Hazardous Pollutants and Waste Management

1. Hazardous Pollutants and Waste Management Chapter 17 and 21 “All substances are poisons: there is none which is not a poison.  The right dose differentiates a poison and a remedy." Paracelsus (1493-1541)

2. Risk: probability of suffering harm from a hazard that can cause injury, disease, death or economic loss or damage • Risk assessment • Risk management • Biological, chemical, natural, cultural and lifestyle hazards

3. Biological Hazards • Infectious disease (flu, malaria, TB) • Transmissible disease (measles, HIV) • Nontransmissible disease (cancer, asthma, diabetes, malnutrition) • Major concerns include flu, AIDS (HIV), Hepatitis B, malaria and emergent diseases (west nile, Ebola) • Eliminate through infectious disease prevention, education, vaccines, improving quality of life and decreasing malnutrition

4. Chemical Hazards • Toxic chemical: can cause temporary or permanent harm or death to humans or animals • Top 5 include: arsenic, lead, mercury, vinyl chloride (plastics) and PCBs • Carcinogen: promotes cancer • Arsenic, benzene, formaldehyde, gamma and UV radiation, PCBs, radon, tobacco smoke, vinyl chloride • Mutagen: increases frequency of mutations • Teratogen: cause harm or birth defects to fetus/embryo • Alcohol, benzene, formaldehyde, lead, mercury, PCBs, phalates, thalidomide, vinyl chloride

5. Chemical Hazards • Neurotoxins (disrupt nervous system—brain, spinal cord) • PCBs, arsenic, lead, pesticides, methylmercury • Endocrine disruptors (alter hormones and development) • BPA, Aluminum, atrazine, DDT, PCBs, mercury, pthalates • Immune system disruptors (limit immune response) • Arsenic, methylmecury, dioxins

6. Evaluating Chemical Hazards • Toxicity: measure of the harmfulness of the product • Dose: amount ingested, inhaled, or absorbed • Response: damage to health, may be acute or chronic • Depends on age, genetic makeup, solubility of compound (water vs. oil) and persistence • Dose-response Studies • Tests on animals with measure doses of chemical • Plot results of chemical tests to determine curve and lethal doses

7. LD50 • Lethal dose 50: Amount of chemical that kills 50% of a test population within 18 days. • Varies depending on substance • Determines if a new substance is more or less lethal than other chemicals used • Usually tested on rats…then extrapolated to humans • Gives values for acute toxicity • Lower LD50 = More toxic

8. The Dirty Dozen *Go to http://toxtown.nlm.nih.gov/text_version/chemicals.php and click on “Chemicals” at the top of the page. *Find your chemical on the list and answer the following questions… 1. Describe what the chemical is. What products/processes is it found in? 2. Where is the chemical located in the environment? How does it get there? How are humans exposed to it? 3. What are the health concerns? • BPA • Dioxins • Pthalates • PCBs • Arsenic • Benzene • Formaldehyde • Mercury • Asbestos • Lead • Vinyl Chloride (PVC) • Ethylene Glycol

9. Waste Management • Solid waste: any unwanted or discarded material we produce that is not a liquid or a gas • Industrial solid waste- produced by mines, farms and industry (40%) • Municipal solid waste (MSW)- produced by homes and workplaces; ends up in landfills/incinerators (60%) • Average 4.5 pounds per person per day! • Hazardous toxic waste- threatens human health because it is poisonous, chemically reactive, corrosive or flammable

10. Waste • Managing waste refers to controlling the environmental harm of waste, not decreasing its production • Reducing waste is concerned with producing less waste and pollution (prevention) • Recycling is reusing or repurposing materials instead of throwing them away

11. What do we throw away? • Paper (31%) • Food (13%) • Yard waste (13%) • Wood (7%) • Rubber, Leather and Clothing (8%) • Plastic (12%) • Metal (8%) • Glass (5%) • Other (3%)

12. Recycling • Importance… • Decreases use of energy making products • Decreases waste and pollution (amount into landfills) • Increases jobs • Saves $$$ • Primary (closed-loop) recycling: materials recycled into new products of the same type (aluminum to aluminum) • Secondary (open-loop) recycling: waste materials converted into different products (plastic to clothing)

13. Burning and Burying Waste • Waste-to-Energy Incinerators (13%) • Garbage and waste is burned, water is boiled and energy is created • Produces high number of pollutants • Sanitary Landfills (54%) • Waste buried underground in layers, alternating with clay, plastic or foam; sides of landfill are lined to prevent leaching of chemicals; pipes to collect leaching liquid (prevent soil and water contamination) • Methane (byproduct of decomposition) is collected and burned for fuel • Concerns about chemicals leaking to groundwater (leachate)

14. Hazardous Waste • Priority in reducing waste • Most comes from industrial processes (textiles, computer manufacturing, dry cleaners, service stations) • Difficult to dispose of…responsibility is on company or homeowner • Can convert to non-hazardous substances • Physical, chemical or biological methods • Must be treated before disposal • Stored forever • Deep well disposal • Surface impoundments • Steel Drums

15. Legislation • Resource Conservation and Recovery Act • Manages hazardous waste, “cradle-to-grave” tracking • CERCLA (Superfund Act) • Identifies contaminated sites • EPA manages National Priorities List • Currently about 1200 sites • Funding for clean-up is lacking • Brownfield: abandoned industrial and commercial sites, contaminated with hazardous waste