Pollution Flashcards
Toxicity
The degree to which a toxin is biologically harmful
Dose-response analysis
Used to test toxicity of a substance
Organisms are exposed to a toxin at different concentrations, and the dosage that causes the death of the organism is recorded. The information from a set of organisms is graphed, and the resulting curve is referred to as a dose-response curve.
LD50
The dosage of toxin it takes to kill 50 percent of the test animals in a dose-response analysis.
Poison
Any substance that has an LD50 of 50 my or less per kg of body weight
ED50
The point at which 50 percent of the test organisms show a negative effect from a toxin
Threshold dose
The dosage at which a negative effect occurs
Acute effect
An effect caused by a short exposure to a high level of toxin; e.g. a snakebite
Chronic effect
What results from long-term exposure to low levels of toxin; e.g. Long term exposure to lead paint in a house
Infection
The result of a pathogen invading our body
Disease
Occurs when an infection causes a change in the state of health
5 main categories of pathogens
Viruses (and other sub cellular infectious particles, such as prions) Bacteria Fungi Protozoa Parasitic worms
How do Pathogens attack
Can attack directly or via a carrier organism (called a vector)
Primary pollutants
Those that are released directly into the lower atmosphere (troposphere) and are toxic
Ex. Carbon monoxide
Secondary pollutants
Those that are formed by the combination of primary pollutants in the atmosphere
Ex. Acid rain
The six criteria pollutants
Carbon monoxide Lead Ozone Nitrogen dioxide Sulfur dioxide Particulates
Carbon Monoxide (CO)
An odorless, colorless gas that’s typically released as a by-product of incompletely burned organic material, such as fossil fuels. It is hazardous to human health because it binds irreversibly to hemoglobin in the blood. More than 60% comes from vehicles that burn fossil fuels
Tropospheric ozone
Powerful respiratory irritant and precursor to secondary air pollutants
How is O3 (the secondary pollutant) formed in the troposphere
The result of the interaction of nitrogen oxides, heat, sunlight, and volatile organic compounds (VOCs)
Effects of acid precipitation (8)
Leaching of some minerals from soil (which alters soil chemistry)
Creating a buildup of sulfur and nitrogen ions in soil
Increasing the aluminum concentration in soil to levels that are toxic for plants
Leaching calcium ions from the needles of conifers
Elevating the aluminum concentration in lakes to levels that are toxic to fish
Lowering the pH of streams, rivers, ponds, and lakes, which may lead to fish kills
Causing human respiratory irritation
Damaging all types of rocks, including statues, monuments, and buildings
Stratospheric ozone
Absorbs UV light from the sun and therefore protects life on our planet
Eutrophication
When warm, nutrient-rich freshwater runoff travels into a body of cold seawater, which allows phytoplankton to grow uncontrollably, zooplankton that feed on them to experience population explosion. When they die, bacteria metabolize the available dissolved oxygen as they decompose this detritus, resulting in a lack of dissolved oxygen in a hypoxic zone.
Clean water act of 1972
Used regulatory and non regulatory tools to protect all surface waters in the United States
Sharply reduced direct pollutant discharges into waterways
Financed municipal wastewater treatment facilities, and manages polluted runoff
Achieved the broader goal of restoring and maintaining the chemical, physical, and biological integrity of the nation’s waters
Supported “the protection and propagation of fish, shellfish, and wildlife, and recreation in and on the water”
Ocean dumping act of 1972
Made it unlawful for any person to dump, or transport for the purpose of dumping, sewage, sludge, or industrial waste into ocean waters
Safe drinking water act of 1974, 1996
Established a federal program to monitor and increase the safety of the drinking water supply. It does not apply to wells that support fewer than 25 people
Oil spill prevention and liability act of 1990
Strengthened EPA’s ability to prevent and respond to catastrophic oil spills. Established a trust fund (financed by a tax on oil), which is available to clean up spills.
