Environmental Risk: Definition, Hazard Types, Perception, & Toxicity

Waste is deemed hazardous based upon what?

1. "Listed"-Its inclusion on a series of lists (four in total) 2. "Characteristic"-Based upon the characteristics of the waste. These characteristics are ignitability, corrosivity, reactivity, and toxicity.

Factors affecting toxicity

1. Form and innate chemical activity- dissolved, gas, solid 2. Dosage, especially dose-time relationship-big dose vs. smaller intermittent. 3. Exposure route-ingenstion, inhalation. 4. Species- certain species of chemicals are toxic. 5. Ability to be absorbed- bioaccumulation. 6. Metabolism- change form during digestion 7. Distribution within the body- concentrate within body or specific organ 8. Excretion- excreted in urine or feces? 9. Presence of other chemicals- react with other chemicals

Risk

=(probability)(consequence) ranges from 0 to 1.

Environmental risk

=f(hazard and exposure)

Endocrine disrupting compounds (EDCs)

A special category of compounds that exert their adverse effects by mimicking the behavior of natural hormones and thus have the potential to disrupt many physiological and developmental processes. They are purported agents responsible for increases in a variety of cancers in humans and many developmental mutations in a variety of aquatic life. Suspected EDCs: dioxins, PCBs, many pesticides and herbicides, BPA, and other chemicals.

Human Health Hazards

Adverse effects to humans upon exposure. Ex. chemicals, pathogens, etc. that harm human beings.

Environmental Hazards

Adverse effects to organisms other than humans. Ex. Chemicals, pathogens, etc. that harm organisms.

Hazardous Waste

Because of its quantity, concentration, or physical, chemical, or infectious characteristics may (A) cause, or significantly contribute to an increase in mortality or an increase in serious irreversible, or incapacitating reversible illness; or (B) pose a substantial present or potential hazard to human health and the environment when improperly treated, stored, transported, or disposed of, or otherwise managed.

Population susceptibility

Certain subsets are more sensitive. -the chronically ill -elderly -young

Design for the environment

Consciously choosing to modify an engineering design to minimize impact.

Toxicity is primarily a function of _______.

Dose.

Life-cycle assessment

Evaluating impact throughout life-cycle of a product or process.

Global Hazards

Large-scale hazards tied to climatological or geopolitical events. Ex. volcano, flood, war.

Toxicity

Likely to leach dangerous concentrations of certain known toxic chemicals into groundwater. Toxic effects are divided into two broad categories: carcinogenic and non-carcinogenic.

Physical Hazards

Non discriminate adverse effects due to proximity to or adverse effects of a hazard. Ex. oxidant or UV radiation.

Synergistic toxicity

Some compounds exhibit enhanced toxin effects when combined with other compounds.

Green Engineering

Substitute chemical-free or low impact materials.

Acute exposure

brief exposure to high concentration

Chronic exposure

long-term exposure to low concentration