World War I saw the horrific introduction of chemical weapons on a large scale. Here are the main poison gases used and their effects:

1. Chlorine:

• First Use:April 22, 1915, by Germany on the Western Front.
• Effects:
  • Severe irritation and burning of the respiratory tract, leading to coughing, choking, and fluid buildup in the lungs (pulmonary edema).
  • Death by suffocation could occur within minutes.
  • Exposure could also cause eye irritation and burning.
• Environmental Impact:
  • Chlorine reacts with water vapor in the air to form hydrochloric acid, which can irritate vegetation and contaminate soil. However, the effects are temporary compared to the other gases used.

2. Phosgene:

• First Use:December 1915, by Germany on the Western Front.
• Effects:
  • Delayed onset (symptoms could take hours to appear).
  • Initially causes irritation of the eyes and respiratory tract.
  • Fluid buildup in the lungs (pulmonary edema) is the primary cause of death, often occurring 24-48 hours after exposure.
• Environmental Impact:
  • Less persistent than chlorine, phosgene breaks down in sunlight and moist air.

3. Mustard Gas (Sulfur Mustard):

• First Use:July 1917, by Germany on the Western Front.
• Effects:
  • Blister agent affecting the skin, eyes, and respiratory tract.
  • Causes severe blistering of exposed skin and eyes, with prolonged healing times.
  • Can damage the respiratory system, leading to bronchitis and pneumonia.
  • Long-term health problems like chronic respiratory issues and even cancer could occur.
• Environmental Impact:
  • Mustard gas is the most persistent of these three gases.
  • It can remain active in the environment for weeks or even months, posing a lingering threat to exposed areas.

The impact of these gases on people was devastating. Thousands died from immediate exposure, and many more suffered long-term health problems. The psychological trauma of chemical warfare was significant as well.

The environmental impact, while not as long-lasting as the human impact, was still considerable. Contaminated areas required decontamination efforts, and agricultural land could be rendered unusable for some time.

The use of poison gases in World War I marked a dark chapter in human history, highlighting the horrors of chemical warfare. These weapons were later outlawed by international conventions, but the threat of their use remains a concern.