Corrosive waste
Waste that corrodes metal
Ignitable waste
Substances such as alcohol or gasoline that can easily catch fire
Reactive waste
Substances that are chemically unstable or react readily with other compounds, resulting in explosions or causing other problems
Toxin
Any substance that is inhaled, ingested, or absorbed at sufficient dosages that it damages a living organism
Toxic waste
Waste that creates health risks when inhaled or ingested, or when it comes into contact with skin
Surface impoundment
Typically used for liquid waste; it involves the creation of shallow, lined pools from which the hazardous liquid evaporates
Deep well injection
Involves drilling a hole in the ground that’s below the water table. These wells must reach below the impervious soil layer into porous rock, and waste is injected into the well.
Brownfield sites
Sites that were contaminated by hazardous waste or pollutants
Hazardous materials transportation act of 1975
Governed the transportation of hazardous material and waste in commerce
Lead Pb
Released into the atmosphere as a particulate then settled on land and water where it is incorporated into the food chain and is part of biomagnification. If it enters the human body, it can cause numerous nervous system disorders, including mental retardation in children. The primary source is industrial smelting.
The resource conservation and recovery act of 1976 (RCRA)
The solid waste program encouraged states to develop comprehensive plans to manage nonhazardous industrial solid waste and municipal solid waste; sets criteria for municipal solid waste landfills and other solid waste disposal facilities; and prohibits the open dumping of solid waste
The hazardous waste program established a system for controlling hazardous waste from the time it is generated until its ultimate disposal (cradle to grave)
The underground storage tank (UST) program regulates underground storage tanks containing hazardous substances and petroleum products
Toxic substances control act (TOSCA) 1976
Gave the EPA the ability to track the 75,000 industrial chemicals currently produced in or imported to the United States. EPA repeatedly screens these chemicals and can require reporting or testing of those that may pose an environmental or human-health hazard. Allows the EPA to ban the manufacture and import of those chemicals that pose an unreasonable risk.
The comprehensive environmental response, compensation, and liability act (CERCLA) commonly known as superfund 1980
Created a tax on the chemical and petroleum industries and provided broad federal authority to respond directly to releases or threatened releases of hazardous substances that may endanger public health or the environment.
Established prohibitions and requirements concerning closed and abandoned hazardous waste sites.
Provided for liability of persons responsible for releases of hazardous waste at these sites.
Established a trust fund to provide for cleanup when no responsible party could be identified.
Nuclear waste policy act 1982
Established both the federal government’s responsibility to provide a place for the permanent disposal of high-level radioactive waste and spent nuclear fuel, and the generators’ responsibility to bear the costs of permanent disposal
Volatile organic compounds (VOCs)
Released as a result of various industrial processes including dry cleaning, the use of industrial solvents, and the use of propane. Can react in the atmosphere with other gases to form ozone and are a major contributed to smog in urban areas.
Nitrogen Oxides
Released as a result of combustion engines, utilities and industrial combustion; commonly found as a secondary pollutant and is a component of smog and acid precipitation
Sulfur dioxide SO2
Colorless gas with a penetrating and suffocating odor. Powerful respiratory irritant, and typically released into the air through the combustion of coal. Sources include metal smelting, paper pulping, and the burning of fossil fuels. Can also be a component of gas heaters, improperly vented gas ranges, and tobacco smoke. Reacts with water vapor to form acid precipitation.
Particulate matter
Small particles of solid or liquid material. Light enough to be carried on air currents, and when humans breathe them in, they act as irritants.
Ex, soot (black carbon), sulfate aerosols
Chlorofluorocarbons (CFCs)
Invented in the 1930s, these were used in items such as propellants, fire extinguishers, and cans of hairspray. Once released, they migrate to the stratosphere through atmospheric mixing (they are very stable, which allows them to survive through the rise). In the upper stratosphere, intense UV radiation breaks them apart and releases chlorine atoms that fork chlorine monoxide while converting 03 to 02.
