L16 Flashcards
What are primary and secondary air pollutants?
Primary pollutants enter the atmosphere directly (e.g., carbon oxides). Secondary pollutants form after chemical modification in the atmosphere (e.g., ozone).
How does thermal inversion affect air pollution?
Thermal inversion traps pollutants near the ground by sandwiching a layer of cold air between layers of warm air, causing high pollutant concentrations.
What is the impact of carbon monoxide on hemoglobin?
Carbon monoxide binds to hemoglobin with high affinity, forming carboxyhemoglobin, reducing oxygen transport. Effects are measurable at 2% binding, with cardiac output increasing at 5%.
What are the health effects of sulfur and nitrogen oxides?
Both are pulmonary irritants that can form acid rain, affecting biodiversity and reducing the pH of aquatic systems.
How do chlorofluorocarbons (CFCs) deplete ozone?
CFCs release chlorine upon UV exposure, which catalyzes the breakdown of ozone into oxygen molecules, destroying thousands of ozone molecules per CFC molecule.
What is eutrophication, and what pollutants cause it?
Eutrophication is bacterial overgrowth due to excessive nitrates and phosphates, depleting oxygen and harming aquatic ecosystems.
What are the primary sources of heavy metal pollution in water?
Sources include smelting, industrial processes, lead pipes, and runoff containing cadmium, arsenic, and mercury.
How do oil spills affect marine ecosystems?
Oil toxicity disrupts cell membranes due to lipid solubility and bioaccumulation, severely impacting species like birds and marine mammals (e.g., Exxon Valdez spill).
What is the role of detoxication in waste management?
Detoxication uses physical, chemical, or biological methods (e.g., UV radiation, biodegradation) to neutralize or remove toxic substances.
What lesson does the Love Canal case teach about waste disposal?
Haphazard waste disposal is temporary and often leads to environmental disasters, emphasizing the need for responsible waste management.
Describe the major categories of air pollutants and their health and environmental effects.
Air pollutants include gases (carbon oxides, sulfur/nitrogen oxides, hydrocarbons), which cause respiratory issues, cardiovascular strain, and environmental effects like acid rain and ozone depletion. Particulates like dust and heavy metals can damage lungs and bioaccumulate in ecosystems. Thermal inversion can exacerbate these impacts by trapping pollutants near the ground.
Explain how nitrates and pesticides contribute to water pollution and their effects on ecosystems and health.
Nitrates from agriculture runoff lead to eutrophication, causing oxygen depletion and fish die-offs. Nitrates in drinking water can cause methemoglobinemia, which impairs oxygen transport. Pesticides like DDT bioaccumulate, disrupting ecosystems and harming species, especially predatory birds, by thinning eggshells. Pesticides also contaminate waterways and are neurotoxic to non-target organisms.
Compare the environmental effects of heavy metals like cadmium, lead, and mercury on aquatic and human health.
Cadmium bioaccumulates in plants and fish, causing kidney dysfunction and osteoporosis (e.g., Japan’s mine water pollution). Lead contaminates water through soil leaching and industrial runoff, causing neurological damage. Mercury, converted to methylmercury by microorganisms, is a potent neurotoxin that bioaccumulates in aquatic food chains.
What are the key methods of toxic waste management, and what are their limitations?
Methods include:
- Reduction: Reducing waste generation at the source.
- Recycling: Recovering solvents and materials.
- Detoxication: Using UV light or filtration for neutralization.
- Incineration: Burns waste at high temperatures, but can release toxic oxides and is not universally effective. Limitations include cost, partial detoxification, and environmental side effects.
Discuss the major contributors to toxic waste production and their impacts on ecosystems and communities.
Toxic waste arises from manufacturing, mining, agriculture, and household activities. Pollutants like heavy metals (lead, chromium) and organic solvents (benzene) contaminate soil and water, disrupt ecosystems, and pose health risks like cancer and organ failure. Examples like the Love Canal highlight the long-term consequences of improper disposal, emphasizing the need for sustainable waste management practices.
