Environmental Monitoring: Understanding Chemical Pollutants and Their Impact

Expert reviewed • 23 November 2024 • 6 minute read

Environmental monitoring is crucial for maintaining ecological balance and human health. This article explores the key chemical compounds we monitor and their environmental implications.

Atmospheric Pollutants

Carbon Compounds

Carbon-based pollutants significantly impact both human health and environmental systems. The two main forms are:

  • Carbon Monoxide (CO):

    • Produced through incomplete combustion
    • Colorless and odorless toxic gas
    • Interferes with oxygen transport in blood

  • Carbon Dioxide (CO2CO_2):

    • Primary greenhouse gas
    • Contributes to ocean acidification through the reaction: CO2(g)+H2O(l)⇌H2CO3(aq)CO_2(g) + H_2O(l) \rightleftharpoons H_2CO_3(aq)

Sulfur Compounds

Sulfur dioxide (SO2)(SO_2) from fossil fuel combustion creates multiple environmental hazards:

  • Causes respiratory problems
  • Forms acid rain through the following reactions: 2SO2(g)+O2(g)→2SO3(g)2SO_2(g) + O_2(g) \rightarrow 2SO_3(g) SO3(g)+H2O(l)→H2SO4(aq)SO_3(g) + H_2O(l) \rightarrow H_2SO_4(aq)

Nitrogen Oxides

These compounds contribute to various environmental issues:

  • Form photochemical smog
  • Create acid rain through the reactions: 2NO(g)+O2(g)→2NO2(g)2NO(g) + O_2(g) \rightarrow 2NO_2(g) 2NO2(g)+H2O(l)→HNO3(aq)+HNO2(aq)2NO_2(g) + H_2O(l) \rightarrow HNO_3(aq) + HNO_2(aq)

Ozone-Depleting Substances

Haloalkanes from aerosols can:

  • Generate free radicals in the atmosphere
  • Deplete the ozone layer
  • Increase UV radiation exposure

Soil Quality Monitoring

Nutrient Balance

  • Nitrogen and phosphorus are essential but can become harmful in excess
  • Excess nutrients lead to:
    • Eutrophication in waterways
    • Disrupted aquatic ecosystems
    • Reduced sunlight penetration
    • Oxygen depletion

Trace Metals

  • Essential metals (zinc, copper, iron) needed in small quantities
  • Excess levels can:
    • Inhibit plant growth
    • Affect food security
    • Contaminate groundwater

Water Quality Parameters

Water Hardness

Caused by calcium and magnesium ions:

  • Hard water:
    • Better for drinking
    • Forms scum with soap
    • Can clog pipes
  • Soft water:
    • Better for cleaning
    • May corrode pipes
    • Lower mineral content

Heavy Metal Contamination

Primary concerns include:

  • Lead (Pb2+)(Pb^{2+}):
    • Sources: lead-based paints, historical fuel residues
    • Causes neurological damage
  • Mercury (Hg2+)(Hg^{2+}):
    • Sources: industrial waste, medical devices
    • Crosses blood-brain barrier
    • Affects fetal development

pH Levels

Critical for aquatic ecosystems:

  • Affects marine life survival
  • Impacts shell formation in marine organisms
  • Influences coral reef health
  • Can cause coral bleaching

Agricultural Impact

Water quality affects:

  • Crop growth and yield
  • Soil nutrient availability
  • Risk of eutrophication
  • Aquatic ecosystem balance

Up Next

Identifying Metal Cations

Return to Module 8: Applying Chemical Ideas