The Air Pollution Problem Pollutants Pollutants harmful materials

The Air Pollution Problem

Pollutants • Pollutants = harmful materials that enter the environment • Air Pollution = harmful substances released into the atmosphere

Pollutants • Most pollutants come from natural sources: – Sand, dust storms, volcanic eruptions, forest fires, ocean spray, gases produced by decaying organisms, etc. • Human activity is also a source of air pollution

Outdoor Pollution • Air pollutants classified as: gases OR particulates • Particulates = Tiny solids suspended in the air – Ash, dust, & soot from burning organic matter – Liquid droplets in smoke or smog – Traces of metals (lead, iron and copper) – Pesticides, herbicides and fertilizer dust

Outdoor Pollutants • Oxides = compounds of oxygen and another element – Compounds of oxygen and carbon, sulfur or nitrogen • Oxides are released when fossil fuels and organic matter are burned: – Automobiles – Coal-burning power plants

Outdoor Pollutants • Photochemical Smog = a yellow-brown haze formed when sunlight reacts with pollutants produced by cars – Ozone (O 3) • Corrosive • Poisonous to plants & animals – Nitrogen Dioxide (NO 2)

Outdoor Pollutants • Hydrocarbons = a group of gaseous pollutants made mostly of hydrogen & carbon (methane) • Chlorofluorocarbons (CFCs) = compounds of carbon, chlorine and fluorine once used in refrigerators, air conditioners, aerosol cans, and in the production of polystyrene foam.

Indoor Pollutants • Indoor air pollutants: – Home products such as plastics, insulation and cleaners give off harmful fumes • Air circulation indoors is poor

Indoor Pollutants • Cigarette smoke = the deadliest of all indoor pollutants – Contains a toxic combination of particulates, gases and other chemicals – Hazardous to smokers and to second-hand smoke inhalers

Indoor Pollutants • Microorganisms such as bacteria and fungi are indoor air pollutants.

Indoor Pollutants • Radon = a colorless, odorless, radioactive gas – ½ of an average person’s yearly radiation exposure – Forms when radium (a radioactive element in soil) breaks down – Enters home through basement – Atoms of radon stick to particulates in the air and enter a person’s lungs

Air Pollution & Living Things

Carbon Monoxide Exposure • Carbon Monoxide = a dangerous air pollutant that readily binds with hemoglobin (carries oxygen in red blood cells) – Binds to hemoglobin more easily than oxygen

Carbon Monoxide Exposure • Moderate levels: – Stress the heart – Cause headaches & dizziness • High levels: – Can be fatal

Ozone & Oxide Exposure • • Sulfur & Nitrogen Irritate eyes & respiratory tract Difficulty and discomfort breathing Trigger for asthma or allergy attacks

Ozone & Oxide Exposure • Emphysema = a disease in which tiny air sacs in the lungs break down – 1. 5 million afflicted in the US – Often caused by cigarette smoking • Cancer = a disease in which cells grow abnormally & without restraint – Can be caused by particulates in the air

Air Pollution & Plants • Sulfur oxides & ozone are most hazardous to plants – Cause stems to become brittle and leaves to become spotted

Air Pollution & Animals • Death of plants disrupts ecosystem’s food chains & deprives animals of nourishment • Pollution related health problems: – Eye & lung irritation, bronchitis, cancer

Industrial Air Pollutants • Lead & Zinc can contaminate rangeland – Accumulate on grass & may enter groundwater – Grazing animals ingest • Bones & teeth of grazing animals become weak – Lameness & weight loss result