Am I stoned?



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Lead

  • Affects brain development; associated with lower IQ, ADHD, hearing loss, depression, panic disorder, early menopause
    • No safe level for neurological development

Lead

  • Levels between 4 and 10 significantly increase risk of cardio- and cerebrovascular disease
  • Elevated levels associated with depression, anxiety, schizophrenia, Alzheimer’s disease, crime, and violent behavior, obesity in children
    • MRI changes in gray matter areas responsible for attention, regulation of emotions, and impulse control; disruption of white matter

Lead

  • Childhood exposure linked to violent crime, impulsiveness/aggressiveness, and teen pregnancy in later life
    • Exposure leads to permanent loss of gray matter in prefrontal cortex
  • Rates of consumption of leaded gasoline correlate with violent crime 20 yrs later

Lead

  • 535,000 US children age 1-5 (1/38) have levels exceeding 5 mcg/dL
  • Poor, African-Americans, and Hispanics more commonly exposed
  • Levels declining in US, however
    • Lead paint still widespread in older buildings (built before 1978)
      • 35% of homes with some lead paint; 22% with significant lead paint

Lead

  • 83,000 tons of lead shot into environment annually in U.S. (bullets)
    • Gun shop/range owners/patrons heavily exposed, as are those who consume shot wild game
    • California bans (2013); Obama’s Interior Department bans on federal lands (2017); Trump administration overturns ban (2017)
    • U.S. military increasing use of “green bullets” (containing copper/copper alloys)

Lead

  • Developing world at risk
    • Due to increased environmental exposure and, possibly, early umbilical cord clamping
    • 12 million people worldwide lead poisoned
    • Economic loss to developing nations estimated at close to $1 trillion (over 1% of worldwide GDP)

Lead

  • Leaded gasoline banned in Canada in 1990, US in 1996 (after 25-year phase-out period), EU in 2002, Africa in 2006
    • Still used in piston-engine aircraft (the chief source of U.S. lead emissions)
    • Ban fought by industry for decades
  • Lead paint banned in U.S. in 1978 after decades of industry push-back
    • Still widely used in developing world
  • Lead banned from plumbing in U.S> in 1986

Leaded Gasoline

  • 6 countries still sell small amounts of leaded gasoline:
    • North Korea, Iraq, Afghanistan, Algeria, Myanmar/Burma, and Yemen (all to phase out by 2013
  • Until recently, used in tire vulcanization
  • Still used in airplanes (mostly U.S.)
    • Alternatives available

Lead Cleanup

  • Lead costs US economy $50 billion/yr
  • Cleanup cost: $20 billion/yr for 20 yrs
  • Benefits: $200 billion dollars annually (cognitive and health benefits and decreased crime)
    • 10:1 return on investment (some estimates as high as 200:1)

Mercury

  • Syphilis Treatment
  • - 15th Century onward
  • - abandoned 1940 for penicillin
  • Recognized as cause of disease in 19th Century (Hunter-Russell Syndrome)
  • - chemists, hatters

Mercury

  • Added by US government to industrial during Prohibition to make it more lethal and discourage moonshine production (1926-1933)
    • Led to more than 10,000 deaths

Mercury: S/S, Dx, and Rx

  • S/S: neuropsychiatric symptoms, excessive salivation/inflammation of gums, rash, nephropathy
    • Linked to autism
  • Dx: mercury levels in air, blood, urine (>100 mcg/l in blood and/or urine = toxic)
  • Rx: chelation with BAL, penicillamine, DMPS, DMSA

Minamata Disease: Signs and Symptoms

  • Acute / Chronic Poisoning:
    • numbness, slurred speech, ataxia, unsteady gait, deafness, poor vision, dysphagia, hypersalivation, confusion, drowsiness/stupor to irritability/restlessness; chronic liver disease, liver cancer, hypertension, autoimmune disorders
    • death within a few months if severe
  • Rx EDTA – only partially effective 

Minamata Disease: Signs and Symptoms

  • Congenital: high dose → infertility; medium dose → spontaneous abortions; low dose → congenital disease (including anencephaly and spina bifida)
  • S/S: poor physical growth, developmental delay, ADHD, impaired speech/chewing/swallowing, muscle tone abnormalities, involuntary movements, constricted visual fields, hearing loss
  • - EDTA not effective

Mercury

  • Released into air by coal combustion, industrial processes, mining, waste disposal, and volcanoes; concentrated (along with lead, arsenic, and other heavy metals) in coal ash
    • 4500 tons/yr

Mercury

  • Travels throughout atmosphere and settles in oceans and waterways
  • Bacteria convert it to toxic methyl-mercury
  • Travels up food chain via fish
    • Avoid top predators (tuna, shark, swordfish)
    • 1/3 of US exposure to methylmercury from canned tuna

Gold Mining Gold = Cyanide + Mercury

  • Mercury used to capture gold particles as an amalgam
  • Gold leached from ore using cyanide
    • Cyanide paralyzes cellular respiration
  • At least 18 tons of mine waste created to obtain the gold for a single 3 oz., 18k ring

Gold Mining and Mercury

  • Contaminated groundwater often sits in large toxic lakes held in place by tenuous dams
  • Release of cyanide and mercury into local waterways kills fish, harms fish-eating animals, and poisons drinking water


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