Environmental pollution happens when harmful substances or forms of energy enter the air, water, soil, or living spaces. This cheat sheet helps students compare major pollution types, identify their sources, and connect pollutants to effects on ecosystems and human health. It is useful for reviewing vocabulary, reading environmental data, and preparing for class discussions or assessments. The most important ideas include how pollutant concentration is measured, how pollution moves through food webs and water systems, and how exposure affects living things. Key measures include concentration in ppm or ppb, pH for acidity, AQI for air quality, and decibels for sound intensity. Solutions focus on reducing pollution at the source, treating waste before release, conserving resources, and using cleaner technology.

Key Facts

  • Pollutant concentration can be written as concentration = amount of pollutant / total amount of mixture.
  • Parts per million means ppm = pollutant parts / 1,000,000 total parts, so 1 ppm is a very small concentration.
  • Parts per billion means ppb = pollutant parts / 1,000,000,000 total parts, often used for very toxic pollutants.
  • The pH scale runs from 0 to 14, with pH less than 7 acidic, pH 7 neutral, and pH greater than 7 basic.
  • Noise level is measured in decibels, and long exposure above about 85 dB can damage hearing.
  • The Air Quality Index reports air pollution risk, with higher AQI values meaning greater health concern.
  • Bioaccumulation means toxins build up in one organism over time, while biomagnification means toxin levels increase higher in a food chain.
  • The best pollution control order is reduce pollution at the source, reuse materials, recycle what remains, and treat or safely dispose of waste.

Vocabulary

Pollutant
A pollutant is any substance or form of energy that harms the environment or living things when it is present at unsafe levels.
Air Quality Index
The Air Quality Index, or AQI, is a number scale that shows how clean or polluted the air is and how risky it is to breathe.
Eutrophication
Eutrophication is the overgrowth of algae caused by too many nutrients, often from fertilizer runoff, which can lower oxygen in water.
Runoff
Runoff is water that flows over land and carries soil, chemicals, trash, or nutrients into streams, lakes, and oceans.
Bioaccumulation
Bioaccumulation is the buildup of a pollutant inside an organism because it takes in the pollutant faster than it can remove it.
Point Source Pollution
Point source pollution comes from one identifiable location, such as a pipe, factory outlet, or sewage discharge.

Common Mistakes to Avoid

  • Confusing weather with air pollution is wrong because weather describes short-term atmospheric conditions, while air pollution describes harmful substances in the air.
  • Assuming clear water is always clean is wrong because dissolved chemicals, bacteria, and nutrients can be invisible but still unsafe.
  • Thinking biodegradable means harmless is wrong because some biodegradable materials still release pollution or require special conditions to break down safely.
  • Comparing ppm and ppb as if they are equal is wrong because 1 ppm equals 1,000 ppb, so the units show very different concentrations.
  • Ignoring exposure time is wrong because health risk depends on both pollutant level and how long a person or organism is exposed.

Practice Questions

  1. 1 A water sample has 3 grams of pollutant in 1,000,000 grams of water mixture. What is the concentration in ppm?
  2. 2 A sound meter reads 92 dB near a machine. If long exposure above 85 dB can harm hearing, is this level a concern for a worker who stays nearby for hours?
  3. 3 A lake changes from pH 7 to pH 5 after acid rain. Did the lake become more acidic or more basic, and what could happen to aquatic organisms?
  4. 4 Explain why reducing plastic use at the source is usually better than only cleaning plastic waste after it reaches a river.