Persistent Bioaccumulative Toxic Substances

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Persistent Bioaccumulative Toxic Substances

• Long Term Public Health Concerns

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What are PBTs?

• POPs?
• PUBs?
• PCBs?
• Persistent Bioaccumulative Toxic substances, or
  PBTs, are chemicals---man-made or natural---that
  persist in the environment, increase in
  concentration (bioaccumulate) as they move up the
  food chain, and cause harm (are toxic) to the
  organism that has the PBTs in its tissues.

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Persistent

• Persistent means that the chemical does not
  readily break down in the soil, water, air or
  living tissue. It persists when exposed to
  sunlight, water, air, earth, or other physical or
  chemical agents. These chemicals travel through
  the environment either through simple chemical or
  physical interactions or by being consumed by
  living organisms

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Bioaccumulative

• Bioaccumulate is the term we use to describe
  the increasing concentration of any chemical
  stored in living tissue. As larger organisms eat
  smaller organisms contaminated with PBTs, the
  larger organism takes on the PBT burden. The
  larger organisms cant easily rid themselves of
  the PBTs because of the chemicals nature.

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Toxic substances

• Finally, toxic means harmful. Toxicity can be
  immediate or long term. In the case of PBTs, the
  chemicals can cause damage over the long run by
  interfering with the nervous system, the immune
  system, and the reproductive system. A number of
  PBTs damage the kidneys and liver. And many are
  known to be cancer-causing.

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Examples

• Pesticides
• By-products of combustion
• Industrial chemicals
• Natural substances released during human
  activities

• DDT Aldrin Dieldrin
• Benzo(a)pyrene dioxin
• PCBs
• Mercury

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The Cycle

• Release into air, water, soil
• Transport
• Uptake by food substances air
• Pathway to humans
• Contact
• Eating
• Drinking
• Breathing
• Maternal/fetal

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• DO YOU WORK WITH ANY OF THESE
• ITEMS THAT MAY CONTAIN MERCURY?
• FLUORESCENT LAMPS
• MERCURY SWITCHES
• MERCURY VAPOR LAMPS
• THERMOSTAT PROBES
• METAL HALIDE LAMPS
• RELAYS
• HIGH PRESSURE SODIUM LAMPS
• THERMOMETERS
• NEON LAMPS
• THERMOSTATS
• DENTAL AMALGAM
• MANOMETERS
• GAUGES
• LABORATORY SOLUTIONS

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Web Site for Mercury in the Workplace

• http//www.state.nj.us/health/eoh/
• survweb/mercpt1.pdf

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Controlling Metallic Mercury Exposure in the
Workplace A Guide for Employers
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HEALTH EFFECTS

• Long-term, low-dose, repeated or chronic exposure
• CANCER
• Nervous system, liver, kidney, reproductive,
  endocrine (hormones), G-I, skin, etc.

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Murky Epidemiology

• Low doses
• Multiple exposures to multiple chemicals
• Subtle effects
• Few studies
• Lengthy latency periods
• Lost in the quagmire

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Quote from The New Yorker

• Often, making science the mediator of truth is
  nothing but a convenient means of ignoring our
  own biases. Julian Bleecker, NYC TNY, September
  2, 2002 p. 9, letters

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The Bell-shaped Curve

• All humans created equal?
• Genetic diversity
• Phenotypic diversity
• Biodiversity
• Concept of the sensitive population

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Precautionary Principle (better safe than
sorry)

• Duty to take steps to prevent harm
• Burden of proof on proponents
• Obligation to examine all alternatives
• Open, informed, democratic decision-making
  process involving all stakeholders

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PUBLIC HEALTH POLICY

• Public health policy must be informed by
  science, driven by common sense, instilled with
  environmental justice, inspired by social and
  societal values, influenced by economics, and
  imbued with fairness. L.B. Sandy Rock, MD

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