Glossary
Air Pollutants
Harmful substances released into the atmosphere that can negatively impact human health, ecosystems, and climate.
Example:
Vehicle exhaust is a major source of air pollutants like nitrogen oxides and particulate matter in urban areas.
Arsenic
A naturally occurring metalloid element that is a known human carcinogen and endocrine disruptor, often found in contaminated drinking water and soil.
Example:
Many communities in Southeast Asia face chronic health issues due to high levels of naturally occurring arsenic in their groundwater.
BPA (Bisphenol A)
A chemical used in the production of certain plastics and epoxy resins, known for its properties as an endocrine disruptor.
Example:
Many baby bottles are now advertised as BPA-free to alleviate concerns about the chemical leaching into liquids and affecting infant development.
Contaminant
A substance or organism present in an environment where it does not belong or is at levels that can cause harm to health or the environment.
Example:
Oil spills introduce a significant contaminant into marine ecosystems, harming wildlife and habitats.
Dose-Response Curve
A graphical representation, typically S-shaped, illustrating the relationship between the dose of a substance and the observed biological response.
Example:
Analyzing the dose-response curve for a new drug helps scientists understand the range of doses that are effective versus those that become toxic.
Dose-Response Studies
Scientific investigations that examine how an organism's response changes with varying levels of exposure to a chemical or substance.
Example:
Researchers conduct dose-response studies to determine the safe concentration of a new pesticide before it's approved for agricultural use.
Endocrine Disruptors
Chemicals that interfere with the body's hormone system, potentially causing adverse developmental, reproductive, neurological, and immune effects.
Example:
Pesticides like atrazine are considered endocrine disruptors because they can alter hormone levels in amphibians, affecting their development.
Food Contaminants
Harmful substances or microorganisms that can be present in food, leading to illness or spoilage.
Example:
Bacteria like Salmonella can be dangerous food contaminants if poultry is not cooked thoroughly.
Formaldehyde
A colorless, flammable gas and volatile organic compound (VOC) used in building materials, household products, and as a preservative, known to be an irritant and carcinogen.
Example:
The 'new car smell' or the odor from new furniture can often be attributed to the off-gassing of formaldehyde and other VOCs.
Human Health Impacts
The adverse effects that environmental contaminants or conditions can have on human physiological systems, well-being, and disease susceptibility.
Example:
Studying the human health impacts of air pollution helps policymakers set stricter emission standards for industries and vehicles.
LD50 (Lethal Dose 50%)
The amount of a substance that, when administered, is lethal to 50% of a test population.
Example:
If a chemical has an LD50 of 5 mg/kg, it means that half of the test animals given that dose per kilogram of body weight are expected to die.
Lead
A heavy metal that is a potent neurotoxin, particularly harmful to children, and was historically used in paint, pipes, and gasoline.
Example:
Renovating older homes can disturb lead-based paint, releasing hazardous dust that can be inhaled or ingested, especially by young children.
Mercury
A heavy metal that can exist in various forms, with methylmercury being a potent neurotoxin that bioaccumulates in aquatic food webs, particularly in predatory fish.
Example:
Consuming large amounts of tuna or swordfish can lead to elevated mercury levels in humans, posing risks to neurological development.
Phthalates
A group of chemicals used to make plastics more flexible and durable, widely found in consumer products and known to be endocrine disruptors.
Example:
Some children's toys and personal care products have been reformulated to exclude phthalates due to their potential reproductive and developmental impacts.
Radiological Contaminants
Radioactive isotopes that can cause adverse health effects and environmental damage due to their emission of ionizing radiation.
Example:
After a nuclear power plant accident, radiological contaminants can spread through the air and water, affecting distant regions.
Soil Pollutants
Harmful substances present in soil that can reduce soil fertility, contaminate crops, and pose risks to human and ecosystem health.
Example:
Improper disposal of industrial waste can introduce heavy metals as soil pollutants, rendering agricultural land unusable.
Water Pollutants
Substances that degrade the quality of water bodies, making them unsafe for consumption, recreation, or aquatic life.
Example:
Runoff from farms carrying excess fertilizers can act as water pollutants, leading to eutrophication in nearby lakes.