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Hazardous chemicals

Hazardous chemicals. The dose makes the poison (from Paracelsus, a Swiss physician and alchemist of the first decades of the 1500s) More than 80,000 chemicals are registered for use in the United States. Each year, an estimated 2,000 new ones are introduced for use. Types of toxicity.

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Hazardous chemicals

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  1. Hazardous chemicals • The dose makes the poison (from Paracelsus, a Swiss physician and alchemist of the first decades of the 1500s) • More than 80,000 chemicals are registered for use in the United States. Each year, an estimated 2,000 new ones are introduced for use

  2. Types of toxicity • Acute toxicity - chemical will only make you sick if you get high dose all at once • Chronic toxicity - chemical will only make you sick if exposure is over a long-term period • Many chemicals have both acute and chronic effects

  3. Effects of toxicity • In addition to being acute or chronic, toxic effects can be any of the following: • Local or systemic • Immediate or delayed • Reversible or irreversible

  4. Exposure may result in: • Reproductive effects: interferes with the production of sex cells or development of sexual characteristics • Teratogenic effects: effects on unborn offspring, such as birth defects. • Carcinogenic effects: produces cancer in living animal tissues. • Oncogenic effects: tumor-forming effects (not necessarily cancerous.) • Mutagenic effects: permanent effects on genetic material that can be inherited. • Neurotoxicity: poisoning of the nervous system, including the brain. • Immunosuppression: blocking of natural responses of the immune system responsible for protecting the body.

  5. Effects of exposure to multiple hazardous chemicals • An additive effect is one in which the combined effect of two chemicals is equal to the sum of the effects of each (ie. 2 + 2 = 4.) • An antagonistic effect occurs when the toxic effect of the combination of chemicals is less than what would be predicted from the individual toxicities. Antagonism is like adding 2 + 2 and getting 3 as the result. • A synergistic effect occurs when the combined toxic effect of two chemicals is much greater, or worse, than the sum of the effects of each by itself. Synergism is similar to adding 2 + 2 and getting 5 as the result.

  6. Heavy metals • Naturally occurring, but can also be concentrated or modified through industrial processes • Mercury • Lead

  7. Mercury Mercury causes neurological damage by triggering an auto-immune response that degrade neural myelin, the tissues that surround neurons

  8. Lead Lead is toxic mainly because it preferentially replaces other metals (e.g., zinc, calcium and iron) in biochemical reactions. Lead was added to paints to give it color and to speed up drying.

  9. Love Canal (1978)

  10. Persistent organic pollutants (POPs) • Widely used during the boom in industrial production after World War II, when thousands of synthetic chemicals were introduced into commercial use. • Despite utility, they are persistent in the environments – they do not decompose rapidly • They can often bioaccumulate and biomagnify • These properties have allowed them to spread globally, with even high concentrations found in relatively pristine environments like the Arctic • Most life on Earth has been exposed to POPs and has them in their body

  11. Stockholm Convention on Persistent Organic Pollutants • Treaty to end the use of POPs • Members of the original “Dirty Dozen” POPs. Some countries still use these: • DDT • Polychlorinated Biphenyls (PCBs) • Domestically manufactured from 1929 banned in 1979 • Used in hundreds of industrial and commercial applications, particularly electrical equipment • Carcinogen, and can also impairs functioning of immune system, reproductive system, nervous system, endocrine system • Dioxin • Byproducts of industrial manufacturing • Carcinogen, liver damage, and can also cause a wide range of impairments nervous system, the endocrine system and reproductive functions. .

  12. Resource Conservation and Recovery Act (RCRA) of 1976 • Public law mandated by Congress and administered by EPA that creates framework for proper management of hazardous and non-hazardous solid waste. • Management is from cradle-to-grave, or final disposal. • Covers rules for hazardous waste producers, transporters, and storage and disposal facilities • Administers permitting requirements, enforcement and corrective action or cleanup. • Focuses only on active and future facilities and does not address abandoned or historical sites

  13. The Toxic Substances Control Act (1976) • Came out same year as RCRA • Mandated the development of the TSCA Inventory • List now contains more than 83,000 chemicals. As new chemicals are commercially manufactured or imported, they are placed on the list. • Requires pre-manufacture notification for "new chemical substances" before manufacture • Requires testing of chemicals by manufacturers, importers, and processors where risks or exposures of concern are found

  14. CERCLA-Superfund (1980)

  15. Municipal Solid Waste Landfill (Subtitle D of RCRA)

  16. Secure hazardous waste landfills (Subtitle C or RCRA)

  17. Increasing regulation of chemical disposal has lead to more criminal activities • Midnight dumping • Orphan sites • Companies set up a landfill to accept hazardous wastes • Industry has to pay for disposing of their hazardous waste, much like you have to pay for your garbage service. • These companies then go out of business and abandon the sites after making a profit

  18. Bhopal, India (1984) • Union Carbide pesticide plant accidently released 30-40 tons of an extremely toxic gas. • 2500-7000 deaths, 50,000 cases of visual impairments, including blindness. • The chemical, while toxic, is very soluble in water. With wet paper towel, effects greatly reduced. • However, because the company did not have to report the chemicals on site at its plant, none of the local authorities were aware of possible hazards from a release, and could not provide the emergency medical response that could have lessened human suffering.

  19. EPCRA (1986) • Emergency Planning and Community Right to Know Act (EPCRA) of 1986 • This legislation was enacted by Congress after Bhopal, India • Requires that industries report the locations and quantities of toxic chemicals stored on site to state and local governments • Requires a toxic release inventory, a TRI, for every company. List is to be publically accessible

  20. Leaking Underground Storage Tanks (LUST) Trust Fund (1986) • Administered under the Solid Waste Disposal Act of 1965 • Funds remediation of underground storage tanks, particularly those for gas stations, petroleum storage facilities that threaten groundwater

  21. OSHA’s Hazard Communication Standard (1994) • OSHA - Occupational Safety and Health Act • Requires that worker’s have the right to know about hazardous materials in the workplace, and the right to have adequate protection • Recently harmonized with a global hazard communication system developed by UN

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