--- title: "Particulate pollutants: sources and effects" subject: "Environment and Pollution Control" chapter: 1 key: "semester_7/environment_and_pollution_control:particulate-pollutants-sources-effects" source: https://www.bctengineer.com/q/semester_7/environment_and_pollution_control/particulate-pollutants-sources-effects site: BCT Engineering --- # Particulate pollutants: sources and effects Environment and Pollution Control · Chapter 1: Air pollution - Asked in: year not given, 5 marks - Video: [Air Pollution](https://www.youtube.com/watch?v=_dTtvtlct9k) — Bozeman Science - Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14 - Page: https://www.bctengineer.com/q/semester_7/environment_and_pollution_control/particulate-pollutants-sources-effects - Whole chapter: https://www.bctengineer.com/md/semester_7/environment_and_pollution_control/chapter-1 ## Question What are particulate pollutants? Describe their types, sources and the effects of PM10 and PM2.5 on human health, plants and materials. ## Short answer Particulate matter (PM) is a mix of solid particles and liquid droplets suspended in air. Types include dust, fume, smoke, mist and fly ash. Sources include fuel combustion, brick kilns, road dust, construction and open burning. PM10 deposits in upper airways causing irritation; PM2.5 reaches alveoli and blood, causing asthma, bronchitis, heart disease and lung cancer. Dust on leaves reduces photosynthesis and soiling damages materials. ## Answer Particulate matter (PM) is a mixture of tiny solid particles and liquid droplets suspended in air. PM10 means particles with aerodynamic diameter $\le 10\ \mu\text{m}$ and PM2.5 means $\le 2.5\ \mu\text{m}$. #### Types | Type | Meaning | Example | |---|---|---| | Dust | Solid particles from crushing/grinding, > 1 $\mu$m | Road and cement dust | | Fume | Solid particles from condensation of vapours, 0.03-0.3 $\mu$m | Metal fumes in welding | | Smoke | Solid/liquid particles from incomplete combustion, < 1 $\mu$m | Wood and diesel smoke | | Mist / fog | Liquid droplets | Sulphuric acid mist | | Fly ash | Fine ash from burning coal | Thermal plants | #### Sources - Fuel combustion (coal, wood, diesel), brick kilns, cement and stone crushers - Road dust, construction and mining activity - Open burning of waste and crop residue - Natural: wind-blown soil, volcanoes, pollen, sea salt - Secondary particles formed from $\text{SO}_2$, $\text{NO}_x$ and ammonia #### Effects - **Health:** PM10 is deposited in the nose and upper airways and causes irritation and cough. PM2.5 reaches the alveoli and enters the blood. It causes asthma, bronchitis, lung cancer, heart disease and early death. Children and the elderly are most affected. Toxic particles (lead, asbestos, silica) cause specific diseases such as lead poisoning, asbestosis and silicosis. - **Plants:** A dust layer on leaves blocks sunlight and clogs stomata, which reduces photosynthesis and yield. - **Materials and buildings:** Soiling, abrasion and corrosion; acid particles attack marble and metals. - **Atmosphere:** Fine particles scatter light and reduce visibility (haze) and can alter rainfall and climate. ## Check yourself The answer's key points as multiple-choice questions, with the correct option and why. 1. PM2.5 refers to particles with: A. Aerodynamic diameter of 2.5 mm or less B. Aerodynamic diameter of 2.5 micrometres or less C. Mass of 2.5 micrograms D. Concentration of 2.5 ppm Answer: B. PM2.5 means particles with aerodynamic diameter <= 2.5 micrometres. (Key point: PM10 and PM2.5 meaning) 2. Why is PM2.5 more dangerous to health than the coarser PM10? A. It reaches the alveoli and enters the blood B. It is always chemically toxic C. It is trapped in the nose D. It only affects plants Answer: A. PM10 deposits in the nose and upper airways, whereas PM2.5 penetrates deep into the alveoli and blood causing heart and lung disease. (Key point: Health effect of PM2.5) 3. Fume is best described as: A. Solid particles from crushing and grinding B. Liquid droplets such as acid mist C. Solid particles from condensation of vapours, e.g. welding D. Fine ash from burning coal Answer: C. Fumes are formed by condensation of vapours (e.g. metal fumes in welding); dust is from crushing/grinding. (Key point: Types of particulates) 4. How does dust on leaves reduce crop yield? A. It adds nutrients that cause overgrowth B. It blocks sunlight and clogs stomata, reducing photosynthesis C. It lowers soil pH directly D. It attracts pollinators away Answer: B. A dust layer blocks light and clogs stomata, so photosynthesis and yield fall. (Key point: Effect on plants) ## Related in Environment and Pollution Control - [Water pollution: sources and effects](https://www.bctengineer.com/question.md?key=semester_7%2Fenvironment_and_pollution_control%3Awater-pollution-sources-effects) — Environment and Pollution Control, chapter 4 - [Indoor air pollutants and their sources](https://www.bctengineer.com/question.md?key=semester_7%2Fenvironment_and_pollution_control%3Aindoor-air-pollutants-sources) — Environment and Pollution Control, chapter 3 - [Sources and effects of SO2, NOx and CO](https://www.bctengineer.com/question.md?key=semester_7%2Fenvironment_and_pollution_control%3Agaseous-pollutants-so2-nox-co) — Environment and Pollution Control, chapter 1 - [Classification and sources of air pollutants](https://www.bctengineer.com/question.md?key=semester_7%2Fenvironment_and_pollution_control%3Aair-pollutants-classification-sources) — Environment and Pollution Control, chapter 1 - [Household smoke pollution and effects on residents](https://www.bctengineer.com/question.md?key=semester_7%2Fenvironment_and_pollution_control%3Ahousehold-smoke-pollution-effects) — Environment and Pollution Control, chapter 3 - [Typical noise levels and effects of noise](https://www.bctengineer.com/question.md?key=semester_7%2Fenvironment_and_pollution_control%3Anoise-levels-places-effects) — Environment and Pollution Control, chapter 6 ## Related in other subjects - [Classification of air pollutants; sources, effects](https://www.bctengineer.com/question.md?key=semester_2%2Fengineering_chemistry%3Aair-pollutants-classified) — Engineering Chemistry, chapter 3 - [Living organisms in water; health effects](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Aliving-organisms-in-water) — Water Supply Engineering, chapter 4 - [Pollutant vs pollution; gaseous and particulate pollutants](https://www.bctengineer.com/question.md?key=semester_2%2Fengineering_chemistry%3Apollutant-vs-pollution) — Engineering Chemistry, chapter 3 - [Air pollutants: effects and remedies](https://www.bctengineer.com/question.md?key=semester_2%2Fengineering_chemistry%3Aair-pollutants-effects) — Engineering Chemistry, chapter 3