s)
-Severe and chronic
exposure to Cd in
drinking water.
-Cd deposits in and
damages the skeletal
system.
-Severe pain felt in joints
and spine.
-Accompanied with renal
tubular dysfunction.
- ~400 patients died.
Distribution of Cadmium in the body:
-Has an intracellular distribution and binds with metallothionein (Cd-MT)
-Low biotransformation (remains in body for a long time) and accumulates in the liver +bone
Therapeutic intervention of cadmium poisoning
No therapeutic agent available
-Since intracellular distribution, it is hard to find a treatment
-There are some new drugs that attempt to compete with MT for Cd binding
